#include "config.h"

#include "buffers.h"
#include "ccdjit.h"
#include "common.h"
#include "ecex.h"
#include "eval.h"
#include "util.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef int (*ecex_config_init_fn)(ecex_t *ed);

typedef struct host_symbol {
    const char *name;
    void *addr;
} host_symbol_t;

void ecex_print_ccdjit_error(ccdjit_context *ctx) {
    const ccdjit_diagnostic *diag = ccdjit_context_last_error(ctx);

    if (!diag) {
        fprintf(stderr, "ccdjit: unknown error\n");
        return;
    }

    fprintf(stderr,
            "ccdjit error [%s] %s:%d:%d: %s\n",
            diag->phase ? diag->phase : "?",
            diag->filename ? diag->filename : "<input>",
            diag->line,
            diag->column,
            diag->message ? diag->message : "(no message)");

    if (diag->source_line) fprintf(stderr, "%s\n", diag->source_line);
    if (diag->caret_line) fprintf(stderr, "%s\n", diag->caret_line);
}

#define HOST_SYMBOL(fn) { #fn, (void *)(fn) }

static const host_symbol_t host_symbols[] = {
    HOST_SYMBOL(ecex_current_buffer),
    HOST_SYMBOL(ecex_create_buffer),
    HOST_SYMBOL(ecex_find_buffer),
    HOST_SYMBOL(ecex_switch_buffer),
    HOST_SYMBOL(ecex_next_buffer),
    HOST_SYMBOL(ecex_previous_buffer),
    HOST_SYMBOL(ecex_current_window),
    HOST_SYMBOL(ecex_window_count),
    HOST_SYMBOL(ecex_split_window_vertically),
    HOST_SYMBOL(ecex_split_window_horizontally),
    HOST_SYMBOL(ecex_other_window),
    HOST_SYMBOL(ecex_previous_window),
    HOST_SYMBOL(ecex_delete_window),
    HOST_SYMBOL(ecex_delete_other_windows),
    HOST_SYMBOL(ecex_kill_buffer),

    HOST_SYMBOL(ecex_register_command),
    HOST_SYMBOL(ecex_execute_command),
    HOST_SYMBOL(ecex_bind_key),
    HOST_SYMBOL(ecex_lookup_key),
    HOST_SYMBOL(ecex_define_major_mode),
    HOST_SYMBOL(ecex_major_mode_by_name),
    HOST_SYMBOL(ecex_major_mode_name),
    HOST_SYMBOL(ecex_buffer_set_major_mode),
    HOST_SYMBOL(ecex_buffer_set_major_mode_by_name),
    HOST_SYMBOL(ecex_buffer_major_mode_name),
    HOST_SYMBOL(ecex_bind_mode_key),
    HOST_SYMBOL(ecex_lookup_key_for_buffer),
    HOST_SYMBOL(ecex_key_sequence_has_prefix_for_buffer),
    HOST_SYMBOL(ecex_auto_set_major_mode),
    HOST_SYMBOL(ecex_list_commands),
    HOST_SYMBOL(ecex_list_buffers),
    HOST_SYMBOL(ecex_create_interactive_buffer),
    HOST_SYMBOL(ecex_interactive_append_line),
    HOST_SYMBOL(ecex_interactive_activate_current_line),
    HOST_SYMBOL(ecex_find_file),
    HOST_SYMBOL(ecex_save_current_buffer),
    HOST_SYMBOL(ecex_write_current_buffer),
    HOST_SYMBOL(ecex_request_prompt),
    HOST_SYMBOL(ecex_clear_prompt_request),
    HOST_SYMBOL(ecex_complete_command),
    HOST_SYMBOL(ecex_eval_source),
    HOST_SYMBOL(ecex_eval_current_buffer),
    HOST_SYMBOL(ecex_eval_current_line),
    HOST_SYMBOL(ecex_eval_current_region),
    HOST_SYMBOL(ecex_eval_file),
    HOST_SYMBOL(ecex_eval_rerun_last),

