#include <iostream>

#include "../Video.h"

#include "Events.h"

#define WINDOW_WIDTH 1280
#define WINDOW_HEIGHT 800

Video video;

Video::Video() {
	// TODO
}

Video::~Video() {
	exit();
}

inline void writePixel(SDL_Surface *surface, unsigned x, unsigned y, Uint8 r, Uint8 g, Uint8 b, Uint8 a) {
	auto row = reinterpret_cast<Uint32*>(static_cast<Uint8*>(surface->pixels) + y * surface->pitch);
	row[x] = SDL_MapRGBA(surface->format, r, g, b, a);
}

void Video::enter() {
	_window = SDL_CreateWindow("game", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 1280, 800, SDL_WINDOW_SHOWN);
	SDL_SetWindowTitle(_window, "meow :3");
	if (!_window) {
		std::cerr << "Error creating SDL window: " << SDL_GetError() << std::endl;
		abort();
	}

	_windowSurface = SDL_GetWindowSurface(_window);
	_fb = SDL_CreateRGBSurfaceWithFormat(0, SCREEN_WIDTH, SCREEN_HEIGHT, 32, SDL_PIXELFORMAT_ARGB8888);
}

void Video::exit() {
	if (_fb) SDL_FreeSurface(_fb);
	_fb = nullptr;

	SDL_DestroyWindow(_window);
}

void Video::SetMode(uint8_t mode) {
	// Ignored
}

uint8_t Video::GetMode() {
	// Fixed
	return 0x13;
}

void Video::SetPaletteEntry(uint8_t index, PaletteEntry entry) {
	SetPaletteEntry(index, &entry);
}

Video::PaletteEntry Video::GetPaletteEntry(uint8_t index) {
	PaletteEntry entry;
	GetPaletteEntry(index, &entry);
	return entry;
}

void Video::SetPaletteEntry(uint8_t index, PaletteEntry *entry) {
	_palette[index] = *entry;
}

void Video::GetPaletteEntry(uint8_t index, PaletteEntry *entry) {
	*entry = _palette[index];
}

void *Video::GetFB() {
	return _renderBuffer;
}

void Video::WaitForVerticalSync() {
	auto targetTime = _lastUpdate + std::chrono::microseconds(14286);
	auto currentTime = std::chrono::steady_clock::now();

	while (currentTime < targetTime) {
		currentTime = std::chrono::steady_clock::now();
	}
	_lastUpdate = currentTime;
}

void Video::UpdateRect(const Rect &rect) {
	// Merge rect if it overlaps with an existing rect
	for (auto i = 0; i < _updateRectIndex; i++) {
		auto &r = _updatedRects[i];
		if (r.overlaps(rect)) {
			r += rect;
			return;
		}
	}

	// Add a new rect to the list
	_updatedRects[_updateRectIndex++] = rect;
}

void Video::Flip() {
	SDL_LockSurface(_fb);

	for (auto i = 0; i <= MAX_UPDATE_RECT_INDEX; i++) {
		auto &rect = _updatedRects[i];
		rect.clamp(0, 0, _fb->w, _fb->h);

		for (auto y = rect.y1; y < rect.y2; y++) {
			for (auto x = rect.x1; x < rect.x2; x++) {
				auto &paletteEntry = _palette[_renderBuffer[y * SCREEN_WIDTH + x]];

				writePixel(_fb, x, y, paletteEntry.r, paletteEntry.g, paletteEntry.b, 255);
			}
		}
	}
	SDL_UnlockSurface(_fb);

	SDL_Rect srcRect{0, 0, SCREEN_WIDTH, SCREEN_HEIGHT};
	SDL_Rect dstRect{0, 0, WINDOW_WIDTH, WINDOW_HEIGHT};

	SDL_BlitScaled(_fb, &srcRect, _windowSurface, &dstRect);
	SDL_UpdateWindowSurface(_window);

	_updateRectIndex = 0;

	events.poll();
}