/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "tga.h"

#include "ifilesystem.h"
#include "iarchive.h"
#include "idatastream.h"

typedef unsigned char byte;

#include <stdlib.h>

#include "generic/bitfield.h"
#include "imagelib.h"
#include "bytestreamutils.h"

// represents x,y origin of tga image being decoded
class Flip00 {}; // no flip
class Flip01 {}; // vertical flip only
class Flip10 {}; // horizontal flip only
class Flip11 {}; // both

template<typename PixelDecoder>
void image_decode( PointerInputStream& istream, PixelDecoder& decode, RGBAImage& image, const Flip00& ){
	RGBAPixel* end = image.pixels + ( image.height * image.width );
	for ( RGBAPixel* row = end; row != image.pixels; row -= image.width )
	{
		for ( RGBAPixel* pixel = row - image.width; pixel != row; ++pixel )
		{
			decode( istream, *pixel );
		}
	}
}

template<typename PixelDecoder>
void image_decode( PointerInputStream& istream, PixelDecoder& decode, RGBAImage& image, const Flip01& ){
	RGBAPixel* end = image.pixels + ( image.height * image.width );
	for ( RGBAPixel* row = image.pixels; row != end; row += image.width )
	{
		for ( RGBAPixel* pixel = row; pixel != row + image.width; ++pixel )
		{
			decode( istream, *pixel );
		}
	}
}

template<typename PixelDecoder>
void image_decode( PointerInputStream& istream, PixelDecoder& decode, RGBAImage& image, const Flip10& ){
	RGBAPixel* end = image.pixels + ( image.height * image.width );
	for ( RGBAPixel* row = end; row != image.pixels; row -= image.width )
	{
		for ( RGBAPixel* pixel = row; pixel != row - image.width; )
		{
			decode( istream, *--pixel );
		}
	}
}

template<typename PixelDecoder>
void image_decode( PointerInputStream& istream, PixelDecoder& decode, RGBAImage& image, const Flip11& ){
	RGBAPixel* end = image.pixels + ( image.height * image.width );
	for ( RGBAPixel* row = image.pixels; row != end; row += image.width )
	{
		for ( RGBAPixel* pixel = row + image.width; pixel != row; )
		{
			decode( istream, *--pixel );
		}
	}
}

inline void istream_read_gray( PointerInputStream& istream, RGBAPixel& pixel ){
	istream.read( &pixel.blue, 1 );
	pixel.red = pixel.green = pixel.blue;
	pixel.alpha = 0xff;
}

inline void istream_read_rgb( PointerInputStream& istream, RGBAPixel& pixel ){
	istream.read( &pixel.blue, 1 );
	istream.read( &pixel.green, 1 );
	istream.read( &pixel.red, 1 );
	pixel.alpha = 0xff;
}

inline void istream_read_rgba( PointerInputStream& istream, RGBAPixel& pixel ){
	istream.read( &pixel.blue, 1 );
	istream.read( &pixel.green, 1 );
	istream.read( &pixel.red, 1 );
	istream.read( &pixel.alpha, 1 );
}

class TargaDecodeGrayPixel
{
public:
void operator()( PointerInputStream& istream, RGBAPixel& pixel ){
	istream_read_gray( istream, pixel );
}
};

template<typename Flip>
void targa_decode_grayscale( PointerInputStream& istream, RGBAImage& image, const Flip& flip ){
	TargaDecodeGrayPixel decode;
	image_decode( istream, decode, image, flip );
}

class TargaDecodeRGBPixel
{
public:
void operator()( PointerInputStream& istream, RGBAPixel& pixel ){
	istream_read_rgb( istream, pixel );
}
};

template<typename Flip>
void targa_decode_rgb( PointerInputStream& istream, RGBAImage& image, const Flip& flip ){
	TargaDecodeRGBPixel decode;
	image_decode( istream, decode, image, flip );
}

class TargaDecodeRGBAPixel
{
public:
void operator()( PointerInputStream& istream, RGBAPixel& pixel ){
	istream_read_rgba( istream, pixel );
}
};