    HOST_SYMBOL(ecex_set_font),
    HOST_SYMBOL(ecex_get_font_size),
    HOST_SYMBOL(ecex_set_font_size),
    HOST_SYMBOL(ecex_adjust_font_size),
    HOST_SYMBOL(ecex_set_bg_color),
    HOST_SYMBOL(ecex_set_fg_color),
    HOST_SYMBOL(ecex_set_status_bg_color),
    HOST_SYMBOL(ecex_set_status_fg_color),
    HOST_SYMBOL(ecex_set_status_border_color),
    HOST_SYMBOL(ecex_set_cursor_color),
    HOST_SYMBOL(ecex_set_region_bg_color),
    HOST_SYMBOL(ecex_set_minibuffer_bg_color),
    HOST_SYMBOL(ecex_set_minibuffer_fg_color),
    HOST_SYMBOL(ecex_set_completion_fg_color),
    HOST_SYMBOL(ecex_set_completion_enabled),
    HOST_SYMBOL(ecex_set_interactive_highlight_bg_color),
    HOST_SYMBOL(ecex_set_interactive_highlight_fg_color),

    HOST_SYMBOL(buffer_clear),
    HOST_SYMBOL(buffer_set_text),
    HOST_SYMBOL(buffer_insert),
    HOST_SYMBOL(buffer_insert_at),
    HOST_SYMBOL(buffer_append),
    HOST_SYMBOL(buffer_prepend),
    HOST_SYMBOL(buffer_insert_char),
    HOST_SYMBOL(buffer_insert_char_at),
    HOST_SYMBOL(buffer_delete_range),
    HOST_SYMBOL(buffer_delete_selection),
    HOST_SYMBOL(buffer_replace_selection),
    HOST_SYMBOL(buffer_backspace),
    HOST_SYMBOL(buffer_delete_forward),
    HOST_SYMBOL(buffer_kill_line),

    HOST_SYMBOL(buffer_set_point),
    HOST_SYMBOL(buffer_move_left),
    HOST_SYMBOL(buffer_move_right),
    HOST_SYMBOL(buffer_move_up),
    HOST_SYMBOL(buffer_move_down),
    HOST_SYMBOL(buffer_move_word_left),
    HOST_SYMBOL(buffer_move_word_right),
    HOST_SYMBOL(buffer_move_beginning_of_line),
    HOST_SYMBOL(buffer_move_end_of_line),
    HOST_SYMBOL(buffer_move_beginning_of_buffer),
    HOST_SYMBOL(buffer_move_end_of_buffer),

    HOST_SYMBOL(buffer_set_mark),
    HOST_SYMBOL(buffer_clear_mark),
    HOST_SYMBOL(buffer_has_selection),
    HOST_SYMBOL(buffer_selection_range),

    HOST_SYMBOL(buffer_line_start_at),
    HOST_SYMBOL(buffer_line_end_at),
    HOST_SYMBOL(buffer_current_line_start),
    HOST_SYMBOL(buffer_current_line_end),
    HOST_SYMBOL(buffer_current_column),
    HOST_SYMBOL(buffer_current_line_number),
    HOST_SYMBOL(buffer_line_count),
    HOST_SYMBOL(buffer_substring),
    HOST_SYMBOL(buffer_current_line_copy),

    HOST_SYMBOL(buffer_load_file),
    HOST_SYMBOL(buffer_save),
    HOST_SYMBOL(buffer_save_as),
    HOST_SYMBOL(buffer_set_interactive),
    HOST_SYMBOL(buffer_is_interactive),
    HOST_SYMBOL(buffer_clear_interactive_actions),
    HOST_SYMBOL(buffer_add_interactive_action),
    HOST_SYMBOL(buffer_interactive_action_at_line),
};

