/**
 * @file llimagej2coj.cpp
 * @brief This is an implementation of JPEG2000 encode/decode using OpenJPEG.
 *
 * $LicenseInfo:firstyear=2006&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"
#include "llimagej2coj.h"

// this is defined so that we get static linking.
#include "openjpeg.h"

#include "lltimer.h"
//#include "llmemory.h"

const char* fallbackEngineInfoLLImageJ2CImpl()
{
	static std::string version_string = std::string("OpenJPEG: ") + opj_version();
	return version_string.c_str();
}

LLImageJ2CImpl* fallbackCreateLLImageJ2CImpl()
{
	return new LLImageJ2COJ();
}

void fallbackDestroyLLImageJ2CImpl(LLImageJ2CImpl* impl)
{
	delete impl;
	impl = NULL;
}

// Return string from message, eliminating final \n if present
static std::string chomp(const char* msg)
{
	// stomp trailing \n
	std::string message = msg;
	if (!message.empty())
	{
		size_t last = message.size() - 1;
		if (message[last] == '\n')
		{
			message.resize( last );
		}
	}
	return message;
}

/**
sample error callback expecting a LLFILE* client object
*/
void error_callback(const char* msg, void*)
{
	lldebugs << "LLImageJ2COJ: " << chomp(msg) << llendl;
}
/**
sample warning callback expecting a LLFILE* client object
*/
void warning_callback(const char* msg, void*)
{
	lldebugs << "LLImageJ2COJ: " << chomp(msg) << llendl;
}
/**
sample debug callback expecting no client object
*/
void info_callback(const char* msg, void*)
{
	lldebugs << "LLImageJ2COJ: " << chomp(msg) << llendl;
}

// Divide a by 2 to the power of b and round upwards
int ceildivpow2(int a, int b)
{
	return (a + (1 << b) - 1) >> b;
}


LLImageJ2COJ::LLImageJ2COJ()
	: LLImageJ2CImpl()
{
}


LLImageJ2COJ::~LLImageJ2COJ()
{
}


BOOL LLImageJ2COJ::decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, S32 first_channel, S32 max_channel_count)
{
	//
	// FIXME: Get the comment field out of the texture
	//

	LLTimer decode_timer;

	opj_dparameters_t parameters;	/* decompression parameters */
	opj_event_mgr_t event_mgr;		/* event manager */
	opj_image_t *image = NULL;

	opj_dinfo_t* dinfo = NULL;	/* handle to a decompressor */
	opj_cio_t *cio = NULL;


	/* configure the event callbacks (not required) */
	memset(&event_mgr, 0, sizeof(opj_event_mgr_t));
	event_mgr.error_handler = error_callback;
	event_mgr.warning_handler = warning_callback;
	event_mgr.info_handler = info_callback;

	/* set decoding parameters to default values */
	opj_set_default_decoder_parameters(&parameters);

	parameters.cp_reduce = base.getRawDiscardLevel();

	if(parameters.cp_reduce == 0 && *(U16*)(base.getData() + base.getDataSize() - 2) != 0xD9FF)
	{
		bool failed = true;
		for(S32 i = base.getDataSize()-1; i > 42; --i)
		{
			if(base.getData()[i] != 0x00)
			{
				failed = *(U16*)(base.getData()+i-1) != 0xD9FF;
				break;
			}
		}
		if(failed)
		{
			opj_image_destroy(image);
			base.decodeFailed();
			return TRUE;
		}
	}


	/* decode the code-stream */
	/* ---------------------- */

	/* JPEG-2000 codestream */

	/* get a decoder handle */
	dinfo = opj_create_decompress(CODEC_J2K);

	/* catch events using our callbacks and give a local context */
	opj_set_event_mgr((opj_common_ptr)dinfo, &event_mgr, stderr);			

	/* setup the decoder decoding parameters using user parameters */
	opj_setup_decoder(dinfo, &parameters);

	/* open a byte stream */
#if 0
	std::vector<U8> data(base.getData(), base.getData()+base.getDataSize());
	S32 size = data.size();
	if (data[size-1] == 0xFF) {
		data.push_back((U8)0xD9);
	} else if (data[size-2] != 0xFF || data[size-1] != 0xD9) {
		data.push_back((U8)0xFF);
		data.push_back((U8)0xD9);
	}
	cio = opj_cio_open((opj_common_ptr)dinfo, &data[0], data.size());
#else
	cio = opj_cio_open((opj_common_ptr)dinfo, base.getData(), base.getDataSize());
#endif