template<typename Flip>
void targa_decode_rgba( PointerInputStream& istream, RGBAImage& image, const Flip& flip ){
	TargaDecodeRGBAPixel decode;
	image_decode( istream, decode, image, flip );
}

typedef byte TargaPacket;
typedef byte TargaPacketSize;

inline void targa_packet_read_istream( TargaPacket& packet, PointerInputStream& istream ){
	istream.read( &packet, 1 );
}

inline bool targa_packet_is_rle( const TargaPacket& packet ){
	return ( packet & 0x80 ) != 0;
}

inline TargaPacketSize targa_packet_size( const TargaPacket& packet ){
	return 1 + ( packet & 0x7f );
}


class TargaDecodeRGBPixelRLE
{
TargaPacketSize m_packetSize;
RGBAPixel m_pixel;
TargaPacket m_packet;
public:
TargaDecodeRGBPixelRLE() : m_packetSize( 0 ){
}
void operator()( PointerInputStream& istream, RGBAPixel& pixel ){
	if ( m_packetSize == 0 ) {
		targa_packet_read_istream( m_packet, istream );
		m_packetSize = targa_packet_size( m_packet );

		if ( targa_packet_is_rle( m_packet ) ) {
			istream_read_rgb( istream, m_pixel );
		}
	}

	if ( targa_packet_is_rle( m_packet ) ) {
		pixel = m_pixel;
	}
	else
	{
		istream_read_rgb( istream, pixel );
	}

	--m_packetSize;
}
};

template<typename Flip>
void targa_decode_rle_rgb( PointerInputStream& istream, RGBAImage& image, const Flip& flip ){
	TargaDecodeRGBPixelRLE decode;
	image_decode( istream, decode, image, flip );
}

class TargaDecodeRGBAPixelRLE
{
TargaPacketSize m_packetSize;
RGBAPixel m_pixel;
TargaPacket m_packet;
public:
TargaDecodeRGBAPixelRLE() : m_packetSize( 0 ){
}
void operator()( PointerInputStream& istream, RGBAPixel& pixel ){
	if ( m_packetSize == 0 ) {
		targa_packet_read_istream( m_packet, istream );
		m_packetSize = targa_packet_size( m_packet );

		if ( targa_packet_is_rle( m_packet ) ) {
			istream_read_rgba( istream, m_pixel );
		}
	}

	if ( targa_packet_is_rle( m_packet ) ) {
		pixel = m_pixel;
	}
	else
	{
		istream_read_rgba( istream, pixel );
	}

	--m_packetSize;
}
};

template<typename Flip>
void targa_decode_rle_rgba( PointerInputStream& istream, RGBAImage& image, const Flip& flip ){
	TargaDecodeRGBAPixelRLE decode;
	image_decode( istream, decode, image, flip );
}

struct TargaHeader
{
	unsigned char id_length, colormap_type, image_type;
	unsigned short colormap_index, colormap_length;
	unsigned char colormap_size;
	unsigned short x_origin, y_origin, width, height;
	unsigned char pixel_size, attributes;
};

inline void targa_header_read_istream( TargaHeader& targa_header, PointerInputStream& istream ){
	targa_header.id_length = istream_read_byte( istream );
	targa_header.colormap_type = istream_read_byte( istream );
	targa_header.image_type = istream_read_byte( istream );

	targa_header.colormap_index = istream_read_int16_le( istream );
	targa_header.colormap_length = istream_read_int16_le( istream );
	targa_header.colormap_size = istream_read_byte( istream );
	targa_header.x_origin = istream_read_int16_le( istream );
	targa_header.y_origin = istream_read_int16_le( istream );
	targa_header.width = istream_read_int16_le( istream );
	targa_header.height = istream_read_int16_le( istream );
	targa_header.pixel_size = istream_read_byte( istream );
	targa_header.attributes = istream_read_byte( istream );

	if ( targa_header.id_length != 0 ) {
		istream.seek( targa_header.id_length ); // skip TARGA image comment
	}
}

