path: root/src/ecex.c

#include "ecex.h"
#include "media.h"

#include "ccdjit.h"
#include "common.h"
#include "config.h"
#include "util.h"
#include "path.h"

#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <unistd.h>

extern FILE *popen(const char *command, const char *type);
extern int pclose(FILE *stream);
extern int kill(pid_t pid, int sig);

#define ECEX_INITIAL_BUFFER_CAP 8
#define ECEX_INITIAL_COMMAND_CAP 32
#define ECEX_INITIAL_KEYBIND_CAP 32
#define ECEX_INITIAL_WINDOW_CAP 4
#define ECEX_INITIAL_MODE_CAP 8
#define ECEX_INITIAL_MODE_KEYBIND_CAP 16
#define ECEX_INITIAL_HOOK_CAP 8

ecex_window_t *ecex_current_window(ecex_t *ed);
static void ecex_clear_command_hooks(ecex_t *ed);
static void ecex_clear_prefix_hooks(ecex_t *ed);
static void ecex_clear_buffer_hooks(ecex_t *ed);
static void ecex_clear_completion_providers(ecex_t *ed);
static int ecex_complete_at_point_direction(ecex_t *ed, int direction);
static int ecex_indent_for_tab(ecex_t *ed);


void *ecex_config_alloc(size_t size) {
    return malloc(size ? size : 1);
}

void *ecex_config_calloc(size_t count, size_t size) {
    if (count == 0) count = 1;
    if (size == 0) size = 1;
    return calloc(count, size);
}

void ecex_config_free(void *ptr) {
    free(ptr);
}

double ecex_time_seconds(void) {
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return (double)tv.tv_sec + (double)tv.tv_usec / 1000000.0;
}

void ecex_mem_zero(void *ptr, size_t size) {
    if (!ptr || size == 0) return;
    memset(ptr, 0, size);
}


int ecex_i32_get(const int *items, size_t index) {
    if (!items) return 0;
    return items[index];
}

void ecex_i32_set(int *items, size_t index, int value) {
    if (!items) return;
    items[index] = value;
}

int ecex_run_plugin_file_handlers(ecex_t *ed, buffer_t *buffer) {
    return ecex_plugin_file_handlers_run(ed, buffer);
}

int ecex_prng_next_bounded(unsigned int *state, int bound) {
    unsigned int x;
    unsigned int limit;

    if (!state || bound <= 0) return 0;

    x = *state;
    if (x == 0u) x = 0x6d2b79f5u;

    /* Xorshift32. Keep this host-side so CCDJIT plugins do not depend on
     * unsigned multiply/divide lowering details for game logic randomness. */
    x ^= x << 13;
    x ^= x >> 17;
    x ^= x << 5;
    if (x == 0u) x = 0xa5a5a5a5u;
    *state = x;

    /* Avoid modulo bias enough for tiny bounds without libc. */
    limit = 0xffffffffu - (0xffffffffu % (unsigned int)bound);
    while (x >= limit) {
        x ^= x << 13;
        x ^= x >> 17;
        x ^= x << 5;
        if (x == 0u) x = 0x9e3779b9u;
        *state = x;
    }

    return (int)(x % (unsigned int)bound);
}


int ecex_random_bounded(int bound) {
    static unsigned int state = 0x7f4a7c15u;
    unsigned int mix;

    if (bound <= 0) return 0;
    /* Host-owned PRNG for plugins that should not pass writable state pointers
     * through the JIT ABI. Stir in a stack address so separate launches differ
     * enough for games/demos without requiring libc time calls from plugins. */
    mix = (unsigned int)(size_t)&bound;
    state ^= mix + 0x9e3779b9u + (state << 6) + (state >> 2);
    return ecex_prng_next_bounded(&state, bound);
}

static int ecex_file_browser_preview_current(ecex_t *ed);
static int ecex_file_browser_update_preview_if_enabled(ecex_t *ed);

static ecex_color_t ecex_color(float r, float g, float b) {
    ecex_color_t c = {r, g, b};
    return c;
}

static void ecex_mark_ui_changed(ecex_t *ed) {
    if (!ed) return;
    ed->ui_revision++;
}

static void ecex_mark_font_changed(ecex_t *ed) {
    if (!ed) return;
    ed->font_revision++;
    ecex_mark_ui_changed(ed);
}

static void ecex_theme_set_defaults(ecex_t *ed) {
    if (!ed) return;

    ed->theme.font_path = NULL;
    ed->theme.font_size = 22.0f;

    ed->theme.bg = ecex_color(0.08f, 0.09f, 0.11f);
    ed->theme.fg = ecex_color(0.88f, 0.88f, 0.86f);

    ed->theme.status_bg = ecex_color(0.15f, 0.15f, 0.18f);
    ed->theme.status_fg = ecex_color(0.86f, 0.86f, 0.84f);
    ed->theme.status_border = ecex_color(0.28f, 0.28f, 0.32f);

    ed->theme.cursor = ecex_color(1.0f, 1.0f, 1.0f);
    ed->theme.region_bg = ecex_color(0.22f, 0.34f, 0.48f);

    ed->theme.minibuffer_bg = ecex_color(0.10f, 0.11f, 0.14f);
    ed->theme.minibuffer_fg = ecex_color(0.95f, 0.95f, 0.90f);

    ed->theme.completion_fg = ecex_color(0.45f, 0.45f, 0.45f);
    ed->theme.completion_enabled = 1;

    ed->theme.interactive_highlight_bg = ecex_color(0.18f, 0.20f, 0.24f);
    ed->theme.interactive_highlight_fg = ecex_color(1.0f, 1.0f, 1.0f);
    ed->theme.current_line_bg = ecex_color(0.12f, 0.13f, 0.16f);
    ed->theme.search_bg = ecex_color(0.55f, 0.42f, 0.12f);
    ed->theme.line_numbers_enabled = 1;
    ed->theme.current_line_enabled = 1;
}

#define ECEX_COMMAND(name, fn) \
    do { \
        if (ecex_register_command(ed, (name), (fn)) != ECEX_OK) return ECEX_ERR; \
    } while (0)

#define ECEX_BIND(key, command) \
    do { \
        if (ecex_bind_key(ed, (key), (command)) != ECEX_OK) return ECEX_ERR; \
    } while (0)

#define CURRENT_BUFFER_OR_ERR(ed) \
    buffer_t *buf = ecex_current_buffer(ed); \
    if (!buf) return ECEX_ERR

static int cmd_quit(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    if (ecex_has_modified_buffers(ed)) {
        fprintf(stderr, "ecex: refusing to quit; modified buffers exist. Save or use force-quit.\n");
        return ECEX_ERR;
    }
    ed->should_quit = 1;
    return ECEX_OK;
}

static int cmd_force_quit(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    ed->should_quit = 1;
    return ECEX_OK;
}

static int cmd_next_buffer(ecex_t *ed) { return ecex_next_buffer(ed); }
static int cmd_previous_buffer(ecex_t *ed) { return ecex_previous_buffer(ed); }
static int cmd_split_window_right(ecex_t *ed) { return ecex_split_window_vertically(ed); }
static int cmd_split_window_below(ecex_t *ed) { return ecex_split_window_horizontally(ed); }
static int cmd_other_window(ecex_t *ed) { return ecex_other_window(ed); }
static int cmd_previous_window(ecex_t *ed) { return ecex_previous_window(ed); }
static int cmd_delete_window(ecex_t *ed) { return ecex_delete_window(ed); }
static int cmd_delete_other_windows(ecex_t *ed) { return ecex_delete_other_windows(ed); }
static int cmd_balance_windows(ecex_t *ed) { return ecex_balance_windows(ed); }

static int cmd_move_left(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_left(buf); return ECEX_OK; }
static int cmd_move_right(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_right(buf); return ECEX_OK; }
static int cmd_move_up(ecex_t *ed) {
    CURRENT_BUFFER_OR_ERR(ed);
    buffer_move_up(buf);
    ecex_file_browser_update_preview_if_enabled(ed);
    return ECEX_OK;
}
static int cmd_move_down(ecex_t *ed) {
    CURRENT_BUFFER_OR_ERR(ed);
    buffer_move_down(buf);
    ecex_file_browser_update_preview_if_enabled(ed);
    return ECEX_OK;
}
static int cmd_move_word_left(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_word_left(buf); return ECEX_OK; }
static int cmd_move_word_right(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_word_right(buf); return ECEX_OK; }
static int cmd_beginning_of_line(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_beginning_of_line(buf); return ECEX_OK; }
static int cmd_end_of_line(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_end_of_line(buf); return ECEX_OK; }
static int cmd_beginning_of_buffer(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_beginning_of_buffer(buf); return ECEX_OK; }
static int cmd_end_of_buffer(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_move_end_of_buffer(buf); return ECEX_OK; }

static int cmd_undo(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); return buffer_undo(buf); }
static int cmd_redo(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); return buffer_redo(buf); }
static int cmd_backspace(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); return buffer_backspace(buf); }
static int cmd_delete_forward(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); return buffer_delete_forward(buf); }
static int cmd_newline(ecex_t *ed) {
    CURRENT_BUFFER_OR_ERR(ed);
    if (buffer_is_interactive(buf)) {
        return ecex_interactive_activate_current_line(ed);
    }
    return buffer_insert_char(buf, '\n');
}
static int cmd_kill_line(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); return buffer_kill_line(buf); }
static int cmd_clear_buffer(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); return buffer_clear(buf); }
static int cmd_set_mark(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_set_mark(buf, buf->point); return ECEX_OK; }
static int cmd_clear_mark(ecex_t *ed) { CURRENT_BUFFER_OR_ERR(ed); buffer_clear_mark(buf); return ECEX_OK; }


static int cmd_yank(ecex_t *ed) {
    CURRENT_BUFFER_OR_ERR(ed);
    const char *text = ecex_clipboard_get(ed);
    if (!text || !text[0]) return ECEX_OK;
    return buffer_replace_selection(buf, text);
}

static int cmd_copy_region(ecex_t *ed) {
    CURRENT_BUFFER_OR_ERR(ed);
    if (!buffer_has_selection(buf)) return ECEX_OK;

    size_t start = 0;
    size_t end = 0;
    buffer_selection_range(buf, &start, &end);

    char *text = buffer_substring(buf, start, end);
    if (!text) return ECEX_ERR;

    int result = ecex_clipboard_set(ed, text);
    free(text);
    return result;
}

static int cmd_kill_region(ecex_t *ed) {
    CURRENT_BUFFER_OR_ERR(ed);
    if (!buffer_has_selection(buf)) return ECEX_OK;

    size_t start = 0;
    size_t end = 0;
    buffer_selection_range(buf, &start, &end);

    char *text = buffer_substring(buf, start, end);
    if (!text) return ECEX_ERR;

    int result = ecex_clipboard_set(ed, text);
    free(text);
    if (result != ECEX_OK) return result;

    return buffer_delete_selection(buf);
}

static int cmd_list_commands(ecex_t *ed) { return ecex_list_commands(ed); }
static int cmd_list_buffers(ecex_t *ed) { return ecex_list_buffers(ed); }
static int cmd_switch_buffer(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_SWITCH_BUFFER, "Switch buffer: "); return ECEX_OK; }
static int cmd_kill_buffer_command(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_KILL_BUFFER, "Kill buffer: "); return ECEX_OK; }
static int cmd_force_kill_buffer_command(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_FORCE_KILL_BUFFER, "Force kill buffer: "); return ECEX_OK; }
static int cmd_compile(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_COMPILE, "Compile: "); return ECEX_OK; }
static int cmd_grep(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_GREP, "Grep: "); return ECEX_OK; }
static int cmd_recompile(ecex_t *ed) { return ecex_rerun_compile(ed); }
static int cmd_regrep(ecex_t *ed) { return ecex_rerun_grep(ed); }
static int cmd_next_error(ecex_t *ed) { return ecex_next_interactive_action(ed); }
static int cmd_previous_error(ecex_t *ed) { return ecex_previous_interactive_action(ed); }
static int cmd_comment_region(ecex_t *ed) { return ecex_comment_region(ed); }
static int cmd_uncomment_region(ecex_t *ed) { return ecex_uncomment_region(ed); }
static int cmd_toggle_line_numbers(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    ecex_set_line_numbers_enabled(ed, !ed->theme.line_numbers_enabled);
    return ECEX_OK;
}

static int cmd_toggle_current_line(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    ecex_set_current_line_enabled(ed, !ed->theme.current_line_enabled);
    return ECEX_OK;
}
static int cmd_isearch_forward(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_ISEARCH_FORWARD, "I-search: "); return ECEX_OK; }
static int cmd_isearch_backward(ecex_t *ed) { ecex_request_prompt(ed, ECEX_PROMPT_ISEARCH_BACKWARD, "I-search backward: "); return ECEX_OK; }

static int cmd_find_file(ecex_t *ed) {
    ecex_request_prompt(ed, ECEX_PROMPT_FIND_FILE, "Find file: ");
    return ECEX_OK;
}

static int cmd_write_file(ecex_t *ed) {
    ecex_request_prompt(ed, ECEX_PROMPT_WRITE_FILE, "Write file: ");
    return ECEX_OK;
}

static int cmd_save_buffer(ecex_t *ed) {
    if (!ed) return ECEX_ERR;

    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf) return ECEX_ERR;

    if (!buf->path) {
        ecex_request_prompt(ed, ECEX_PROMPT_WRITE_FILE, "Write file: ");
        return ECEX_OK;
    }

    return ecex_save_current_buffer(ed);
}

static int cmd_eval_buffer(ecex_t *ed) {
    return ecex_eval_current_buffer(ed);
}

static int cmd_eval_line(ecex_t *ed) {
    return ecex_eval_current_line(ed);
}

static int cmd_eval_region(ecex_t *ed) {
    return ecex_eval_current_region(ed);
}

static int cmd_eval_file(ecex_t *ed) {
    ecex_request_prompt(ed, ECEX_PROMPT_EVAL_FILE, "Eval file: ");
    return ECEX_OK;
}

static int cmd_eval_rerun_last(ecex_t *ed) {
    return ecex_eval_rerun_last(ed);
}

static int cmd_quit_window(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    if (ecex_window_count(ed) > 1) return ecex_delete_window(ed);
    return ecex_previous_buffer(ed);
}

static int cmd_reload_config(ecex_t *ed) {
    return ecex_reload_config(ed);
}

static int cmd_indent_for_tab(ecex_t *ed) {
    return ecex_indent_for_tab(ed);
}

static int cmd_complete_at_point(ecex_t *ed) {
    return ecex_complete_at_point(ed);
}

static int cmd_complete_at_point_previous(ecex_t *ed) {
    return ecex_complete_at_point_direction(ed, -1);
}


/* Built-in file browser -------------------------------------------------- */

typedef struct ecex_file_entry {
    char *name;
    char *path;
    int is_dir;
    int is_image;
    long long size;
} ecex_file_entry_t;

static char ecex_fb_cwd[4096] = ".";
static char ecex_fb_history[64][4096];
static size_t ecex_fb_history_count = 0;
static size_t ecex_fb_history_index = 0;
static int ecex_fb_preview_expanded = 0;

static void ecex_file_entry_free(ecex_file_entry_t *entries, size_t count) {
    if (!entries) return;
    for (size_t i = 0; i < count; i++) {
        free(entries[i].name);
        free(entries[i].path);
    }
    free(entries);
}

static int ecex_file_entry_compare(const void *a, const void *b) {
    const ecex_file_entry_t *ea = (const ecex_file_entry_t *)a;
    const ecex_file_entry_t *eb = (const ecex_file_entry_t *)b;
    if (ea->is_dir != eb->is_dir) return eb->is_dir - ea->is_dir;
    return strcmp(ea->name ? ea->name : "", eb->name ? eb->name : "");
}

static int ecex_file_browser_collect(const char *dir, ecex_file_entry_t **out_entries, size_t *out_count) {
    if (out_entries) *out_entries = NULL;
    if (out_count) *out_count = 0;
    if (!dir || !out_entries || !out_count) return ECEX_ERR;

    DIR *d = opendir(dir);
    if (!d) return ECEX_ERR;

    size_t cap = 64;
    size_t count = 0;
    ecex_file_entry_t *entries = calloc(cap, sizeof(*entries));
    if (!entries) { closedir(d); return ECEX_ERR; }

    struct dirent *entry;
    while ((entry = readdir(d)) != NULL) {
        const char *name = entry->d_name;
        if (strcmp(name, ".") == 0 || strcmp(name, "..") == 0) continue;

        if (count == cap) {
            size_t new_cap = cap * 2;
            ecex_file_entry_t *grown = realloc(entries, new_cap * sizeof(*entries));
            if (!grown) break;
            memset(grown + cap, 0, (new_cap - cap) * sizeof(*grown));
            entries = grown;
            cap = new_cap;
        }

        char *path = ecex_path_join(dir, name);
        if (!path) continue;
        char *name_copy = ecex_strdup(name);
        if (!name_copy) { free(path); continue; }

        entries[count].name = name_copy;
        entries[count].path = path;
        entries[count].is_dir = ecex_path_is_dir(path);
        entries[count].is_image = ecex_path_is_image(path);
        entries[count].size = ecex_path_file_size(path);
        count++;
    }

    closedir(d);
    qsort(entries, count, sizeof(*entries), ecex_file_entry_compare);
    *out_entries = entries;
    *out_count = count;
    return ECEX_OK;
}

static void ecex_file_browser_push_history(const char *dir) {
    if (!dir || !dir[0]) return;
    if (ecex_fb_history_count > 0 && strcmp(ecex_fb_history[ecex_fb_history_index], dir) == 0) return;

    if (ecex_fb_history_index + 1 < ecex_fb_history_count) {
        ecex_fb_history_count = ecex_fb_history_index + 1;
    }

    if (ecex_fb_history_count == 64) {
        memmove(ecex_fb_history, ecex_fb_history + 1, sizeof(ecex_fb_history[0]) * 63);
        ecex_fb_history_count = 63;
        if (ecex_fb_history_index > 0) ecex_fb_history_index--;
    }

    ecex_path_copy(ecex_fb_history[ecex_fb_history_count], sizeof(ecex_fb_history[0]), dir);
    ecex_fb_history_index = ecex_fb_history_count;
    ecex_fb_history_count++;
}

static int ecex_file_browser_populate(ecex_t *ed, const char *dir, int push_history);
static int ecex_file_browser_move_to_action(buffer_t *buf, size_t action_index);

static int ecex_file_browser_open_action(ecex_t *ed,
                                         buffer_t *buffer,
                                         size_t line,
                                         const char *payload,
                                         void *userdata) {
    (void)buffer;
    (void)line;
    (void)userdata;
    if (!ed || !payload) return ECEX_ERR;

    char selected[4096];
    ecex_path_copy(selected, sizeof(selected), payload);

    if (ecex_path_is_dir(selected)) return ecex_file_browser_populate(ed, selected, 1);
    if (ecex_path_is_file(selected) && ecex_path_is_media(selected)) return ecex_media_open(ed, selected);
    if (ecex_path_is_file(selected)) return ecex_find_file(ed, selected);
    return ECEX_ERR;
}

static int ecex_file_browser_populate(ecex_t *ed, const char *dir, int push_history) {
    if (!ed) return ECEX_ERR;

    char *normalized = ecex_path_normalize((dir && dir[0]) ? dir : ecex_fb_cwd);
    if (!normalized) return ECEX_ERR;
    if (!ecex_path_is_dir(normalized)) {
        char *parent = ecex_path_dirname(normalized);
        free(normalized);
        normalized = parent;
        if (!normalized) return ECEX_ERR;
    }

    ecex_path_copy(ecex_fb_cwd, sizeof(ecex_fb_cwd), normalized);
    if (push_history) ecex_file_browser_push_history(ecex_fb_cwd);

    buffer_t *buf = ecex_find_buffer(ed, "*file-browser*");
    if (!buf) buf = ecex_create_interactive_buffer(ed, "*file-browser*");
    if (!buf) { free(normalized); return ECEX_ERR; }

    buffer_clear(buf);
    buffer_set_interactive(buf, 1);
    ecex_buffer_set_major_mode_by_name(ed, buf, "file-browser-mode");

    char line[8192];
    snprintf(line, sizeof(line),
             "File browser: %s\n\nKeys: RET/l open, h parent, g refresh, b/f history, v preview, m toggle preview, q quit.\n\n",
             ecex_fb_cwd);
    buffer_append(buf, line);

    char *parent = ecex_path_dirname(ecex_fb_cwd);
    if (parent) {
        ecex_interactive_append_line(ed, buf, "[..] parent", ecex_file_browser_open_action, parent, NULL);
        free(parent);
    }