	/* decode the stream and fill the image structure */
	image = opj_decode(dinfo, cio);

	/* close the byte stream */
	opj_cio_close(cio);

	/* free remaining structures */
	if(dinfo)
	{
		opj_destroy_decompress(dinfo);
	}

	// The image decode failed if the return was NULL or the component
	// count was zero.  The latter is just a sanity check before we
	// dereference the array.
	if(!image || !image->numcomps)
	{
		LL_WARNS("Texture") << "ERROR -> decodeImpl: failed to decode image!" << LL_ENDL;
		if (image)
		{
			opj_image_destroy(image);
		}
#if 0
		std::stringstream filename;
		filename << "err" << (int)base.getRawDiscardLevel() << "_" << rand() << ".jp2";
		FILE* file = fopen(filename.str().c_str(), "wb");
		if (file) {
			fwrite(base.getData(), base.getDataSize(), 1, file);
			fclose(file);
		}
#endif
		base.decodeFailed();
		return TRUE; // done
	}

	// sometimes we get bad data out of the cache - check to see if the decode succeeded
	for (S32 i = 0; i < image->numcomps; i++)
	{
		if (image->comps[i].factor != base.getRawDiscardLevel())
		{
			LL_WARNS("Texture") <<  "Expected discard level not reached!" << llendl;			
			// if we didn't get the discard level we're expecting, fail
			opj_image_destroy(image);
			base.decodeFailed();
			return TRUE;
		}
	}
	
	if(image->numcomps <= first_channel)
	{
		LL_WARNS("Texture") << "trying to decode more channels than are present in image: numcomps: " << image->numcomps << " first_channel: " << first_channel << llendl;
		if (image)
		{
			opj_image_destroy(image);
		}

		base.decodeFailed();
		return TRUE;
	}

	// Copy image data into our raw image format (instead of the separate channel format

	S32 img_components = image->numcomps;
	S32 channels = img_components - first_channel;
	if( channels > max_channel_count )
		channels = max_channel_count;

	// Component buffers are allocated in an image width by height buffer.
	// The image placed in that buffer is ceil(width/2^factor) by
	// ceil(height/2^factor) and if the factor isn't zero it will be at the
	// top left of the buffer with black filled in the rest of the pixels.
	// It is integer math so the formula is written in ceildivpo2.
	// (Assuming all the components have the same width, height and
	// factor.)
	S32 comp_width = image->comps[0].w;
	S32 f=image->comps[0].factor;
	S32 width = ceildivpow2(image->x1 - image->x0, f);
	S32 height = ceildivpow2(image->y1 - image->y0, f);
	raw_image.resize(width, height, channels);
	U8 *rawp = raw_image.getData();

	// first_channel is what channel to start copying from
	// dest is what channel to copy to.  first_channel comes from the
	// argument, dest always starts writing at channel zero.
	for (S32 comp = first_channel, dest=0; comp < first_channel + channels;
		comp++, dest++)
	{
		if (image->comps[comp].data)
		{
			S32 offset = dest;
			for (S32 y = (height - 1); y >= 0; y--)
			{
				for (S32 x = 0; x < width; x++)
				{
					rawp[offset] = image->comps[comp].data[y*comp_width + x];
					offset += channels;
				}
			}
		}
		else // Some rare OpenJPEG versions have this bug.
		{
			LL_WARNS("Texture") << "ERROR -> decodeImpl: failed to decode image! (NULL comp data - OpenJPEG bug)" << llendl;
			opj_image_destroy(image);
			
			base.decodeFailed();
			return TRUE; // done
		}
	}

	/* free image data structure */
	opj_image_destroy(image);

	return TRUE; // done
}


BOOL LLImageJ2COJ::encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, const char* comment_text, F32 encode_time, BOOL reversible)
{
	const S32 MAX_COMPS = 5;
	opj_cparameters_t parameters;	/* compression parameters */
	opj_event_mgr_t event_mgr;		/* event manager */


	/* 
	configure the event callbacks (not required)
	setting of each callback is optional 
	*/
	memset(&event_mgr, 0, sizeof(opj_event_mgr_t));
	event_mgr.error_handler = error_callback;
	event_mgr.warning_handler = warning_callback;
	event_mgr.info_handler = info_callback;

