/*
* This file is part of rasdaman community.
*
* Rasdaman community 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 3 of the License, or
* (at your option) any later version.
*
* Rasdaman community 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 rasdaman community.  If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 Peter Baumann /
rasdaman GmbH.
*
* For more information please see <http://www.rasdaman.org>
* or contact Peter Baumann via <baumann@rasdaman.com>.
/
/**
 * SOURCE: png.cc
 *
 * MODULE:  conversion
 * Provides functions to convert data to PNG and back.
 *
 * CLASSES: r_Conv_PNG
 *
 * COMMENTS:
 * - option parsing known bugs:
 *	* no overflow check on options string buffer
 *	* missing ")" is silently ignored
 *	* on hex input, non-hex chars are silently discarded (!)
 *	* too large numbers are mapped to unsigned short's max int
 *	* negative numbers are mapped to unsigned short's max int
 * - do not use "," within an option because this is the parse_param separator
 * - FIXME: define some 3xxx error codes instead of general exception
 *
*/

#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <string.h>

#include "png.h"

#include "raslib/rminit.hh"
#include "raslib/rmdebug.hh"
#include "debug.hh"

#include "conversion/png.hh"
#include "conversion/memfs.hh"

#include "raslib/parseparams.hh"


// transparency keyword in option string (cf. PNG standard):
#define TRANSP_KEY "tRNS"


/* memfs interface functions in C namespace */

extern "C" {

static void png_mem_read_data(png_struct *png_ptr, png_byte *data, png_size_t length)
{
  void *handle=NULL;

  handle = (void*)png_get_io_ptr(png_ptr);
  memfs_chunk_read(handle, (tdata_t)data, (tsize_t)length);
}


static void png_mem_write_data(png_struct *png_ptr, png_byte *data, png_size_t length)
{
  void *handle=NULL;

  handle = (void*)png_get_io_ptr(png_ptr);
  memfs_write(handle, (tdata_t)data, (tsize_t)length);
}


static void png_mem_flush_data(png_struct *png_ptr)
{
  void *handle=NULL;

  handle = (void*)png_get_io_ptr(png_ptr);
}


/* Customized error handling */
static void *png_user_error_ptr = NULL;

static void png_user_warning_fn(png_struct *png_ptr, const char *warning_msg)
{
  fprintf(stdout, "r_Conv_PNG warning: %s\n", warning_msg); fflush(stdout);
}

static void png_user_error_fn(png_struct *png_ptr, const char *error_msg)
{
  fprintf(stderr, "r_Conv_PNG error: %s\n", error_msg);
  // return from this routine, exception will be thrown in setjmp code
}

} // end of C namespace




/*
 *  r_Conv_PNG class for converting MDD to PNG and back
 */

const char *r_Conv_PNG::name_InfoKey = "Description";
const char *r_Conv_PNG::name_InfoText = "rasdaman MDD encoded as PNG";
const char *r_Conv_PNG::method_convertTo = "r_Conv_PNG::convertTo()";
const char *r_Conv_PNG::method_convertFrom = "r_Conv_PNG::convertFrom()";

r_Conv_PNG::r_Conv_PNG(const char *src, const r_Minterval &interv, int tp) throw(r_Error)
: r_Convert_Memory(src, interv, tp)
{
}


r_Conv_PNG::r_Conv_PNG(const char *src, const r_Minterval &interv, const r_Type *tp) throw(r_Error)
: r_Convert_Memory(src, interv, tp)
{
}


r_Conv_PNG::~r_Conv_PNG(void)
{
}


r_convDesc &r_Conv_PNG::convertTo( const char *options ) throw(r_Error)
{
  ENTER( "r_Conv_PNG::convertTo( " << (options==NULL?"(null)":options) << " )" );

  png_struct *write_ptr=NULL;
  png_info *info_ptr = NULL;
  int i=0, j=0;
  png_uint_32 width=0, height=0;
  int colourType=0, compType=0;
  int spp=0, bps=0, lineAdd=0, pixelAdd=0;
  png_color_8 sig_bit;
  png_text infotext[1];
  char *trans_string = NULL;		// transparency string buffer
  int itemsScanned = 0;			// # of items scanned in options string
  bool transpFound = false;		// keyword for transparency found in options?

