/**
 * Copyright (c) 2006-2017 LOVE Development Team
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 **/

#include "Image.h"
#include "Graphics.h"

// C++
#include <algorithm>

namespace love
{
namespace graphics
{

love::Type Image::type("Image", &Texture::type);

int Image::imageCount = 0;

Image::Image(const Slices &data, const Settings &settings, bool validatedata)
	: Texture(data.getTextureType())
	, settings(settings)
	, data(data)
	, mipmapsType(settings.mipmaps ? MIPMAPS_GENERATED : MIPMAPS_NONE)
	, sRGB(isGammaCorrect() && !settings.linear)
{
	if (validatedata && data.validate() == MIPMAPS_DATA)
		mipmapsType = MIPMAPS_DATA;

	++imageCount;
}

Image::~Image()
{
	--imageCount;
}

Image::Slices::Slices(TextureType textype)
	: textureType(textype)
{
}

void Image::Slices::clear()
{
	data.clear();
}

void Image::Slices::set(int slice, int mipmap, love::image::ImageDataBase *d)
{
	if (textureType == TEXTURE_VOLUME)
	{
		if (mipmap >= (int) data.size())
			data.resize(mipmap + 1);

		if (slice >= (int) data[mipmap].size())
			data[mipmap].resize(slice + 1);

		data[mipmap][slice].set(d);
	}
	else
	{
		if (slice >= (int) data.size())
			data.resize(slice + 1);

		if (mipmap >= (int) data[slice].size())
			data[slice].resize(mipmap + 1);

		data[slice][mipmap].set(d);
	}
}

love::image::ImageDataBase *Image::Slices::get(int slice, int mipmap) const
{
	if (slice < 0 || slice >= getSliceCount(mipmap))
		return nullptr;

	if (mipmap < 0 || mipmap >= getMipmapCount(slice))
		return nullptr;

	if (textureType == TEXTURE_VOLUME)
		return data[mipmap][slice].get();
	else
		return data[slice][mipmap].get();
}

void Image::Slices::add(love::image::CompressedImageData *cdata, int startslice, int startmip, bool addallslices, bool addallmips)
{
	int slicecount = addallslices ? cdata->getSliceCount() : 1;
	int mipcount = addallmips ? cdata->getMipmapCount() : 1;

	for (int mip = 0; mip < mipcount; mip++)
	{
		for (int slice = 0; slice < slicecount; slice++)
			set(startslice + slice, startmip + mip, cdata->getSlice(slice, mip));
	}
}

int Image::Slices::getSliceCount(int mip) const
{
	if (textureType == TEXTURE_VOLUME)
	{
		if (mip < 0 || mip >= (int) data.size())
			return 0;

		return (int) data[mip].size();
	}
	else
		return (int) data.size();
}

int Image::Slices::getMipmapCount(int slice) const
{
	if (textureType == TEXTURE_VOLUME)
		return (int) data.size();
	else
	{
		if (slice < 0 || slice >= (int) data.size())
			return 0;

		return data[slice].size();
	}
}

Image::MipmapsType Image::Slices::validate() const
{
	int slicecount = getSliceCount();
	int mipcount = getMipmapCount(0);

	if (slicecount == 0 || mipcount == 0)
		throw love::Exception("At least one ImageData or CompressedImageData is required!");

	if (textureType == TEXTURE_CUBE && slicecount != 6)
		throw love::Exception("Cube textures must have exactly 6 sides.");

	image::ImageDataBase *firstdata = get(0, 0);

	int w = firstdata->getWidth();
	int h = firstdata->getHeight();
	PixelFormat format = firstdata->getFormat();

	int expectedmips = Texture::getMipmapCount(w, h);

	if (mipcount != expectedmips && mipcount != 1)
		throw love::Exception("Image does not have all required mipmap levels (expected %d, got %d)", expectedmips, mipcount);

	if (textureType == TEXTURE_CUBE && w != h)
		throw love::Exception("Cube images must have equal widths and heights for each cube face.");

	int mipw = w;
	int miph = h;
	int mipslices = slicecount;

	for (int mip = 0; mip < mipcount; mip++)
	{
		if (textureType == TEXTURE_VOLUME)
		{
			slicecount = getSliceCount(mip);

			if (slicecount != mipslices)
				throw love::Exception("Invalid number of image data layers in mipmap level %d (expected %d, got %d)", mip+1, mipslices, slicecount);
		}

		for (int slice = 0; slice < slicecount; slice++)
		{
			auto slicedata = get(slice, mip);

			if (slicedata == nullptr)
				throw love::Exception("Missing image data (slice %d, mipmap level %d)", slice+1, mip+1);

			int realw = slicedata->getWidth();
			int realh = slicedata->getHeight();

			if (getMipmapCount(slice) != mipcount)
				throw love::Exception("All Image layers must have the same mipmap count.");

			if (mipw != realw)
				throw love::Exception("Width of image data (slice %d, mipmap level %d) is incorrect (expected %d, got %d)", slice+1, mip+1, mipw, realw);

			if (miph != realh)
				throw love::Exception("Height of image data (slice %d, mipmap level %d) is incorrect (expected %d, got %d)", slice+1, mip+1, miph, realh);

			if (format != slicedata->getFormat())
				throw love::Exception("All Image slices and mipmaps must have the same pixel format.");
		}

		mipw = std::max(mipw / 2, 1);
		miph = std::max(miph / 2, 1);

		if (textureType == TEXTURE_VOLUME)
			mipslices = std::max(mipslices / 2, 1);
	}
	
	if (mipcount > 1)
		return MIPMAPS_DATA;
	else
		return MIPMAPS_NONE;
}

} // graphics
} // love