#include "texture.h"
#include <SDL2/SDL_error.h>	  // for SDL_GetError
#include <SDL2/SDL_surface.h> // for SDL_CreateRGBSurfaceWithFormatFrom
#include <fcntl.h>			  // for SEEK_END, SEEK_SET
#include <stdio.h>			  // for fseek, fclose, fopen, fread, ftell, NULL
#include <stdlib.h>			  // for malloc, free, exit
#include <iostream>			  // for basic_ostream, operator<<, cout, endl
#include "gif.c"			  // for LoadGif, LoadPalette
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h" // for stbi_failure_reason, stbi_image_free

// Constructor
Texture::Texture(SDL_Renderer *renderer, std::string path)
	: renderer_(renderer), path_(path)
{
	// Inicializa
	surface_ = nullptr;
	texture_ = nullptr;
	width_ = 0;
	height_ = 0;
	paletteIndex_ = 0;
	palettes_.clear();

	// Carga el fichero en la textura
	if (!path_.empty())
	{
		// Obtiene la extensión
		const std::string extension = path_.substr(path_.find_last_of(".") + 1);

		// .png
		if (extension == "png")
		{
			loadFromFile(path_);
		}

		// .gif
		else if (extension == "gif")
		{
			surface_ = loadSurface(path_.c_str());
			addPalette(path_.c_str());
			setPaletteColor(0, 0, 0x00000000);
			createBlank(width_, height_, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STREAMING);
			SDL_SetTextureBlendMode(texture_, SDL_BLENDMODE_BLEND);
			flipSurface();
		}
	}
}

// Destructor
Texture::~Texture()
{
	unload();
}

// Carga una imagen desde un fichero
bool Texture::loadFromFile(std::string path)
{
	const std::string file_name = path.substr(path.find_last_of("\\/") + 1);
	int req_format = STBI_rgb_alpha;
	int width, height, orig_format;
	unsigned char *data = stbi_load(path.c_str(), &width, &height, &orig_format, req_format);
	if (data == nullptr)
	{
#ifdef VERBOSE
		std::cout << "Loading image failed: " << stbi_failure_reason() << std::endl;
#endif
		exit(1);
	}
	else
	{
#ifdef VERBOSE
		std::cout << "Image loaded: " << file_name.c_str() << std::endl;
#endif
	}

	int depth, pitch;
	Uint32 pixel_format;
	if (req_format == STBI_rgb)
	{
		depth = 24;
		pitch = 3 * width; // 3 bytes por pixel * pixels por linea
		pixel_format = SDL_PIXELFORMAT_RGB24;
	}
	else
	{ // STBI_rgb_alpha (RGBA)
		depth = 32;
		pitch = 4 * width;
		pixel_format = SDL_PIXELFORMAT_RGBA32;
	}

	// Limpia
	unload();

	// La textura final
	SDL_Texture *newTexture = nullptr;

	// Carga la imagen desde una ruta específica
	SDL_Surface *loadedSurface = SDL_CreateRGBSurfaceWithFormatFrom((void *)data, width, height, depth, pitch, pixel_format);
	if (loadedSurface == nullptr)
	{
#ifdef VERBOSE
		std::cout << "Unable to load image " << path.c_str() << std::endl;
#endif
	}
	else
	{
		// Crea la textura desde los pixels de la surface
		newTexture = SDL_CreateTextureFromSurface(renderer_, loadedSurface);
		if (newTexture == nullptr)
		{
#ifdef VERBOSE
			std::cout << "Unable to create texture from " << path.c_str() << "! SDL Error: " << SDL_GetError() << std::endl;
#endif
		}
		else
		{
			// Obtiene las dimensiones de la imagen
			width_ = loadedSurface->w;
			height_ = loadedSurface->h;
		}

		// Elimina la textura cargada
		SDL_FreeSurface(loadedSurface);
	}

	// Return success
	stbi_image_free(data);
	texture_ = newTexture;
	return texture_ != nullptr;
}

// Crea una textura en blanco
bool Texture::createBlank(int width, int height, SDL_PixelFormatEnum format, SDL_TextureAccess access)
{
	// Crea una textura sin inicializar
	texture_ = SDL_CreateTexture(renderer_, format, access, width, height);
	if (!texture_)
	{
		#ifdef VERBOSE
		std::cout << "Unable to create blank texture! SDL Error: " << SDL_GetError() << std::endl;
		#endif
	}
	else
	{
		width_ = width;
		height_ = height;
	}

	return texture_ != nullptr;
}

// Libera la memoria de la textura
void Texture::unload()
{
	// Libera la textura
	if (texture_)
	{
		SDL_DestroyTexture(texture_);
		texture_ = nullptr;
		width_ = 0;
		height_ = 0;
	}

	// Libera la surface
	if (surface_)
	{
		deleteSurface(surface_);
		surface_ = nullptr;
	}
}

// Establece el color para la modulacion
void Texture::setColor(Uint8 red, Uint8 green, Uint8 blue)
{
	SDL_SetTextureColorMod(texture_, red, green, blue);
}