  i = 0;				// error state: 0 is ok, !=0 is error

  // option analysis: create parse object -- PB 2005-jul-12
  if (params == NULL)
    params = new r_Parse_Params();
  params->add(TRANSP_KEY, &trans_string, r_Parse_Params::param_type_string);
  transpFound = params->process(options);

  // check for good options, if any
  if (options != NULL && ! transpFound)
  {
    RMInit::logOut << "Error: illegal PNG option string: " << options << endl;  
    throw r_Error(r_Error::r_Error_General);
  }

  write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, png_user_error_ptr, png_user_error_fn, png_user_warning_fn);

  if (write_ptr == NULL)
    i=1;
  else
  {
    info_ptr = png_create_info_struct(write_ptr);
    if (info_ptr == NULL)
    {
      RMInit::logOut << "Error: unable to allocate PNG header." << endl;  
      i=1;
    }
    else if (setjmp(write_ptr->jmpbuf))
    {
      png_destroy_write_struct(&write_ptr, &info_ptr);
      RMInit::logOut << "Error: unable to save PNG stack" << endl;  
      throw r_Error(r_Error::r_Error_General);
    }
  }

  if (i != 0)
  {
    png_destroy_write_struct(&write_ptr, &info_ptr);
    throw r_Error(r_Error::r_Error_General);
  }

  memfs_newfile(handle);

  png_set_write_fn(write_ptr, (void*)handle, png_mem_write_data, png_mem_flush_data);

  // Compression
  compType = PNG_COMPRESSION_TYPE_BASE;

  // Size
  width  = desc.srcInterv[0].high() - desc.srcInterv[0].low() + 1;
  height = desc.srcInterv[1].high() - desc.srcInterv[1].low() + 1;

  // Depth and sample format and transparency
  // added transparency -- PB 2005-jul-12
  switch (desc.baseType)
  {
    case ctype_bool:
      spp = 1; bps = 1; pixelAdd = height; lineAdd = 1;
      colourType = PNG_COLOR_TYPE_GRAY; sig_bit.gray = 1;
      if (transpFound)
      {
        itemsScanned = sscanf( trans_string, " %hi ", &(info_ptr->trans_values.gray) );
        if (itemsScanned == 1)			// all required items found?
        {
          info_ptr->valid |= PNG_INFO_tRNS;	// activate tRNS chunk
        }
        else
        {
          RMInit::logOut << "Error: illegal syntax in transparency color specification - should be \"%i\", but is: " << trans_string << endl;
          throw r_Error(r_Error::r_Error_General);
        }
      }
      break;

    case ctype_char:
      spp = 1; bps = 8; pixelAdd = height; lineAdd = 1;
      colourType = PNG_COLOR_TYPE_GRAY; sig_bit.gray = 8;
      if (transpFound)
      {
        itemsScanned = sscanf( trans_string, " %hi ", &(info_ptr->trans_values.gray) );
        if (itemsScanned == 1)			// all required items found?
        {
          info_ptr->valid |= PNG_INFO_tRNS;	// activate tRNS chunk
        }
        else
        {
          RMInit::logOut << "Error: illegal syntax in transparency color specification - should be \"%i\", but is: " << trans_string << endl;
          throw r_Error(r_Error::r_Error_General);
        }
      }
      break;