    ecex_file_entry_t *entries = NULL;
    size_t count = 0;
    if (ecex_file_browser_collect(ecex_fb_cwd, &entries, &count) != ECEX_OK) {
        buffer_append(buf, "\nCould not read directory.\n");
    } else {
        for (size_t i = 0; i < count; i++) {
            const char *tag = entries[i].is_dir ? "[D]" : (entries[i].is_image ? "[I]" : (ecex_path_is_video(entries[i].path) ? "[V]" : "   "));
            if (entries[i].is_dir) {
                snprintf(line, sizeof(line), "%s %s/", tag, entries[i].name);
            } else if (entries[i].size >= 0) {
                snprintf(line, sizeof(line), "%s %s  (%lld bytes)", tag, entries[i].name, entries[i].size);
            } else {
                snprintf(line, sizeof(line), "%s %s", tag, entries[i].name);
            }
            ecex_interactive_append_line(ed, buf, line, ecex_file_browser_open_action, entries[i].path, NULL);
        }
    }
    ecex_file_entry_free(entries, count);

    if (ecex_fb_preview_expanded) {
        buffer_append(buf, "\nPreview pane is active: move up/down to update it, v refreshes, m closes it.\n");
    }

    buf->point = 0;
    buf->scroll_line = 0;
    buf->scroll_col = 0;
    if (buf->interactive_action_count > 0) {
        /* Start on the first actual directory entry instead of the [..] parent row.
         * That makes pressing m/v immediately show a useful preview. */
        ecex_file_browser_move_to_action(buf, buf->interactive_action_count > 1 ? 1 : 0);
    }
    buf->modified = 0;
    free(normalized);
    int result = ecex_switch_buffer(ed, "*file-browser*");
    if (result == ECEX_OK && ecex_fb_preview_expanded) {
        ecex_file_browser_update_preview_if_enabled(ed);
    }
    return result;
}

static int ecex_file_browser_current_payload(ecex_t *ed, char *out, size_t out_size) {
    if (!ed || !out || out_size == 0) return ECEX_ERR;
    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf || !buffer_is_interactive(buf)) return ECEX_ERR;
    size_t line = buffer_current_line_number(buf);
    if (line > 0) line--;
    ecex_interactive_line_action_t *action = buffer_interactive_action_at_line(buf, line);
    if ((!action || !action->payload) && buf->interactive_action_count > 0) {
        action = &buf->interactive_actions[0];
    }
    if (!action || !action->payload) return ECEX_ERR;
    return ecex_path_copy(out, out_size, action->payload) == 0 ? ECEX_OK : ECEX_ERR;
}

static int ecex_file_browser_move_to_action(buffer_t *buf, size_t action_index) {
    if (!buf || !buffer_is_interactive(buf) || buf->interactive_action_count == 0) return ECEX_ERR;
    if (action_index >= buf->interactive_action_count) action_index = buf->interactive_action_count - 1;
    size_t target_line = buf->interactive_actions[action_index].line;
    size_t pos = 0;
    for (size_t line = 0; line < target_line && pos < buf->len; pos++) {
        if (buf->data[pos] == '\n') line++;
    }
    buffer_set_point(buf, pos);
    return ECEX_OK;
}

static buffer_t *ecex_file_preview_buffer(ecex_t *ed) {
    if (!ed) return NULL;
    buffer_t *preview = ecex_find_buffer(ed, "*file-preview*");
    if (!preview) preview = ecex_create_buffer(ed, "*file-preview*", NULL, 0);
    return preview;
}

static int ecex_file_browser_show_preview_pane(ecex_t *ed, buffer_t *preview) {
    if (!ed || !preview || ed->window_count == 0) return ECEX_ERR;

    size_t browser_window = ed->current_window_index;
    if (ed->window_count == 1) {
        if (ecex_split_window_vertically(ed) != ECEX_OK) return ECEX_ERR;
        ed->windows[ed->current_window_index].buffer = preview;
        ed->current_window_index = browser_window;
        return ecex_sync_current_buffer(ed);
    }

    size_t preview_window = (browser_window + 1) % ed->window_count;
    if (preview_window == browser_window && ed->window_count > 1) preview_window = 1;
    ed->windows[preview_window].buffer = preview;
    ed->current_window_index = browser_window;
    return ecex_sync_current_buffer(ed);
}

static int ecex_file_browser_close_preview_pane(ecex_t *ed) {
    if (!ed || ed->window_count <= 1) return ECEX_OK;
    buffer_t *preview = ecex_find_buffer(ed, "*file-preview*");
    if (!preview) return ECEX_OK;

    for (size_t i = 0; i < ed->window_count; i++) {
        if (ed->windows[i].buffer != preview) continue;
        memmove(&ed->windows[i], &ed->windows[i + 1], (ed->window_count - i - 1) * sizeof(ed->windows[0]));
        ed->window_count--;
        if (ed->current_window_index >= ed->window_count) ed->current_window_index = ed->window_count - 1;
        ecex_balance_windows(ed);
        return ecex_sync_current_buffer(ed);
    }
    return ECEX_OK;
}

static int ecex_file_browser_fill_preview(ecex_t *ed, buffer_t *preview, const char *path) {
    if (!ed || !preview || !path) return ECEX_ERR;

    if (ecex_path_is_media(path)) {
        return ecex_media_load_into_buffer(ed, path, preview);
    }

    ecex_media_buffer_clear(preview);
    ecex_buffer_set_major_mode_by_name(ed, preview, "special-mode");
    preview->read_only = 0;
    buffer_clear(preview);
    char line[8192];
    snprintf(line, sizeof(line), "Preview: %s\n\n", path);
    buffer_append(preview, line);

    if (ecex_path_is_dir(path)) {
        buffer_append(preview, "Directory. Press RET/l in *file-browser* to open it.\n");
    } else if (ecex_path_is_file(path)) {
        long long size = ecex_path_file_size(path);
        snprintf(line, sizeof(line), "File size: %lld bytes.\n\n", size);
        buffer_append(preview, line);
        FILE *f = fopen(path, "rb");
        if (f) {
            char chunk[8193];
            size_t n = fread(chunk, 1, sizeof(chunk) - 1, f);
            fclose(f);
            chunk[n] = '\0';
            int binary = 0;
            for (size_t i = 0; i < n; i++) {
                unsigned char c = (unsigned char)chunk[i];
                if (c == 0 || (c < 8) || (c > 13 && c < 32)) { binary = 1; break; }
            }
            if (binary) buffer_append(preview, "Binary file; text preview suppressed.\n");
            else buffer_append(preview, chunk);
        }
    }

    preview->modified = 0;
    preview->read_only = 1;
    return ECEX_OK;
}

static int ecex_file_browser_preview_current(ecex_t *ed) {
    char path[4096];
    if (ecex_file_browser_current_payload(ed, path, sizeof(path)) != ECEX_OK) return ECEX_ERR;

    buffer_t *preview = ecex_file_preview_buffer(ed);
    if (!preview) return ECEX_ERR;

    int result = ecex_file_browser_fill_preview(ed, preview, path);
    ecex_file_browser_show_preview_pane(ed, preview);
    return result;
}

static int ecex_file_browser_update_preview_if_enabled(ecex_t *ed) {
    if (!ed || !ecex_fb_preview_expanded) return ECEX_OK;
    buffer_t *buf = ecex_current_buffer(ed);
    const char *mode = buf ? ecex_buffer_major_mode_name(ed, buf) : NULL;
    if (!mode || strcmp(mode, "file-browser-mode") != 0) return ECEX_OK;
    return ecex_file_browser_preview_current(ed);
}

static int cmd_file_browser(ecex_t *ed) {
    char cwd[4096];
    ecex_path_cwd(cwd, sizeof(cwd));
    return ecex_file_browser_populate(ed, cwd, 1);
}

static int cmd_file_browser_here(ecex_t *ed) {
    buffer_t *buf = ecex_current_buffer(ed);
    if (buf && buf->path && buf->path[0]) {
        char *dir = ecex_path_dirname(buf->path);
        if (!dir) return ECEX_ERR;
        int result = ecex_file_browser_populate(ed, dir, 1);
        free(dir);
        return result;
    }
    return cmd_file_browser(ed);
}

static int cmd_file_browser_refresh(ecex_t *ed) { return ecex_file_browser_populate(ed, ecex_fb_cwd, 0); }

static int cmd_file_browser_parent(ecex_t *ed) {
    char *parent = ecex_path_dirname(ecex_fb_cwd);
    if (!parent) return ECEX_ERR;
    int result = ecex_file_browser_populate(ed, parent, 1);
    free(parent);
    return result;
}

static int cmd_file_browser_open(ecex_t *ed) { return ecex_interactive_activate_current_line(ed); }
static int cmd_file_browser_preview(ecex_t *ed) { return ecex_file_browser_preview_current(ed); }

static int cmd_file_browser_toggle_preview(ecex_t *ed) {
    ecex_fb_preview_expanded = !ecex_fb_preview_expanded;
    if (!ecex_fb_preview_expanded) {
        ecex_file_browser_close_preview_pane(ed);
        return ecex_file_browser_populate(ed, ecex_fb_cwd, 0);
    }
    int result = ecex_file_browser_populate(ed, ecex_fb_cwd, 0);
    if (result == ECEX_OK) ecex_file_browser_preview_current(ed);
    return result;
}

static int cmd_file_browser_history_back(ecex_t *ed) {
    if (ecex_fb_history_count == 0 || ecex_fb_history_index == 0) return ECEX_ERR;
    ecex_fb_history_index--;
    return ecex_file_browser_populate(ed, ecex_fb_history[ecex_fb_history_index], 0);
}

static int cmd_file_browser_history_forward(ecex_t *ed) {
    if (ecex_fb_history_count == 0 || ecex_fb_history_index + 1 >= ecex_fb_history_count) return ECEX_ERR;
    ecex_fb_history_index++;
    return ecex_file_browser_populate(ed, ecex_fb_history[ecex_fb_history_index], 0);
}

static int cmd_media_play_pause(ecex_t *ed) { return ecex_media_toggle_playback(ed); }

static int ecex_register_builtins(ecex_t *ed) {
    ECEX_COMMAND("quit", cmd_quit);
    ECEX_COMMAND("force-quit", cmd_force_quit);
    ECEX_COMMAND("find-file", cmd_find_file);
    ECEX_COMMAND("file-browser", cmd_file_browser);
    ECEX_COMMAND("file-browser-here", cmd_file_browser_here);
    ECEX_COMMAND("file-browser-refresh", cmd_file_browser_refresh);
    ECEX_COMMAND("file-browser-parent", cmd_file_browser_parent);
    ECEX_COMMAND("file-browser-open", cmd_file_browser_open);
    ECEX_COMMAND("file-browser-preview", cmd_file_browser_preview);
    ECEX_COMMAND("file-browser-toggle-preview", cmd_file_browser_toggle_preview);
    ECEX_COMMAND("file-browser-history-back", cmd_file_browser_history_back);
    ECEX_COMMAND("file-browser-history-forward", cmd_file_browser_history_forward);
    ECEX_COMMAND("media-play-pause", cmd_media_play_pause);
    ECEX_COMMAND("save-buffer", cmd_save_buffer);
    ECEX_COMMAND("write-file", cmd_write_file);
    ECEX_COMMAND("eval-buffer", cmd_eval_buffer);
    ECEX_COMMAND("eval-line", cmd_eval_line);
    ECEX_COMMAND("eval-region", cmd_eval_region);
    ECEX_COMMAND("eval-selection", cmd_eval_region);
    ECEX_COMMAND("eval-file", cmd_eval_file);
    ECEX_COMMAND("eval-rerun-last", cmd_eval_rerun_last);
    ECEX_COMMAND("revert-eval-buffer", cmd_eval_rerun_last);
    ECEX_COMMAND("quit-window", cmd_quit_window);
    ECEX_COMMAND("reload-config", cmd_reload_config);
    ECEX_COMMAND("list-commands", cmd_list_commands);
    ECEX_COMMAND("list-buffers", cmd_list_buffers);
    ECEX_COMMAND("switch-buffer", cmd_switch_buffer);
    ECEX_COMMAND("kill-buffer", cmd_kill_buffer_command);
    ECEX_COMMAND("force-kill-buffer", cmd_force_kill_buffer_command);
    ECEX_COMMAND("compile", cmd_compile);
    ECEX_COMMAND("recompile", cmd_recompile);
    ECEX_COMMAND("grep", cmd_grep);
    ECEX_COMMAND("regrep", cmd_regrep);
    ECEX_COMMAND("next-error", cmd_next_error);
    ECEX_COMMAND("previous-error", cmd_previous_error);
    ECEX_COMMAND("comment-region", cmd_comment_region);
    ECEX_COMMAND("uncomment-region", cmd_uncomment_region);
    ECEX_COMMAND("toggle-line-numbers", cmd_toggle_line_numbers);
    ECEX_COMMAND("toggle-current-line", cmd_toggle_current_line);
    ECEX_COMMAND("isearch-forward", cmd_isearch_forward);
    ECEX_COMMAND("isearch-backward", cmd_isearch_backward);
    ECEX_COMMAND("indent-for-tab-command", cmd_indent_for_tab);
    ECEX_COMMAND("complete-at-point", cmd_complete_at_point);
    ECEX_COMMAND("complete-at-point-previous", cmd_complete_at_point_previous);

    ECEX_COMMAND("next-buffer", cmd_next_buffer);
    ECEX_COMMAND("previous-buffer", cmd_previous_buffer);
    ECEX_COMMAND("split-window-right", cmd_split_window_right);
    ECEX_COMMAND("split-window-vertically", cmd_split_window_right);
    ECEX_COMMAND("split-window-below", cmd_split_window_below);
    ECEX_COMMAND("split-window-horizontally", cmd_split_window_below);
    ECEX_COMMAND("other-window", cmd_other_window);
    ECEX_COMMAND("previous-window", cmd_previous_window);
    ECEX_COMMAND("delete-window", cmd_delete_window);
    ECEX_COMMAND("delete-other-windows", cmd_delete_other_windows);
    ECEX_COMMAND("balance-windows", cmd_balance_windows);

    ECEX_COMMAND("move-left", cmd_move_left);
    ECEX_COMMAND("move-right", cmd_move_right);
    ECEX_COMMAND("move-up", cmd_move_up);
    ECEX_COMMAND("move-down", cmd_move_down);
    ECEX_COMMAND("move-word-left", cmd_move_word_left);
    ECEX_COMMAND("move-word-right", cmd_move_word_right);
    ECEX_COMMAND("beginning-of-line", cmd_beginning_of_line);
    ECEX_COMMAND("end-of-line", cmd_end_of_line);
    ECEX_COMMAND("beginning-of-buffer", cmd_beginning_of_buffer);
    ECEX_COMMAND("end-of-buffer", cmd_end_of_buffer);

    ECEX_COMMAND("undo", cmd_undo);
    ECEX_COMMAND("redo", cmd_redo);
    ECEX_COMMAND("backspace", cmd_backspace);
    ECEX_COMMAND("delete-forward", cmd_delete_forward);
    ECEX_COMMAND("newline", cmd_newline);
    ECEX_COMMAND("kill-line", cmd_kill_line);
    ECEX_COMMAND("clear-buffer", cmd_clear_buffer);
    ECEX_COMMAND("set-mark", cmd_set_mark);
    ECEX_COMMAND("clear-mark", cmd_clear_mark);
    ECEX_COMMAND("yank", cmd_yank);
    ECEX_COMMAND("paste", cmd_yank);
    ECEX_COMMAND("clipboard-yank", cmd_yank);
    ECEX_COMMAND("copy", cmd_copy_region);
    ECEX_COMMAND("copy-region", cmd_copy_region);
    ECEX_COMMAND("copy-region-as-kill", cmd_copy_region);
    ECEX_COMMAND("cut", cmd_kill_region);
    ECEX_COMMAND("kill-region", cmd_kill_region);
    ECEX_COMMAND("clipboard-kill-region", cmd_kill_region);

    ECEX_BIND("LEFT", "move-left");
    ECEX_BIND("RIGHT", "move-right");
    ECEX_BIND("UP", "move-up");
    ECEX_BIND("DOWN", "move-down");
    ECEX_BIND("HOME", "beginning-of-line");
    ECEX_BIND("END", "end-of-line");
    ECEX_BIND("C-HOME", "beginning-of-buffer");
    ECEX_BIND("C-END", "end-of-buffer");

    ECEX_BIND("C-b", "move-left");
    ECEX_BIND("C-f", "move-right");
    ECEX_BIND("C-p", "move-up");
    ECEX_BIND("C-n", "move-down");
    ECEX_BIND("M-b", "move-word-left");
    ECEX_BIND("M-f", "move-word-right");
    ECEX_BIND("C-a", "beginning-of-line");
    ECEX_BIND("C-e", "end-of-line");
    ECEX_BIND("M-<", "beginning-of-buffer");
    ECEX_BIND("M->", "end-of-buffer");
    ECEX_BIND("C-k", "kill-line");
    ECEX_BIND("C-SPC", "set-mark");
    ECEX_BIND("C-y", "yank");
    ECEX_BIND("C-v", "paste");
    ECEX_BIND("C-S-v", "paste");
    ECEX_BIND("C-c", "copy-region");
    ECEX_BIND("C-S-c", "copy-region");
    ECEX_BIND("C-S-x", "kill-region");
    ECEX_BIND("M-w", "copy-region-as-kill");
    ECEX_BIND("C-w", "kill-region");
    ECEX_BIND("C-s", "isearch-forward");
    ECEX_BIND("C-r", "isearch-backward");
    ECEX_BIND("C-/", "undo");
    ECEX_BIND("C-?", "undo");
    ECEX_BIND("C-_", "undo");
    ECEX_BIND("C-z", "undo");
    ECEX_BIND("C-S-z", "redo");
    ECEX_BIND("C-x u", "undo");
    ECEX_BIND("C-x C-u", "undo");

    ECEX_BIND("C-x C-f", "find-file");
    ECEX_BIND("C-x f", "find-file");
    ECEX_BIND("C-x d", "file-browser");
    ECEX_BIND("C-x C-d", "file-browser-here");
    ECEX_BIND("C-x C-s", "save-buffer");
    ECEX_BIND("C-x C-w", "write-file");
    ECEX_BIND("C-x C-b", "list-buffers");
    ECEX_BIND("C-x b", "switch-buffer");
    ECEX_BIND("C-x k", "kill-buffer");
    ECEX_BIND("C-x K", "force-kill-buffer");
    ECEX_BIND("C-x 2", "split-window-below");
    ECEX_BIND("C-x 3", "split-window-right");
    ECEX_BIND("C-x o", "other-window");
    ECEX_BIND("C-x O", "previous-window");
    ECEX_BIND("C-x 0", "delete-window");
    ECEX_BIND("C-x 1", "delete-other-windows");
    ECEX_BIND("C-x +", "balance-windows");
    ECEX_BIND("C-x C-c", "quit");
    ECEX_BIND("C-x C-S-c", "force-quit");
    ECEX_BIND("C-x e b", "eval-buffer");
    ECEX_BIND("C-x e l", "eval-line");
    ECEX_BIND("C-x C-e", "eval-line");
    ECEX_BIND("C-x e r", "eval-region");
    ECEX_BIND("C-x e f", "eval-file");
    ECEX_BIND("C-x C-r", "reload-config");
    ECEX_BIND("F5", "reload-config");
    ECEX_BIND("M-g n", "next-error");
    ECEX_BIND("M-g p", "previous-error");
    ECEX_BIND("M-;", "comment-region");

