/*
** jpegtexture.cpp
** Texture class for JPEG images
**
**---------------------------------------------------------------------------
** Copyright 2005-2016 Randy Heit
** Copyright 2005-2019 Christoph Oelckers
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
**
*/

#include <stdio.h>
extern "C"
{
#include <jpeglib.h>
}

#include "files.h"
#include "filesystem.h"
#include "printf.h"
#include "bitmap.h"
#include "imagehelpers.h"
#include "image.h"


struct FLumpSourceMgr : public jpeg_source_mgr
{
	FileReader *Lump;
	JOCTET Buffer[4096];
	bool StartOfFile;

	FLumpSourceMgr (FileReader *lump, j_decompress_ptr cinfo);
	static void InitSource (j_decompress_ptr cinfo);
	static boolean FillInputBuffer (j_decompress_ptr cinfo);
	static void SkipInputData (j_decompress_ptr cinfo, long num_bytes);
	static void TermSource (j_decompress_ptr cinfo);
};


//==========================================================================
//
//
//
//==========================================================================

void FLumpSourceMgr::InitSource (j_decompress_ptr cinfo)
{
	((FLumpSourceMgr *)(cinfo->src))->StartOfFile = true;
}

//==========================================================================
//
//
//
//==========================================================================

boolean FLumpSourceMgr::FillInputBuffer (j_decompress_ptr cinfo)
{
	FLumpSourceMgr *me = (FLumpSourceMgr *)(cinfo->src);
	auto nbytes = me->Lump->Read (me->Buffer, sizeof(me->Buffer));

	if (nbytes <= 0)
	{
		me->Buffer[0] = (JOCTET)0xFF;
		me->Buffer[1] = (JOCTET)JPEG_EOI;
		nbytes = 2;
	}
	me->next_input_byte = me->Buffer;
	me->bytes_in_buffer = nbytes;
	me->StartOfFile = false;
	return TRUE;
}

//==========================================================================
//
//
//
//==========================================================================

void FLumpSourceMgr::SkipInputData (j_decompress_ptr cinfo, long num_bytes)
{
	FLumpSourceMgr *me = (FLumpSourceMgr *)(cinfo->src);
	if (num_bytes <= (long)me->bytes_in_buffer)
	{
		me->bytes_in_buffer -= num_bytes;
		me->next_input_byte += num_bytes;
	}
	else
	{
		num_bytes -= (long)me->bytes_in_buffer;
		me->Lump->Seek (num_bytes, FileReader::SeekCur);
		FillInputBuffer (cinfo);
	}
}

//==========================================================================
//
//
//
//==========================================================================

void FLumpSourceMgr::TermSource (j_decompress_ptr cinfo)
{
}

//==========================================================================
//
//
//
//==========================================================================

FLumpSourceMgr::FLumpSourceMgr (FileReader *lump, j_decompress_ptr cinfo)
: Lump (lump)
{
	cinfo->src = this;
	init_source = InitSource;
	fill_input_buffer = FillInputBuffer;
	skip_input_data = SkipInputData;
	resync_to_restart = jpeg_resync_to_restart;
	term_source = TermSource;
	bytes_in_buffer = 0;
	next_input_byte = NULL;
}

//==========================================================================
//
//
//
//==========================================================================

void JPEG_ErrorExit (j_common_ptr cinfo)
{
	(*cinfo->err->output_message) (cinfo);
	throw -1;
}

//==========================================================================
//
//
//
//==========================================================================

void JPEG_OutputMessage (j_common_ptr cinfo)
{
	char buffer[JMSG_LENGTH_MAX];

	(*cinfo->err->format_message) (cinfo, buffer);
	Printf (TEXTCOLOR_ORANGE "JPEG failure: %s\n", buffer);
}

//==========================================================================
//
// A JPEG texture
//
//==========================================================================

class FJPEGTexture : public FImageSource
{
public:
	FJPEGTexture (int lumpnum, int width, int height);

	int CopyPixels(FBitmap *bmp, int conversion) override;
	TArray<uint8_t> CreatePalettedPixels(int conversion) override;
};

//==========================================================================
//
//
//
//==========================================================================

FImageSource *JPEGImage_TryCreate(FileReader & data, int lumpnum)
{
	union
	{
		uint32_t dw;
		uint16_t w[2];
		uint8_t b[4];
	} first4bytes;

	data.Seek(0, FileReader::SeekSet);
	if (data.Read(&first4bytes, 4) < 4) return NULL;

	if (first4bytes.b[0] != 0xFF || first4bytes.b[1] != 0xD8 || first4bytes.b[2] != 0xFF)
		return NULL;