    case ctype_rgb:
      spp = 3; bps = 8; pixelAdd = 3*height; lineAdd = 3;
      colourType = PNG_COLOR_TYPE_RGB;
      sig_bit.red = 8; sig_bit.green = 8; sig_bit.blue = 8;
      if (transpFound)
      {
        itemsScanned = sscanf( trans_string, " ( %hi ; %hi ; %hi ) ", &(info_ptr->trans_values.red), &(info_ptr->trans_values.green), &(info_ptr->trans_values.blue) );
        if (itemsScanned == 3)			// all required items found?
        {
          info_ptr->valid |= PNG_INFO_tRNS;	// activate tRNS chunk
        }
        else
        {
          RMInit::logOut << "Error: illegal syntax in item #" << itemsScanned << " of transparency color specification - should be \"(%i;%i;%i)\", but is: " << trans_string << endl;
          throw r_Error(r_Error::r_Error_General);
        }
      }
      break;

    default:
      RMInit::logOut << "Error: " << method_convertTo << ": Unknown base type." << endl;
      throw r_Error(r_Error::r_Error_General);
  } // switch

  // adjust transparency color value to pixel depth (unconditionally, even if transparency is unused)
  if (bps == 8)
  {
    info_ptr->trans_values.red   &= 0xff;
    info_ptr->trans_values.green &= 0xff;
    info_ptr->trans_values.blue  &= 0xff;
    info_ptr->trans_values.gray  &= 0xff;
  }

  if (trans_string != NULL)
  {
    delete [] trans_string;
    trans_string = NULL;
  }


  png_set_IHDR(write_ptr, info_ptr, width, height, bps, colourType, PNG_INTERLACE_NONE, compType, PNG_FILTER_TYPE_BASE);
  png_set_sBIT(write_ptr, info_ptr, &sig_bit);

  // Info text
  infotext[0].key = new char[strlen(name_InfoKey)+1];
  strcpy(infotext[0].key, name_InfoKey);
  infotext[0].text = new char[strlen(name_InfoText)+1];
  strcpy(infotext[0].text, name_InfoText);
  infotext[0].compression = PNG_TEXT_COMPRESSION_NONE;
  infotext[0].text_length = strlen(infotext[0].text);
  png_set_text(write_ptr, info_ptr, infotext, 1);

  // Write header
  png_write_info(write_ptr, info_ptr);

  png_byte *row=NULL, *rowPtr=NULL;
  const unsigned char *src=NULL, *srcPtr=NULL;

  row = new png_byte[((bps * spp * width + 7) >> 3)];
  src = (const unsigned char*)(desc.src);

  for (j=0; j<height; j++)
  {
    rowPtr = row; srcPtr = src;

    switch (desc.baseType)
    {
      case ctype_bool:
	{
	  int mask=0;
	  png_byte val=0;
	  
	  val = 0; mask = 0x80;	// png docs: leftmost pixel in high-order bits
	  for (i=0; i<width; i++, srcPtr += pixelAdd)
	  {
	    if (*srcPtr != 0) val |= mask;
	    mask >>= 1;
	    if (mask == 0)
	    {
	      *rowPtr++ = val; val = 0; mask = 0x80;
	    }
	  }
	  if (mask != 0x80) *rowPtr++ = val;
	}
	break;
      case ctype_char:
	{
	  for (i=0; i<width; i++, srcPtr += pixelAdd)
	  {
	    *rowPtr++ = *srcPtr;
	  }
	}
	break;
      case ctype_rgb:
	{
	  for (i=0; i<width; i++, srcPtr += pixelAdd)
	  {
	    *rowPtr++ = srcPtr[0];
	    *rowPtr++ = srcPtr[1];
	    *rowPtr++ = srcPtr[2];
	  }
	}
	break;
    }

    png_write_row(write_ptr, row);

    src += lineAdd;
  }
  
  delete [] row; row=NULL;

  png_write_end(write_ptr, info_ptr);