	/* set encoding parameters to default values */
	opj_set_default_encoder_parameters(&parameters);
	parameters.cod_format = 0;
	parameters.cp_disto_alloc = 1;

	if (reversible)
	{
		parameters.tcp_numlayers = 1;
		parameters.tcp_rates[0] = 0.0f;
	}
	else
	{
		parameters.tcp_numlayers = 5;
                parameters.tcp_rates[0] = 1920.0f;
                parameters.tcp_rates[1] = 480.0f;
                parameters.tcp_rates[2] = 120.0f;
                parameters.tcp_rates[3] = 30.0f;
		parameters.tcp_rates[4] = 10.0f;
		parameters.irreversible = 1;
		if (raw_image.getComponents() >= 3)
		{
			parameters.tcp_mct = 1;
		}
	}

	if (!comment_text)
	{
		parameters.cp_comment = (char *) "";
	}
	else
	{
		// Awful hacky cast, too lazy to copy right now.
		parameters.cp_comment = (char *) comment_text;
	}

	//
	// Fill in the source image from our raw image
	//
	OPJ_COLOR_SPACE color_space = CLRSPC_SRGB;
	opj_image_cmptparm_t cmptparm[MAX_COMPS];
	opj_image_t * image = NULL;
	S32 numcomps = llmin((S32)raw_image.getComponents(), MAX_COMPS);
	S32 width = raw_image.getWidth();
	S32 height = raw_image.getHeight();

	memset(&cmptparm[0], 0, MAX_COMPS * sizeof(opj_image_cmptparm_t));
	for(S32 c = 0; c < numcomps; c++) {
		cmptparm[c].prec = 8;
		cmptparm[c].bpp = 8;
		cmptparm[c].sgnd = 0;
		cmptparm[c].dx = parameters.subsampling_dx;
		cmptparm[c].dy = parameters.subsampling_dy;
		cmptparm[c].w = width;
		cmptparm[c].h = height;
	}

	/* create the image */
	image = opj_image_create(numcomps, &cmptparm[0], color_space);

	image->x1 = width;
	image->y1 = height;

	S32 i = 0;
	const U8 *src_datap = raw_image.getData();
	for (S32 y = height - 1; y >= 0; y--)
	{
		for (S32 x = 0; x < width; x++)
		{
			const U8 *pixel = src_datap + (y*width + x) * numcomps;
			for (S32 c = 0; c < numcomps; c++)
			{
				image->comps[c].data[i] = *pixel;
				pixel++;
			}
			i++;
		}
	}



	/* encode the destination image */
	/* ---------------------------- */

	int codestream_length;
	opj_cio_t *cio = NULL;

	/* get a J2K compressor handle */
	opj_cinfo_t* cinfo = opj_create_compress(CODEC_J2K);

	/* catch events using our callbacks and give a local context */
	opj_set_event_mgr((opj_common_ptr)cinfo, &event_mgr, stderr);			

	/* setup the encoder parameters using the current image and using user parameters */
	opj_setup_encoder(cinfo, &parameters, image);

	/* open a byte stream for writing */
	/* allocate memory for all tiles */
	cio = opj_cio_open((opj_common_ptr)cinfo, NULL, 0);

	/* encode the image */
	bool bSuccess = opj_encode(cinfo, cio, image, NULL);
	if (!bSuccess)
	{
		opj_cio_close(cio);
		LL_WARNS("Texture") << "Failed to encode image." << llendl;
		return FALSE;
	}
	codestream_length = cio_tell(cio);

	base.copyData(cio->buffer, codestream_length);
	base.updateData(); // set width, height

	/* close and free the byte stream */
	opj_cio_close(cio);

	/* free remaining compression structures */
	opj_destroy_compress(cinfo);


	/* free user parameters structure */
	if(parameters.cp_matrice) free(parameters.cp_matrice);

