#include <math.h>
#include <SDL.h>
#include "init.h"
#include "logging.h"
#include "resources/image.h"
#include "resources/map.h"
#include "viewport.h"
#include "area.h"

#define CYCLE_LINEAR(t_max, r1, g1, b1, r2, g2, b2)                            \
	do {                                                                   \
		x = (double) t / (double) t_max;                               \
		y_end = (i % 8) * 36;                                          \
		y_start = y_end * r1;                                          \
		y_end = y_end * r2;                                            \
		colors[i].r = x * (y_end - y_start) + y_start;                 \
		y_end = (i % 64 / 8) * 36;                                     \
		y_start = y_end * g1;                                          \
		y_end = y_end * g2;                                            \
		colors[i].g = x * (y_end - y_start) + y_start;                 \
		y_end = (i / 64) * 85;                                         \
		y_start = y_end * b1;                                          \
		y_end = y_end * b2;                                            \
		colors[i].b = x * (y_end - y_start) + y_start;                 \
	} while (0)
#define CYCLE_COS(t_max, r1, g1, b1, r2, g2, b2)                               \
	do {                                                                   \
		x = t * 3.14159 / t_max;                                       \
		y_end = (i % 8) * 36;                                          \
		y_start = y_end * r2;                                          \
		y_end = y_end * r1;                                            \
		colors[i].r = ((cos(x) + 1) / 2) *                             \
			(y_end - y_start) + y_start;                           \
		y_end = (i % 64 / 8) * 36;                                     \
		y_start = y_end * g2;                                          \
		y_end = y_end * g1;                                            \
		colors[i].g = ((cos(x) + 1) / 2) *                             \
			(y_end - y_start) + y_start;                           \
		y_end = (i / 64) * 85;                                         \
		y_start = y_end * b2;                                          \
		y_end = y_end * b1;                                            \
		colors[i].b = ((cos(x) + 1) / 2) *                             \
			(y_end - y_start) + y_start;                           \
	} while (0)

#define DEMO()                                                                 \
	do {                                                                   \
		vp->x = x + map->tilewidth / 2 - vp->w / 2;                    \
		vp->y = y + map->tileheight / 2 - vp->h / 2;                   \
		render_area_to_viewport(a, vp);                                \
		SDL_Flip(vp->screen);                                          \
		SDL_Delay(10);                                                 \
		++i;                                                           \
	} while (0)

int
main(void)
{
	struct viewport *vp;
	struct map *map;
	struct area *a;
	SDL_Color colors[256];
	int i;
	struct map_exit *e;

	init();
	vp = init_viewport(240, 160, 8);

	map = map_get(MAPSDIR "/forest1-8bit.tmx");
	if (map == NULL) {
		map = map_get("data/maps/forest1-8bit.tmx");
	}
	if (map == NULL) {
		err(1, "Where's the map, George?");
	}
	for (i = 0; i < 256; ++i) {
		colors[i].r = (i % 8) * 36;
		colors[i].g = (i % 64 / 8) * 36;
		colors[i].b = (i / 64) * 85;
	}
	if (!SDL_SetPalette(vp->screen, SDL_LOGPAL, colors, 0, 256)) {
		warn("Failed to set palette");
	}
	a = area_new(map, vp);

	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);
	}

	render_area_to_viewport(a, vp);
	{
		Uint32 d, t;
		double x;
		int y_start, y_end;

		for (d = 0; d < 4; ++d) {
			/* morn -> day */
			for (t = 0; t < 360; t += 1) {
				for (i = 0; i < 256; ++i) {
					CYCLE_COS(360,
							1.000, 0.875, 0.625,
							1.000, 1.000, 1.000
							);
				}
				if (!SDL_SetPalette(vp->screen, SDL_LOGPAL,
							colors, 0, 256)) {
					warn("Failed to set palette");
				}
				SDL_Flip(vp->screen);
				SDL_Delay(10);
			}
			/* day -> eve */
			for (t = 0; t < 360; t += 1) {
				for (i = 0; i < 256; ++i) {
					CYCLE_COS(360,
							1.000, 1.000, 1.000,
							0.875, 0.625, 0.625
							);
				}
				if (!SDL_SetPalette(vp->screen, SDL_LOGPAL,
							colors, 0, 256)) {
					warn("Failed to set palette");
				}
				SDL_Flip(vp->screen);
				SDL_Delay(10);
			}
			/* eve -> night */
			for (t = 0; t < 360; t += 1) {
				for (i = 0; i < 256; ++i) {
					CYCLE_COS(360,
							0.875, 0.625, 0.625,
							0.250, 0.250, 0.500
							);
				}
				if (!SDL_SetPalette(vp->screen, SDL_LOGPAL,
							colors, 0, 256)) {
					warn("Failed to set palette");
				}
				SDL_Flip(vp->screen);
				SDL_Delay(10);
			}
			/* night -> morn */
			for (t = 0; t < 360; t += 1) {
				for (i = 0; i < 256; ++i) {
					CYCLE_COS(360,
							0.250, 0.250, 0.500,
							1.000, 0.875, 0.625
							);
				}
				if (!SDL_SetPalette(vp->screen, SDL_LOGPAL,
							colors, 0, 256)) {
					warn("Failed to set palette");
				}
				SDL_Flip(vp->screen);
				SDL_Delay(10);
			}
		}
	}
	quit(0);

	/* Demo */
	for (i = 0; i < 256; ++i) {
		colors[i].r = (i % 8) * 36;
		colors[i].g = (i % 64 / 8) * 36;
		colors[i].b = (i / 64) * 85;
	}
	if (!SDL_SetPalette(vp->screen, SDL_LOGPAL, colors, 0, 256)) {
		warn("Failed to set palette");
	}

	{
		Uint32 start, end;
		int x, y;

		i = 0;
		start = SDL_GetTicks();
		x = 19 * map->tilewidth ;
		y = 38 * map->tileheight;
		for (; y > 34 * map->tileheight; y -= 2) DEMO(); /* Up */
		for (; x < 23 * map->tilewidth ; x += 2) DEMO(); /* Right */
		for (; y > 16 * map->tileheight; y -= 2) DEMO(); /* Up */
		for (; x > 15 * map->tilewidth ; x -= 2) DEMO(); /* Left */
		for (; y < 25 * map->tileheight; y += 2) DEMO(); /* Down */
		for (; x >  4 * map->tilewidth ; x -= 2) DEMO(); /* Left */
		for (; y > 18 * map->tileheight; y -= 2) DEMO(); /* Up */
		for (; x <  9 * map->tilewidth ; x += 2) DEMO(); /* Right */
		for (; y >  5 * map->tileheight; y -= 2) DEMO(); /* Up */
		for (; x < 15 * map->tilewidth ; x += 2) DEMO(); /* Right */
		for (; y >  1 * map->tileheight; y -= 2) DEMO(); /* Up */
		end = SDL_GetTicks();
		debug("Rendered %d frames in %d milliseconds", i, end - start);
	}

	quit(0);

	/* Control doesn't actually reach here. */
	return 0;
}