#include "config.h"
#include "render.h"
#include "input.h"

#if defined(plat_emscripten)
#include <emscripten.h>
#endif

#if defined(plat_posix) || defined(plat_emscripten)
#define _POSIX_SOURCE

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <stdarg.h>

void platform_log(const char* message, ...) {
	va_list args;
	va_start(args, message);
	vfprintf(stdout, message, args);
	va_end(args);
}

void platform_err(const char* message, ...) {
	va_list args;
	va_start(args, message);

	if (isatty(fileno(stderr))) {
		fprintf(stderr, "\033[31;31m");
	}

	vfprintf(stderr, message, args);

	if (isatty(fileno(stderr))) {
		fprintf(stderr, "\033[0m");
	}

	va_end(args);
}

void platform_abort(int code) {
#if defined(DEBUG) && defined(plat_x86)
	__asm__("int3;");
#else
	exit(code);
#endif
}
#endif

#if defined(plat_sdl2)

#define max_joysticks 16

#include <SDL2/SDL.h>
#include <stdio.h>
#include <string.h>

extern void on_init(int argc, char** argv);
extern void on_update();
extern void on_deinit();

int held_btns[btn_count];
int pressed_btns[btn_count];
int released_btns[btn_count];
int app_running = 1;

int texture_w = default_window_w, texture_h = default_window_h;

int button_pressed(Button btn) {
	return held_btns[btn];
}

int button_just_pressed(Button btn) {
	return pressed_btns[btn];
}

int button_just_released(Button btn) {
	return released_btns[btn];
}

Button sdl_to_btn(const SDL_Event* event) {
	switch (event->key.keysym.sym) {
		case SDLK_z:
		case SDLK_RETURN:
			return btn_jump;
		case SDLK_x:
			return btn_shoot;
		case SDLK_LEFT:
		case SDLK_h:
			return btn_dpad_left;
		case SDLK_RIGHT:
		case SDLK_l:
			return btn_dpad_right;
		case SDLK_UP:
		case SDLK_k:
			return btn_dpad_up;
		case SDLK_DOWN:
		case SDLK_j:
			return btn_dpad_down;
		case SDLK_ESCAPE:
			return btn_pause;
		case SDLK_F12:
			return btn_edit;
		case SDLK_s:
			return btn_save_level;
		default: return btn_unknown;
	}
}

Button joy_btn_to_btn(int button) {
	switch (button) {
		case 0:
			return btn_jump;
		case 2:
			return btn_shoot;
		case 7:
			return btn_pause;
		default: return btn_unknown;
	}
}

void reset_dpad() {
	int i;

	for (
		i = btn_dpad_left;
		i <= btn_dpad_down;
		i++
	) {
		if (held_btns[i]) {
			held_btns[i] = 0;
			released_btns[i] = 1;
		}
	}
}

void update_dpad(Button btn) {
	reset_dpad();

	held_btns[btn] = 1;
	pressed_btns[btn] = 1;
}

int audio_len, audio_pos;
int ticker;

void fill_audio(void *udata, Uint8 *stream, int len) {
	/*if (audio_len == 0) {
		audio_len = 1024;
		audio_pos = 0;
	}

	len = (len > audio_len ? audio_len : len);

	sound_sys.mix(((unsigned short*)stream), len);

	audio_pos += len;
	audio_len -= len;*/
}

void reset_input() {
	int i;

	for (i = 0; i < btn_count; i++) {
		pressed_btns[i] = 0;
		released_btns[i] = 0;
	}
}

void platform_quit() {
	app_running = 0;
}

/* lol, lmao
 * haha */
static SDL_Window* window;
static SDL_Renderer* renderer;
static SDL_Texture* backbuffer;
static void* bb_pixels;
static SDL_Event event;
static SDL_Rect src_rect, dst_rect;
#if !no_sound
static SDL_AudioSpec aud_spec;
#endif
static Button button;
static int ww, wh, bb_pitch, ntw, nth;
static int to_sleep, begin_time, end_time;
static SDL_Joystick* joysticks[max_joysticks];

int platform_get_time() {
	return SDL_GetTicks();
}

static void fit_texture(int w, int h) {
	ntw = renderer_w;
	nth = renderer_h;
	texture_w = ntw;
	texture_h = nth;

