#include "app.h"
#include "config.h"
#include "font.h"
#include "media.h"
#include "render.h"

#include <GLFW/glfw3.h>

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

#define WINDOW_WIDTH 1000
#define WINDOW_HEIGHT 700

static void print_usage(const char *argv0) {
    fprintf(stderr, "usage:\n");
    fprintf(stderr, "  %s [--config path/to/ecexrc.c] [--font path/to/font.ttf]\n", argv0);
    fprintf(stderr, "\n");
    fprintf(stderr, "keys:\n");
    fprintf(stderr, "  F1 opens M-x\n");
    fprintf(stderr, "  Tab completes M-x command names\n");
    fprintf(stderr, "  Alt+x opens M-x when the OS/window-manager allows it\n");
    fprintf(stderr, "  C-x is reserved for prefix maps\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "env:\n");
    fprintf(stderr, "  ECEX_FONT=/path/to/font.ttf\n");
    fprintf(stderr, "  ECEX_INCLUDE=/path/to/ecex/include\n");
}

static int parse_args(int argc,
                      char **argv,
                      const char **config_path,
                      const char **font_path_arg) {
    *config_path = NULL;
    *font_path_arg = NULL;

    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "--config") == 0) {
            if (i + 1 >= argc) {
                print_usage(argv[0]);
                return -1;
            }

            *config_path = argv[++i];
        } else if (strcmp(argv[i], "--font") == 0) {
            if (i + 1 >= argc) {
                print_usage(argv[0]);
                return -1;
            }

            *font_path_arg = argv[++i];
        } else if (strcmp(argv[i], "--help") == 0 ||
                   strcmp(argv[i], "-h") == 0) {
            print_usage(argv[0]);
            return 1;
        } else {
            *font_path_arg = argv[i];
        }
    }

    return 0;
}

static const char *select_font_path(ecex_t *ed, const char *font_path_arg) {
    if (font_path_arg) return font_path_arg;
    if (ed && ed->theme.font_path) return ed->theme.font_path;
    return font_choose_path(NULL);
}

int main(int argc, char **argv) {
    const char *config_path = NULL;
    const char *font_path_arg = NULL;

    int args_result = parse_args(argc, argv, &config_path, &font_path_arg);
    if (args_result != 0) {
        return args_result < 0 ? 1 : 0;
    }

    ecex_t *ed = ecex_new();
    if (!ed) {
        fprintf(stderr, "failed to create editor\n");
        return 1;
    }

    if (config_path) {
        if (ecex_load_c_config(ed, config_path) != 0) {
            fprintf(stderr, "ecex: continuing without config\n");
        }
    }

    if (!glfwInit()) {
        fprintf(stderr, "failed to initialize GLFW\n");
        ecex_free(ed);
        return 1;
    }

    GLFWwindow *window = glfwCreateWindow(
        WINDOW_WIDTH,
        WINDOW_HEIGHT,
        "ecex",
        NULL,
        NULL
    );

    if (!window) {
        fprintf(stderr, "failed to create GLFW window\n");
        glfwTerminate();
        ecex_free(ed);
        return 1;
    }

    glfwMakeContextCurrent(window);
    glfwSwapInterval(1);

    app_t app;
    app_init(&app, ed);
    app_set_window(&app, window);

    const char *font_path = select_font_path(ed, font_path_arg);
    if (!font_path) {
        fprintf(stderr, "ecex: could not find a font automatically\n");
        fprintf(stderr, "try:\n");
        fprintf(stderr, "  export ECEX_FONT=/path/to/font.ttf\n");
        fprintf(stderr, "  %s --font /path/to/font.ttf\n", argv[0]);

        glfwDestroyWindow(window);
        glfwTerminate();
        ecex_free(ed);
        return 1;
    }

    if (font_load(&app.font, font_path, ed->theme.font_size) != 0) {
        fprintf(stderr, "ecex: could not load font\n");
        fprintf(stderr, "try an explicit font path:\n");
        fprintf(stderr, "  %s --font /path/to/font.ttf\n", argv[0]);

        glfwDestroyWindow(window);
        glfwTerminate();
        ecex_free(ed);
        return 1;
    }

    snprintf(app.font_path, sizeof(app.font_path), "%s", font_path);

    app_install_callbacks(&app);
    app_message(&app, "F1 for M-x. Tab completes commands.");

    while (!glfwWindowShouldClose(window) && !ed->should_quit) {
        double now = glfwGetTime();
        if (ecex_media_tick(ed, now) || ecex_tick_animations(ed, now)) {
            app.dirty = 1;
        }

        if (app.dirty) {
            render(&app);
            glfwSwapBuffers(window);
            app.dirty = 0;
        }

        glfwWaitEventsTimeout(1.0 / 60.0);
    }

    font_free(&app.font);

    glfwDestroyWindow(window);
    glfwTerminate();

    ecex_free(ed);
    return 0;
}