	// Find the SOFn marker to extract the image dimensions,
	// where n is 0, 1, or 2 (other types are unsupported).
	while ((unsigned)first4bytes.b[3] - 0xC0 >= 3)
	{
		if (data.Read (first4bytes.w, 2) != 2)
		{
			return NULL;
		}
		data.Seek (BigShort(first4bytes.w[0]) - 2, FileReader::SeekCur);
		if (data.Read (first4bytes.b + 2, 2) != 2 || first4bytes.b[2] != 0xFF)
		{
			return NULL;
		}
	}
	if (data.Read (first4bytes.b, 3) != 3)
	{
		return NULL;
	}
	if (BigShort (first4bytes.w[0]) < 5)
	{
		return NULL;
	}
	if (data.Read (first4bytes.b, 4) != 4)
	{
		return NULL;
	}
	return new FJPEGTexture (lumpnum, BigShort(first4bytes.w[1]), BigShort(first4bytes.w[0]));
}

//==========================================================================
//
//
//
//==========================================================================

FJPEGTexture::FJPEGTexture (int lumpnum, int width, int height)
: FImageSource(lumpnum)
{
	bMasked = false;

	Width = width;
	Height = height;
}

//==========================================================================
//
//
//
//==========================================================================

TArray<uint8_t> FJPEGTexture::CreatePalettedPixels(int conversion)
{
	auto lump = fileSystem.OpenFileReader (SourceLump);
	JSAMPLE *buff = NULL;

	jpeg_decompress_struct cinfo;
	jpeg_error_mgr jerr;

	TArray<uint8_t> Pixels(Width * Height, true);
	memset (Pixels.Data(), 0xBA, Width * Height);

	cinfo.err = jpeg_std_error(&jerr);
	cinfo.err->output_message = JPEG_OutputMessage;
	cinfo.err->error_exit = JPEG_ErrorExit;
	jpeg_create_decompress(&cinfo);

	FLumpSourceMgr sourcemgr(&lump, &cinfo);
	try
	{
		bool doalpha = conversion == luminance;
		jpeg_read_header(&cinfo, TRUE);
		if (!((cinfo.out_color_space == JCS_RGB && cinfo.num_components == 3) ||
			(cinfo.out_color_space == JCS_CMYK && cinfo.num_components == 4) ||
			(cinfo.out_color_space == JCS_YCbCr && cinfo.num_components == 3) ||
			(cinfo.out_color_space == JCS_GRAYSCALE && cinfo.num_components == 1)))
		{
			Printf(TEXTCOLOR_ORANGE "Unsupported color format in %s\n", fileSystem.GetFileFullPath(SourceLump).GetChars());
		}
		else
		{
			jpeg_start_decompress(&cinfo);

			int y = 0;
			buff = new uint8_t[cinfo.output_width * cinfo.output_components];

			while (cinfo.output_scanline < cinfo.output_height)
			{
				jpeg_read_scanlines(&cinfo, &buff, 1);
				uint8_t *in = buff;
				uint8_t *out = Pixels.Data() + y;
				switch (cinfo.out_color_space)
				{
				case JCS_RGB:
					for (int x = Width; x > 0; --x)
					{
						*out = ImageHelpers::RGBToPalette(doalpha, in[0], in[1], in[2]);
						out += Height;
						in += 3;
					}
					break;

				case JCS_GRAYSCALE:
				{
					auto remap = ImageHelpers::GetRemap(doalpha, true);
					for (int x = Width; x > 0; --x)
					{
						*out = remap[in[0]];
						out += Height;
						in += 1;
					}
					break;
				}
				case JCS_CMYK:
					// What are you doing using a CMYK image? :)
					for (int x = Width; x > 0; --x)
					{
						// To be precise, these calculations should use 255, but
						// 256 is much faster and virtually indistinguishable.
						int r = in[3] - (((256 - in[0])*in[3]) >> 8);
						int g = in[3] - (((256 - in[1])*in[3]) >> 8);
						int b = in[3] - (((256 - in[2])*in[3]) >> 8);
						*out = ImageHelpers::RGBToPalette(doalpha, r, g, b);
						out += Height;
						in += 4;
					}
					break;