    ECEX_BIND("BACKSPACE", "backspace");
    ECEX_BIND("DELETE", "delete-forward");
    ECEX_BIND("ENTER", "newline");
    ECEX_BIND("TAB", "indent-for-tab-command");
    ECEX_BIND("C-TAB", "complete-at-point");
    ECEX_BIND("C-S-TAB", "complete-at-point-previous");

    ecex_define_major_mode(ed, "fundamental-mode");
    ecex_define_major_mode(ed, "eval-output-mode");
    ecex_define_major_mode(ed, "special-mode");
    ecex_define_major_mode(ed, "file-browser-mode");
    ecex_define_major_mode(ed, "media-preview-mode");
    ecex_define_major_mode(ed, "markdown-mode");
    ecex_bind_mode_key(ed, "eval-output-mode", "g", "eval-rerun-last");
    ecex_bind_mode_key(ed, "eval-output-mode", "q", "quit-window");
    ecex_bind_mode_key(ed, "eval-output-mode", "r", "eval-rerun-last");
    ecex_bind_mode_key(ed, "special-mode", "q", "quit-window");

    ecex_bind_mode_key(ed, "file-browser-mode", "g", "file-browser-refresh");
    ecex_bind_mode_key(ed, "file-browser-mode", "r", "file-browser-refresh");
    ecex_bind_mode_key(ed, "file-browser-mode", "h", "file-browser-parent");
    ecex_bind_mode_key(ed, "file-browser-mode", "l", "file-browser-open");
    ecex_bind_mode_key(ed, "file-browser-mode", "v", "file-browser-preview");
    ecex_bind_mode_key(ed, "file-browser-mode", "m", "file-browser-toggle-preview");
    ecex_bind_mode_key(ed, "file-browser-mode", "b", "file-browser-history-back");
    ecex_bind_mode_key(ed, "file-browser-mode", "f", "file-browser-history-forward");
    ecex_bind_mode_key(ed, "file-browser-mode", "q", "quit-window");
    ecex_bind_mode_key(ed, "media-preview-mode", "SPC", "media-play-pause");
    ecex_bind_mode_key(ed, "media-preview-mode", "p", "media-play-pause");
    ecex_bind_mode_key(ed, "media-preview-mode", "q", "quit-window");
    ecex_bind_mode_key(ed, "special-mode", "g", "recompile");
    ecex_bind_mode_key(ed, "special-mode", "n", "next-error");
    ecex_bind_mode_key(ed, "special-mode", "p", "previous-error");

    return ECEX_OK;
}

#undef ECEX_COMMAND
#undef ECEX_BIND
#undef CURRENT_BUFFER_OR_ERR

ecex_t *ecex_new(void) {
    ecex_t *ed = calloc(1, sizeof(*ed));
    if (!ed) return NULL;

    ed->plugins = ecex_plugin_runtime_new();
    if (!ed->plugins) {
        ecex_free(ed);
        return NULL;
    }

    ecex_theme_set_defaults(ed);

    buffer_t *scratch = buffer_new("*scratch*", NULL, 0);
    if (!scratch || ecex_add_buffer(ed, scratch) != ECEX_OK) {
        buffer_free(scratch);
        ecex_free(ed);
        return NULL;
    }

    ed->current_buffer_index = 0;
    ed->current_buffer = scratch;
    ed->next_major_mode_id = 1;

    ed->window_cap = ECEX_INITIAL_WINDOW_CAP;
    ed->windows = calloc(ed->window_cap, sizeof(*ed->windows));
    if (!ed->windows) {
        ecex_free(ed);
        return NULL;
    }
    ed->window_count = 1;
    ed->current_window_index = 0;
    ed->windows[0].buffer = scratch;
    ed->windows[0].x = 0.0f;
    ed->windows[0].y = 0.0f;
    ed->windows[0].w = 1.0f;
    ed->windows[0].h = 1.0f;

    if (ecex_register_builtins(ed) != ECEX_OK) {
        ecex_free(ed);
        return NULL;
    }

    ecex_buffer_set_major_mode_by_name(ed, scratch, "fundamental-mode");

    return ed;
}

void ecex_free(ecex_t *ed) {
    if (!ed) return;

    /* Buffers may hold renderer/animation callbacks and userdata destructors
     * compiled by CCDJIT config modules. Run those destructors while their JIT
     * modules are still alive; freeing modules first leaves callback pointers
     * dangling and can segfault during buffer teardown. */
    for (size_t i = 0; i < ed->buffer_count; i++) {
        buffer_free(ed->buffers[i]);
    }

    ecex_clear_command_hooks(ed);
    ecex_clear_prefix_hooks(ed);
    ecex_clear_buffer_hooks(ed);
    ecex_clear_completion_providers(ed);

    for (size_t i = 0; i < ed->jit_module_count; i++) {
        ccdjit_module_free((ccdjit_module *)ed->jit_modules[i]);
    }

    ecex_plugin_runtime_free(ed->plugins);
    ed->plugins = NULL;

    for (size_t i = 0; i < ed->command_count; i++) {
        free(ed->commands[i].name);
    }

    for (size_t i = 0; i < ed->keybind_count; i++) {
        free(ed->keybinds[i].key);
        free(ed->keybinds[i].command);
    }

    for (size_t i = 0; i < ed->mode_keybind_count; i++) {
        free(ed->mode_keybinds[i].key);
        free(ed->mode_keybinds[i].command);
    }

    for (size_t i = 0; i < ed->major_mode_count; i++) {
        free(ed->major_modes[i].name);
    }

    free(ed->jit_modules);
    free(ed->windows);
    free(ed->buffers);
    free(ed->commands);
    free(ed->keybinds);
    free(ed->mode_keybinds);
    free(ed->command_hooks);
    free(ed->prefix_hooks);
    free(ed->buffer_hooks);
    free(ed->completion_providers);
    free(ed->major_modes);
    free(ed->last_eval_source);
    free(ed->last_eval_filename);
    free(ed->last_compile_command);
    free(ed->last_grep_command);
    free(ed->config_path);
    free(ed->clipboard_text);
    free(ed->theme.font_path);
    free(ed);
    ecex_log_flush();
}

int ecex_reserve_buffers(ecex_t *ed, size_t needed) {
    ECEX_RETURN_ERR_IF_NULL(ed);
    if (needed <= ed->buffer_cap) return ECEX_OK;

    while (ed->buffer_cap < needed) {
        if (ECEX_GROW_ARRAY(ed->buffers,
                            ed->buffer_count,
                            ed->buffer_cap,
                            ECEX_INITIAL_BUFFER_CAP) != ECEX_OK) {
            return ECEX_ERR;
        }
    }

    return ECEX_OK;
}

int ecex_add_buffer(ecex_t *ed, buffer_t *buffer) {
    if (!ed || !buffer) return ECEX_ERR;

    if (ecex_reserve_buffers(ed, ed->buffer_count + 1) != ECEX_OK) return ECEX_ERR;

    ed->buffers[ed->buffer_count++] = buffer;

    if (!ed->current_buffer) {
        ed->current_buffer_index = 0;
        ed->current_buffer = buffer;
    }

    return ECEX_OK;
}

buffer_t *ecex_create_buffer(ecex_t *ed,
                             const char *name,
                             const char *path,
                             int read_only) {
    if (!ed || !name) return NULL;

    buffer_t *buffer = buffer_new(name, path, read_only);
    if (!buffer) return NULL;

    if (ecex_add_buffer(ed, buffer) != ECEX_OK) {
        buffer_free(buffer);
        return NULL;
    }

    ecex_notify_buffer_hooks(ed, buffer, ECEX_BUFFER_HOOK_CREATE);
    return buffer;
}

buffer_t *ecex_find_buffer(ecex_t *ed, const char *name) {
    if (!ed || !name) return NULL;

    for (size_t i = 0; i < ed->buffer_count; i++) {
        if (strcmp(ed->buffers[i]->name, name) == 0) {
            return ed->buffers[i];
        }
    }

    return NULL;
}


static int ecex_buffer_index_of(ecex_t *ed, buffer_t *buffer, size_t *out_index) {
    if (!ed || !buffer) return ECEX_ERR;
    for (size_t i = 0; i < ed->buffer_count; i++) {
        if (ed->buffers[i] == buffer) {
            if (out_index) *out_index = i;
            return ECEX_OK;
        }
    }
    return ECEX_ERR;
}

static int ecex_set_current_buffer_index(ecex_t *ed, size_t index) {
    if (!ed || index >= ed->buffer_count) return ECEX_ERR;

    buffer_t *next = ed->buffers[index];
    if (ed->current_buffer && ed->current_buffer != next) {
        ed->previous_buffer = ed->current_buffer;
    }

    ed->current_buffer_index = index;
    ed->current_buffer = next;
    ecex_window_t *win = ecex_current_window(ed);
    if (win) win->buffer = ed->current_buffer;
    ecex_notify_buffer_hooks(ed, next, ECEX_BUFFER_HOOK_SWITCH);
    return ECEX_OK;
}

int ecex_sync_current_buffer(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    ecex_window_t *win = ecex_current_window(ed);
    if (!win || !win->buffer) return ECEX_ERR;

    buffer_t *next = win->buffer;
    if (ed->current_buffer && ed->current_buffer != next) {
        ed->previous_buffer = ed->current_buffer;
    }

    ed->current_buffer = next;
    for (size_t i = 0; i < ed->buffer_count; i++) {
        if (ed->buffers[i] == next) {
            ed->current_buffer_index = i;
            ecex_notify_buffer_hooks(ed, next, ECEX_BUFFER_HOOK_SWITCH);
            return ECEX_OK;
        }
    }
    return ECEX_ERR;
}

int ecex_switch_buffer(ecex_t *ed, const char *name) {
    if (!ed) return ECEX_ERR;

    if (!name || name[0] == '\0') {
        buffer_t *other = ecex_other_buffer(ed);
        size_t index = 0;
        if (!other || ecex_buffer_index_of(ed, other, &index) != ECEX_OK) return ECEX_ERR;
        return ecex_set_current_buffer_index(ed, index);
    }

    for (size_t i = 0; i < ed->buffer_count; i++) {
        if (strcmp(ed->buffers[i]->name, name) == 0) {
            return ecex_set_current_buffer_index(ed, i);
        }
    }

    return ECEX_ERR;
}

buffer_t *ecex_current_buffer(ecex_t *ed) {
    if (!ed) return NULL;
    ecex_window_t *win = ecex_current_window(ed);
    if (win && win->buffer) return win->buffer;
    return ed->current_buffer;
}

buffer_t *ecex_other_buffer(ecex_t *ed) {
    if (!ed || ed->buffer_count == 0) return NULL;

    buffer_t *current = ecex_current_buffer(ed);
    if (ed->previous_buffer && ed->previous_buffer != current &&
        ecex_buffer_index_of(ed, ed->previous_buffer, NULL) == ECEX_OK) {
        return ed->previous_buffer;
    }

    for (size_t i = 0; i < ed->buffer_count; i++) {
        if (ed->buffers[i] && ed->buffers[i] != current) return ed->buffers[i];
    }

    return current;
}

ecex_window_t *ecex_current_window(ecex_t *ed) {
    if (!ed || ed->window_count == 0 || ed->current_window_index >= ed->window_count) return NULL;
    return &ed->windows[ed->current_window_index];
}

size_t ecex_window_count(ecex_t *ed) {
    return ed ? ed->window_count : 0;
}

static int ecex_reserve_windows(ecex_t *ed, size_t needed) {
    if (!ed) return ECEX_ERR;
    if (needed <= ed->window_cap) return ECEX_OK;
    while (ed->window_cap < needed) {
        if (ECEX_GROW_ARRAY(ed->windows,
                            ed->window_count,
                            ed->window_cap,
                            ECEX_INITIAL_WINDOW_CAP) != ECEX_OK) {
            return ECEX_ERR;
        }
    }
    return ECEX_OK;
}

static int ecex_add_window(ecex_t *ed, ecex_window_t win) {
    if (!ed || !win.buffer) return ECEX_ERR;
    if (ecex_reserve_windows(ed, ed->window_count + 1) != ECEX_OK) return ECEX_ERR;
    ed->windows[ed->window_count++] = win;
    return ECEX_OK;
}

int ecex_split_window_vertically(ecex_t *ed) {
    ecex_window_t *active = ecex_current_window(ed);
    if (!active || !active->buffer || active->w < 0.08f) return ECEX_ERR;

    ecex_window_t new_win = *active;
    float half = active->w * 0.5f;
    active->w = half;
    new_win.x = active->x + half;
    new_win.w = half;

    if (ecex_add_window(ed, new_win) != ECEX_OK) return ECEX_ERR;
    ed->current_window_index = ed->window_count - 1;
    return ecex_sync_current_buffer(ed);
}

int ecex_split_window_horizontally(ecex_t *ed) {
    ecex_window_t *active = ecex_current_window(ed);
    if (!active || !active->buffer || active->h < 0.08f) return ECEX_ERR;

    ecex_window_t new_win = *active;
    float half = active->h * 0.5f;
    active->h = half;
    new_win.y = active->y + half;
    new_win.h = half;

    if (ecex_add_window(ed, new_win) != ECEX_OK) return ECEX_ERR;
    ed->current_window_index = ed->window_count - 1;
    return ecex_sync_current_buffer(ed);
}

int ecex_other_window(ecex_t *ed) {
    if (!ed || ed->window_count == 0) return ECEX_ERR;
    ed->current_window_index = (ed->current_window_index + 1) % ed->window_count;
    return ecex_sync_current_buffer(ed);
}

int ecex_previous_window(ecex_t *ed) {
    if (!ed || ed->window_count == 0) return ECEX_ERR;
    if (ed->current_window_index == 0) ed->current_window_index = ed->window_count - 1;
    else ed->current_window_index--;
    return ecex_sync_current_buffer(ed);
}

int ecex_delete_window(ecex_t *ed) {
    if (!ed || ed->window_count <= 1 || ed->current_window_index >= ed->window_count) return ECEX_ERR;

    size_t index = ed->current_window_index;
    for (size_t i = index; i + 1 < ed->window_count; i++) {
        ed->windows[i] = ed->windows[i + 1];
    }
    ed->window_count--;
    if (ed->current_window_index >= ed->window_count) ed->current_window_index = ed->window_count - 1;
    return ecex_sync_current_buffer(ed);
}

int ecex_delete_other_windows(ecex_t *ed) {
    ecex_window_t *active = ecex_current_window(ed);
    if (!ed || !active) return ECEX_ERR;
    ecex_window_t keep = *active;
    keep.x = 0.0f; keep.y = 0.0f; keep.w = 1.0f; keep.h = 1.0f;
    ed->windows[0] = keep;
    ed->window_count = 1;
    ed->current_window_index = 0;
    return ecex_sync_current_buffer(ed);
}

int ecex_balance_windows(ecex_t *ed) {
    if (!ed || ed->window_count == 0) return ECEX_ERR;
    size_t n = ed->window_count;
    size_t cols = 1;
    while (cols * cols < n) cols++;
    size_t rows = (n + cols - 1) / cols;
    for (size_t i = 0; i < n; i++) {
        size_t row = i / cols;
        size_t col = i % cols;
        ed->windows[i].x = (float)col / (float)cols;
        ed->windows[i].y = (float)row / (float)rows;
        ed->windows[i].w = 1.0f / (float)cols;
        ed->windows[i].h = 1.0f / (float)rows;
    }
    return ecex_sync_current_buffer(ed);
}

int ecex_next_buffer(ecex_t *ed) {
    if (!ed || ed->buffer_count == 0) return ECEX_ERR;
    ecex_sync_current_buffer(ed);
    return ecex_set_current_buffer_index(ed, (ed->current_buffer_index + 1) % ed->buffer_count);
}

int ecex_previous_buffer(ecex_t *ed) {
    if (!ed || ed->buffer_count == 0) return ECEX_ERR;
    ecex_sync_current_buffer(ed);

    if (ed->current_buffer_index == 0) {
        ed->current_buffer_index = ed->buffer_count - 1;
    } else {
        ed->current_buffer_index--;
    }

    return ecex_set_current_buffer_index(ed, ed->current_buffer_index);
}

static int ecex_kill_buffer_impl(ecex_t *ed, const char *name, int force) {
    if (!ed || ed->buffer_count == 0) return ECEX_ERR;

    size_t index = ed->buffer_count;
    if (!name || name[0] == '\0') {
        buffer_t *current = ecex_current_buffer(ed);
        if (!current || ecex_buffer_index_of(ed, current, &index) != ECEX_OK) return ECEX_ERR;
    } else {
        for (size_t i = 0; i < ed->buffer_count; i++) {
            if (strcmp(ed->buffers[i]->name, name) == 0) {
                index = i;
                break;
            }
        }
    }

    if (index == ed->buffer_count) return ECEX_ERR;

    buffer_t *victim = ed->buffers[index];
    if (ed->previous_buffer == victim) ed->previous_buffer = NULL;
    if (!force && victim->modified && !victim->read_only) {
        fprintf(stderr,
                "ecex: refusing to kill modified buffer '%s'; save it or use force-kill-buffer.\n",
                victim->name ? victim->name : "<unnamed>");
        return ECEX_ERR;
    }

    for (size_t i = index; i + 1 < ed->buffer_count; i++) ed->buffers[i] = ed->buffers[i + 1];
    ed->buffer_count--;

    buffer_t *fallback = ecex_other_buffer(ed);
    if (fallback == victim) fallback = ed->buffer_count > 0 ? ed->buffers[0] : NULL;
    for (size_t i = 0; i < ed->window_count; i++) {
        if (ed->windows[i].buffer == victim) ed->windows[i].buffer = fallback;
    }

    ecex_notify_buffer_hooks(ed, victim, ECEX_BUFFER_HOOK_KILL);
    buffer_free(victim);

    if (ed->buffer_count == 0) {
        ed->current_buffer = NULL;
        ed->current_buffer_index = 0;
        ed->window_count = 0;
        ed->current_window_index = 0;
        return ECEX_OK;
    }

    if (ed->current_window_index >= ed->window_count) {
        ed->current_window_index = ed->window_count ? ed->window_count - 1 : 0;
    }

    return ecex_sync_current_buffer(ed);
}

int ecex_kill_buffer(ecex_t *ed, const char *name) {
    return ecex_kill_buffer_impl(ed, name, 0);
}

int ecex_kill_buffer_force(ecex_t *ed, const char *name) {
    return ecex_kill_buffer_impl(ed, name, 1);
}

int ecex_has_modified_buffers(ecex_t *ed) {
    if (!ed) return 0;
    for (size_t i = 0; i < ed->buffer_count; i++) {
        buffer_t *buf = ed->buffers[i];
        if (buf && buf->modified && !buf->read_only) return 1;
    }
    return 0;
}

int ecex_keep_jit_module(ecex_t *ed, void *module) {
    if (!ed || !module) return ECEX_ERR;

    if (ECEX_GROW_ARRAY(ed->jit_modules,
                        ed->jit_module_count,
                        ed->jit_module_cap,
                        8) != ECEX_OK) {
        return ECEX_ERR;
    }

    ed->jit_modules[ed->jit_module_count++] = module;
    return ECEX_OK;
}

int ecex_set_config_path(ecex_t *ed, const char *path) {
    if (!ed) return ECEX_ERR;

    char *copy = NULL;
    if (path && path[0]) {
        copy = ecex_strdup(path);
        if (!copy) return ECEX_ERR;
    }

    free(ed->config_path);
    ed->config_path = copy;
    return ECEX_OK;
}

const char *ecex_config_path(ecex_t *ed) {
    if (!ed) return NULL;
    return ed->config_path;
}

static void ecex_clear_commands(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->command_count; i++) {
        free(ed->commands[i].name);
    }
    ed->command_count = 0;
}

static void ecex_clear_keybinds(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->keybind_count; i++) {
        free(ed->keybinds[i].key);
        free(ed->keybinds[i].command);
    }
    ed->keybind_count = 0;
}

static void ecex_clear_mode_keybinds(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->mode_keybind_count; i++) {
        free(ed->mode_keybinds[i].key);
        free(ed->mode_keybinds[i].command);
    }
    ed->mode_keybind_count = 0;
}

static void ecex_command_hook_clear(ecex_command_hook_t *hook) {
    if (!hook) return;
    if (hook->free_fn && hook->userdata) hook->free_fn(hook->userdata);
    free(hook->name);
    memset(hook, 0, sizeof(*hook));
}

static void ecex_prefix_hook_clear(ecex_prefix_hook_t *hook) {
    if (!hook) return;
    if (hook->free_fn && hook->userdata) hook->free_fn(hook->userdata);
    free(hook->name);
    memset(hook, 0, sizeof(*hook));
}

static void ecex_buffer_hook_clear(ecex_buffer_hook_t *hook) {
    if (!hook) return;
    if (hook->free_fn && hook->userdata) hook->free_fn(hook->userdata);
    free(hook->name);
    memset(hook, 0, sizeof(*hook));
}

static void ecex_completion_provider_clear(ecex_completion_provider_t *provider) {
    if (!provider) return;
    if (provider->free_fn && provider->userdata) provider->free_fn(provider->userdata);
    for (size_t i = 0; i < provider->word_count; i++) {
        free(provider->words[i]);
    }
    free(provider->words);
    free(provider->detail);
    free(provider->name);
    memset(provider, 0, sizeof(*provider));
}

static void ecex_clear_command_hooks(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->command_hook_count; i++) {
        ecex_command_hook_clear(&ed->command_hooks[i]);
    }
    ed->command_hook_count = 0;
}

static void ecex_clear_prefix_hooks(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->prefix_hook_count; i++) {
        ecex_prefix_hook_clear(&ed->prefix_hooks[i]);
    }
    ed->prefix_hook_count = 0;
}

static void ecex_clear_buffer_hooks(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->buffer_hook_count; i++) {
        ecex_buffer_hook_clear(&ed->buffer_hooks[i]);
    }
    ed->buffer_hook_count = 0;
}

static void ecex_clear_completion_providers(ecex_t *ed) {
    if (!ed) return;