template<typename Type>
class ScopeDelete
{
Type* m_value;
ScopeDelete( const ScopeDelete& );
ScopeDelete& operator=( const ScopeDelete& );
public:
ScopeDelete( Type* value ) : m_value( value ){
}
~ScopeDelete(){
	delete m_value;
}
Type* get_pointer() const {
	return m_value;
}
};

template<typename Flip>
Image* Targa_decodeImageData( const TargaHeader& targa_header, PointerInputStream& istream, const Flip& flip ){
	RGBAImage* image = new RGBAImage( targa_header.width, targa_header.height );

	if ( targa_header.image_type == 2 || targa_header.image_type == 3 ) {
		switch ( targa_header.pixel_size )
		{
		case 8:
			targa_decode_grayscale( istream, *image, flip );
			break;
		case 24:
			targa_decode_rgb( istream, *image, flip );
			break;
		case 32:
			targa_decode_rgba( istream, *image, flip );
			break;
		default:
			globalErrorStream() << "LoadTGA: illegal pixel_size '" << targa_header.pixel_size << "'\n";
			image->release();
			return 0;
		}
	}
	else if ( targa_header.image_type == 10 ) {
		switch ( targa_header.pixel_size )
		{
		case 24:
			targa_decode_rle_rgb( istream, *image, flip );
			break;
		case 32:
			targa_decode_rle_rgba( istream, *image, flip );
			break;
		default:
			globalErrorStream() << "LoadTGA: illegal pixel_size '" << targa_header.pixel_size << "'\n";
			image->release();
			return 0;
		}
	}

	return image;
}

const unsigned int TGA_FLIP_HORIZONTAL = 0x10;
const unsigned int TGA_FLIP_VERTICAL = 0x20;

Image* LoadTGABuff( const byte* buffer ){
	PointerInputStream istream( buffer );
	TargaHeader targa_header;

	targa_header_read_istream( targa_header, istream );

	if ( targa_header.image_type != 2 && targa_header.image_type != 10 && targa_header.image_type != 3 ) {
		globalErrorStream() << "LoadTGA: TGA type " << targa_header.image_type << " not supported\n";
		globalErrorStream() << "LoadTGA: Only type 2 (RGB), 3 (gray), and 10 (RGB) TGA images supported\n";
		return 0;
	}

	if ( targa_header.colormap_type != 0 ) {
		globalErrorStream() << "LoadTGA: colormaps not supported\n";
		return 0;
	}

	if ( ( targa_header.pixel_size != 32 && targa_header.pixel_size != 24 )
		 && targa_header.image_type != 3 ) {
		globalErrorStream() << "LoadTGA: Only 32 or 24 bit images supported\n";
		return 0;
	}

	if ( !bitfield_enabled( targa_header.attributes, TGA_FLIP_HORIZONTAL )
		 && !bitfield_enabled( targa_header.attributes, TGA_FLIP_VERTICAL ) ) {
		return Targa_decodeImageData( targa_header, istream, Flip00() );
	}
	if ( !bitfield_enabled( targa_header.attributes, TGA_FLIP_HORIZONTAL )
		 && bitfield_enabled( targa_header.attributes, TGA_FLIP_VERTICAL ) ) {
		return Targa_decodeImageData( targa_header, istream, Flip01() );
	}
	if ( bitfield_enabled( targa_header.attributes, TGA_FLIP_HORIZONTAL )
		 && !bitfield_enabled( targa_header.attributes, TGA_FLIP_VERTICAL ) ) {
		return Targa_decodeImageData( targa_header, istream, Flip10() );
	}
	if ( bitfield_enabled( targa_header.attributes, TGA_FLIP_HORIZONTAL )
		 && bitfield_enabled( targa_header.attributes, TGA_FLIP_VERTICAL ) ) {
		return Targa_decodeImageData( targa_header, istream, Flip11() );
	}

	// unreachable
	return 0;
}

Image* LoadTGA( ArchiveFile& file ){
	ScopedArchiveBuffer buffer( file );
	return LoadTGABuff( buffer.buffer );
}