#define TB_IMPL
#include "termbox2.h"

#include <gio/gdesktopappinfo.h>
#include <gio/gio.h>

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

#include "mimetypes.h"

// Configuration Constants
#define COL_WIDTH_CATEGORIES 22
#define COL_WIDTH_APPS 40
#define X_OFF_CATEGORIES 2
#define X_OFF_APPS (X_OFF_CATEGORIES + COL_WIDTH_CATEGORIES)
#define X_OFF_FILE (X_OFF_APPS + COL_WIDTH_APPS + 2)
#define Y_OFF_START 3
#define Y_OFF_TITLES 1

// Color Scheme
#define COLOR_TITLE (TB_YELLOW | TB_BOLD)
#define COLOR_SELECTED TB_BLUE
#define COLOR_DEFAULT TB_WHITE
#define COLOR_DIM TB_DIM
#define COLOR_SUCCESS TB_GREEN
#define COLOR_ERROR TB_RED

typedef struct {
	int category_idx;
	int app_idx;
	int col; // 0 for category, 1 for app
	char message[512];
	GList *cached_apps;
} State;

void draw_text(int x, int y, uint16_t fg, uint16_t bg, const char *str) {
	while (*str) {
		uint32_t uni;
		tb_utf8_char_to_unicode(&uni, str);
		tb_set_cell(x++, y, uni, fg, bg);
		str += tb_utf8_char_length(*str);
	}
}

GList *get_apps_for_category(int category_idx) {
	GList *apps = NULL;
	for (int m = 0; categories[category_idx].mimetypes[m] != NULL; ++m) {
		GList *type_apps = g_app_info_get_all_for_type(categories[category_idx].mimetypes[m]);
		for (GList *l = type_apps; l != NULL; l = l->next) {
			GAppInfo *app = (GAppInfo *)l->data;
			int found = 0;
			for (GList *a = apps; a != NULL; a = a->next) {
				if (g_app_info_equal(app, (GAppInfo *)a->data)) {
					found = 1;
					break;
				}
			}
			if (!found) {
				apps = g_list_append(apps, g_object_ref(app));
			}
		}
		g_list_free_full(type_apps, g_object_unref);
	}
	return apps;
}

void update_cached_apps(State *state) {
	if (state->cached_apps) {
		g_list_free_full(state->cached_apps, g_object_unref);
	}
	state->cached_apps = get_apps_for_category(state->category_idx);
	state->app_idx = 0;
}

void draw_titles() {
	draw_text(X_OFF_CATEGORIES, Y_OFF_TITLES, COLOR_TITLE, TB_DEFAULT, "CATEGORIES");
	draw_text(X_OFF_APPS, Y_OFF_TITLES, COLOR_TITLE, TB_DEFAULT, "APPLICATIONS");
	draw_text(X_OFF_FILE, Y_OFF_TITLES, COLOR_TITLE, TB_DEFAULT, "FILE");
}

void draw_categories(State *state) {
	for (int i = 0; categories[i].name != NULL; ++i) {
		uint16_t fg = COLOR_DEFAULT;
		uint16_t bg = TB_DEFAULT;
		if (state->col == 0 && state->category_idx == i) {
			bg = COLOR_SELECTED;
		} else if (state->category_idx == i) {
			fg = COLOR_SELECTED;
			bg = COLOR_DEFAULT;
		}
		draw_text(X_OFF_CATEGORIES, Y_OFF_START + i, fg, bg, categories[i].name);
	}
}

void draw_apps_list(State *state) {
	GList *defaults = NULL;
	for (int m = 0; categories[state->category_idx].mimetypes[m] != NULL; ++m) {
		GAppInfo *d = g_app_info_get_default_for_type(categories[state->category_idx].mimetypes[m], FALSE);
		if (d) {
			int found = 0;
			for (GList *l = defaults; l != NULL; l = l->next) {
				if (g_app_info_equal(d, (GAppInfo *)l->data)) {
					found = 1;
					break;
				}
			}
			if (!found)
				defaults = g_list_append(defaults, d);
			else
				g_object_unref(d);
		}
	}