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        ecex_completion_provider_clear(&ed->completion_providers[i]);
    }
    ed->completion_provider_count = 0;
}

typedef struct ecex_binding_snapshot {
    ecex_command_t *commands;
    size_t command_count;
    size_t command_cap;
    ecex_keybind_t *keybinds;
    size_t keybind_count;
    size_t keybind_cap;
    ecex_mode_keybind_t *mode_keybinds;
    size_t mode_keybind_count;
    size_t mode_keybind_cap;
    ecex_command_hook_t *command_hooks;
    size_t command_hook_count;
    size_t command_hook_cap;
    ecex_prefix_hook_t *prefix_hooks;
    size_t prefix_hook_count;
    size_t prefix_hook_cap;
    ecex_buffer_hook_t *buffer_hooks;
    size_t buffer_hook_count;
    size_t buffer_hook_cap;
    ecex_completion_provider_t *completion_providers;
    size_t completion_provider_count;
    size_t completion_provider_cap;
    ecex_theme_t theme;
} ecex_binding_snapshot_t;

static void ecex_theme_snapshot_free(ecex_theme_t *theme) {
    if (!theme) return;
    free(theme->font_path);
    theme->font_path = NULL;
}

static int ecex_theme_clone(ecex_theme_t *out, const ecex_theme_t *in) {
    if (!out || !in) return ECEX_ERR;
    *out = *in;
    out->font_path = NULL;
    if (in->font_path) {
        out->font_path = ecex_strdup(in->font_path);
        if (!out->font_path) return ECEX_ERR;
    }
    return ECEX_OK;
}

static void ecex_snapshot_free(ecex_binding_snapshot_t *snap) {
    if (!snap) return;
    for (size_t i = 0; i < snap->command_count; i++) free(snap->commands[i].name);
    for (size_t i = 0; i < snap->keybind_count; i++) {
        free(snap->keybinds[i].key);
        free(snap->keybinds[i].command);
    }
    for (size_t i = 0; i < snap->mode_keybind_count; i++) {
        free(snap->mode_keybinds[i].key);
        free(snap->mode_keybinds[i].command);
    }
    for (size_t i = 0; i < snap->command_hook_count; i++) {
        ecex_command_hook_clear(&snap->command_hooks[i]);
    }
    for (size_t i = 0; i < snap->prefix_hook_count; i++) {
        ecex_prefix_hook_clear(&snap->prefix_hooks[i]);
    }
    for (size_t i = 0; i < snap->buffer_hook_count; i++) {
        ecex_buffer_hook_clear(&snap->buffer_hooks[i]);
    }
    for (size_t i = 0; i < snap->completion_provider_count; i++) {
        ecex_completion_provider_clear(&snap->completion_providers[i]);
    }
    free(snap->commands);
    free(snap->keybinds);
    free(snap->mode_keybinds);
    free(snap->command_hooks);
    free(snap->prefix_hooks);
    free(snap->buffer_hooks);
    free(snap->completion_providers);
    ecex_theme_snapshot_free(&snap->theme);
    memset(snap, 0, sizeof(*snap));
}

static int ecex_snapshot_clone(ecex_binding_snapshot_t *snap, ecex_t *ed) {
    if (!snap || !ed) return ECEX_ERR;
    memset(snap, 0, sizeof(*snap));

    if (ecex_theme_clone(&snap->theme, &ed->theme) != ECEX_OK) return ECEX_ERR;

    if (ed->command_cap) {
        snap->commands = calloc(ed->command_cap, sizeof(*snap->commands));
        if (!snap->commands) goto fail;
        snap->command_cap = ed->command_cap;
        snap->command_count = ed->command_count;
        for (size_t i = 0; i < ed->command_count; i++) {
            snap->commands[i].fn = ed->commands[i].fn;
            snap->commands[i].name = ecex_strdup(ed->commands[i].name);
            if (!snap->commands[i].name) goto fail;
        }
    }

    if (ed->keybind_cap) {
        snap->keybinds = calloc(ed->keybind_cap, sizeof(*snap->keybinds));
        if (!snap->keybinds) goto fail;
        snap->keybind_cap = ed->keybind_cap;
        snap->keybind_count = ed->keybind_count;
        for (size_t i = 0; i < ed->keybind_count; i++) {
            snap->keybinds[i].key = ecex_strdup(ed->keybinds[i].key);
            snap->keybinds[i].command = ecex_strdup(ed->keybinds[i].command);
            if (!snap->keybinds[i].key || !snap->keybinds[i].command) goto fail;
        }
    }

    if (ed->mode_keybind_cap) {
        snap->mode_keybinds = calloc(ed->mode_keybind_cap, sizeof(*snap->mode_keybinds));
        if (!snap->mode_keybinds) goto fail;
        snap->mode_keybind_cap = ed->mode_keybind_cap;
        snap->mode_keybind_count = ed->mode_keybind_count;
        for (size_t i = 0; i < ed->mode_keybind_count; i++) {
            snap->mode_keybinds[i].mode = ed->mode_keybinds[i].mode;
            snap->mode_keybinds[i].key = ecex_strdup(ed->mode_keybinds[i].key);
            snap->mode_keybinds[i].command = ecex_strdup(ed->mode_keybinds[i].command);
            if (!snap->mode_keybinds[i].key || !snap->mode_keybinds[i].command) goto fail;
        }
    }

    snap->command_hooks = ed->command_hooks;
    snap->command_hook_count = ed->command_hook_count;
    snap->command_hook_cap = ed->command_hook_cap;
    ed->command_hooks = NULL;
    ed->command_hook_count = 0;
    ed->command_hook_cap = 0;

    snap->prefix_hooks = ed->prefix_hooks;
    snap->prefix_hook_count = ed->prefix_hook_count;
    snap->prefix_hook_cap = ed->prefix_hook_cap;
    ed->prefix_hooks = NULL;
    ed->prefix_hook_count = 0;
    ed->prefix_hook_cap = 0;

    snap->buffer_hooks = ed->buffer_hooks;
    snap->buffer_hook_count = ed->buffer_hook_count;
    snap->buffer_hook_cap = ed->buffer_hook_cap;
    ed->buffer_hooks = NULL;
    ed->buffer_hook_count = 0;
    ed->buffer_hook_cap = 0;

    snap->completion_providers = ed->completion_providers;
    snap->completion_provider_count = ed->completion_provider_count;
    snap->completion_provider_cap = ed->completion_provider_cap;
    ed->completion_providers = NULL;
    ed->completion_provider_count = 0;
    ed->completion_provider_cap = 0;

    return ECEX_OK;

fail:
    ecex_snapshot_free(snap);
    return ECEX_ERR;
}

static void ecex_restore_snapshot(ecex_t *ed, ecex_binding_snapshot_t *snap) {
    if (!ed || !snap) return;

    ecex_clear_commands(ed);
    ecex_clear_keybinds(ed);
    ecex_clear_mode_keybinds(ed);
    ecex_clear_command_hooks(ed);
    ecex_clear_prefix_hooks(ed);
    ecex_clear_buffer_hooks(ed);
    ecex_clear_completion_providers(ed);
    free(ed->commands);
    free(ed->keybinds);
    free(ed->mode_keybinds);
    free(ed->command_hooks);
    free(ed->prefix_hooks);
    free(ed->buffer_hooks);
    free(ed->completion_providers);
    free(ed->theme.font_path);

    ed->commands = snap->commands;
    ed->command_count = snap->command_count;
    ed->command_cap = snap->command_cap;
    ed->keybinds = snap->keybinds;
    ed->keybind_count = snap->keybind_count;
    ed->keybind_cap = snap->keybind_cap;
    ed->mode_keybinds = snap->mode_keybinds;
    ed->mode_keybind_count = snap->mode_keybind_count;
    ed->mode_keybind_cap = snap->mode_keybind_cap;
    ed->command_hooks = snap->command_hooks;
    ed->command_hook_count = snap->command_hook_count;
    ed->command_hook_cap = snap->command_hook_cap;
    ed->prefix_hooks = snap->prefix_hooks;
    ed->prefix_hook_count = snap->prefix_hook_count;
    ed->prefix_hook_cap = snap->prefix_hook_cap;
    ed->buffer_hooks = snap->buffer_hooks;
    ed->buffer_hook_count = snap->buffer_hook_count;
    ed->buffer_hook_cap = snap->buffer_hook_cap;
    ed->completion_providers = snap->completion_providers;
    ed->completion_provider_count = snap->completion_provider_count;
    ed->completion_provider_cap = snap->completion_provider_cap;
    ed->theme = snap->theme;

    memset(snap, 0, sizeof(*snap));
}

int ecex_reload_config(ecex_t *ed) {
    if (!ed || !ed->config_path || !ed->config_path[0]) {
        fprintf(stderr, "ecex: no config file to reload; start with --config path/to/ecexrc.c\n");
        return ECEX_ERR;
    }

    char *path = ecex_strdup(ed->config_path);
    if (!path) return ECEX_ERR;

    ecex_binding_snapshot_t snapshot;
    if (ecex_snapshot_clone(&snapshot, ed) != ECEX_OK) {
        free(path);
        fprintf(stderr, "ecex: failed to snapshot config state before reload\n");
        return ECEX_ERR;
    }

    ecex_clear_commands(ed);
    ecex_clear_keybinds(ed);
    ecex_clear_mode_keybinds(ed);

    int result = ECEX_ERR;
    if (ecex_register_builtins(ed) == ECEX_OK) {
        result = ecex_load_c_config(ed, path);
        if (result == ECEX_OK) result = ecex_validate_bindings(ed);
    }

    if (result != ECEX_OK) {
        fprintf(stderr, "ecex: config reload failed; keeping previous config active\n");
        ecex_restore_snapshot(ed, &snapshot);
    } else {
        ecex_snapshot_free(&snapshot);
    }

    free(path);
    return result;
}


int ecex_config_register_commands(ecex_t *ed, const ecex_config_command_t *commands, size_t count) {
    if (!ed || (!commands && count != 0)) return ECEX_ERR;
    for (size_t i = 0; i < count; i++) {
        if (!commands[i].name || !commands[i].fn) return ECEX_ERR;
        if (ecex_register_command(ed, commands[i].name, commands[i].fn) != ECEX_OK) return ECEX_ERR;
    }
    return ECEX_OK;
}

int ecex_config_bind_keys(ecex_t *ed, const ecex_config_keybind_t *bindings, size_t count) {
    if (!ed || (!bindings && count != 0)) return ECEX_ERR;
    for (size_t i = 0; i < count; i++) {
        if (!bindings[i].key || !bindings[i].command) return ECEX_ERR;
        if (ecex_bind_key(ed, bindings[i].key, bindings[i].command) != ECEX_OK) return ECEX_ERR;
    }
    return ECEX_OK;
}

int ecex_config_bind_mode_keys(ecex_t *ed, const ecex_config_mode_keybind_t *bindings, size_t count) {
    if (!ed || (!bindings && count != 0)) return ECEX_ERR;
    for (size_t i = 0; i < count; i++) {
        if (!bindings[i].mode || !bindings[i].key || !bindings[i].command) return ECEX_ERR;
        if (ecex_bind_mode_key(ed, bindings[i].mode, bindings[i].key, bindings[i].command) != ECEX_OK) return ECEX_ERR;
    }
    return ECEX_OK;
}

int ecex_config_define_modes(ecex_t *ed, const char *const *modes, size_t count) {
    if (!ed || (!modes && count != 0)) return ECEX_ERR;
    for (size_t i = 0; i < count; i++) {
        if (!modes[i] || !ecex_define_major_mode(ed, modes[i])) return ECEX_ERR;
    }
    return ECEX_OK;
}

int ecex_apply_theme(ecex_t *ed, const ecex_theme_t *theme) {
    if (!ed || !theme) return ECEX_ERR;
    char *font = NULL;
    if (theme->font_path) {
        font = ecex_strdup(theme->font_path);
        if (!font) return ECEX_ERR;
    }
    int font_changed =
        ed->theme.font_size != theme->font_size ||
        ((ed->theme.font_path || theme->font_path) &&
         (!ed->theme.font_path || !theme->font_path ||
          strcmp(ed->theme.font_path, theme->font_path) != 0));
    free(ed->theme.font_path);
    ed->theme = *theme;
    ed->theme.font_path = font;
    if (font_changed) ecex_mark_font_changed(ed);
    else ecex_mark_ui_changed(ed);
    return ECEX_OK;
}

int ecex_register_command(ecex_t *ed, const char *name, ecex_command_fn fn) {
    if (!ed || !name || !fn) return ECEX_ERR;

    for (size_t i = 0; i < ed->command_count; i++) {
        if (strcmp(ed->commands[i].name, name) == 0) {
            fprintf(stderr, "ecex: command warning: replacing existing command '%s'\n", name);
            ed->commands[i].fn = fn;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->commands,
                        ed->command_count,
                        ed->command_cap,
                        ECEX_INITIAL_COMMAND_CAP) != ECEX_OK) {
        return ECEX_ERR;
    }

    char *copy = ecex_strdup(name);
    if (!copy) return ECEX_ERR;

    ed->commands[ed->command_count].name = copy;
    ed->commands[ed->command_count].fn = fn;
    ed->command_count++;
    return ECEX_OK;
}

int ecex_execute_command(ecex_t *ed, const char *name) {
    if (!ed || !name) return ECEX_ERR;

    for (size_t i = 0; i < ed->command_count; i++) {
        if (strcmp(ed->commands[i].name, name) == 0) {
            ecex_command_fn fn = ed->commands[i].fn;
            for (size_t j = 0; j < ed->command_hook_count; j++) {
                ecex_command_hook_t *hook = &ed->command_hooks[j];
                if (hook->fn) hook->fn(ed, name, ECEX_COMMAND_HOOK_BEFORE, 0, hook->userdata);
            }

            int result = fn(ed);

            for (size_t j = 0; j < ed->command_hook_count; j++) {
                ecex_command_hook_t *hook = &ed->command_hooks[j];
                if (hook->fn) hook->fn(ed, name, ECEX_COMMAND_HOOK_AFTER, result, hook->userdata);
            }

            return result;
        }
    }

    return ECEX_ERR;
}

int ecex_add_command_hook(ecex_t *ed,
                          const char *name,
                          ecex_command_hook_fn fn,
                          void *userdata,
                          ecex_hook_free_fn free_fn) {
    if (!ed || !name || !name[0] || !fn) return ECEX_ERR;

    char *name_copy = ecex_strdup(name);
    if (!name_copy) return ECEX_ERR;

    for (size_t i = 0; i < ed->command_hook_count; i++) {
        if (strcmp(ed->command_hooks[i].name, name) == 0) {
            ecex_command_hook_clear(&ed->command_hooks[i]);
            ed->command_hooks[i].name = name_copy;
            ed->command_hooks[i].fn = fn;
            ed->command_hooks[i].userdata = userdata;
            ed->command_hooks[i].free_fn = free_fn;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->command_hooks,
                        ed->command_hook_count,
                        ed->command_hook_cap,
                        ECEX_INITIAL_HOOK_CAP) != ECEX_OK) {
        free(name_copy);
        return ECEX_ERR;
    }

    ecex_command_hook_t *hook = &ed->command_hooks[ed->command_hook_count++];
    memset(hook, 0, sizeof(*hook));
    hook->name = name_copy;
    hook->fn = fn;
    hook->userdata = userdata;
    hook->free_fn = free_fn;
    return ECEX_OK;
}

int ecex_remove_command_hook(ecex_t *ed, const char *name) {
    if (!ed || !name) return ECEX_ERR;

    for (size_t i = 0; i < ed->command_hook_count; i++) {
        if (strcmp(ed->command_hooks[i].name, name) != 0) continue;
        ecex_command_hook_clear(&ed->command_hooks[i]);
        if (i + 1 < ed->command_hook_count) {
            memmove(&ed->command_hooks[i],
                    &ed->command_hooks[i + 1],
                    (ed->command_hook_count - i - 1) * sizeof(ed->command_hooks[i]));
        }
        ed->command_hook_count--;
        return ECEX_OK;
    }

    return ECEX_ERR;
}

int ecex_add_prefix_hook(ecex_t *ed,
                         const char *name,
                         ecex_prefix_hook_fn fn,
                         void *userdata,
                         ecex_hook_free_fn free_fn) {
    if (!ed || !name || !name[0] || !fn) return ECEX_ERR;

    char *name_copy = ecex_strdup(name);
    if (!name_copy) return ECEX_ERR;

    for (size_t i = 0; i < ed->prefix_hook_count; i++) {
        if (strcmp(ed->prefix_hooks[i].name, name) == 0) {
            ecex_prefix_hook_clear(&ed->prefix_hooks[i]);
            ed->prefix_hooks[i].name = name_copy;
            ed->prefix_hooks[i].fn = fn;
            ed->prefix_hooks[i].userdata = userdata;
            ed->prefix_hooks[i].free_fn = free_fn;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->prefix_hooks,
                        ed->prefix_hook_count,
                        ed->prefix_hook_cap,
                        ECEX_INITIAL_HOOK_CAP) != ECEX_OK) {
        free(name_copy);
        return ECEX_ERR;
    }

    ecex_prefix_hook_t *hook = &ed->prefix_hooks[ed->prefix_hook_count++];
    memset(hook, 0, sizeof(*hook));
    hook->name = name_copy;
    hook->fn = fn;
    hook->userdata = userdata;
    hook->free_fn = free_fn;
    return ECEX_OK;
}

int ecex_remove_prefix_hook(ecex_t *ed, const char *name) {
    if (!ed || !name) return ECEX_ERR;

    for (size_t i = 0; i < ed->prefix_hook_count; i++) {
        if (strcmp(ed->prefix_hooks[i].name, name) != 0) continue;
        ecex_prefix_hook_clear(&ed->prefix_hooks[i]);
        if (i + 1 < ed->prefix_hook_count) {
            memmove(&ed->prefix_hooks[i],
                    &ed->prefix_hooks[i + 1],
                    (ed->prefix_hook_count - i - 1) * sizeof(ed->prefix_hooks[i]));
        }
        ed->prefix_hook_count--;
        return ECEX_OK;
    }

    return ECEX_ERR;
}

void ecex_notify_prefix_hooks(ecex_t *ed, const char *prefix, int event) {
    if (!ed || !prefix) return;

    for (size_t i = 0; i < ed->prefix_hook_count; i++) {
        ecex_prefix_hook_t *hook = &ed->prefix_hooks[i];
        if (hook->fn) hook->fn(ed, prefix, event, hook->userdata);
    }
}

int ecex_add_buffer_hook(ecex_t *ed,
                         const char *name,
                         ecex_buffer_hook_fn fn,
                         void *userdata,
                         ecex_hook_free_fn free_fn) {
    if (!ed || !name || !name[0] || !fn) return ECEX_ERR;

    char *name_copy = ecex_strdup(name);
    if (!name_copy) return ECEX_ERR;

    for (size_t i = 0; i < ed->buffer_hook_count; i++) {
        if (strcmp(ed->buffer_hooks[i].name, name) == 0) {
            ecex_buffer_hook_clear(&ed->buffer_hooks[i]);
            ed->buffer_hooks[i].name = name_copy;
            ed->buffer_hooks[i].fn = fn;
            ed->buffer_hooks[i].userdata = userdata;
            ed->buffer_hooks[i].free_fn = free_fn;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->buffer_hooks,
                        ed->buffer_hook_count,
                        ed->buffer_hook_cap,
                        ECEX_INITIAL_HOOK_CAP) != ECEX_OK) {
        free(name_copy);
        return ECEX_ERR;
    }

    ecex_buffer_hook_t *hook = &ed->buffer_hooks[ed->buffer_hook_count++];
    memset(hook, 0, sizeof(*hook));
    hook->name = name_copy;
    hook->fn = fn;
    hook->userdata = userdata;
    hook->free_fn = free_fn;
    return ECEX_OK;
}

int ecex_remove_buffer_hook(ecex_t *ed, const char *name) {
    if (!ed || !name) return ECEX_ERR;

    for (size_t i = 0; i < ed->buffer_hook_count; i++) {
        if (strcmp(ed->buffer_hooks[i].name, name) != 0) continue;
        ecex_buffer_hook_clear(&ed->buffer_hooks[i]);
        if (i + 1 < ed->buffer_hook_count) {
            memmove(&ed->buffer_hooks[i],
                    &ed->buffer_hooks[i + 1],
                    (ed->buffer_hook_count - i - 1) * sizeof(ed->buffer_hooks[i]));
        }
        ed->buffer_hook_count--;
        return ECEX_OK;
    }

    return ECEX_ERR;
}

void ecex_notify_buffer_hooks(ecex_t *ed, buffer_t *buffer, int event) {
    if (!ed || !buffer) return;

    for (size_t i = 0; i < ed->buffer_hook_count; i++) {
        ecex_buffer_hook_t *hook = &ed->buffer_hooks[i];
        if (hook->fn) hook->fn(ed, buffer, event, hook->userdata);
    }
}

void ecex_message(ecex_t *ed, const char *message) {
    if (!ed) return;
    snprintf(ed->message, sizeof(ed->message), "%s", message ? message : "");
    ed->message_revision++;
    ecex_mark_ui_changed(ed);
}

static int ecex_path_is_executable(const char *path) {
    return path && path[0] && access(path, X_OK) == 0;
}

int ecex_dependency_available(const char *program) {
    if (!program || !program[0]) return 0;
    if (strchr(program, '/')) return ecex_path_is_executable(program);

    const char *path = getenv("PATH");
    if (!path || !path[0]) path = "/bin:/usr/bin:/usr/local/bin";

    const char *start = path;
    while (*start) {
        const char *end = strchr(start, ':');
        size_t dir_len = end ? (size_t)(end - start) : strlen(start);
        if (dir_len == 0) {
            start = end ? end + 1 : start + strlen(start);
            continue;
        }

        char candidate[4096];
        size_t prog_len = strlen(program);
        if (dir_len + 1 + prog_len < sizeof(candidate)) {
            memcpy(candidate, start, dir_len);
            candidate[dir_len] = '/';
            memcpy(candidate + dir_len + 1, program, prog_len + 1);
            if (ecex_path_is_executable(candidate)) return 1;
        }

        if (!end) break;
        start = end + 1;
    }

    return 0;
}

int ecex_plugin_require_dependency(ecex_t *ed, const char *plugin_id, const char *program) {
    if (!program || !program[0]) return ECEX_ERR;
    if (ecex_dependency_available(program)) return ECEX_OK;

    char message[256];
    snprintf(message,
             sizeof(message),
             "%s disabled: missing dependency '%s'",
             plugin_id && plugin_id[0] ? plugin_id : "plugin",
             program);
    ecex_message(ed, message);
    fprintf(stderr, "ecex: %s\n", message);
    return ECEX_ERR;
}

int ecex_add_completion_provider(ecex_t *ed,
                                 const char *name,
                                 const char *mode_name,
                                 ecex_completion_provider_fn fn,
                                 void *userdata,
                                 ecex_hook_free_fn free_fn) {
    if (!ed || !name || !name[0] || !fn) return ECEX_ERR;

    int mode = 0;
    if (mode_name && mode_name[0]) {
        mode = ecex_define_major_mode(ed, mode_name);
        if (mode == 0) return ECEX_ERR;
    }

    char *name_copy = ecex_strdup(name);
    if (!name_copy) return ECEX_ERR;

