/**
 * @brief imgviewer - Display bitmaps in a graphical window.
 *
 * This is probably the 4th time I've (re)written a version of
 * this application... This uses the libtoaru_graphics sprite
 * functionality to load images, so it will support whatever
 * that ends up supporting - which at the time of writing is
 * just bitmaps of various types.
 *
 * @copyright
 * This file is part of ToaruOS and is released under the terms
 * of the NCSA / University of Illinois License - see LICENSE.md
 * Copyright (C) 2018 K. Lange
 */

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <getopt.h>
#include <libgen.h>

#include <toaru/yutani.h>
#include <toaru/graphics.h>
#include <toaru/decorations.h>
#include <toaru/menu.h>

/* Pointer to graphics memory */
static yutani_t * yctx;
static yutani_window_t * window = NULL;
static gfx_context_t * ctx = NULL;

static int decor_left_width = 0;
static int decor_top_height = 0;
static int decor_right_width = 0;
static int decor_bottom_height = 0;
static int decor_width = 0;
static int decor_height = 0;

int left   = 40;
int top    = 40;
int width  = 300;
int height = 300;

int current_scale = 100;

sprite_t img = {0};

#define APPLICATION_TITLE "Image Viewer"
static char window_title[1024] = APPLICATION_TITLE;

void usage(char * argv[]) {
	printf(
			"Image Viewer - Shows images.\n"
			"\n"
			"usage: %s \033[3mimage\033[0m\n"
			"\n"
			" -? --help      \033[3mShow this help message.\033[0m\n",
			argv[0]);
}

static void decors() {
	if (current_scale != 100) {
		char tmp[1100];
		snprintf(tmp, 1100, "%s [%d%%]", window_title, current_scale);
		render_decorations(window, ctx, tmp);
	} else {
		render_decorations(window, ctx, window_title);
	}
}

void redraw() {
	uint32_t dark  = rgb(107,107,107);
	uint32_t light = rgb(147,147,147);
	uint32_t black = rgb(0,0,0);

	int calc_width = img.width * (current_scale / 100.0);
	int calc_height = img.height * (current_scale / 100.0);

	int image_left  = width / 2 - calc_width / 2;
	int image_right = image_left + calc_width; /* TODO scaling */
	int image_top   = height / 2 - calc_height / 2;
	int image_bot   = image_top + calc_height;

	for (int y = 0; y < height; ++y) {
		for (int x = 0; x < width; ++x) {
			uint32_t color = (x < image_left || x >= image_right || y < image_top || y >= image_bot) ? black :
			((((y / 10) % 2 == 0) ^ ((x / 10) % 2 == 0)) ? dark : light);
			GFX(ctx,x+decor_left_width,y+decor_top_height) = color;
		}
	}

	if (current_scale != 100) {
		draw_sprite_scaled(ctx, &img, decor_left_width + image_left, decor_top_height + image_top, calc_width, calc_height);
	} else {
		draw_sprite(ctx, &img, decor_left_width + image_left, decor_top_height + image_top);
	}
	decors();
	flip(ctx);
}

void resize_finish(int w, int h) {
	yutani_window_resize_accept(yctx, window, w, h);
	reinit_graphics_yutani(ctx, window);

	struct decor_bounds bounds;
	decor_get_bounds(window, &bounds);

	decor_left_width = bounds.left_width;
	decor_top_height = bounds.top_height;
	decor_right_width = bounds.right_width;
	decor_bottom_height = bounds.bottom_height;
	decor_width = bounds.width;
	decor_height = bounds.height;

	width  = w - decor_left_width - decor_right_width;
	height = h - decor_top_height - decor_bottom_height;

	redraw();
	yutani_window_resize_done(yctx, window);

	yutani_flip(yctx, window);
}

static int one_fifth(int scale) {
	int out = scale * 0.05;
	if (out) return out;
	return 1;
}

int main(int argc, char * argv[]) {

	static struct option long_opts[] = {
		{"help",   no_argument,       0, '?'},
		{0,0,0,0}
	};