	int i = 0;
	for (GList *l = state->cached_apps; l != NULL; l = l->next, ++i) {
		GAppInfo *app = (GAppInfo *)l->data;
		uint16_t fg = COLOR_DEFAULT;
		uint16_t bg = TB_DEFAULT;
		if (state->col == 1 && state->app_idx == i) {
			bg = COLOR_SELECTED;
		}

		int is_default = 0;
		for (GList *d = defaults; d != NULL; d = d->next) {
			if (g_app_info_equal(app, (GAppInfo *)d->data)) {
				is_default = 1;
				break;
			}
		}

		char name[256];
		snprintf(name, sizeof(name), "%s %s", is_default ? "*" : " ", g_app_info_get_name(app));
		draw_text(X_OFF_APPS, Y_OFF_START + i, fg, bg, name);

		if (G_IS_DESKTOP_APP_INFO(app)) {
			const char *filename = g_desktop_app_info_get_filename(G_DESKTOP_APP_INFO(app));
			if (filename) {
				draw_text(X_OFF_FILE, Y_OFF_START + i, COLOR_DIM, bg, filename);
			}
		}
	}
	g_list_free_full(defaults, g_object_unref);
}

void draw(State *state) {
	tb_clear();
	draw_titles();
	draw_categories(state);
	draw_apps_list(state);

	if (state->message[0] != '\0') {
		uint16_t msg_col = COLOR_SUCCESS;
		if (strncmp(state->message, "Failed", 6) == 0) {
			msg_col = COLOR_ERROR;
		}
		draw_text(X_OFF_CATEGORIES, tb_height() - 1, msg_col, TB_DEFAULT, state->message);
	}

	tb_present();
}

int main() {
	if (tb_init() != 0) {
		return 1;
	}

	State state = {0, 0, 0, {0}, NULL};
	update_cached_apps(&state);

	struct tb_event ev;
	while (1) {
		draw(&state);
		tb_poll_event(&ev);

		if (ev.type == TB_EVENT_KEY) {
			if (ev.key == TB_KEY_ESC || ev.ch == 'q') {
				break;
			}

			if (ev.key == TB_KEY_ARROW_UP) {
				if (state.col == 0) {
					if (state.category_idx > 0) {
						state.category_idx--;
						update_cached_apps(&state);
						state.message[0] = '\0';
					}
				} else {
					if (state.app_idx > 0) {
						state.app_idx--;
						state.message[0] = '\0';
					}
				}
			} else if (ev.key == TB_KEY_ARROW_DOWN) {
				if (state.col == 0) {
					int count = 0;
					while (categories[count].name)
						count++;
					if (state.category_idx < count - 1) {
						state.category_idx++;
						update_cached_apps(&state);
						state.message[0] = '\0';
					}
				} else {
					int count = g_list_length(state.cached_apps);
					if (state.app_idx < count - 1) {
						state.app_idx++;
						state.message[0] = '\0';
					}
				}
			} else if (ev.key == TB_KEY_ARROW_RIGHT || ev.key == TB_KEY_TAB) {
				if (state.col == 0) {
					state.col = 1;
					state.app_idx = 0;
				}
			} else if (ev.key == TB_KEY_ARROW_LEFT) {
				if (state.col == 1) {
					state.col = 0;
				}
			} else if (ev.key == TB_KEY_ENTER) {
				if (state.col == 1) {
					GAppInfo *selected_app = (GAppInfo *)g_list_nth_data(state.cached_apps, state.app_idx);
					if (selected_app) {
						snprintf(state.message, sizeof(state.message),
								 "%s is now default %s",
								 g_app_info_get_name(selected_app), categories[state.category_idx].name);
						for (int m = 0; categories[state.category_idx].mimetypes[m] != NULL; ++m) {
							GError *error = NULL;
							g_app_info_set_as_default_for_type(selected_app, categories[state.category_idx].mimetypes[m], &error);
							if (error) {
								snprintf(state.message, sizeof(state.message), "Failed to set default application");
								g_error_free(error);
								break;
							}
						}
					}
				}
			}
		}
	}

	if (state.cached_apps) {
		g_list_free_full(state.cached_apps, g_object_unref);
	}
	tb_shutdown();
	return 0;
}