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        if (strcmp(ed->completion_providers[i].name, name) == 0) {
            ecex_completion_provider_clear(&ed->completion_providers[i]);
            ed->completion_providers[i].name = name_copy;
            ed->completion_providers[i].mode = mode;
            ed->completion_providers[i].fn = fn;
            ed->completion_providers[i].userdata = userdata;
            ed->completion_providers[i].free_fn = free_fn;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->completion_providers,
                        ed->completion_provider_count,
                        ed->completion_provider_cap,
                        ECEX_INITIAL_HOOK_CAP) != ECEX_OK) {
        free(name_copy);
        return ECEX_ERR;
    }

    ecex_completion_provider_t *provider =
        &ed->completion_providers[ed->completion_provider_count++];
    memset(provider, 0, sizeof(*provider));
    provider->name = name_copy;
    provider->mode = mode;
    provider->fn = fn;
    provider->userdata = userdata;
    provider->free_fn = free_fn;
    return ECEX_OK;
}

static int ecex_completion_provider_mode(ecex_t *ed, const char *mode_name, int *out_mode) {
    if (!ed || !out_mode) return ECEX_ERR;
    *out_mode = 0;
    if (mode_name && mode_name[0]) {
        *out_mode = ecex_define_major_mode(ed, mode_name);
        if (*out_mode == 0) return ECEX_ERR;
    }
    return ECEX_OK;
}

static char **ecex_completion_words_copy(const char *const *words, size_t count) {
    if (!words || count == 0) return NULL;
    char **copy = calloc(count, sizeof(*copy));
    if (!copy) return NULL;

    for (size_t i = 0; i < count; i++) {
        copy[i] = ecex_strdup(words[i] ? words[i] : "");
        if (!copy[i]) {
            for (size_t j = 0; j < i; j++) free(copy[j]);
            free(copy);
            return NULL;
        }
    }

    return copy;
}

int ecex_define_word_completion_provider(ecex_t *ed,
                                         const char *name,
                                         const char *mode_name,
                                         int flags) {
    if (!ed || !name || !name[0]) return ECEX_ERR;

    int mode = 0;
    if (ecex_completion_provider_mode(ed, mode_name, &mode) != ECEX_OK) return ECEX_ERR;

    char *name_copy = ecex_strdup(name);
    if (!name_copy) return ECEX_ERR;

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        if (strcmp(ed->completion_providers[i].name, name) == 0) {
            ecex_completion_provider_clear(&ed->completion_providers[i]);
            ed->completion_providers[i].name = name_copy;
            ed->completion_providers[i].mode = mode;
            ed->completion_providers[i].flags = flags;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->completion_providers,
                        ed->completion_provider_count,
                        ed->completion_provider_cap,
                        ECEX_INITIAL_HOOK_CAP) != ECEX_OK) {
        free(name_copy);
        return ECEX_ERR;
    }

    ecex_completion_provider_t *provider =
        &ed->completion_providers[ed->completion_provider_count++];
    memset(provider, 0, sizeof(*provider));
    provider->name = name_copy;
    provider->mode = mode;
    provider->flags = flags;
    return ECEX_OK;
}

int ecex_completion_provider_add_word(ecex_t *ed, const char *name, const char *word) {
    if (!ed || !name || !word || !word[0]) return ECEX_ERR;

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        ecex_completion_provider_t *provider = &ed->completion_providers[i];
        if (strcmp(provider->name, name) != 0) continue;

        char **grown = realloc(provider->words,
                               (provider->word_count + 1) * sizeof(*provider->words));
        if (!grown) return ECEX_ERR;
        provider->words = grown;

        provider->words[provider->word_count] = ecex_strdup(word);
        if (!provider->words[provider->word_count]) return ECEX_ERR;
        provider->word_count++;
        return ECEX_OK;
    }

    return ECEX_ERR;
}

int ecex_completion_provider_add_words(ecex_t *ed, const char *name, const char *words) {
    if (!ed || !name || !words) return ECEX_ERR;

    const char *p = words;
    while (*p) {
        while (*p == ' ' || *p == '\t' || *p == '\n' || *p == '\r') p++;
        if (!*p) break;

        char word[256];
        size_t len = 0;
        while (*p && *p != ' ' && *p != '\t' && *p != '\n' && *p != '\r') {
            if (len + 1 < sizeof(word)) word[len++] = *p;
            p++;
        }
        word[len] = '\0';

        if (len > 0 && ecex_completion_provider_add_word(ed, name, word) != ECEX_OK) {
            return ECEX_ERR;
        }
    }

    return ECEX_OK;
}

int ecex_completion_provider_set_detail(ecex_t *ed, const char *name, const char *detail) {
    if (!ed || !name || !name[0]) return ECEX_ERR;

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        ecex_completion_provider_t *provider = &ed->completion_providers[i];
        if (strcmp(provider->name, name) != 0) continue;

        char *copy = NULL;
        if (detail && detail[0]) {
            copy = ecex_strdup(detail);
            if (!copy) return ECEX_ERR;
        }

        free(provider->detail);
        provider->detail = copy;
        return ECEX_OK;
    }

    return ECEX_ERR;
}

int ecex_add_word_completion_provider(ecex_t *ed,
                                      const char *name,
                                      const char *mode_name,
                                      const char *const *words,
                                      size_t word_count,
                                      int flags) {
    if (!ed || !name || !name[0] || !words || word_count == 0) return ECEX_ERR;

    int mode = 0;
    if (ecex_completion_provider_mode(ed, mode_name, &mode) != ECEX_OK) return ECEX_ERR;

    char *name_copy = ecex_strdup(name);
    if (!name_copy) return ECEX_ERR;

    char **words_copy = ecex_completion_words_copy(words, word_count);
    if (!words_copy) {
        free(name_copy);
        return ECEX_ERR;
    }

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        if (strcmp(ed->completion_providers[i].name, name) == 0) {
            ecex_completion_provider_clear(&ed->completion_providers[i]);
            ed->completion_providers[i].name = name_copy;
            ed->completion_providers[i].mode = mode;
            ed->completion_providers[i].words = words_copy;
            ed->completion_providers[i].word_count = word_count;
            ed->completion_providers[i].flags = flags;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->completion_providers,
                        ed->completion_provider_count,
                        ed->completion_provider_cap,
                        ECEX_INITIAL_HOOK_CAP) != ECEX_OK) {
        for (size_t i = 0; i < word_count; i++) free(words_copy[i]);
        free(words_copy);
        free(name_copy);
        return ECEX_ERR;
    }

    ecex_completion_provider_t *provider =
        &ed->completion_providers[ed->completion_provider_count++];
    memset(provider, 0, sizeof(*provider));
    provider->name = name_copy;
    provider->mode = mode;
    provider->words = words_copy;
    provider->word_count = word_count;
    provider->flags = flags;
    return ECEX_OK;
}

int ecex_remove_completion_provider(ecex_t *ed, const char *name) {
    if (!ed || !name) return ECEX_ERR;

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        if (strcmp(ed->completion_providers[i].name, name) != 0) continue;
        ecex_completion_provider_clear(&ed->completion_providers[i]);
        if (i + 1 < ed->completion_provider_count) {
            memmove(&ed->completion_providers[i],
                    &ed->completion_providers[i + 1],
                    (ed->completion_provider_count - i - 1) * sizeof(ed->completion_providers[i]));
        }
        ed->completion_provider_count--;
        return ECEX_OK;
    }

    return ECEX_ERR;
}

void ecex_set_clipboard_callbacks(ecex_t *ed,
                                  ecex_clipboard_get_fn get_fn,
                                  ecex_clipboard_set_fn set_fn,
                                  void *userdata) {
    if (!ed) return;
    ed->clipboard_get = get_fn;
    ed->clipboard_set = set_fn;
    ed->clipboard_userdata = userdata;
}

const char *ecex_clipboard_get(ecex_t *ed) {
    if (!ed) return NULL;

    if (ed->clipboard_get) {
        const char *external = ed->clipboard_get(ed->clipboard_userdata);
        if (external) {
            if (!ed->clipboard_text || strcmp(ed->clipboard_text, external) != 0) {
                char *copy = ecex_strdup(external);
                if (copy) {
                    free(ed->clipboard_text);
                    ed->clipboard_text = copy;
                }
            }
        }
    }

    return ed->clipboard_text;
}

int ecex_clipboard_set(ecex_t *ed, const char *text) {
    if (!ed || !text) return ECEX_ERR;

    char *copy = ecex_strdup(text);
    if (!copy) return ECEX_ERR;

    free(ed->clipboard_text);
    ed->clipboard_text = copy;

    if (ed->clipboard_set) {
        ed->clipboard_set(ed->clipboard_userdata, text);
    }

    return ECEX_OK;
}

static int ecex_command_exists(ecex_t *ed, const char *name) {
    if (!ed || !name) return 0;
    for (size_t i = 0; i < ed->command_count; i++) {
        if (ed->commands[i].name && strcmp(ed->commands[i].name, name) == 0) return 1;
    }
    return 0;
}

static int ecex_key_is_prefix_of(const char *prefix, const char *key) {
    if (!prefix || !key) return 0;
    size_t n = strlen(prefix);
    return strncmp(prefix, key, n) == 0 && key[n] == ' ';
}

static void ecex_warn_keybind_issue(const char *scope, const char *key, const char *detail) {
    if (scope && scope[0]) {
        fprintf(stderr,
                "ecex: keybind warning [%s]: %s%s%s\n",
                scope,
                key ? key : "<null>",
                detail && detail[0] ? " " : "",
                detail ? detail : "");
    } else {
        fprintf(stderr,
                "ecex: keybind warning: %s%s%s\n",
                key ? key : "<null>",
                detail && detail[0] ? " " : "",
                detail ? detail : "");
    }
}

static void ecex_warn_keybind_conflicts(ecex_t *ed, const char *scope, const char *key, int mode) {
    if (!ed || !key) return;

    for (size_t i = 0; i < ed->keybind_count; i++) {
        if (mode != 0) break;
        const char *existing = ed->keybinds[i].key;
        if (existing && ecex_key_is_prefix_of(key, existing)) ecex_warn_keybind_issue(scope, key, "is a prefix of an existing binding");
        if (existing && ecex_key_is_prefix_of(existing, key)) ecex_warn_keybind_issue(scope, key, "extends an existing complete binding");
    }

    for (size_t i = 0; i < ed->mode_keybind_count; i++) {
        if (mode != ed->mode_keybinds[i].mode) continue;
        const char *existing = ed->mode_keybinds[i].key;
        if (existing && ecex_key_is_prefix_of(key, existing)) ecex_warn_keybind_issue(scope, key, "is a prefix of an existing mode binding");
        if (existing && ecex_key_is_prefix_of(existing, key)) ecex_warn_keybind_issue(scope, key, "extends an existing complete mode binding");
    }
}

int ecex_bind_key(ecex_t *ed, const char *key, const char *command) {
    if (!ed || !key || !command) return ECEX_ERR;

    if (!ecex_command_exists(ed, command)) {
        ecex_warn_keybind_issue("global", key, "targets a command that is not registered yet");
    }
    ecex_warn_keybind_conflicts(ed, "global", key, 0);

    for (size_t i = 0; i < ed->keybind_count; i++) {
        if (strcmp(ed->keybinds[i].key, key) == 0) {
            fprintf(stderr, "ecex: keybind warning [global]: replacing %s from %s to %s\n", key, ed->keybinds[i].command, command);
            char *new_command = ecex_strdup(command);
            if (!new_command) return ECEX_ERR;

            free(ed->keybinds[i].command);
            ed->keybinds[i].command = new_command;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->keybinds,
                        ed->keybind_count,
                        ed->keybind_cap,
                        ECEX_INITIAL_KEYBIND_CAP) != ECEX_OK) {
        return ECEX_ERR;
    }

    char *key_copy = ecex_strdup(key);
    char *command_copy = ecex_strdup(command);
    if (!key_copy || !command_copy) {
        free(key_copy);
        free(command_copy);
        return ECEX_ERR;
    }

    ed->keybinds[ed->keybind_count].key = key_copy;
    ed->keybinds[ed->keybind_count].command = command_copy;
    ed->keybind_count++;
    return ECEX_OK;
}

const char *ecex_lookup_key(ecex_t *ed, const char *key) {
    if (!ed || !key) return NULL;

    for (size_t i = 0; i < ed->keybind_count; i++) {
        if (strcmp(ed->keybinds[i].key, key) == 0) {
            return ed->keybinds[i].command;
        }
    }

    return NULL;
}

int ecex_define_major_mode(ecex_t *ed, const char *name) {
    if (!ed || !name || !name[0]) return 0;

    for (size_t i = 0; i < ed->major_mode_count; i++) {
        if (strcmp(ed->major_modes[i].name, name) == 0) {
            return ed->major_modes[i].id;
        }
    }

    if (ECEX_GROW_ARRAY(ed->major_modes,
                        ed->major_mode_count,
                        ed->major_mode_cap,
                        ECEX_INITIAL_MODE_CAP) != ECEX_OK) {
        return 0;
    }

    char *copy = ecex_strdup(name);
    if (!copy) return 0;

    int id = ed->next_major_mode_id++;
    ed->major_modes[ed->major_mode_count].id = id;
    ed->major_modes[ed->major_mode_count].name = copy;
    ed->major_mode_count++;
    return id;
}

int ecex_major_mode_by_name(ecex_t *ed, const char *name) {
    if (!ed || !name) return 0;
    for (size_t i = 0; i < ed->major_mode_count; i++) {
        if (strcmp(ed->major_modes[i].name, name) == 0) return ed->major_modes[i].id;
    }
    return 0;
}

const char *ecex_major_mode_name(ecex_t *ed, int mode) {
    if (!ed || mode == 0) return "fundamental-mode";
    for (size_t i = 0; i < ed->major_mode_count; i++) {
        if (ed->major_modes[i].id == mode) return ed->major_modes[i].name;
    }
    return "unknown-mode";
}

int ecex_buffer_set_major_mode(buffer_t *buffer, int mode) {
    if (!buffer) return ECEX_ERR;
    buffer->major_mode = mode;
    return ECEX_OK;
}

int ecex_buffer_set_major_mode_by_name(ecex_t *ed, buffer_t *buffer, const char *name) {
    if (!ed || !buffer || !name) return ECEX_ERR;
    int mode = ecex_define_major_mode(ed, name);
    if (!mode) return ECEX_ERR;
    int old_mode = buffer->major_mode;
    int result = ecex_buffer_set_major_mode(buffer, mode);
    if (result == ECEX_OK && old_mode != mode) {
        ecex_notify_buffer_hooks(ed, buffer, ECEX_BUFFER_HOOK_MODE_CHANGE);
    }
    return result;
}

const char *ecex_buffer_major_mode_name(ecex_t *ed, buffer_t *buffer) {
    if (!buffer) return "fundamental-mode";
    return ecex_major_mode_name(ed, buffer->major_mode);
}

int ecex_bind_mode_key(ecex_t *ed, const char *mode_name, const char *key, const char *command) {
    if (!ed || !mode_name || !key || !command) return ECEX_ERR;

    int mode = ecex_define_major_mode(ed, mode_name);
    if (!mode) return ECEX_ERR;

    if (!ecex_command_exists(ed, command)) {
        ecex_warn_keybind_issue(mode_name, key, "targets a command that is not registered yet");
    }
    ecex_warn_keybind_conflicts(ed, mode_name, key, mode);

    for (size_t i = 0; i < ed->mode_keybind_count; i++) {
        if (ed->mode_keybinds[i].mode == mode && strcmp(ed->mode_keybinds[i].key, key) == 0) {
            fprintf(stderr, "ecex: keybind warning [%s]: replacing %s from %s to %s\n", mode_name, key, ed->mode_keybinds[i].command, command);
            char *new_command = ecex_strdup(command);
            if (!new_command) return ECEX_ERR;
            free(ed->mode_keybinds[i].command);
            ed->mode_keybinds[i].command = new_command;
            return ECEX_OK;
        }
    }

    if (ECEX_GROW_ARRAY(ed->mode_keybinds,
                        ed->mode_keybind_count,
                        ed->mode_keybind_cap,
                        ECEX_INITIAL_MODE_KEYBIND_CAP) != ECEX_OK) {
        return ECEX_ERR;
    }

    char *key_copy = ecex_strdup(key);
    char *command_copy = ecex_strdup(command);
    if (!key_copy || !command_copy) {
        free(key_copy);
        free(command_copy);
        return ECEX_ERR;
    }

    ed->mode_keybinds[ed->mode_keybind_count].mode = mode;
    ed->mode_keybinds[ed->mode_keybind_count].key = key_copy;
    ed->mode_keybinds[ed->mode_keybind_count].command = command_copy;
    ed->mode_keybind_count++;
    return ECEX_OK;
}

int ecex_validate_bindings(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    int ok = ECEX_OK;

    for (size_t i = 0; i < ed->keybind_count; i++) {
        const char *command = ed->keybinds[i].command;
        if (!ecex_command_exists(ed, command)) {
            ecex_warn_keybind_issue("global", ed->keybinds[i].key, "targets a missing command");
            ok = ECEX_ERR;
        }
        for (size_t j = i + 1; j < ed->keybind_count; j++) {
            if (ecex_key_is_prefix_of(ed->keybinds[i].key, ed->keybinds[j].key) ||
                ecex_key_is_prefix_of(ed->keybinds[j].key, ed->keybinds[i].key)) {
                ecex_warn_keybind_issue("global", ed->keybinds[i].key, "has a prefix conflict");
            }
        }
    }

    for (size_t i = 0; i < ed->mode_keybind_count; i++) {
        const char *command = ed->mode_keybinds[i].command;
        const char *mode = ecex_major_mode_name(ed, ed->mode_keybinds[i].mode);
        if (!ecex_command_exists(ed, command)) {
            ecex_warn_keybind_issue(mode, ed->mode_keybinds[i].key, "targets a missing command");
            ok = ECEX_ERR;
        }
        for (size_t j = i + 1; j < ed->mode_keybind_count; j++) {
            if (ed->mode_keybinds[i].mode != ed->mode_keybinds[j].mode) continue;
            if (ecex_key_is_prefix_of(ed->mode_keybinds[i].key, ed->mode_keybinds[j].key) ||
                ecex_key_is_prefix_of(ed->mode_keybinds[j].key, ed->mode_keybinds[i].key)) {
                ecex_warn_keybind_issue(mode, ed->mode_keybinds[i].key, "has a mode prefix conflict");
            }
        }
    }

    return ok;
}

const char *ecex_lookup_key_for_buffer(ecex_t *ed, buffer_t *buffer, const char *key) {
    if (!ed || !key) return NULL;