				case JCS_YCbCr:
					// Probably useless but since I had the formula available...
					for (int x = Width; x > 0; --x)
					{
						double Y = in[0], Cb = in[1], Cr = in[2];
						int r = clamp((int)(Y + 1.40200 * (Cr - 0x80)), 0, 255);
						int g = clamp((int)(Y - 0.34414 * (Cb - 0x80) - 0.71414 * (Cr - 0x80)), 0, 255);
						int b = clamp((int)(Y + 1.77200 * (Cb - 0x80)), 0, 255);
						*out = ImageHelpers::RGBToPalette(doalpha, r, g, b);
						out += Height;
						in += 4;
					}
					break;

				default:
					// The other colorspaces were considered above and discarded,
					// but GCC will complain without a default for them here.
					break;
				}
				y++;
			}
			jpeg_finish_decompress(&cinfo);
		}
	}
	catch (int)
	{
		Printf(TEXTCOLOR_ORANGE "JPEG error in %s\n", fileSystem.GetFileFullPath(SourceLump).GetChars());
	}
	jpeg_destroy_decompress(&cinfo);
	if (buff != NULL)
	{
		delete[] buff;
	}
	return Pixels;
}


//===========================================================================
//
// FJPEGTexture::CopyPixels
//
// Preserves the full color information (unlike software mode)
//
//===========================================================================

int FJPEGTexture::CopyPixels(FBitmap *bmp, int conversion)
{
	PalEntry pe[256];

	auto lump = fileSystem.OpenFileReader (SourceLump);

	jpeg_decompress_struct cinfo;
	jpeg_error_mgr jerr;

	cinfo.err = jpeg_std_error(&jerr);
	cinfo.err->output_message = JPEG_OutputMessage;
	cinfo.err->error_exit = JPEG_ErrorExit;
	jpeg_create_decompress(&cinfo);

	FLumpSourceMgr sourcemgr(&lump, &cinfo);
	try
	{
		jpeg_read_header(&cinfo, TRUE);

		if (!((cinfo.out_color_space == JCS_RGB && cinfo.num_components == 3) ||
			(cinfo.out_color_space == JCS_CMYK && cinfo.num_components == 4) ||
			(cinfo.out_color_space == JCS_YCbCr && cinfo.num_components == 3) ||
			(cinfo.out_color_space == JCS_GRAYSCALE && cinfo.num_components == 1)))
		{
			Printf(TEXTCOLOR_ORANGE "Unsupported color format in %s\n", fileSystem.GetFileFullPath(SourceLump).GetChars());
		}
		else
		{
			jpeg_start_decompress(&cinfo);

			int yc = 0;
			TArray<uint8_t>	buff(cinfo.output_height * cinfo.output_width * cinfo.output_components, true);

			while (cinfo.output_scanline < cinfo.output_height)
			{
				uint8_t * ptr = buff.Data() + cinfo.output_width * cinfo.output_components * yc;
				jpeg_read_scanlines(&cinfo, &ptr, 1);
				yc++;
			}

			switch (cinfo.out_color_space)
			{
			case JCS_RGB:
				bmp->CopyPixelDataRGB(0, 0, buff.Data(), cinfo.output_width, cinfo.output_height,
					3, cinfo.output_width * cinfo.output_components, 0, CF_RGB);
				break;

			case JCS_GRAYSCALE:
				for (int i = 0; i < 256; i++) pe[i] = PalEntry(255, i, i, i);	// default to a gray map
				bmp->CopyPixelData(0, 0, buff.Data(), cinfo.output_width, cinfo.output_height,
					1, cinfo.output_width, 0, pe);
				break;

			case JCS_CMYK:
				bmp->CopyPixelDataRGB(0, 0, buff.Data(), cinfo.output_width, cinfo.output_height,
					4, cinfo.output_width * cinfo.output_components, 0, CF_CMYK);
				break;

			case JCS_YCbCr:
				bmp->CopyPixelDataRGB(0, 0, buff.Data(), cinfo.output_width, cinfo.output_height,
					4, cinfo.output_width * cinfo.output_components, 0, CF_YCbCr);
				break;

			default:
				assert(0);
				break;
			}
			jpeg_finish_decompress(&cinfo);
		}
	}
	catch (int)
	{
		Printf(TEXTCOLOR_ORANGE "JPEG error in %s\n", fileSystem.GetFileFullPath(SourceLump).GetChars());
	}
	jpeg_destroy_decompress(&cinfo);
	return 0;
}