/*
 * Copyright (C) 2013  Patrick "P. J." McDermott
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include <SDL.h>
#include "logging.h"
#include "resources/image.h"
#include "resources/map.h"
#include "viewport.h"
#include "area.h"
#include "palettes.h"
#include "demo.h"

#define DEMO()                                                                 \
	do {                                                                   \
		vp->x = x + map->tilewidth / 2 - vp->w / 2;                    \
		vp->y = y + map->tileheight / 2 - vp->h / 2;                   \
		/*                                                             \
		 * See the following resources when computing realistic        \
		 * daylight cycles:                                            \
		 *   * <https://en.wikipedia.org/wiki/Sunrise_equation>        \
		 *   * <http://www.esrl.noaa.gov/gmd/grad/solcalc/sunrise.html>\
		 */                                                            \
		if (i % i_max < i_max / 6 * 2) {                               \
			/* 00:00 - 04:00 */                                    \
			t_max = i_max / 6 * 2;                                 \
			pal_start = map->palettes[MAP_PALETTE_MORN]            \
				.palette->palette;                             \
			pal_end = map->palettes[MAP_PALETTE_DAY]               \
				.palette->palette;                             \
		} else if (i % i_max < i_max / 6 * 4) {                        \
			/* 04:00 - 12:00 */                                    \
			t_max = i_max / 6 * 2;                                 \
			pal_start = map->palettes[MAP_PALETTE_DAY]             \
				.palette->palette;                             \
			pal_end = map->palettes[MAP_PALETTE_EVE]               \
				.palette->palette;                             \
		} else if (i % i_max < i_max / 6 * 5) {                        \
			/* 12:00 - 20:00 */                                    \
			t_max = i_max / 6 * 1;                                 \
			pal_start = map->palettes[MAP_PALETTE_EVE]             \
				.palette->palette;                             \
			pal_end = map->palettes[MAP_PALETTE_NIGHT]             \
				.palette->palette;                             \
		} else {                                                       \
			/* 04:00 - 12:00 */                                    \
			t_max = i_max / 6 * 1;                                 \
			pal_start = map->palettes[MAP_PALETTE_NIGHT]           \
				.palette->palette;                             \
			pal_end = map->palettes[MAP_PALETTE_MORN]              \
				.palette->palette;                             \
		}                                                              \
		if (!cycle_palettes_cosine(i, t_max,                           \
					pal_start, pal_end, pal)) {            \
			warn("Failed to cycle palettes");                      \
		}                                                              \
		set_area_palette(a, pal);                                      \
		if (!SDL_SetPalette(vp->screen, SDL_LOGPAL,                    \
					pal->colors, 0, pal->ncolors)) {       \
			warn("Failed to set palette");                         \
		}                                                              \
		render_area_to_viewport(a, vp);                                \
		SDL_Flip(vp->screen);                                          \
		SDL_Delay(10);                                                 \
		++i;                                                           \
	} while (0)

void
demo(void)
{
	struct viewport *vp;
	struct map *map;
	struct area *a;
	SDL_Palette *pal;
	struct map_exit *e;

	vp = init_viewport(320, 240, 8);

	map = map_get(MAPSDIR "/db16-route.tmx");
	if (map == NULL) {
		map = map_get("data/maps/db16-route.tmx");
	}
	if (map == NULL) {
		err(1, "Where's the map, George?");
	}
	pal = map->palettes[MAP_PALETTE_DAY].palette->palette;
	if (!SDL_SetPalette(vp->screen, SDL_LOGPAL, pal->colors,
				0, pal->ncolors)) {
		warn("Failed to set palette");
	}
	a = area_new(map, vp->screen->format->palette);

	for (e = map->map_exits_head; e != NULL; e = e->next) {
		debug("Map exit (size %dx%d) at (%d,%d) "
				"to map %s (size %dx%d) at (%d,%d)",
				e->width, e->height,
				e->x, e->y,
				e->target_map_name,
				e->target_map->width, e->target_map->height,
				e->target_x_coord, e->target_y_coord);
	}

	/* Demo */
	{
		Uint32 start, end;
		int i, i_max, t_max;
		int x, y;
		SDL_Palette *pal_start, *pal_end;

		pal = malloc(sizeof(*pal));
		pal->colors = calloc(64, sizeof(*pal->colors));
		pal->ncolors = 64;

		i = 0;
		i_max = 1440;
		start = SDL_GetTicks();
		x =  9 * map->tilewidth ;
		y = 58 * map->tileheight;
		for (; y > 50 * map->tileheight; y -= 1) DEMO(); /* Up */
		for (; x < 12 * map->tilewidth ; x += 1) DEMO(); /* Right */
		for (; y > 43 * map->tileheight; y -= 1) DEMO(); /* Up */
		for (; x >  5 * map->tilewidth ; x -= 1) DEMO(); /* Left */
		for (; y > 32 * map->tileheight; y -= 1) DEMO(); /* Up */
		for (; x < 13 * map->tilewidth ; x += 1) DEMO(); /* Right */
		for (; y > 31 * map->tileheight; y -= 1) DEMO(); /* Up */
		for (; x < 16 * map->tilewidth ; x += 1) DEMO(); /* Right */
		for (; y < 34 * map->tileheight; y += 1) DEMO(); /* Down */
		for (; x < 24 * map->tilewidth ; x += 1) DEMO(); /* Right */
		for (; y > 15 * map->tileheight; y -= 1) DEMO(); /* Up */
		for (; x > 11 * map->tilewidth ; x -= 1) DEMO(); /* Left */
		for (; y >  5 * map->tileheight; y -= 1) DEMO(); /* Up */
		for (; x < 17 * map->tilewidth ; x += 1) DEMO(); /* Right */
		for (; y >  1 * map->tileheight; y -= 1) DEMO(); /* Up */
		end = SDL_GetTicks();
		debug("Rendered %d frames in %d milliseconds", i, end - start);
	}
}