    int mode = buffer ? buffer->major_mode : 0;
    if (mode) {
        for (size_t i = 0; i < ed->mode_keybind_count; i++) {
            if (ed->mode_keybinds[i].mode == mode && strcmp(ed->mode_keybinds[i].key, key) == 0) {
                return ed->mode_keybinds[i].command;
            }
        }
    }

    return ecex_lookup_key(ed, key);
}

int ecex_key_sequence_has_prefix_for_buffer(ecex_t *ed, buffer_t *buffer, const char *prefix) {
    if (!ed || !prefix) return 0;
    size_t prefix_len = strlen(prefix);
    int mode = buffer ? buffer->major_mode : 0;

    if (mode) {
        for (size_t i = 0; i < ed->mode_keybind_count; i++) {
            const char *key = ed->mode_keybinds[i].key;
            if (ed->mode_keybinds[i].mode == mode &&
                strncmp(key, prefix, prefix_len) == 0 && key[prefix_len] == ' ') {
                return 1;
            }
        }
    }

    for (size_t i = 0; i < ed->keybind_count; i++) {
        const char *key = ed->keybinds[i].key;
        if (strncmp(key, prefix, prefix_len) == 0 && key[prefix_len] == ' ') return 1;
    }

    return 0;
}

typedef struct ecex_key_prefix_item {
    char key[64];
    char command[128];
    int has_children;
} ecex_key_prefix_item_t;

static int ecex_key_prefix_item_exists(ecex_key_prefix_item_t *items,
                                       size_t count,
                                       const char *key) {
    for (size_t i = 0; i < count; i++) {
        if (strcmp(items[i].key, key) == 0) return 1;
    }
    return 0;
}

static void ecex_key_prefix_collect_binding(ecex_key_prefix_item_t *items,
                                            size_t *count,
                                            size_t cap,
                                            const char *prefix,
                                            const char *binding,
                                            const char *command) {
    if (!items || !count || *count >= cap || !prefix || !binding || !command) return;

    size_t prefix_len = strlen(prefix);
    if (strncmp(binding, prefix, prefix_len) != 0 || binding[prefix_len] != ' ') return;

    const char *rest = binding + prefix_len + 1;
    if (!rest[0]) return;

    const char *space = strchr(rest, ' ');
    size_t key_len = space ? (size_t)(space - rest) : strlen(rest);
    if (key_len == 0) return;

    char key[64];
    if (key_len >= sizeof(key)) key_len = sizeof(key) - 1;
    memcpy(key, rest, key_len);
    key[key_len] = '\0';

    if (ecex_key_prefix_item_exists(items, *count, key)) return;

    ecex_key_prefix_item_t *item = &items[(*count)++];
    memset(item, 0, sizeof(*item));
    snprintf(item->key, sizeof(item->key), "%s", key);
    item->has_children = space ? 1 : 0;
    snprintf(item->command,
             sizeof(item->command),
             "%s",
             item->has_children ? "prefix" : command);
}

int ecex_describe_key_prefix(ecex_t *ed,
                             buffer_t *buffer,
                             const char *prefix,
                             char *out,
                             size_t out_size,
                             size_t max_items) {
    if (out && out_size) out[0] = '\0';
    if (!ed || !prefix || !prefix[0] || !out || out_size == 0) return ECEX_ERR;

    ecex_key_prefix_item_t items[64];
    size_t count = 0;
    int mode = buffer ? buffer->major_mode : 0;

    if (mode) {
        for (size_t i = 0; i < ed->mode_keybind_count; i++) {
            if (ed->mode_keybinds[i].mode != mode) continue;
            ecex_key_prefix_collect_binding(items,
                                            &count,
                                            ECEX_ARRAY_LEN(items),
                                            prefix,
                                            ed->mode_keybinds[i].key,
                                            ed->mode_keybinds[i].command);
        }
    }

    for (size_t i = 0; i < ed->keybind_count; i++) {
        ecex_key_prefix_collect_binding(items,
                                        &count,
                                        ECEX_ARRAY_LEN(items),
                                        prefix,
                                        ed->keybinds[i].key,
                                        ed->keybinds[i].command);
    }

    if (count == 0) {
        snprintf(out, out_size, "%s: no continuations", prefix);
        return 0;
    }

    if (max_items == 0 || max_items > count) max_items = count;

    size_t used = (size_t)snprintf(out, out_size, "%s: ", prefix);
    if (used >= out_size) {
        out[out_size - 1] = '\0';
        return (int)count;
    }

    size_t items_per_row = max_items > 8 ? 4 : max_items + 1;
    for (size_t i = 0; i < max_items; i++) {
        const char *sep = "";
        if (i > 0) sep = (i % items_per_row) == 0 ? "\n  " : "  |  ";

        int n = snprintf(out + used,
                         out_size - used,
                         "%s%s %s",
                         sep,
                         items[i].key,
                         items[i].command);
        if (n < 0) break;
        if ((size_t)n >= out_size - used) {
            used = out_size - 1;
            out[used] = '\0';
            break;
        }
        used += (size_t)n;
    }

    if (max_items < count && used + 16 < out_size) {
        snprintf(out + used, out_size - used, "  |  +%zu more", count - max_items);
    }

    return (int)count;
}

int ecex_auto_set_major_mode(ecex_t *ed, buffer_t *buffer) {
    if (!ed || !buffer) return ECEX_ERR;

    const char *name = "fundamental-mode";

    if (buffer_is_interactive(buffer) && buffer->name && buffer->name[0] == '*') {
        name = "special-mode";
    }

    return ecex_buffer_set_major_mode_by_name(ed, buffer, name);
}

int ecex_list_commands(ecex_t *ed) {
    if (!ed) return ECEX_ERR;

    buffer_t *buf = ecex_find_buffer(ed, "*commands*");
    if (!buf) {
        buf = ecex_create_buffer(ed, "*commands*", NULL, 0);
        if (!buf) return ECEX_ERR;
    }

    if (buffer_clear(buf) != ECEX_OK) return ECEX_ERR;
    buffer_append(buf, "Commands:\n\n");

    for (size_t i = 0; i < ed->command_count; i++) {
        const char *command_name = ed->commands[i].name;
        int first_key = 1;

        buffer_append(buf, "  ");
        buffer_append(buf, command_name);

        for (size_t j = 0; j < ed->keybind_count; j++) {
            if (strcmp(ed->keybinds[j].command, command_name) == 0) {
                buffer_append(buf, first_key ? "    [" : ", ");
                buffer_append(buf, ed->keybinds[j].key);
                first_key = 0;
            }
        }

        for (size_t j = 0; j < ed->mode_keybind_count; j++) {
            if (strcmp(ed->mode_keybinds[j].command, command_name) == 0) {
                buffer_append(buf, first_key ? "    [" : ", ");
                buffer_append(buf, ecex_major_mode_name(ed, ed->mode_keybinds[j].mode));
                buffer_append(buf, ":");
                buffer_append(buf, ed->mode_keybinds[j].key);
                first_key = 0;
            }
        }

        if (!first_key) buffer_append(buf, "]");
        buffer_append(buf, "\n");
    }

    buf->point = 0;
    buf->modified = 0;
    return ecex_switch_buffer(ed, "*commands*");
}



static int ecex_interactive_switch_buffer_action(ecex_t *ed,
                                                 buffer_t *buffer,
                                                 size_t line,
                                                 const char *payload,
                                                 void *userdata) {
    (void)buffer;
    (void)line;
    (void)userdata;

    if (!ed || !payload) return ECEX_ERR;
    return ecex_switch_buffer(ed, payload);
}

int ecex_list_buffers(ecex_t *ed) {
    if (!ed) return ECEX_ERR;

    buffer_t *buf = ecex_find_buffer(ed, "*buffers*");
    if (!buf) {
        buf = ecex_create_interactive_buffer(ed, "*buffers*");
        if (!buf) return ECEX_ERR;
    }

    buffer_set_interactive(buf, 1);
    if (buffer_clear(buf) != ECEX_OK) return ECEX_ERR;
    buffer_set_interactive(buf, 1);

    buffer_append(buf, "Buffers:\n");
    buffer_append(buf, "Press ENTER on a buffer to switch to it.\n\n");

    for (size_t i = 0; i < ed->buffer_count; i++) {
        buffer_t *b = ed->buffers[i];
        char line[1024];

        snprintf(line,
                 sizeof(line),
                 "%s %s %-24s %-18s size:%zu%s%s",
                 b == ed->current_buffer ? "*" : " ",
                 b->modified ? "+" : " ",
                 b->name ? b->name : "(unnamed)",
                 ecex_buffer_major_mode_name(ed, b),
                 b->len,
                 b->path ? "    " : "",
                 b->path ? b->path : "");

        if (ecex_interactive_append_line(ed,
                                         buf,
                                         line,
                                         ecex_interactive_switch_buffer_action,
                                         b->name,
                                         NULL) != ECEX_OK) {
            return ECEX_ERR;
        }
    }

    buf->point = 0;
    buf->modified = 0;
    return ecex_switch_buffer(ed, "*buffers*");
}

buffer_t *ecex_create_interactive_buffer(ecex_t *ed, const char *name) {
    if (!ed || !name) return NULL;

    buffer_t *buffer = ecex_find_buffer(ed, name);
    if (!buffer) {
        buffer = ecex_create_buffer(ed, name, NULL, 0);
        if (!buffer) return NULL;
    }

    buffer_set_interactive(buffer, 1);
    if (buffer->major_mode == 0) ecex_buffer_set_major_mode_by_name(ed, buffer, "special-mode");
    return buffer;
}

int ecex_interactive_append_line(ecex_t *ed,
                                 buffer_t *buffer,
                                 const char *text,
                                 ecex_interactive_line_fn fn,
                                 const char *payload,
                                 void *userdata) {
    (void)ed;

    if (!buffer || !text) return ECEX_ERR;

    size_t line = buffer_line_count(buffer);
    if (line > 0) line--;

    if (fn) {
        if (buffer_add_interactive_action(buffer, line, fn, payload, userdata) != ECEX_OK) {
            return ECEX_ERR;
        }
    }

    if (buffer_append(buffer, text) != ECEX_OK) return ECEX_ERR;
    if (buffer_append(buffer, "\n") != ECEX_OK) return ECEX_ERR;

    buffer_set_interactive(buffer, 1);
    return ECEX_OK;
}

int ecex_interactive_activate_current_line(ecex_t *ed) {
    if (!ed) return ECEX_ERR;

    buffer_t *buffer = ecex_current_buffer(ed);
    if (!buffer || !buffer_is_interactive(buffer)) return ECEX_ERR;

    size_t line = buffer_current_line_number(buffer);
    if (line > 0) line--;

    ecex_interactive_line_action_t *action =
        buffer_interactive_action_at_line(buffer, line);

    if (!action || !action->fn) return ECEX_ERR;
    return action->fn(ed, buffer, line, action->payload, action->userdata);
}

static int ecex_buffer_path_equal(buffer_t *buffer, const char *path) {
    return buffer && buffer->path && path && strcmp(buffer->path, path) == 0;
}

int ecex_find_file(ecex_t *ed, const char *path) {
    if (!ed || !path || !path[0]) return ECEX_ERR;

    char *normal_path = ecex_path_normalize(path);
    if (!normal_path) return ECEX_ERR;

    if (ecex_path_is_dir(normal_path)) {
        int result = ecex_file_browser_populate(ed, normal_path, 1);
        free(normal_path);
        return result;
    }

    if (ecex_path_is_file(normal_path) && ecex_path_is_media(normal_path)) {
        int result = ecex_media_open(ed, normal_path);
        free(normal_path);
        return result;
    }

    for (size_t i = 0; i < ed->buffer_count; i++) {
        if (ecex_buffer_path_equal(ed->buffers[i], normal_path)) {
            int result;
            free(normal_path);
            result = ecex_set_current_buffer_index(ed, i);
            if (result == ECEX_OK && !ecex_buffer_has_renderer(ed->buffers[i])) ecex_run_plugin_file_handlers(ed, ed->buffers[i]);
            return result;
        }
    }

    char *name = ecex_path_basename_dup(normal_path);
    if (!name) { free(normal_path); return ECEX_ERR; }
    buffer_t *buf = ecex_create_buffer(ed, name, NULL, 0);
    free(name);
    if (!buf) { free(normal_path); return ECEX_ERR; }

    if (ecex_file_exists(normal_path)) {
        if (buffer_load_file(buf, normal_path) != ECEX_OK) {
            ecex_kill_buffer_force(ed, buf->name);
            free(normal_path);
            return ECEX_ERR;
        }
    } else {
        free(buf->path);
        buf->path = normal_path;
        normal_path = NULL;
        buf->modified = 0;
    }

    free(normal_path);
    ecex_auto_set_major_mode(ed, buf);
    int switch_result = ecex_set_current_buffer_index(ed, ed->buffer_count ? ed->buffer_count - 1 : 0);
    if (switch_result == ECEX_OK) ecex_run_plugin_file_handlers(ed, buf);
    return switch_result;
}

int ecex_save_current_buffer(ecex_t *ed) {
    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf) return ECEX_ERR;
    int result = buffer_save(buf);
    if (result == ECEX_OK) ecex_notify_buffer_hooks(ed, buf, ECEX_BUFFER_HOOK_SAVE);
    return result;
}

int ecex_write_current_buffer(ecex_t *ed, const char *path) {
    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf || !path || !path[0]) return ECEX_ERR;
    char *normal_path = ecex_path_normalize(path);
    if (!normal_path) return ECEX_ERR;
    int result = buffer_save_as(buf, normal_path);
    free(normal_path);
    if (result == ECEX_OK) {
        ecex_notify_buffer_hooks(ed, buf, ECEX_BUFFER_HOOK_SAVE);
        ecex_auto_set_major_mode(ed, buf);
    }
    return result;
}

void ecex_request_prompt(ecex_t *ed,
                         ecex_prompt_request_t request,
                         const char *message) {
    if (!ed) return;

    ed->prompt_request = request;
    snprintf(ed->prompt_message,
             sizeof(ed->prompt_message),
             "%s",
             message ? message : "");
}

void ecex_clear_prompt_request(ecex_t *ed) {
    if (!ed) return;
    ed->prompt_request = ECEX_PROMPT_NONE;
    ed->prompt_message[0] = '\0';
}

int ecex_indent_line_to(buffer_t *buffer, int target_cols) {
    if (!buffer || buffer->read_only || buffer_is_interactive(buffer)) return ECEX_ERR;
    if (target_cols < 0) target_cols = 0;
    if (target_cols > 240) target_cols = 240;

    size_t line_start = buffer_current_line_start(buffer);
    size_t line_end = buffer_current_line_end(buffer);
    size_t first = line_start;
    while (first < line_end && (buffer->data[first] == ' ' || buffer->data[first] == '\t')) first++;

    size_t point = buffer->point;
    size_t point_after_indent = point > first ? point - first : 0;

    char spaces[256];
    memset(spaces, ' ', (size_t)target_cols);
    spaces[target_cols] = '\0';

    if (buffer_delete_range(buffer, line_start, first) != ECEX_OK) return ECEX_ERR;
    if (target_cols > 0 && buffer_insert_at(buffer, line_start, spaces) != ECEX_OK) return ECEX_ERR;

    size_t new_first = line_start + (size_t)target_cols;
    if (point <= first) {
        buffer_set_point(buffer, new_first);
    } else {
        buffer_set_point(buffer, new_first + point_after_indent);
    }

    return ECEX_OK;
}

static int ecex_indent_for_tab(ecex_t *ed) {
    if (!ed) return ECEX_ERR;
    buffer_t *buffer = ecex_current_buffer(ed);
    if (!buffer || buffer->read_only || buffer_is_interactive(buffer)) return ECEX_ERR;

    size_t col = buffer_current_column(buffer);
    size_t spaces = 4 - (col % 4);
    if (spaces == 0) spaces = 4;

    char text[5];
    memset(text, ' ', spaces);
    text[spaces] = '\0';
    return buffer_insert(buffer, text);
}

static int ecex_fuzzy_score(const char *candidate, const char *query) {
    if (!candidate || !query) return -1;
    if (query[0] == '\0') return 0;

    int score = 0;
    int consecutive = 0;
    int last_match = -1;
    size_t ci = 0;
    size_t qi = 0;

    while (candidate[ci] && query[qi]) {
        char c = candidate[ci];
        char q = query[qi];

        if (c >= 'A' && c <= 'Z') c = (char)(c - 'A' + 'a');
        if (q >= 'A' && q <= 'Z') q = (char)(q - 'A' + 'a');

        if (c == q) {
            score += 10;

            if ((int)ci == last_match + 1) {
                consecutive++;
                score += 5 * consecutive;
            } else {
                consecutive = 0;
            }

            if (ci == 0) score += 20;
            if (ci > 0 && (candidate[ci - 1] == '-' ||
                           candidate[ci - 1] == '_' ||
                           candidate[ci - 1] == ' ')) {
                score += 15;
            }

            last_match = (int)ci;
            qi++;
        }

        ci++;
    }

    if (query[qi] != '\0') return -1;

    score -= (int)strlen(candidate);
    if (strncmp(candidate, query, strlen(query)) == 0) score += 100;
    return score;
}

#define ECEX_COMPLETION_MAX_CANDIDATES 96

typedef struct ecex_completion_candidate {
    char text[256];
    char detail[256];
    int score;
} ecex_completion_candidate_t;

static void ecex_completion_cycle_reset(ecex_t *ed) {
    if (!ed) return;
    ed->completion_cycle_active = 0;
    ed->completion_cycle_buffer = NULL;
    ed->completion_cycle_start = 0;
    ed->completion_cycle_index = 0;
    ed->completion_cycle_prefix[0] = '\0';
    ed->completion_cycle_current[0] = '\0';
}

static int ecex_completion_candidates_add(ecex_completion_candidate_t *items,
                                          size_t cap,
                                          size_t *count,
                                          const char *text,
                                          const char *detail,
                                          int score) {
    if (!items || !count || *count >= cap || !text || !text[0] || score < 0) return ECEX_ERR;

    for (size_t i = 0; i < *count; i++) {
        if (strcmp(items[i].text, text) == 0) {
            if (score > items[i].score) items[i].score = score;
            if ((!items[i].detail[0]) && detail && detail[0]) {
                snprintf(items[i].detail, sizeof(items[i].detail), "%s", detail);
            }
            return ECEX_OK;
        }
    }

    ecex_completion_candidate_t *item = &items[(*count)++];
    memset(item, 0, sizeof(*item));
    snprintf(item->text, sizeof(item->text), "%s", text);
    if (detail && detail[0]) snprintf(item->detail, sizeof(item->detail), "%s", detail);
    item->score = score;
    return ECEX_OK;
}

static int ecex_completion_candidate_compare(const void *a, const void *b) {
    const ecex_completion_candidate_t *ca = (const ecex_completion_candidate_t *)a;
    const ecex_completion_candidate_t *cb = (const ecex_completion_candidate_t *)b;
    if (ca->score != cb->score) return cb->score - ca->score;
    size_t la = strlen(ca->text);
    size_t lb = strlen(cb->text);
    if (la != lb) return la < lb ? -1 : 1;
    return strcmp(ca->text, cb->text);
}