	if (argc > 1) {
		/* Read some arguments */
		int index, c;
		while ((c = getopt_long(argc, argv, "h", long_opts, &index)) != -1) {
			if (!c) {
				if (long_opts[index].flag == 0) {
					c = long_opts[index].val;
				}
			}
			switch (c) {
				case 'h':
					usage(argv);
					exit(0);
					break;
				default:
					break;
			}
		}
	}

	if (optind >= argc) {
		usage(argv);
		return 1;
	}

	yctx = yutani_init();
	if (!yctx) {
		fprintf(stderr, "%s: failed to connect to compositor\n", argv[0]);
		return 1;
	}
	init_decorations();

	struct decor_bounds bounds;
	decor_get_bounds(NULL, &bounds);

	decor_left_width = bounds.left_width;
	decor_top_height = bounds.top_height;
	decor_right_width = bounds.right_width;
	decor_bottom_height = bounds.bottom_height;
	decor_width = bounds.width;
	decor_height = bounds.height;

	int status = load_sprite(&img, argv[optind]);
	if (status) {
		fprintf(stderr, "%s: failed to open image %s\n", argv[0], argv[optind]);
		return 1;
	}

	width  = img.width  < 300 ? 300 : img.width;
	height = img.height < 300 ? 300 : img.height;

	window = yutani_window_create(yctx, width + decor_width, height + decor_height);
	yutani_window_move(yctx, window, left, top);

	snprintf(window_title, 1023, "%s - " APPLICATION_TITLE, basename(argv[1]));

	yutani_window_advertise_icon(yctx, window, window_title, "image");

	ctx = init_graphics_yutani_double_buffer(window);

	redraw();
	yutani_flip(yctx, window);

	int playing = 1;
	while (playing) {
		yutani_msg_t * m = yutani_poll(yctx);
		while (m) {
			if (menu_process_event(yctx, m)) {
				/* just decorations should be fine */
				decors();
				flip(ctx);
				yutani_flip(yctx, window);
			}
			switch (m->type) {
				case YUTANI_MSG_KEY_EVENT:
					{
						struct yutani_msg_key_event * ke = (void*)m->data;
						if (ke->event.action == KEY_ACTION_DOWN && ke->event.keycode == 'q') {
							playing = 0;
						}
					}
					break;
				case YUTANI_MSG_WINDOW_FOCUS_CHANGE:
					{
						struct yutani_msg_window_focus_change * wf = (void*)m->data;
						yutani_window_t * win = hashmap_get(yctx->windows, (void*)(uintptr_t)wf->wid);
						if (win && win == window) {
							win->focused = wf->focused;
							decors();
							flip(ctx);
							yutani_flip(yctx, window);
						}
					}
					break;
				case YUTANI_MSG_RESIZE_OFFER:
					{
						struct yutani_msg_window_resize * wr = (void*)m->data;
						resize_finish(wr->width, wr->height);
					}
					break;
				case YUTANI_MSG_WINDOW_MOUSE_EVENT:
					{
						struct yutani_msg_window_mouse_event * me = (void*)m->data;
						int result = decor_handle_event(yctx, m);
						switch (result) {
							case DECOR_CLOSE:
								playing = 0;
								break;
							case DECOR_RIGHT:
								/* right click in decoration, show appropriate menu */
								decor_show_default_menu(window, window->x + me->new_x, window->y + me->new_y);
								break;
							default:
								/* Other actions */
								break;
						}
						if (me->wid == window->wid) {
							if (me->buttons & YUTANI_MOUSE_SCROLL_UP) {
								current_scale = current_scale + one_fifth(current_scale);
								redraw();
								yutani_flip(yctx, window);
							} else if (me->buttons & YUTANI_MOUSE_SCROLL_DOWN) {
								current_scale = current_scale - one_fifth(current_scale);
								redraw();
								yutani_flip(yctx, window);
							}
						}
					}
					break;
				case YUTANI_MSG_WINDOW_CLOSE:
				case YUTANI_MSG_SESSION_END:
					playing = 0;
					break;
				default:
					break;
			}
			free(m);
			m = yutani_poll_async(yctx);
		}
	}

	yutani_close(yctx, window);

	return 0;
}