	/* This is kinda shit lmao. */
	while (1) {
		ntw *= 2;
		nth *= 2;

		if (
			ntw > w ||
			nth > h
		) {
			break;
		}

		texture_w = ntw;
		texture_h = nth;
	}
}

static void main_loop() {
#if !defined(plat_emscripten)
	while (app_running) {
#endif
		begin_time = SDL_GetTicks();

		reset_input();

		while (SDL_PollEvent(&event)) {
			switch (event.type) {
				case SDL_QUIT:
					app_running = 0;
					break;
				case SDL_KEYDOWN:
					button = sdl_to_btn(&event);
					held_btns[(int)button] = 1;
					pressed_btns[(int)button] = 1;
					break;
				case SDL_KEYUP:
					button = sdl_to_btn(&event);
					held_btns[(int)button] = 0;
					released_btns[(int)button] = 1;
					break;
				case SDL_JOYDEVICEADDED:
					joysticks[event.jdevice.which] =
						SDL_JoystickOpen(event.jdevice.which);
					break;
				case SDL_JOYDEVICEREMOVED:
					SDL_JoystickClose(joysticks[event.jdevice.which]);
					break;
				case SDL_JOYHATMOTION:
					switch (event.jhat.value) {
						case SDL_HAT_LEFT:
							update_dpad(btn_dpad_left);
							break;
						case SDL_HAT_UP:
							update_dpad(btn_dpad_up);
							break;
						case SDL_HAT_RIGHT:
							update_dpad(btn_dpad_right);
							break;
						case SDL_HAT_DOWN:
							update_dpad(btn_dpad_down);
							break;
						case SDL_HAT_CENTERED:
							reset_dpad();
						default:
							break;
					}
					break;
				case SDL_JOYBUTTONDOWN:
					button = joy_btn_to_btn(event.jbutton.button);
					held_btns[(int)button] = 1;
					pressed_btns[(int)button] = 1;
					break;
				case SDL_JOYBUTTONUP:
					button = joy_btn_to_btn(event.jbutton.button);
					held_btns[(int)button] = 0;
					released_btns[(int)button] = 1;
					break;
				case SDL_WINDOWEVENT:
					switch (event.window.event) {
						case SDL_WINDOWEVENT_RESIZED:
							fit_texture(event.window.data1, event.window.data2);
							break;
					}
				default:
					break;
			}
		}

		on_update();

		SDL_GetWindowSize(window, &ww, &wh);

		src_rect.x = 0;
		src_rect.y = 0;
		src_rect.w = renderer_w;
		src_rect.h = renderer_h;

		src_rect.x = 0;
		src_rect.y = 0;
		src_rect.w = renderer_w;
		src_rect.h = renderer_h;

		dst_rect.x = ww / 2 - texture_w / 2;
		dst_rect.y = wh / 2 - texture_h / 2;
		dst_rect.w = texture_w;
		dst_rect.h = texture_h;

		SDL_LockTexture(
			backbuffer,
			0,
			&bb_pixels,
			&bb_pitch
		);

		memcpy(bb_pixels,
			get_render_pixels(),
			renderer_w * renderer_h * sizeof(Colour)
		);

		SDL_UnlockTexture(backbuffer);

		SDL_UpdateTexture(
			backbuffer,
			0,
			get_render_pixels(),
			renderer_w * sizeof(Colour)
		);

		SDL_RenderClear(renderer);
		SDL_RenderCopy(
			renderer,
			backbuffer,
			&src_rect,
			&dst_rect
		);
		SDL_RenderPresent(renderer);

		end_time = SDL_GetTicks();

		to_sleep = 20 - ((end_time - begin_time));
		if (to_sleep > 0) {
			SDL_Delay(to_sleep);
		}
#if !defined(plat_emscripten)
	}
#endif
}

int main(int argc, char** argv) {
	audio_pos = 0;
	audio_len = 1024;
	ticker = 0;

	SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_JOYSTICK);

	SDL_CreateWindowAndRenderer(
		default_window_w * renderer_scale,
		default_window_h * renderer_scale,
		SDL_WINDOW_RESIZABLE,
		&window,
		&renderer
	);

	SDL_SetWindowTitle(window, game_name);

#if !no_sound
	aud_spec.freq = 22050;
	aud_spec.format = AUDIO_U16;
	aud_spec.channels = 1;
	aud_spec.samples = 1024;
	aud_spec.callback = fill_audio;
	aud_spec.userdata = 0;

	if (SDL_OpenAudio(&aud_spec, 0) < 0) {
		fprintf(
			stderr,
			"Sound error: %s.\n",
			SDL_GetError()
		);
	}
	SDL_PauseAudio(0);
#endif

	on_init(argc, argv);

	backbuffer = SDL_CreateTexture(
		renderer,
		SDL_PIXELFORMAT_ABGR8888,
		SDL_TEXTUREACCESS_STREAMING,
		renderer_w,
		renderer_h
	);

	fit_texture(
		renderer_w * renderer_scale,
		renderer_h * renderer_scale
	);

#if defined(plat_emscripten)
	emscripten_set_main_loop(main_loop, 0, 1);
#else
	main_loop();
#endif

	on_deinit();

	SDL_DestroyTexture(backbuffer);
	SDL_DestroyRenderer(renderer);
	SDL_DestroyWindow(window);

#if !no_sound
	SDL_CloseAudio();
#endif

	SDL_Quit();

	return 0;
}

#else
#define No platform defined.
#endif