#define ECEX_CLANGD_TIMEOUT_MS 4500
#define ECEX_CLANGD_MAX_MESSAGES 96

typedef struct ecex_lsp_process {
    pid_t pid;
    int in_fd;
    int out_fd;
} ecex_lsp_process_t;

static char *ecex_lsp_format(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    int needed = vsnprintf(NULL, 0, fmt, ap);
    va_end(ap);
    if (needed < 0) return NULL;

    char *out = malloc((size_t)needed + 1);
    if (!out) return NULL;

    va_start(ap, fmt);
    vsnprintf(out, (size_t)needed + 1, fmt, ap);
    va_end(ap);
    return out;
}

static int ecex_lsp_write_all(int fd, const char *data, size_t len) {
    size_t written = 0;
    while (written < len) {
        ssize_t n = write(fd, data + written, len - written);
        if (n < 0 && errno == EINTR) continue;
        if (n <= 0) return ECEX_ERR;
        written += (size_t)n;
    }
    return ECEX_OK;
}

static int ecex_lsp_send(int fd, const char *json) {
    if (!json) return ECEX_ERR;
    char header[80];
    int n = snprintf(header, sizeof(header), "Content-Length: %zu\r\n\r\n", strlen(json));
    if (n <= 0 || (size_t)n >= sizeof(header)) return ECEX_ERR;
    if (ecex_lsp_write_all(fd, header, (size_t)n) != ECEX_OK) return ECEX_ERR;
    return ecex_lsp_write_all(fd, json, strlen(json));
}

static int ecex_lsp_wait_readable(int fd, int timeout_ms) {
    struct pollfd pfd;
    pfd.fd = fd;
    pfd.events = POLLIN;
    pfd.revents = 0;

    for (;;) {
        int rc = poll(&pfd, 1, timeout_ms);
        if (rc < 0 && errno == EINTR) continue;
        if (rc <= 0) return ECEX_ERR;
        if (pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) return ECEX_ERR;
        if (pfd.revents & POLLIN) return ECEX_OK;
    }
}

static int ecex_lsp_read_byte(int fd, char *out, int timeout_ms) {
    if (!out) return ECEX_ERR;
    if (ecex_lsp_wait_readable(fd, timeout_ms) != ECEX_OK) return ECEX_ERR;

    for (;;) {
        ssize_t n = read(fd, out, 1);
        if (n < 0 && errno == EINTR) continue;
        if (n == 1) return ECEX_OK;
        return ECEX_ERR;
    }
}

static int ecex_lsp_read_line(int fd, char *out, size_t out_size, int timeout_ms) {
    if (!out || out_size == 0) return ECEX_ERR;
    size_t used = 0;

    for (;;) {
        char ch = '\0';
        if (ecex_lsp_read_byte(fd, &ch, timeout_ms) != ECEX_OK) return ECEX_ERR;
        if (ch == '\n') break;
        if (used + 1 < out_size) out[used++] = ch;
    }

    if (used > 0 && out[used - 1] == '\r') used--;
    out[used] = '\0';
    return ECEX_OK;
}

static int ecex_lsp_read_exact(int fd, char *out, size_t len, int timeout_ms) {
    if (!out) return ECEX_ERR;
    size_t got = 0;

    while (got < len) {
        if (ecex_lsp_wait_readable(fd, timeout_ms) != ECEX_OK) return ECEX_ERR;
        ssize_t n = read(fd, out + got, len - got);
        if (n < 0 && errno == EINTR) continue;
        if (n <= 0) return ECEX_ERR;
        got += (size_t)n;
    }

    return ECEX_OK;
}

static int ecex_lsp_read_message(int fd, char **out_body, int timeout_ms) {
    if (!out_body) return ECEX_ERR;
    *out_body = NULL;

    size_t content_len = 0;
    int have_content_len = 0;

    for (int i = 0; i < 64; i++) {
        char line[256];
        if (ecex_lsp_read_line(fd, line, sizeof(line), timeout_ms) != ECEX_OK) return ECEX_ERR;
        if (line[0] == '\0') break;

        if (strncmp(line, "Content-Length:", 15) == 0) {
            char *end = NULL;
            unsigned long n = strtoul(line + 15, &end, 10);
            if (n > 0) {
                content_len = (size_t)n;
                have_content_len = 1;
            }
        }
    }

    if (!have_content_len || content_len == 0 || content_len > 32u * 1024u * 1024u) {
        return ECEX_ERR;
    }

    char *body = malloc(content_len + 1);
    if (!body) return ECEX_ERR;
    if (ecex_lsp_read_exact(fd, body, content_len, timeout_ms) != ECEX_OK) {
        free(body);
        return ECEX_ERR;
    }
    body[content_len] = '\0';
    *out_body = body;
    return ECEX_OK;
}

static int ecex_json_has_id(const char *json, int id) {
    if (!json) return 0;
    const char *p = json;
    while ((p = strstr(p, "\"id\"")) != NULL) {
        p += 4;
        while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') p++;
        if (*p != ':') continue;
        p++;
        while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') p++;
        char *end = NULL;
        long value = strtol(p, &end, 10);
        if (end != p && value == id) return 1;
    }
    return 0;
}

static int ecex_lsp_read_response(int fd, int id, char **out_body) {
    if (!out_body) return ECEX_ERR;
    *out_body = NULL;

    for (int i = 0; i < ECEX_CLANGD_MAX_MESSAGES; i++) {
        char *body = NULL;
        if (ecex_lsp_read_message(fd, &body, ECEX_CLANGD_TIMEOUT_MS) != ECEX_OK) return ECEX_ERR;
        if (ecex_json_has_id(body, id)) {
            *out_body = body;
            return ECEX_OK;
        }
        free(body);
    }

    return ECEX_ERR;
}

static int ecex_lsp_start_clangd(ecex_lsp_process_t *proc) {
    if (!proc) return ECEX_ERR;
    memset(proc, 0, sizeof(*proc));
    proc->pid = -1;
    proc->in_fd = -1;
    proc->out_fd = -1;
    signal(SIGPIPE, SIG_IGN);

    int in_pipe[2];
    int out_pipe[2];
    if (pipe(in_pipe) != 0) return ECEX_ERR;
    if (pipe(out_pipe) != 0) {
        close(in_pipe[0]);
        close(in_pipe[1]);
        return ECEX_ERR;
    }

    pid_t pid = fork();
    if (pid < 0) {
        close(in_pipe[0]);
        close(in_pipe[1]);
        close(out_pipe[0]);
        close(out_pipe[1]);
        return ECEX_ERR;
    }

    if (pid == 0) {
        dup2(in_pipe[0], STDIN_FILENO);
        dup2(out_pipe[1], STDOUT_FILENO);

        int null_fd = open("/dev/null", O_WRONLY);
        if (null_fd >= 0) {
            dup2(null_fd, STDERR_FILENO);
            close(null_fd);
        }

        close(in_pipe[0]);
        close(in_pipe[1]);
        close(out_pipe[0]);
        close(out_pipe[1]);

        execlp("clangd", "clangd", "--log=error", "--pretty=false", (char *)NULL);
        _exit(127);
    }

    close(in_pipe[0]);
    close(out_pipe[1]);

    proc->pid = pid;
    proc->in_fd = in_pipe[1];
    proc->out_fd = out_pipe[0];
    return ECEX_OK;
}

static void ecex_lsp_finish(ecex_lsp_process_t *proc) {
    if (!proc || proc->pid <= 0) return;

    if (proc->in_fd >= 0) {
        const char *shutdown = "{\"jsonrpc\":\"2.0\",\"id\":99,\"method\":\"shutdown\",\"params\":null}";
        const char *exit_msg = "{\"jsonrpc\":\"2.0\",\"method\":\"exit\",\"params\":{}}";
        ecex_lsp_send(proc->in_fd, shutdown);
        ecex_lsp_send(proc->in_fd, exit_msg);
        close(proc->in_fd);
        proc->in_fd = -1;
    }

    if (proc->out_fd >= 0) {
        close(proc->out_fd);
        proc->out_fd = -1;
    }

    for (int i = 0; i < 50; i++) {
        int status = 0;
        pid_t rc = waitpid(proc->pid, &status, WNOHANG);
        if (rc == proc->pid) {
            proc->pid = -1;
            return;
        }
        if (rc < 0 && errno != EINTR) break;
        poll(NULL, 0, 10);
    }

    kill(proc->pid, SIGKILL);
    waitpid(proc->pid, NULL, 0);
    proc->pid = -1;
}

static char *ecex_json_escape_len(const char *text, size_t len) {
    if (!text && len != 0) return NULL;

    size_t cap = len * 6 + 1;
    char *out = malloc(cap);
    if (!out) return NULL;

    size_t used = 0;
    static const char hex[] = "0123456789abcdef";
    for (size_t i = 0; i < len; i++) {
        unsigned char c = (unsigned char)text[i];
        if (c == '"' || c == '\\') {
            out[used++] = '\\';
            out[used++] = (char)c;
        } else if (c == '\n') {
            out[used++] = '\\';
            out[used++] = 'n';
        } else if (c == '\r') {
            out[used++] = '\\';
            out[used++] = 'r';
        } else if (c == '\t') {
            out[used++] = '\\';
            out[used++] = 't';
        } else if (c < 0x20) {
            out[used++] = '\\';
            out[used++] = 'u';
            out[used++] = '0';
            out[used++] = '0';
            out[used++] = hex[(c >> 4) & 0x0f];
            out[used++] = hex[c & 0x0f];
        } else {
            out[used++] = (char)c;
        }
    }
    out[used] = '\0';
    return out;
}

static char *ecex_json_escape(const char *text) {
    return ecex_json_escape_len(text ? text : "", text ? strlen(text) : 0);
}

static int ecex_uri_unreserved(unsigned char c) {
    return (c >= 'a' && c <= 'z') ||
           (c >= 'A' && c <= 'Z') ||
           (c >= '0' && c <= '9') ||
           c == '-' || c == '_' || c == '.' || c == '~' || c == '/';
}

static char *ecex_lsp_file_uri(const char *path) {
    if (!path || !path[0]) return NULL;
    char *normal = ecex_path_normalize(path);
    if (!normal) return NULL;

    size_t len = strlen(normal);
    char *out = malloc(7 + len * 3 + 1);
    if (!out) {
        free(normal);
        return NULL;
    }

    memcpy(out, "file://", 7);
    size_t used = 7;
    static const char hex[] = "0123456789ABCDEF";
    for (size_t i = 0; i < len; i++) {
        unsigned char c = (unsigned char)normal[i];
        if (ecex_uri_unreserved(c)) {
            out[used++] = (char)c;
        } else {
            out[used++] = '%';
            out[used++] = hex[(c >> 4) & 0x0f];
            out[used++] = hex[c & 0x0f];
        }
    }
    out[used] = '\0';
    free(normal);
    return out;
}

static const char *ecex_lsp_language_id(const char *path) {
    if (!path) return "c";
    const char *dot = strrchr(path, '.');
    if (!dot) return "c";
    if (strcmp(dot, ".cc") == 0 ||
        strcmp(dot, ".cpp") == 0 ||
        strcmp(dot, ".cxx") == 0 ||
        strcmp(dot, ".hh") == 0 ||
        strcmp(dot, ".hpp") == 0 ||
        strcmp(dot, ".hxx") == 0) {
        return "cpp";
    }
    return "c";
}

static void ecex_buffer_lsp_position(buffer_t *buffer, int *out_line, int *out_character) {
    int line = 0;
    int character = 0;
    if (buffer && buffer->data) {
        size_t point = buffer->point > buffer->len ? buffer->len : buffer->point;
        for (size_t i = 0; i < point; i++) {
            if (buffer->data[i] == '\n') {
                line++;
                character = 0;
            } else {
                character++;
            }
        }
    }
    if (out_line) *out_line = line;
    if (out_character) *out_character = character;
}

static int ecex_json_hex_value(char c) {
    if (c >= '0' && c <= '9') return c - '0';
    if (c >= 'a' && c <= 'f') return c - 'a' + 10;
    if (c >= 'A' && c <= 'F') return c - 'A' + 10;
    return -1;
}

static const char *ecex_json_decode_string(const char *p, char *out, size_t out_size) {
    if (!p || *p != '"' || !out || out_size == 0) return NULL;
    p++;
    size_t used = 0;

    while (*p && *p != '"') {
        unsigned char c = (unsigned char)*p++;
        if (c == '\\') {
            char esc = *p++;
            if (esc == '"' || esc == '\\' || esc == '/') c = (unsigned char)esc;
            else if (esc == 'b') c = '\b';
            else if (esc == 'f') c = '\f';
            else if (esc == 'n') c = '\n';
            else if (esc == 'r') c = '\r';
            else if (esc == 't') c = '\t';
            else if (esc == 'u') {
                int h1 = ecex_json_hex_value(p[0]);
                int h2 = ecex_json_hex_value(p[1]);
                int h3 = ecex_json_hex_value(p[2]);
                int h4 = ecex_json_hex_value(p[3]);
                if (h1 < 0 || h2 < 0 || h3 < 0 || h4 < 0) return NULL;
                unsigned int code = (unsigned int)((h1 << 12) | (h2 << 8) | (h3 << 4) | h4);
                p += 4;
                c = code < 0x80 ? (unsigned char)code : '?';
            } else {
                return NULL;
            }
        }

        if (used + 1 < out_size) out[used++] = (char)c;
    }

    if (*p != '"') return NULL;
    out[used] = '\0';
    return p + 1;
}

static int ecex_json_string_between(const char *start,
                                    const char *end,
                                    const char *key,
                                    char *out,
                                    size_t out_size) {
    if (out && out_size) out[0] = '\0';
    if (!start || !end || !key || !out || out_size == 0 || start >= end) return 0;

    char pattern[64];
    snprintf(pattern, sizeof(pattern), "\"%s\"", key);
    const char *p = start;
    while ((p = strstr(p, pattern)) != NULL && p < end) {
        p += strlen(pattern);
        while (p < end && (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n')) p++;
        if (p >= end || *p != ':') continue;
        p++;
        while (p < end && (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n')) p++;
        if (p >= end || *p != '"') continue;
        return ecex_json_decode_string(p, out, out_size) ? 1 : 0;
    }

    return 0;
}

static void ecex_trim_in_place(char *text) {
    if (!text) return;
    char *start = text;
    while (*start == ' ' || *start == '\t' || *start == '\r' || *start == '\n') start++;
    if (start != text) memmove(text, start, strlen(start) + 1);

    size_t len = strlen(text);
    while (len > 0 &&
           (text[len - 1] == ' ' ||
            text[len - 1] == '\t' ||
            text[len - 1] == '\r' ||
            text[len - 1] == '\n')) {
        text[--len] = '\0';
    }
}

static void ecex_lsp_completion_detail(const char *label,
                                       const char *item_start,
                                       const char *item_end,
                                       char *out,
                                       size_t out_size) {
    if (out && out_size) out[0] = '\0';
    if (!label || !item_start || !item_end || !out || out_size == 0) return;

    char detail[192];
    char description[128];
    char documentation[192];
    detail[0] = '\0';
    description[0] = '\0';
    documentation[0] = '\0';

    ecex_json_string_between(item_start, item_end, "detail", detail, sizeof(detail));
    ecex_json_string_between(item_start, item_end, "description", description, sizeof(description));
    ecex_json_string_between(item_start, item_end, "documentation", documentation, sizeof(documentation));
    ecex_trim_in_place(detail);
    ecex_trim_in_place(description);
    ecex_trim_in_place(documentation);

    if (detail[0] == '(') {
        snprintf(out,
                 out_size,
                 "%s%s%s%s",
                 label,
                 detail,
                 description[0] ? " -> " : "",
                 description);
    } else if (detail[0] && description[0]) {
        snprintf(out, out_size, "%s; %s", detail, description);
    } else if (detail[0]) {
        snprintf(out, out_size, "%s", detail);
    } else if (description[0]) {
        snprintf(out, out_size, "%s", description);
    } else if (documentation[0]) {
        snprintf(out, out_size, "%s", documentation);
    }
}

static int ecex_lsp_collect_completions(const char *json,
                                        const char *prefix,
                                        ecex_completion_candidate_t *items,
                                        size_t cap,
                                        size_t *count) {
    if (!json || !prefix || !items || !count) return ECEX_ERR;

    const char *p = json;
    while ((p = strstr(p, "\"label\"")) != NULL) {
        const char *item_start = p;
        p += 7;
        while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') p++;
        if (*p != ':') continue;
        p++;
        while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') p++;
        if (*p != '"') continue;

        char label[256];
        const char *next = ecex_json_decode_string(p, label, sizeof(label));
        if (!next) {
            p++;
            continue;
        }
        p = next;

        char *trimmed = label;
        while (*trimmed == ' ' || *trimmed == '\t' || *trimmed == '\r' || *trimmed == '\n') trimmed++;
        size_t trimmed_len = strlen(trimmed);
        while (trimmed_len > 0 &&
               (trimmed[trimmed_len - 1] == ' ' ||
                trimmed[trimmed_len - 1] == '\t' ||
                trimmed[trimmed_len - 1] == '\r' ||
                trimmed[trimmed_len - 1] == '\n')) {
            trimmed[--trimmed_len] = '\0';
        }
        if (trimmed_len == 0) continue;

        int score = ecex_fuzzy_score(trimmed, prefix);
        if (score < 0) continue;
        score += 7000;

        const char *item_end = strstr(p, "\"label\"");
        if (!item_end) item_end = json + strlen(json);

        char detail[256];
        ecex_lsp_completion_detail(trimmed, item_start, item_end, detail, sizeof(detail));

        ecex_completion_candidates_add(items, cap, count, trimmed, detail, score);
    }

    return *count > 0 ? ECEX_OK : ECEX_ERR;
}

static int ecex_clangd_collect_candidates(buffer_t *buffer,
                                          const char *prefix,
                                          ecex_completion_candidate_t *items,
                                          size_t cap,
                                          size_t *count) {
    if (!buffer || !buffer->path || !buffer->path[0] || !prefix || !items || !count) return ECEX_ERR;

    char *uri = ecex_lsp_file_uri(buffer->path);
    char *root_path = ecex_path_dirname(buffer->path);
    char *root_uri = root_path ? ecex_lsp_file_uri(root_path) : NULL;
    char *escaped_uri = ecex_json_escape(uri);
    char *escaped_root_uri = ecex_json_escape(root_uri ? root_uri : uri);
    char *escaped_text = ecex_json_escape_len(buffer->data ? buffer->data : "", buffer->len);
    if (!uri || !escaped_uri || !escaped_root_uri || !escaped_text) {
        free(uri);
        free(root_path);
        free(root_uri);
        free(escaped_uri);
        free(escaped_root_uri);
        free(escaped_text);
        return ECEX_ERR;
    }

    int line = 0;
    int character = 0;
    ecex_buffer_lsp_position(buffer, &line, &character);

    const char *language_id = ecex_lsp_language_id(buffer->path);
    char *initialize = ecex_lsp_format(
        "{\"jsonrpc\":\"2.0\",\"id\":1,\"method\":\"initialize\","
        "\"params\":{\"processId\":null,\"rootUri\":\"%s\","
        "\"capabilities\":{\"textDocument\":{\"completion\":{\"completionItem\":{"
        "\"snippetSupport\":false,\"labelDetailsSupport\":true,"
        "\"documentationFormat\":[\"plaintext\"]}}}},"
        "\"clientInfo\":{\"name\":\"ecex\",\"version\":\"0\"}}}",
        escaped_root_uri);
    char *initialized = ecex_lsp_format(
        "{\"jsonrpc\":\"2.0\",\"method\":\"initialized\",\"params\":{}}");
    char *did_open = ecex_lsp_format(
        "{\"jsonrpc\":\"2.0\",\"method\":\"textDocument/didOpen\","
        "\"params\":{\"textDocument\":{\"uri\":\"%s\",\"languageId\":\"%s\","
        "\"version\":1,\"text\":\"%s\"}}}",
        escaped_uri,
        language_id,
        escaped_text);
    char *completion = ecex_lsp_format(
        "{\"jsonrpc\":\"2.0\",\"id\":2,\"method\":\"textDocument/completion\","
        "\"params\":{\"textDocument\":{\"uri\":\"%s\"},"
        "\"position\":{\"line\":%d,\"character\":%d},"
        "\"context\":{\"triggerKind\":1}}}",
        escaped_uri,
        line,
        character);

    free(uri);
    free(root_path);
    free(root_uri);
    free(escaped_uri);
    free(escaped_root_uri);
    free(escaped_text);

    if (!initialize || !initialized || !did_open || !completion) {
        free(initialize);
        free(initialized);
        free(did_open);
        free(completion);
        return ECEX_ERR;
    }

    int result = ECEX_ERR;
    ecex_lsp_process_t proc;
    if (ecex_lsp_start_clangd(&proc) == ECEX_OK) {
        char *response = NULL;
        if (ecex_lsp_send(proc.in_fd, initialize) == ECEX_OK &&
            ecex_lsp_read_response(proc.out_fd, 1, &response) == ECEX_OK) {
            free(response);
            response = NULL;
            if (ecex_lsp_send(proc.in_fd, initialized) == ECEX_OK &&
                ecex_lsp_send(proc.in_fd, did_open) == ECEX_OK &&
                ecex_lsp_send(proc.in_fd, completion) == ECEX_OK &&
                ecex_lsp_read_response(proc.out_fd, 2, &response) == ECEX_OK) {
                result = ecex_lsp_collect_completions(response, prefix, items, cap, count);
            }
        }
        free(response);
        ecex_lsp_finish(&proc);
    }

    free(initialize);
    free(initialized);
    free(did_open);
    free(completion);
    return result;
}

static int ecex_clangd_completion_provider(ecex_t *ed,
                                           buffer_t *buffer,
                                           const char *prefix,
                                           char *out,
                                           size_t out_size,
                                           void *userdata) {
    (void)ed;
    (void)userdata;
    if (out && out_size) out[0] = '\0';
    if (!buffer || !prefix || !out || out_size == 0) return -1;

    ecex_completion_candidate_t items[ECEX_COMPLETION_MAX_CANDIDATES];
    size_t count = 0;
    memset(items, 0, sizeof(items));

    if (ecex_clangd_collect_candidates(buffer,
                                       prefix,
                                       items,
                                       ECEX_COMPLETION_MAX_CANDIDATES,
                                       &count) != ECEX_OK ||
        count == 0) {
        return -1;
    }

