#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <SDL2/SDL_keycode.h>
#include <SDL2/SDL_rect.h>
#include <SDL2/SDL_render.h>
#include <SDL2/SDL_surface.h>
#include <SDL2/SDL_video.h>
#include <cmath>
#include <cstddef>
#include <functional>
#include <memory>
#include <stdexcept>

#include "../api/Camera.h"
#include "../api/Config.h"
#include "../api/Sprite.h"
#include "../api/Texture.h"
#include "../util/Log.h"

#include "SDLContext.h"
#include "types.h"

using namespace crepe;
using namespace std;

SDLContext & SDLContext::get_instance() {
	static SDLContext instance;
	return instance;
}

SDLContext::SDLContext() {
	dbg_trace();

	if (SDL_Init(SDL_INIT_VIDEO) != 0) {
		throw runtime_error(format("SDLContext: SDL_Init error: {}", SDL_GetError()));
	}

	auto & cfg = Config::get_instance().window_settings;
	SDL_Window * tmp_window
		= SDL_CreateWindow(cfg.window_title.c_str(), SDL_WINDOWPOS_CENTERED,
						   SDL_WINDOWPOS_CENTERED, cfg.default_size.x, cfg.default_size.y, 0);
	if (!tmp_window) {
		throw runtime_error(format("SDLContext: SDL_Window error: {}", SDL_GetError()));
	}
	this->game_window = {tmp_window, [](SDL_Window * window) { SDL_DestroyWindow(window); }};

	SDL_Renderer * tmp_renderer
		= SDL_CreateRenderer(this->game_window.get(), -1, SDL_RENDERER_ACCELERATED);
	if (!tmp_renderer) {
		throw runtime_error(
			format("SDLContext: SDL_CreateRenderer error: {}", SDL_GetError()));
	}

	this->game_renderer
		= {tmp_renderer, [](SDL_Renderer * renderer) { SDL_DestroyRenderer(renderer); }};

	int img_flags = IMG_INIT_PNG;
	if (!(IMG_Init(img_flags) & img_flags)) {
		throw runtime_error("SDLContext: SDL_image could not initialize!");
	}
}

SDLContext::~SDLContext() {
	dbg_trace();

	this->game_renderer.reset();
	this->game_window.reset();

	// TODO: how are we going to ensure that these are called from the same
	// thread that SDL_Init() was called on? This has caused problems for me
	// before.
	IMG_Quit();
	SDL_Quit();
}
void SDLContext::handle_events(bool & running) {
	//TODO: wouter i need events
	/*
	SDL_Event event;
	SDL_PollEvent(&event);
	switch (event.type) {
		case SDL_QUIT:
			running = false;
			break;
		case SDL_KEYDOWN:
			triggerEvent(KeyPressedEvent(getCustomKey(event.key.keysym.sym)));
			break;
		case SDL_MOUSEBUTTONDOWN:
			int x, y;
			SDL_GetMouseState(&x, &y);
			triggerEvent(MousePressedEvent(x, y));
			break;
	}
	*/
}

void SDLContext::clear_screen() { SDL_RenderClear(this->game_renderer.get()); }
void SDLContext::present_screen() {
	SDL_SetRenderDrawColor(this->game_renderer.get(), 0, 0, 0, 255);
	SDL_RenderFillRectF(this->game_renderer.get(), &black_bars[0]);
	SDL_RenderFillRectF(this->game_renderer.get(), &black_bars[1]);
	SDL_RenderPresent(this->game_renderer.get());
}

SDL_Rect SDLContext::get_src_rect(const Sprite & sprite) const {
	return SDL_Rect{
		.x = sprite.mask.x,
		.y = sprite.mask.y,
		.w = sprite.mask.w,
		.h = sprite.mask.h,
	};
}

SDL_FRect SDLContext::get_dst_rect(const DstRect & ctx) const {

	const Sprite::Data & data = ctx.sprite.data;

	vec2 size = {
		data.size.x == 0 && data.size.y != 0 ? data.size.y * ctx.sprite.aspect_ratio : data.size.x,
		data.size.y == 0 && data.size.x != 0 ? data.size.x / ctx.sprite.aspect_ratio : data.size.y};

	const CameraValues & cam = ctx.cam;

	size *= cam.render_scale * ctx.img_scale * data.scale_offset;

	vec2 screen_pos = (ctx.pos - cam.cam_pos + (cam.zoomed_viewport) / 2) * cam.render_scale
					  - size / 2 + cam.bar_size;

	return SDL_FRect{
		.x = screen_pos.x,
		.y = screen_pos.y,
		.w = size.x,
		.h = size.y,
	};
}

void SDLContext::draw(const RenderContext & ctx) {

	const Sprite::Data & data = ctx.sprite.data;
	SDL_RendererFlip render_flip
		= (SDL_RendererFlip) ((SDL_FLIP_HORIZONTAL * data.flip.flip_x)
							  | (SDL_FLIP_VERTICAL * data.flip.flip_y));