#ifdef RMANDEBUG
  // if (RManDebug >= 4)
  {
    RMInit::dbgOut << "wrote PNG image: width=" << width << ", height=" << height << ", bps=" << bps << ", colour=";
    switch (desc.baseType)
    {
      case ctype_bool:
        RMInit::dbgOut << "bw";
        if (transpFound)
          RMInit::dbgOut << ", transparent=" << info_ptr->trans_values.gray;
        break;
      case ctype_char:
        RMInit::dbgOut << "grey";
        if (transpFound)
          RMInit::dbgOut << ", transparent=" << info_ptr->trans_values.gray;
        break;
      case ctype_rgb:
        RMInit::dbgOut << "rgb";
        if (transpFound)
          RMInit::dbgOut << ", transparent=(" << info_ptr->trans_values.red << info_ptr->trans_values.green << info_ptr->trans_values.blue << ")";
        break;
      default:
        RMInit::dbgOut << "(illegal)";
        break;
    }
    RMInit::dbgOut << endl;
  }
#endif

  // --- Cleanup -------------------------------------------------------
  png_destroy_write_struct(&write_ptr, &info_ptr);
  
  delete [] infotext[0].key; infotext[0].key=NULL;
  delete [] infotext[0].text; infotext[0].text=NULL;

  r_Long pngSize = memfs_size(handle);

  if ((desc.dest = (char*)mystore.storage_alloc(pngSize)) == NULL)
  {
    RMInit::logOut << "Error: " << method_convertTo << ": out of memory." << endl;
    throw r_Error(MEMMORYALLOCATIONERROR);
  }
  memfs_seek(handle, 0, SEEK_SET);
  memfs_read(handle, desc.dest, pngSize);

  desc.destInterv = r_Minterval(1);
  desc.destInterv << r_Sinterval((r_Range)0, (r_Range)pngSize - 1);

  // set result type to char string
  desc.destType = r_Type::get_any_type("char");

  LEAVE( "r_Conv_PNG::convertTo()" );
  return desc;
}


r_convDesc &r_Conv_PNG::convertFrom(const char *options) throw(r_Error)
{
  png_struct *read_ptr=NULL;
  png_info *info_ptr = NULL;
  int i=0, j=0, pass=0, numPasses=0;
  png_uint_32 width=0, height=0, pitch=0;
  int colourType=0, interlaceType=0, compType=0, filterType=0;
  int spp=0, bps=0, lineAdd=0, pixelAdd=0;

  i = 0;
  read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, png_user_error_ptr, png_user_error_fn, png_user_warning_fn);
  if (read_ptr == NULL) i=1;
  else
  {
    info_ptr = png_create_info_struct(read_ptr);
    if (info_ptr == NULL) i=1;
    else if (setjmp(read_ptr->jmpbuf))
    {
      png_destroy_read_struct(&read_ptr, &info_ptr, NULL);
      RMInit::logOut << "r_Conv_PNG::convertFrom(" << options << "): unable to save the stack" << endl;  
      throw r_Error(r_Error::r_Error_General);
    }
  }
  if (i != 0)
  {
    png_destroy_read_struct(&read_ptr, &info_ptr, NULL);
    throw r_Error(r_Error::r_Error_General);
  }

  memfs_chunk_initfs(handle, (char*)desc.src, (r_Long)(desc.srcInterv[0].high() - desc.srcInterv[0].low() + 1));

  desc.dest = NULL;

  png_set_read_fn(read_ptr, (void*)handle, png_mem_read_data);

  png_read_info(read_ptr, info_ptr);

  png_get_IHDR(read_ptr, info_ptr, &width, &height, &bps, &colourType, &interlaceType, &compType, &filterType);

  if (bps > 8)
  {
    RMInit::logOut << method_convertFrom << " warning: 16 bit samples quantized to 8 bit" << endl;
    png_set_strip_16(read_ptr);
  }

  if ((colourType & PNG_COLOR_MASK_ALPHA) != 0)
  {
    RMInit::logOut << method_convertFrom << " warning: image contains alpha channel which will be lost" << endl;
    png_set_strip_alpha(read_ptr);
  }

  if (bps < 8)
  {
    png_set_packing(read_ptr);	// extract depths 1-4 as 1 byte per pixel
  }