    qsort(items, count, sizeof(items[0]), ecex_completion_candidate_compare);
    snprintf(out, out_size, "%s", items[0].text);
    return items[0].score;
}

int ecex_add_clangd_completion_provider(ecex_t *ed, const char *name, const char *mode_name) {
    return ecex_add_completion_provider(ed,
                                        name,
                                        mode_name,
                                        ecex_clangd_completion_provider,
                                        NULL,
                                        NULL);
}

const char *ecex_complete_command(ecex_t *ed, const char *query) {
    if (!ed || !query || !ed->theme.completion_enabled) return NULL;

    const char *best = NULL;
    int best_score = -1;

    for (size_t i = 0; i < ed->command_count; i++) {
        const char *name = ed->commands[i].name;
        int score = ecex_fuzzy_score(name, query);

        if (score > best_score) {
            best_score = score;
            best = name;
        }
    }

    return best;
}

static int ecex_identifier_char(int c) {
    return (c >= 'a' && c <= 'z') ||
           (c >= 'A' && c <= 'Z') ||
           (c >= '0' && c <= '9') ||
           c == '_';
}

static size_t ecex_buffer_identifier_start(buffer_t *buffer) {
    if (!buffer || !buffer->data) return 0;
    size_t pos = buffer->point > buffer->len ? buffer->len : buffer->point;
    while (pos > 0 && ecex_identifier_char((unsigned char)buffer->data[pos - 1])) {
        pos--;
    }
    return pos;
}

int ecex_buffer_identifier_prefix(buffer_t *buffer, char *out, size_t out_size) {
    if (out && out_size) out[0] = '\0';
    if (!buffer || !out || out_size == 0) return ECEX_ERR;

    size_t end = buffer->point > buffer->len ? buffer->len : buffer->point;
    size_t start = ecex_buffer_identifier_start(buffer);
    size_t len = end > start ? end - start : 0;

    if (len >= out_size) len = out_size - 1;
    if (len > 0) memcpy(out, buffer->data + start, len);
    out[len] = '\0';
    return (int)len;
}

static int ecex_buffer_ed_arrow_context(buffer_t *buffer, const char *prefix) {
    if (!buffer || !buffer->data || !prefix) return 0;

    size_t prefix_len = strlen(prefix);
    size_t point = buffer->point > buffer->len ? buffer->len : buffer->point;
    if (point < prefix_len + 2) return 0;

    size_t start = point - prefix_len;
    if (buffer->data[start - 2] != '-' || buffer->data[start - 1] != '>') return 0;

    size_t name_end = start - 2;
    size_t name_start = name_end;
    while (name_start > 0 && ecex_identifier_char((unsigned char)buffer->data[name_start - 1])) {
        name_start--;
    }

    return name_end - name_start == 2 &&
           buffer->data[name_start] == 'e' &&
           buffer->data[name_start + 1] == 'd';
}

static int ecex_completion_provider_context_matches(ecex_completion_provider_t *provider,
                                                    int ed_arrow_context) {
    if (!provider) return 0;
    if (ed_arrow_context) return (provider->flags & ECEX_COMPLETION_ED_ARROW) != 0;
    return (provider->flags & ECEX_COMPLETION_ED_ARROW) == 0;
}

static const char *ecex_completion_provider_detail(ecex_completion_provider_t *provider) {
    if (!provider || !provider->name) return "";
    if (provider->detail && provider->detail[0]) return provider->detail;
    return provider->name;
}

static void ecex_completion_collect_from_provider(ecex_t *ed,
                                                  buffer_t *buffer,
                                                  ecex_completion_provider_t *provider,
                                                  const char *prefix,
                                                  ecex_completion_candidate_t *items,
                                                  size_t cap,
                                                  size_t *count) {
    if (!ed || !buffer || !provider || !prefix || !items || !count) return;

    const char *detail = ecex_completion_provider_detail(provider);

    if (provider->word_count > 0) {
        for (size_t i = 0; i < provider->word_count; i++) {
            int score = ecex_fuzzy_score(provider->words[i], prefix);
            if (score < 0) continue;
            ecex_completion_candidates_add(items, cap, count, provider->words[i], detail, score);
        }
        return;
    }

    if (provider->fn == ecex_clangd_completion_provider) {
        ecex_clangd_collect_candidates(buffer, prefix, items, cap, count);
        return;
    }

    if (provider->fn) {
        char candidate[256];
        candidate[0] = '\0';
        int score = provider->fn(ed,
                                 buffer,
                                 prefix,
                                 candidate,
                                 sizeof(candidate),
                                 provider->userdata);
        if (score == 0) score = ecex_fuzzy_score(candidate, prefix);
        if (score >= 0 && candidate[0]) {
            ecex_completion_candidates_add(items, cap, count, candidate, detail, score);
        }
    }
}

static int ecex_completion_cycle_valid(ecex_t *ed, buffer_t *buffer) {
    if (!ed || !buffer || !ed->completion_cycle_active) return 0;
    if (ed->completion_cycle_buffer != buffer) return 0;

    size_t len = strlen(ed->completion_cycle_current);
    size_t start = ed->completion_cycle_start;
    if (start + len > buffer->len || start + len != buffer->point) return 0;
    return strncmp(buffer->data + start, ed->completion_cycle_current, len) == 0;
}

static void ecex_completion_describe(ecex_t *ed,
                                     const ecex_completion_candidate_t *item,
                                     size_t index,
                                     size_t count) {
    if (!ed || !item) return;

    char message[700];
    if (item->detail[0]) {
        size_t text_len = strlen(item->text);
        if (strncmp(item->detail, item->text, text_len) == 0) {
            snprintf(message,
                     sizeof(message),
                     "Completion %zu/%zu: %s",
                     index + 1,
                     count,
                     item->detail);
        } else {
            snprintf(message,
                     sizeof(message),
                     "Completion %zu/%zu: %s - %s",
                     index + 1,
                     count,
                     item->text,
                     item->detail);
        }
    } else {
        snprintf(message,
                 sizeof(message),
                 "Completion %zu/%zu: %s",
                 index + 1,
                 count,
                 item->text);
    }
    ecex_message(ed, message);
}

static int ecex_complete_at_point_direction(ecex_t *ed, int direction) {
    if (!ed) return ECEX_ERR;

    buffer_t *buffer = ecex_current_buffer(ed);
    if (!buffer || buffer->read_only || buffer_is_interactive(buffer)) return ECEX_ERR;

    char prefix[256];
    size_t start = 0;
    size_t end = buffer->point > buffer->len ? buffer->len : buffer->point;
    int cycling = ecex_completion_cycle_valid(ed, buffer);

    if (cycling) {
        snprintf(prefix, sizeof(prefix), "%s", ed->completion_cycle_prefix);
        start = ed->completion_cycle_start;
    } else {
        int prefix_len = ecex_buffer_identifier_prefix(buffer, prefix, sizeof(prefix));
        if (prefix_len <= 0) {
            ecex_completion_cycle_reset(ed);
            ecex_message(ed, "No completion prefix");
            return ECEX_OK;
        }
        start = ecex_buffer_identifier_start(buffer);
    }

    if (!prefix[0]) {
        ecex_completion_cycle_reset(ed);
        ecex_message(ed, "No completion prefix");
        return ECEX_OK;
    }

    ecex_completion_candidate_t items[ECEX_COMPLETION_MAX_CANDIDATES];
    size_t count = 0;
    memset(items, 0, sizeof(items));

    int mode = buffer->major_mode;
    int ed_arrow_context = ecex_buffer_ed_arrow_context(buffer, prefix);

    for (size_t i = 0; i < ed->completion_provider_count; i++) {
        ecex_completion_provider_t *provider = &ed->completion_providers[i];
        if (provider->mode != 0 && provider->mode != mode) continue;
        if (!ecex_completion_provider_context_matches(provider, ed_arrow_context)) continue;
        ecex_completion_collect_from_provider(ed,
                                              buffer,
                                              provider,
                                              prefix,
                                              items,
                                              ECEX_COMPLETION_MAX_CANDIDATES,
                                              &count);
    }

    if (count == 0) {
        ecex_completion_cycle_reset(ed);
        ecex_message(ed, "No completion");
        return ECEX_OK;
    }

    qsort(items, count, sizeof(items[0]), ecex_completion_candidate_compare);

    size_t index = direction < 0 ? count - 1 : 0;
    if (cycling) {
        size_t current = count;
        for (size_t i = 0; i < count; i++) {
            if (strcmp(items[i].text, ed->completion_cycle_current) == 0) {
                current = i;
                break;
            }
        }

        if (current < count) {
            if (direction < 0) index = current == 0 ? count - 1 : current - 1;
            else index = (current + 1) % count;
        }
    }

    ecex_completion_candidate_t *choice = &items[index];
    size_t current_len = end >= start ? end - start : 0;
    if (current_len == strlen(choice->text) &&
        strncmp(buffer->data + start, choice->text, current_len) == 0) {
        ed->completion_cycle_active = 1;
        ed->completion_cycle_buffer = buffer;
        ed->completion_cycle_start = start;
        ed->completion_cycle_index = index;
        snprintf(ed->completion_cycle_prefix, sizeof(ed->completion_cycle_prefix), "%s", prefix);
        snprintf(ed->completion_cycle_current, sizeof(ed->completion_cycle_current), "%s", choice->text);
        ecex_completion_describe(ed, choice, index, count);
        return ECEX_OK;
    }

    if (buffer_delete_range(buffer, start, end) != ECEX_OK) return ECEX_ERR;
    if (buffer_insert_at(buffer, start, choice->text) != ECEX_OK) return ECEX_ERR;

    ed->completion_cycle_active = 1;
    ed->completion_cycle_buffer = buffer;
    ed->completion_cycle_start = start;
    ed->completion_cycle_index = index;
    snprintf(ed->completion_cycle_prefix, sizeof(ed->completion_cycle_prefix), "%s", prefix);
    snprintf(ed->completion_cycle_current, sizeof(ed->completion_cycle_current), "%s", choice->text);

    ecex_completion_describe(ed, choice, index, count);
    return ECEX_OK;
}

int ecex_complete_at_point(ecex_t *ed) {
    return ecex_complete_at_point_direction(ed, 1);
}


static int ecex_set_owned_string(char **slot, const char *value) {
    if (!slot) return ECEX_ERR;
    char *copy = NULL;
    if (value && value[0]) {
        copy = ecex_strdup(value);
        if (!copy) return ECEX_ERR;
    }
    free(*slot);
    *slot = copy;
    return ECEX_OK;
}

static int ecex_parse_file_line(const char *text, char *path, size_t path_size, size_t *out_line) {
    if (!text || !path || path_size == 0 || !out_line) return ECEX_ERR;
    const char *colon = strchr(text, ':');
    if (!colon || colon == text) return ECEX_ERR;
    char *end = NULL;
    long line = strtol(colon + 1, &end, 10);
    if (line <= 0 || end == colon + 1) return ECEX_ERR;
    size_t len = (size_t)(colon - text);
    if (len >= path_size) len = path_size - 1;
    memcpy(path, text, len);
    path[len] = '\0';
    *out_line = (size_t)line;
    return ECEX_OK;
}

static int ecex_goto_file_line_action(ecex_t *ed, buffer_t *buffer, size_t line, const char *payload, void *userdata) {
    (void)buffer;
    (void)line;
    (void)userdata;
    if (!ed || !payload) return ECEX_ERR;
    char path[1024];
    size_t target_line = 1;
    if (ecex_parse_file_line(payload, path, sizeof(path), &target_line) != ECEX_OK) return ECEX_ERR;
    if (ecex_find_file(ed, path) != ECEX_OK) return ECEX_ERR;
    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf) return ECEX_ERR;
    size_t pos = 0;
    for (size_t l = 1; l < target_line && pos < buf->len; pos++) {
        if (buf->data[pos] == '\n') l++;
    }
    buffer_set_point(buf, pos);
    return ECEX_OK;
}

static int ecex_append_shell_output(ecex_t *ed, const char *name, const char *command) {
    if (!ed || !name || !command || !command[0]) return ECEX_ERR;
    buffer_t *buf = ecex_create_interactive_buffer(ed, name);
    if (!buf) return ECEX_ERR;
    buffer_set_interactive(buf, 1);
    if (buffer_clear(buf) != ECEX_OK) return ECEX_ERR;
    buffer_set_interactive(buf, 1);
    ecex_buffer_set_major_mode_by_name(ed, buf, "special-mode");

    char header[2048];
    snprintf(header, sizeof(header), "%s\n\nKeys: g/r rerun, n/p next/previous result, RET jump, q quit.\n\n", command);
    buffer_append(buf, header);

    char shell_command[4096];
    snprintf(shell_command, sizeof(shell_command), "%s 2>&1", command);
    FILE *pipe = popen(shell_command, "r");
    if (!pipe) {
        buffer_append(buf, "Failed to start command.\n");
        return ecex_switch_buffer(ed, name);
    }

    char line[4096];
    while (fgets(line, sizeof(line), pipe)) {
        size_t len = strlen(line);
        while (len > 0 && (line[len - 1] == '\n' || line[len - 1] == '\r')) line[--len] = '\0';
        char path[1024];
        size_t target = 0;
        ecex_interactive_line_fn fn = NULL;
        char payload[1200];
        payload[0] = '\0';
        if (ecex_parse_file_line(line, path, sizeof(path), &target) == ECEX_OK) {
            snprintf(payload, sizeof(payload), "%s:%zu", path, target);
            fn = ecex_goto_file_line_action;
        }
        ecex_interactive_append_line(ed, buf, line, fn, payload[0] ? payload : NULL, NULL);
    }

    int status = pclose(pipe);
    char footer[128];
    snprintf(footer, sizeof(footer), "\n[process exited: %d]\n", status);
    buffer_append(buf, footer);
    buf->point = 0;
    buf->modified = 0;
    return ecex_switch_buffer(ed, name);
}

int ecex_compile(ecex_t *ed, const char *command) {
    if (!ed || !command || !command[0]) return ECEX_ERR;
    if (ecex_set_owned_string(&ed->last_compile_command, command) != ECEX_OK) return ECEX_ERR;
    return ecex_append_shell_output(ed, "*compilation*", command);
}

int ecex_grep(ecex_t *ed, const char *command) {
    if (!ed || !command || !command[0]) return ECEX_ERR;
    if (ecex_set_owned_string(&ed->last_grep_command, command) != ECEX_OK) return ECEX_ERR;
    return ecex_append_shell_output(ed, "*grep*", command);
}

int ecex_rerun_compile(ecex_t *ed) {
    if (!ed || !ed->last_compile_command) return ECEX_ERR;
    return ecex_append_shell_output(ed, "*compilation*", ed->last_compile_command);
}

int ecex_rerun_grep(ecex_t *ed) {
    if (!ed || !ed->last_grep_command) return ECEX_ERR;
    return ecex_append_shell_output(ed, "*grep*", ed->last_grep_command);
}

int ecex_next_interactive_action(ecex_t *ed) {
    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf || !buffer_is_interactive(buf) || buf->interactive_action_count == 0) return ECEX_ERR;
    size_t current = buffer_current_line_number(buf);
    if (current > 0) current--;
    size_t best = (size_t)-1;
    for (size_t i = 0; i < buf->interactive_action_count; i++) {
        size_t line = buf->interactive_actions[i].line;
        if (line > current && (best == (size_t)-1 || line < best)) best = line;
    }
    if (best == (size_t)-1) best = buf->interactive_actions[0].line;
    size_t pos = 0;
    for (size_t l = 0; l < best && pos < buf->len; pos++) if (buf->data[pos] == '\n') l++;
    buffer_set_point(buf, pos);
    return ECEX_OK;
}

int ecex_previous_interactive_action(ecex_t *ed) {
    buffer_t *buf = ecex_current_buffer(ed);
    if (!buf || !buffer_is_interactive(buf) || buf->interactive_action_count == 0) return ECEX_ERR;
    size_t current = buffer_current_line_number(buf);
    if (current > 0) current--;
    size_t best = (size_t)-1;
    for (size_t i = 0; i < buf->interactive_action_count; i++) {
        size_t line = buf->interactive_actions[i].line;
        if (line < current && (best == (size_t)-1 || line > best)) best = line;
    }
    if (best == (size_t)-1) best = buf->interactive_actions[buf->interactive_action_count - 1].line;
    size_t pos = 0;
    for (size_t l = 0; l < best && pos < buf->len; pos++) if (buf->data[pos] == '\n') l++;
    buffer_set_point(buf, pos);
    return ECEX_OK;
}

static int ecex_region_lines(buffer_t *buf, size_t *out_start, size_t *out_end) {
    if (!buf || !buffer_has_selection(buf)) return ECEX_ERR;
    size_t start = 0, end = 0;
    buffer_selection_range(buf, &start, &end);
    start = buffer_line_start_at(buf, start);
    end = buffer_line_end_at(buf, end);
    if (end < buf->len) end++;
    if (out_start) *out_start = start;
    if (out_end) *out_end = end;
    return ECEX_OK;
}

int ecex_comment_region(ecex_t *ed) {
    buffer_t *buf = ecex_current_buffer(ed);
    size_t start = 0, end = 0;
    if (!buf || ecex_region_lines(buf, &start, &end) != ECEX_OK) return ECEX_ERR;
    size_t pos = start;
    while (pos <= end && pos <= buf->len) {
        if (buffer_insert_at(buf, pos, "// ") != ECEX_OK) return ECEX_ERR;
        pos += 3;
        end += 3;
        size_t eol = buffer_line_end_at(buf, pos);
        if (eol >= end || eol >= buf->len) break;
        pos = eol + 1;
    }
    return ECEX_OK;
}

int ecex_uncomment_region(ecex_t *ed) {
    buffer_t *buf = ecex_current_buffer(ed);
    size_t start = 0, end = 0;
    if (!buf || ecex_region_lines(buf, &start, &end) != ECEX_OK) return ECEX_ERR;
    size_t pos = start;
    while (pos < end && pos < buf->len) {
        if (pos + 2 <= buf->len && memcmp(buf->data + pos, "//", 2) == 0) {
            size_t del = (pos + 3 <= buf->len && buf->data[pos + 2] == ' ') ? 3 : 2;
            if (buffer_delete_range(buf, pos, pos + del) != ECEX_OK) return ECEX_ERR;
            end = end > del ? end - del : 0;
        }
        size_t eol = buffer_line_end_at(buf, pos);
        if (eol >= end || eol >= buf->len) break;
        pos = eol + 1;
    }
    return ECEX_OK;
}

int ecex_set_font(ecex_t *ed, const char *path) {
    if (!ed || !path) return ECEX_ERR;
    if (ed->theme.font_path && strcmp(ed->theme.font_path, path) == 0) return ECEX_OK;

    char *copy = ecex_strdup(path);
    if (!copy) return ECEX_ERR;

    free(ed->theme.font_path);
    ed->theme.font_path = copy;
    ecex_mark_font_changed(ed);
    return ECEX_OK;
}

float ecex_get_font_size(ecex_t *ed) {
    if (!ed) return 0.0f;
    return ed->theme.font_size;
}

int ecex_set_font_size(ecex_t *ed, float size) {
    if (!ed) return ECEX_ERR;
    float clamped = ECEX_CLAMP(size, 8.0f, 96.0f);
    if (ed->theme.font_size == clamped) return ECEX_OK;
    ed->theme.font_size = clamped;
    ecex_mark_font_changed(ed);
    return ECEX_OK;
}

int ecex_adjust_font_size(ecex_t *ed, float delta) {
    if (!ed) return ECEX_ERR;
    return ecex_set_font_size(ed, ed->theme.font_size + delta);
}

void ecex_set_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_fg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.fg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_status_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.status_bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_status_fg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.status_fg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_status_border_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.status_border = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_cursor_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.cursor = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_region_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.region_bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_minibuffer_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.minibuffer_bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_minibuffer_fg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.minibuffer_fg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_completion_fg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.completion_fg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_completion_enabled(ecex_t *ed, int enabled) { if (ed) { ed->theme.completion_enabled = enabled ? 1 : 0; ecex_mark_ui_changed(ed); } }
void ecex_set_interactive_highlight_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.interactive_highlight_bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_interactive_highlight_fg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.interactive_highlight_fg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_current_line_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.current_line_bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_search_bg_color(ecex_t *ed, float r, float g, float b) { if (ed) { ed->theme.search_bg = ecex_color(r, g, b); ecex_mark_ui_changed(ed); } }
void ecex_set_line_numbers_enabled(ecex_t *ed, int enabled) { if (ed) { ed->theme.line_numbers_enabled = enabled ? 1 : 0; ecex_mark_ui_changed(ed); } }
void ecex_set_current_line_enabled(ecex_t *ed, int enabled) { if (ed) { ed->theme.current_line_enabled = enabled ? 1 : 0; ecex_mark_ui_changed(ed); } }