/*  Ocradlib - Optical Character Recognition library
    Copyright (C) 2009-2019 Antonio Diaz Diaz.

    This library 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.

    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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this library.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <climits>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>

#include "ocradlib.h"
#include "common.h"
#include "rectangle.h"
#include "ucs.h"
#include "track.h"
#include "bitmap.h"
#include "blob.h"
#include "character.h"
#include "page_image.h"
#include "textline.h"
#include "textblock.h"
#include "textpage.h"


struct OCRAD_Descriptor
  {
  Page_image * page_image;
  Textpage * textpage;
  OCRAD_Errno ocr_errno;
  Control control;
  std::string text;

  OCRAD_Descriptor()
    :
    page_image( 0 ),
    textpage( 0 ),
    ocr_errno( OCRAD_ok )
    { control.outfile = 0; }
  };


bool verify_descriptor( OCRAD_Descriptor * const ocrdes,
                        const bool result = false )
  {
  if( !ocrdes ) return false;
  if( !ocrdes->page_image || ( result && !ocrdes->textpage ) )
    { ocrdes->ocr_errno = OCRAD_sequence_error; return false; }
  return true;
  }


const char * OCRAD_version() { return OCRAD_version_string; }


OCRAD_Descriptor * OCRAD_open()
  {
  verbosity = -1;			// keep library silent
  OCRAD_Descriptor * const ocrdes = new( std::nothrow ) OCRAD_Descriptor;
  if( !ocrdes ) return 0;
  return ocrdes;
  }


int OCRAD_close( OCRAD_Descriptor * const ocrdes )
  {
  if( !ocrdes ) return -1;
  if( ocrdes->textpage ) delete ocrdes->textpage;
  if( ocrdes->page_image ) delete ocrdes->page_image;
  delete ocrdes;
  return 0;
  }


OCRAD_Errno OCRAD_get_errno( OCRAD_Descriptor * const ocrdes )
  {
  if( !ocrdes ) return OCRAD_bad_argument;
  return ocrdes->ocr_errno;
  }


int OCRAD_set_image( OCRAD_Descriptor * const ocrdes,
                     const OCRAD_Pixmap * const image, const bool invert )
  {
  if( !ocrdes ) return -1;
  if( !image || image->height < 3 || image->width < 3 ||
      INT_MAX / image->width < image->height ||
      ( image->mode != OCRAD_bitmap && image->mode != OCRAD_greymap &&
        image->mode != OCRAD_colormap ) )
    { ocrdes->ocr_errno = OCRAD_bad_argument; return -1; }

  try
    {
    Page_image * const page_image = new Page_image( *image, invert );
    if( ocrdes->textpage )
      { delete ocrdes->textpage; ocrdes->textpage = 0; }
    if( ocrdes->page_image ) delete ocrdes->page_image;
    ocrdes->page_image = page_image;
    }
  catch( std::bad_alloc & )
    { ocrdes->ocr_errno = OCRAD_mem_error; return -1; }
  return 0;
  }


int OCRAD_set_image_from_file( OCRAD_Descriptor * const ocrdes,
                               const char * const filename, const bool invert )
  {
  if( !ocrdes ) return -1;
  FILE * infile = 0;
  if( filename && filename[0] )
    {
    if( std::strcmp( filename, "-" ) == 0 ) infile = stdin;
    else infile = std::fopen( filename, "rb" );
    }
  if( !infile ) { ocrdes->ocr_errno = OCRAD_bad_argument; return -1; }
  int retval = 0;
  try
    {
    Page_image * const page_image = new Page_image( infile, invert );
    if( ocrdes->textpage )
      { delete ocrdes->textpage; ocrdes->textpage = 0; }
    if( ocrdes->page_image ) delete ocrdes->page_image;
    ocrdes->page_image = page_image;
    }
  catch( std::bad_alloc & )
    { ocrdes->ocr_errno = OCRAD_mem_error; retval = -1; }
  catch( ... )
    { ocrdes->ocr_errno = OCRAD_bad_argument; retval = -1; }
  std::fclose( infile );
  return retval;
  }