#undef HOST_SYMBOL

int ecex_register_host_symbols(ccdjit_context *ctx) {
    for (size_t i = 0; i < ECEX_ARRAY_LEN(host_symbols); i++) {
        if (ccdjit_context_register_symbol(ctx,
                                           host_symbols[i].name,
                                           host_symbols[i].addr) != 0) {
            fprintf(stderr, "ecex: failed to register symbol: %s\n", host_symbols[i].name);
            ecex_print_ccdjit_error(ctx);
            return ECEX_ERR;
        }
    }

    return ECEX_OK;
}

static int add_include_path(ccdjit_context *ctx, const char *path) {
    if (ccdjit_context_add_include_path(ctx, path) == 0) return ECEX_OK;

    fprintf(stderr, "ecex: failed to add include path: %s\n", path);
    ecex_print_ccdjit_error(ctx);
    return ECEX_ERR;
}

int ecex_add_ccdjit_include_paths(ccdjit_context *ctx) {
    if (add_include_path(ctx, "include") != ECEX_OK) return ECEX_ERR;
    if (add_include_path(ctx, "../include") != ECEX_OK) return ECEX_ERR;

    const char *env_include = getenv("ECEX_INCLUDE");
    if (env_include && env_include[0]) {
        if (add_include_path(ctx, env_include) != ECEX_OK) return ECEX_ERR;
    }

    return ECEX_OK;
}

static char *make_config_source_with_forced_main(const char *path) {
    size_t source_size = 0;
    char *source = ecex_read_entire_file(path, &source_size);
    if (!source) return NULL;

    const char *forced_main =
        "\n"
        "\n"
        "int main(int argc, char **argv) {\n"
        "    (void)argc;\n"
        "    (void)argv;\n"
        "    return ecex_config_init((ecex_t *)0);\n"
        "}\n";

    size_t forced_main_len = strlen(forced_main);
    char *combined = malloc(source_size + forced_main_len + 1);
    if (!combined) {
        free(source);
        return NULL;
    }

    memcpy(combined, source, source_size);
    memcpy(combined + source_size, forced_main, forced_main_len + 1);

    free(source);
    return combined;
}

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

    ccdjit_context *ctx = ccdjit_context_new(NULL);
    if (!ctx) {
        fprintf(stderr, "ecex: failed to create ccdjit context\n");
        return ECEX_ERR;
    }

    if (ecex_add_ccdjit_include_paths(ctx) != ECEX_OK || ecex_register_host_symbols(ctx) != ECEX_OK) {
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    char *source = make_config_source_with_forced_main(path);
    if (!source) {
        fprintf(stderr, "ecex: failed to read or prepare config: %s\n", path);
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    ccdjit_module *module = NULL;
    if (ccdjit_compile_string(ctx, source, path, &module) != 0) {
        fprintf(stderr, "ecex: failed to compile config: %s\n", path);
        ecex_print_ccdjit_error(ctx);
        free(source);
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    free(source);

    ecex_config_init_fn init =
        (ecex_config_init_fn)ccdjit_module_symbol(module, "ecex_config_init");

    if (!init) {
        fprintf(stderr, "ecex: config missing function: ecex_config_init\n");
        ecex_print_ccdjit_error(ctx);
        ccdjit_module_free(module);
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    int result = init(ed);
    if (result != 0) {
        fprintf(stderr, "ecex: config init failed with code: %d\n", result);
        ccdjit_module_free(module);
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    if (ecex_keep_jit_module(ed, module) != ECEX_OK) {
        fprintf(stderr, "ecex: failed to retain config module\n");
        ccdjit_module_free(module);
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    if (ecex_set_config_path(ed, path) != ECEX_OK) {
        fprintf(stderr, "ecex: failed to remember config path: %s\n", path);
        ccdjit_context_free(ctx);
        return ECEX_ERR;
    }

    ccdjit_context_free(ctx);
    fprintf(stderr, "ecex: loaded config: %s\n", path);
    return ECEX_OK;
}