  switch (colourType)
  {
    case PNG_COLOR_TYPE_GRAY:
    case PNG_COLOR_TYPE_GRAY_ALPHA:
      pitch = width; lineAdd = 1; pixelAdd = height;
      if (bps == 1) desc.baseType = ctype_bool; else desc.baseType = ctype_char;
      break;
    case PNG_COLOR_TYPE_PALETTE:
      png_set_expand(read_ptr);
    case PNG_COLOR_TYPE_RGB:
    case PNG_COLOR_TYPE_RGB_ALPHA:
      pitch = 3*width; lineAdd = 3; pixelAdd = 3*height;
      desc.baseType = ctype_rgb;
      break;
    default:
      RMInit::logOut << method_convertFrom << ": don't understand image format" << endl;
      throw r_Error(r_Error::r_Error_General);
  }

  numPasses = png_set_interlace_handling(read_ptr);

#ifdef RMANDEBUG
  if (RManDebug >= 4)
  {
    RMInit::dbgOut << "PNG image: width " << width << ", height " << height << ", bps " << bps;
    RMInit::dbgOut << ", colour ";
    switch (desc.baseType)
    {
      case ctype_bool: RMInit::dbgOut << "bw"; break;
      case ctype_char: RMInit::dbgOut << "grey"; break;
      case ctype_rgb: RMInit::dbgOut << "rgb"; break;
    }
    RMInit::dbgOut << ", interlace level " << numPasses << endl;
  }
#endif

  png_byte *row = new png_byte[pitch];

  desc.dest = (char*)mystore.storage_alloc(pitch * height);

  for (pass=0; pass < numPasses; pass++)
  {
    unsigned char *dest, *destPtr;
    
    dest = (unsigned char*)(desc.dest);
    for (j=0; j<height; j++, dest += lineAdd)
    {
      png_byte *rowPtr=NULL;

      destPtr = dest; rowPtr = row;
      switch (desc.baseType)
      {
	case ctype_bool:
	case ctype_char:
	  {
	    // In case of multiple passes set up the buffer according to the last pass
	    if (pass != 0)
	    {
	      for (i=0; i<width; i++, destPtr += pixelAdd)
	      {
		*rowPtr++ = *destPtr;
	      }
	      destPtr = dest; rowPtr = row;
	    }
	    png_read_row(read_ptr, row, NULL);
	    for (i=0; i<width; i++, destPtr += pixelAdd)
	    {
	      *destPtr = *rowPtr++;
	    }
	  }
	  break;
	case ctype_rgb:
	  {
	    if (pass != 0)
	    {
	      for (i=0; i<width; i++, destPtr += pixelAdd)
	      {
		*rowPtr++ = destPtr[0]; *rowPtr++ = destPtr[1]; *rowPtr++ = destPtr[2];
	      }
	      destPtr = dest; rowPtr = row;
	    }
	    png_read_row(read_ptr, row, NULL);
	    for (i=0; i<width; i++, destPtr += pixelAdd)
	    {
	      destPtr[0] = *rowPtr++; destPtr[1] = *rowPtr++; destPtr[2] = *rowPtr++;
	    }
	  }
	  break;
      }
    }
  }

  png_read_end(read_ptr, info_ptr);

  delete [] row; row=NULL;

  png_destroy_read_struct(&read_ptr, &info_ptr, NULL);

  desc.destInterv = r_Minterval(2);
  desc.destInterv << r_Sinterval((r_Range)0, (r_Range)width-1)
		  << r_Sinterval((r_Range)0, (r_Range)height-1);

  desc.destType = get_external_type(desc.baseType);

  return desc;
}



const char *r_Conv_PNG::get_name( void ) const
{
  return format_name_png;
}


r_Data_Format r_Conv_PNG::get_data_format( void ) const
{
  return r_PNG;
}


r_Convertor *r_Conv_PNG::clone( void ) const
{
  return new r_Conv_PNG(desc.src, desc.srcInterv, desc.baseType);
}