#include <SDL3/SDL.h>

#define SDL_MAIN_USE_CALLBACKS
#include <SDL3/SDL_main.h>

#include "game.h"
#include "maps.h"

#define MAXFPS (60)

static yeti_t yeti;
static u16 backbuffer[YETI_FRAMEBUFFER_WIDTH * YETI_FRAMEBUFFER_HEIGHT];

static SDL_Window *window = NULL;
static SDL_Renderer *renderer = NULL;
static SDL_Texture *texture = NULL;

static bool focused = true;

static Sint64 now = 0, then = 0;

static int requested_map = -1;

static int screenshot_idx = 0;

static void die(const char *fmt, ...)
{
	static char error[1024];
	va_list ap;

	va_start(ap, fmt);
	SDL_vsnprintf(error, sizeof(error), fmt, ap);
	va_end(ap);

	SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, error);
	SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Error", error, NULL);

	exit(1);
}

static void dump_textures(void)
{
	int i;
	SDL_Palette *pal;

	pal = SDL_CreatePalette(256);

	for (i = 0; i < pal->ncolors; i++)
	{
		pal->colors[i].r = palette[i][0];
		pal->colors[i].g = palette[i][1];
		pal->colors[i].b = palette[i][2];
		pal->colors[i].a = 255;
	}

	for (i = 0; i < TEXTURE_MAX; i++)
	{
		char filename[256];
		SDL_Surface *surf;

		surf = SDL_CreateSurfaceFrom(TEXTURE_WIDTH, TEXTURE_HEIGHT, SDL_PIXELFORMAT_INDEX8, textures[i], TEXTURE_WIDTH * sizeof(u8));
		SDL_SetSurfacePalette(surf, pal);
		SDL_FlipSurface(surf, SDL_FLIP_VERTICAL);

		SDL_snprintf(filename, sizeof(filename), "texture%03d.bmp", i);
		SDL_SaveBMP(surf, filename);
		SDL_DestroySurface(surf);
	}

	SDL_DestroyPalette(pal);
}

SDL_AppResult SDL_AppInit(void **appstate, int argc, char **argv)
{
	Uint32 format;

	if (!SDL_Init(SDL_INIT_VIDEO))
		die(SDL_GetError());

	window = SDL_CreateWindow(YETI_STR_CAPTION, YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT, SDL_WINDOW_RESIZABLE | SDL_WINDOW_MAXIMIZED);
	if (!window)
		die(SDL_GetError());

	SDL_SetWindowRelativeMouseMode(window, focused);

	SDL_SetWindowMinimumSize(window, YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT);

	renderer = SDL_CreateRenderer(window, NULL);
	if (!renderer)
		die(SDL_GetError());

	SDL_SetRenderVSync(renderer, 1);
	SDL_SetRenderLogicalPresentation(renderer, YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT, SDL_LOGICAL_PRESENTATION_LETTERBOX);

	SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
	SDL_RenderClear(renderer);
	SDL_RenderPresent(renderer);

	texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_XBGR1555, SDL_TEXTUREACCESS_STREAMING, YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT);
	if (!texture)
		die(SDL_GetError());

	SDL_SetTextureScaleMode(texture, SDL_SCALEMODE_NEAREST);

	yeti_init(&yeti, backbuffer, backbuffer, textures, palette);
	yeti_init_lua(&yeti, YETI_GAMMA);
	game_init(&yeti);

	/* get requested map */
	if (argc > 1)
	{
		requested_map = SDL_atoi(argv[1]);
		SDL_Log("Loading map %d", requested_map);
		game_load_map(&yeti, maps[requested_map]);
	}
	else
	{
		game_load_map(&yeti, &map_e1m1);
	}

	game_goto(&yeti.game, GAME_MODE_PLAY);

	/* start counting time */
	then = SDL_GetTicks();

	return SDL_APP_CONTINUE;
}

void do_frame(Sint64 dt)
{
	static Sint64 frame_delta = 1000;
	const bool *keys = SDL_GetKeyboardState(NULL);

	yeti.keyboard.state.up = keys[SDL_SCANCODE_UP] || keys[SDL_SCANCODE_W];
	yeti.keyboard.state.down = keys[SDL_SCANCODE_DOWN] || keys[SDL_SCANCODE_S];
	yeti.keyboard.state.left = keys[SDL_SCANCODE_LEFT];
	yeti.keyboard.state.right = keys[SDL_SCANCODE_RIGHT];
	yeti.keyboard.state.a = keys[SDL_SCANCODE_RCTRL];
	yeti.keyboard.state.b = keys[SDL_SCANCODE_SPACE];
	yeti.keyboard.state.l = keys[SDL_SCANCODE_A];
	yeti.keyboard.state.r = keys[SDL_SCANCODE_Z];
	yeti.keyboard.state.select = keys[SDL_SCANCODE_ESCAPE];

	frame_delta += dt;

	if (frame_delta > (1000 / MAXFPS))
	{
		game_loop(&yeti);
		frame_delta = 0;
	}
}

SDL_AppResult SDL_AppIterate(void *appstate)
{
	void *pixels;
	int pitch;

	/* speed limiter */
	now = SDL_GetTicks();
	do_frame(now - then);
	then = now;

	if (SDL_LockTexture(texture, NULL, &pixels, &pitch))
	{
		SDL_memcpy(pixels, backbuffer, sizeof(backbuffer));
		SDL_UnlockTexture(texture);
	}

	SDL_RenderClear(renderer);
	SDL_RenderTexture(renderer, texture, NULL, NULL);
	SDL_RenderPresent(renderer);

	return SDL_APP_CONTINUE;
}

static bool file_exists(const char *filename)
{
	SDL_IOStream *io = SDL_IOFromFile(filename, "rb");

	if (io)
	{
		SDL_CloseIO(io);
		return true;
	}

	return false;
}

SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
{
	switch (event->type)
	{
		case SDL_EVENT_QUIT:
			return SDL_APP_SUCCESS;

		case SDL_EVENT_KEY_DOWN:
			if (event->key.scancode == SDL_SCANCODE_ESCAPE)
			{
				focused = !focused;
				SDL_SetWindowRelativeMouseMode(window, focused);
			}
			else if (event->key.scancode == SDL_SCANCODE_F12)
			{
				SDL_Surface *screen;
				char filename[256];

				screen = SDL_CreateSurfaceFrom(YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT, SDL_PIXELFORMAT_XBGR1555, backbuffer, YETI_FRAMEBUFFER_WIDTH * sizeof(u16));
				if (!screen)
					die("%s", SDL_GetError());

				SDL_snprintf(filename, sizeof(filename), "yeti%03d.bmp", screenshot_idx++);
				while (file_exists(filename))
					SDL_snprintf(filename, sizeof(filename), "yeti%03d.bmp", screenshot_idx++);

				SDL_SaveBMP(screen, filename);
				SDL_Log("Saved screenshot %s", filename);

				SDL_DestroySurface(screen);
			}
			break;

		case SDL_EVENT_MOUSE_MOTION:
			if (focused)
			{
				yeti.camera->p += fl2f(event->motion.yrel);
				yeti.camera->t += fl2f(event->motion.xrel);
			}
			break;
	}

	return SDL_APP_CONTINUE;
}

void SDL_AppQuit(void *appstate, SDL_AppResult result)
{
	if (window) SDL_DestroyWindow(window);
	if (renderer) SDL_DestroyRenderer(renderer);
	if (texture) SDL_DestroyTexture(texture);

	SDL_Quit();
}