	/* free image data */
	opj_image_destroy(image);
	return TRUE;
}

inline S32 extractLong4( U8 const *aBuffer, int nOffset )
{
	S32 ret = aBuffer[ nOffset ] << 24;
	ret += aBuffer[ nOffset + 1 ] << 16;
	ret += aBuffer[ nOffset + 2 ] << 8;
	ret += aBuffer[ nOffset + 3 ];
	return ret;
}

inline S32 extractShort2( U8 const *aBuffer, int nOffset )
{
	S32 ret = aBuffer[ nOffset ] << 8;
	ret += aBuffer[ nOffset + 1 ];

	return ret;
}

inline bool isSOC( U8 const *aBuffer )
{
	return aBuffer[ 0 ] == 0xFF && aBuffer[ 1 ] == 0x4F;
}

inline bool isSIZ( U8 const *aBuffer )
{
	return aBuffer[ 0 ] == 0xFF && aBuffer[ 1 ] == 0x51;
}

bool getMetadataFast( LLImageJ2C &aImage, S32 &aW, S32 &aH, S32 &aComps )
{
	const int J2K_HDR_LEN( 42 );
	const int J2K_HDR_X1( 8 );
	const int J2K_HDR_Y1( 12 );
	const int J2K_HDR_X0( 16 );
	const int J2K_HDR_Y0( 20 );
	const int J2K_HDR_NUMCOMPS( 40 );

	if( aImage.getDataSize() < J2K_HDR_LEN )
		return false;

	U8 const* pBuffer = aImage.getData();

	if( !isSOC( pBuffer ) || !isSIZ( pBuffer+2 ) )
		return false;

	S32 x1 = extractLong4( pBuffer, J2K_HDR_X1 );
	S32 y1 = extractLong4( pBuffer, J2K_HDR_Y1 );
	S32 x0 = extractLong4( pBuffer, J2K_HDR_X0 );
	S32 y0 = extractLong4( pBuffer, J2K_HDR_Y0 );
	S32 numComps = extractShort2( pBuffer, J2K_HDR_NUMCOMPS );

	aComps = numComps;
	aW = x1 - x0;
	aH = y1 - y0;

	return true;
}

BOOL LLImageJ2COJ::getMetadata(LLImageJ2C &base)
{
	//
	// FIXME: We get metadata by decoding the ENTIRE image.
	//

	// Update the raw discard level
	base.updateRawDiscardLevel();

	S32 width(0);
	S32 height(0);
	S32 img_components(0);

	if ( getMetadataFast( base, width, height, img_components ) )
	{
		base.setSize(width, height, img_components);
		return TRUE;
	}

	// Do it the old and slow way, decode the image with openjpeg

	opj_dparameters_t parameters;	/* decompression parameters */
	opj_event_mgr_t event_mgr;		/* event manager */
	opj_image_t *image = NULL;

	opj_dinfo_t* dinfo = NULL;	/* handle to a decompressor */
	opj_cio_t *cio = NULL;


	/* configure the event callbacks (not required) */
	memset(&event_mgr, 0, sizeof(opj_event_mgr_t));
	event_mgr.error_handler = error_callback;
	event_mgr.warning_handler = warning_callback;
	event_mgr.info_handler = info_callback;

	/* set decoding parameters to default values */
	opj_set_default_decoder_parameters(&parameters);

	// Only decode what's required to get the size data.
	parameters.cp_limit_decoding=LIMIT_TO_MAIN_HEADER;

	//parameters.cp_reduce = mRawDiscardLevel;

	/* decode the code-stream */
	/* ---------------------- */

	/* JPEG-2000 codestream */

	/* get a decoder handle */
	dinfo = opj_create_decompress(CODEC_J2K);

	/* catch events using our callbacks and give a local context */
	opj_set_event_mgr((opj_common_ptr)dinfo, &event_mgr, stderr);			

	/* setup the decoder decoding parameters using user parameters */
	opj_setup_decoder(dinfo, &parameters);

	/* open a byte stream */
	cio = opj_cio_open((opj_common_ptr)dinfo, base.getData(), base.getDataSize());

	/* decode the stream and fill the image structure */
	image = opj_decode(dinfo, cio);

	/* close the byte stream */
	opj_cio_close(cio);

	/* free remaining structures */
	if(dinfo)
	{
		opj_destroy_decompress(dinfo);
	}

	if(!image)
	{
		llwarns << "ERROR -> getMetadata: failed to decode image!" << llendl;
		return FALSE;
	}

	// Copy image data into our raw image format (instead of the separate channel format

	img_components = image->numcomps;
	width = image->x1 - image->x0;
	height = image->y1 - image->y0;

	base.setSize(width, height, img_components);

	/* free image data structure */
	opj_image_destroy(image);
	return TRUE;
}