	SDL_Rect srcrect = this->get_src_rect(ctx.sprite);
	SDL_FRect dstrect = this->get_dst_rect(SDLContext::DstRect{
		.sprite = ctx.sprite,
		.cam = ctx.cam,
		.pos = ctx.pos,
		.img_scale = ctx.scale,
	});

	double angle = ctx.angle + data.angle_offset;

	SDL_RenderCopyExF(this->game_renderer.get(), ctx.sprite.texture.texture.get(), &srcrect,
					  &dstrect, angle, NULL, render_flip);
}

SDLContext::CameraValues SDLContext::set_camera(const Camera & cam) {

	const Camera::Data & cam_data = cam.data;
	CameraValues ret_cam;
	// resize window
	int w, h;
	SDL_GetWindowSize(this->game_window.get(), &w, &h);
	if (w != cam.screen.x || h != cam.screen.y) {
		SDL_SetWindowSize(this->game_window.get(), cam.screen.x, cam.screen.y);
	}

	vec2 & zoomed_viewport = ret_cam.zoomed_viewport;
	vec2 & bar_size = ret_cam.bar_size;
	vec2 & render_scale = ret_cam.render_scale;

	zoomed_viewport = cam.viewport_size * cam_data.zoom;
	double screen_aspect = static_cast<double>(cam.screen.x) / cam.screen.y;
	double viewport_aspect = zoomed_viewport.x / zoomed_viewport.y;

	// calculate black bars
	if (screen_aspect > viewport_aspect) {
		// pillarboxing
		float scale = cam.screen.y / zoomed_viewport.y;
		float adj_width = zoomed_viewport.x * scale;
		float bar_width = (cam.screen.x - adj_width) / 2;
		this->black_bars[0] = {0, 0, bar_width, (float) cam.screen.y};
		this->black_bars[1]
			= {(cam.screen.x - bar_width), 0, bar_width, (float) cam.screen.y};

		bar_size = {bar_width, 0};
		render_scale.x = render_scale.y = scale;
	} else {
		// letterboxing
		float scale = cam.screen.x / (cam.viewport_size.x * cam_data.zoom);
		float adj_height = cam.viewport_size.y * scale;
		float bar_height = (cam.screen.y - adj_height) / 2;
		this->black_bars[0] = {0, 0, (float) cam.screen.x, bar_height};
		this->black_bars[1]
			= {0, (cam.screen.y - bar_height), (float) cam.screen.x, bar_height};

		bar_size = {0, bar_height};
		render_scale.x = render_scale.y = scale;
	}

	SDL_SetRenderDrawColor(this->game_renderer.get(), cam_data.bg_color.r, cam_data.bg_color.g,
						   cam_data.bg_color.b, cam_data.bg_color.a);

	SDL_Rect bg = {
		.x = 0,
		.y = 0,
		.w = cam.screen.x,
		.h = cam.screen.y,
	};

	// fill bg color
	SDL_RenderFillRect(this->game_renderer.get(), &bg);


	return ret_cam;
}

uint64_t SDLContext::get_ticks() const { return SDL_GetTicks64(); }

std::unique_ptr<SDL_Texture, std::function<void(SDL_Texture *)>>
SDLContext::texture_from_path(const std::string & path) {

	SDL_Surface * tmp = IMG_Load(path.c_str());
	if (tmp == nullptr)
		throw runtime_error(format("SDLContext: IMG_Load error: {}", SDL_GetError()));

	std::unique_ptr<SDL_Surface, std::function<void(SDL_Surface *)>> img_surface;
	img_surface = {tmp, [](SDL_Surface * surface) { SDL_FreeSurface(surface); }};

	SDL_Texture * tmp_texture
		= SDL_CreateTextureFromSurface(this->game_renderer.get(), img_surface.get());

	if (tmp_texture == nullptr) {
		throw runtime_error(format("SDLContext: Texture cannot be load from {}", path));
	}

	std::unique_ptr<SDL_Texture, std::function<void(SDL_Texture *)>> img_texture;
	img_texture = {tmp_texture, [](SDL_Texture * texture) { SDL_DestroyTexture(texture); }};

	return img_texture;
}
int SDLContext::get_width(const Texture & ctx) const {
	int w;
	SDL_QueryTexture(ctx.texture.get(), NULL, NULL, &w, NULL);
	return w;
}
int SDLContext::get_height(const Texture & ctx) const {
	int h;
	SDL_QueryTexture(ctx.texture.get(), NULL, NULL, NULL, &h);
	return h;
}
void SDLContext::delay(int ms) const { SDL_Delay(ms); }