// Establece el blending
void Texture::setBlendMode(SDL_BlendMode blending)
{
	SDL_SetTextureBlendMode(texture_, blending);
}

// Establece el alpha para la modulación
void Texture::setAlpha(Uint8 alpha)
{
	SDL_SetTextureAlphaMod(texture_, alpha);
}

// Renderiza la textura en un punto específico
void Texture::render(int x, int y, SDL_Rect *clip, float zoomW, float zoomH, double angle, SDL_Point *center, SDL_RendererFlip flip)
{
	// Establece el destino de renderizado en la pantalla
	SDL_Rect renderQuad = {x, y, width_, height_};

	// Obtiene las dimesiones del clip de renderizado
	if (clip != nullptr)
	{
		renderQuad.w = clip->w;
		renderQuad.h = clip->h;
	}

	renderQuad.w = renderQuad.w * zoomW;
	renderQuad.h = renderQuad.h * zoomH;

	// Renderiza a pantalla
	SDL_RenderCopyEx(renderer_, texture_, clip, &renderQuad, angle, center, flip);
}

// Establece la textura como objetivo de renderizado
void Texture::setAsRenderTarget(SDL_Renderer *renderer)
{
	SDL_SetRenderTarget(renderer, texture_);
}

// Obtiene el ancho de la imagen
int Texture::getWidth()
{
	return width_;
}

// Obtiene el alto de la imagen
int Texture::getHeight()
{
	return height_;
}

// Recarga la textura
bool Texture::reLoad()
{
	return loadFromFile(path_);
}

// Obtiene la textura
SDL_Texture *Texture::getSDLTexture()
{
	return texture_;
}

// Crea una nueva surface
Surface Texture::newSurface(int w, int h)
{
	Surface surf = (Surface)malloc(sizeof(surface_s));
	surf->w = w;
	surf->h = h;
	surf->data = (Uint8 *)malloc(w * h);
	return surf;
}

// Elimina una surface
void Texture::deleteSurface(Surface surface)
{
	if (surface == nullptr)
	{
		return;
	}

	if (surface->data != nullptr)
	{
		free(surface->data);
	}

	free(surface);
}

// Crea una surface desde un fichero .gif
Surface Texture::loadSurface(const char *file_name)
{
	FILE *f = fopen(file_name, "rb");
	if (!f)
	{
		return NULL;
	}

	fseek(f, 0, SEEK_END);
	long size = ftell(f);
	fseek(f, 0, SEEK_SET);
	Uint8 *buffer = (Uint8 *)malloc(size);
	fread(buffer, size, 1, f);
	fclose(f);

	Uint16 w, h;
	Uint8 *pixels = LoadGif(buffer, &w, &h);
	if (pixels == NULL)
	{
		return NULL;
	}

	Surface surface = (Surface)malloc(sizeof(surface_s));
	surface->w = w;
	surface->h = h;
	surface->data = pixels;
	free(buffer);

	width_ = w;
	height_ = h;

	return surface;
}

// Vuelca la surface en la textura
void Texture::flipSurface()
{
	// Limpia la textura
	auto temp = SDL_GetRenderTarget(renderer_);
	SDL_SetRenderTarget(renderer_, texture_);
	SDL_SetRenderDrawColor(renderer_, 0, 0, 0, 0);
	SDL_RenderClear(renderer_);
	SDL_SetRenderTarget(renderer_, temp);

	// Vuelca los datos
	Uint32 *pixels;
	int pitch;
	SDL_LockTexture(texture_, nullptr, (void **)&pixels, &pitch);
	for (int i = 0; i < width_ * height_; ++i)
	{
		pixels[i] = palettes_[paletteIndex_][surface_->data[i]];
	}
	SDL_UnlockTexture(texture_);
}

// Establece un color de la paleta
void Texture::setPaletteColor(int palette, int index, Uint32 color)
{
	palettes_.at(palette)[index] = color;
}

// Carga una paleta desde un fichero
std::vector<Uint32> Texture::loadPal(const char *file_name)
{
	std::vector<Uint32> palette;

	FILE *f = fopen(file_name, "rb");
	if (!f)
	{
		return palette;
	}

	fseek(f, 0, SEEK_END);
	long size = ftell(f);
	fseek(f, 0, SEEK_SET);
	Uint8 *buffer = (Uint8 *)malloc(size);
	fread(buffer, size, 1, f);
	fclose(f);

	Uint32 *pal = LoadPalette(buffer);
	if (pal == nullptr)
	{
		return palette;
	}

	free(buffer);

	for (int i = 0; i < 256; ++i)
	{
		palette.push_back((pal[i] << 8) + 255);
	}

	return palette;
}

// Añade una paleta a la lista
void Texture::addPalette(std::string path)
{
	palettes_.push_back(loadPal(path.c_str()));
	setPaletteColor((int)palettes_.size() - 1, 0, 0x00000000);
}

// Cambia la paleta de la textura
void Texture::setPalette(int palette)
{
	if (palette < (int)palettes_.size())
	{
		paletteIndex_ = palette;
		flipSurface();
	}
}

// Obtiene el renderizador
SDL_Renderer *Texture::getRenderer()
{
	return renderer_;
}