int OCRAD_set_utf8_format( OCRAD_Descriptor * const ocrdes, const bool utf8 )
  {
  if( !verify_descriptor( ocrdes ) ) return -1;
  ocrdes->control.utf8 = utf8;
  return 0;
  }


int OCRAD_set_threshold( OCRAD_Descriptor * const ocrdes, const int threshold )
  {
  if( !verify_descriptor( ocrdes ) ) return -1;
  if( threshold < -1 || threshold > 255 )
    { ocrdes->ocr_errno = OCRAD_bad_argument; return -1; }
  ocrdes->page_image->threshold( threshold );
  return 0;
  }


int OCRAD_scale( OCRAD_Descriptor * const ocrdes, const int value )
  {
  if( !verify_descriptor( ocrdes ) ) return -1;
  int retval = 0;
  try { if( !ocrdes->page_image->change_scale( value ) ) retval = -1; }
  catch( ... ) { retval = -1; }
  if( retval < 0 ) ocrdes->ocr_errno = OCRAD_bad_argument;
  return retval;
  }


int OCRAD_recognize( OCRAD_Descriptor * const ocrdes, const bool layout )
  {
  if( !verify_descriptor( ocrdes ) ) return -1;
  Textpage * const textpage =
    new( std::nothrow ) Textpage( *ocrdes->page_image, "",
                                  ocrdes->control, layout );
  if( !textpage )
    { ocrdes->ocr_errno = OCRAD_mem_error; return -1; }
  if( ocrdes->textpage ) delete ocrdes->textpage;
  ocrdes->textpage = textpage;
  return 0;
  }


int OCRAD_result_blocks( OCRAD_Descriptor * const ocrdes )
  {
  if( !verify_descriptor( ocrdes, true ) ) return -1;
  return ocrdes->textpage->textblocks();
  }


int OCRAD_result_lines( OCRAD_Descriptor * const ocrdes, const int blocknum )
  {
  if( !verify_descriptor( ocrdes, true ) ) return -1;
  if( blocknum < 0 || blocknum >= ocrdes->textpage->textblocks() )
    { ocrdes->ocr_errno = OCRAD_bad_argument; return -1; }
  return ocrdes->textpage->textblock( blocknum ).textlines();
  }


int OCRAD_result_chars_total( OCRAD_Descriptor * const ocrdes )
  {
  if( !verify_descriptor( ocrdes, true ) ) return -1;
  int c = 0;
  for( int b = 0; b < ocrdes->textpage->textblocks(); ++b )
    for( int i = 0; i < ocrdes->textpage->textblock( b ).textlines(); ++i )
      c += ocrdes->textpage->textblock( b ).textline( i ).characters();
  return c;
  }


int OCRAD_result_chars_block( OCRAD_Descriptor * const ocrdes,
                              const int blocknum )
  {
  if( !verify_descriptor( ocrdes, true ) ) return -1;
  if( blocknum < 0 || blocknum >= ocrdes->textpage->textblocks() )
    { ocrdes->ocr_errno = OCRAD_bad_argument; return -1; }
  int c = 0;
  for( int i = 0; i < ocrdes->textpage->textblock( blocknum ).textlines(); ++i )
    c += ocrdes->textpage->textblock( blocknum ).textline( i ).characters();
  return c;
  }


int OCRAD_result_chars_line( OCRAD_Descriptor * const ocrdes,
                             const int blocknum, const int linenum )
  {
  if( !verify_descriptor( ocrdes, true ) ) return -1;
  if( blocknum < 0 || blocknum >= ocrdes->textpage->textblocks() ||
      linenum < 0 ||
      linenum >= ocrdes->textpage->textblock( blocknum ).textlines() )
    { ocrdes->ocr_errno = OCRAD_bad_argument; return -1; }
  return
    ocrdes->textpage->textblock( blocknum ).textline( linenum ).characters();
  }


const char * OCRAD_result_line( OCRAD_Descriptor * const ocrdes,
                                const int blocknum, const int linenum )
  {
  if( !verify_descriptor( ocrdes, true ) ) return 0;
  if( blocknum < 0 || blocknum >= ocrdes->textpage->textblocks() ||
      linenum < 0 ||
      linenum >= ocrdes->textpage->textblock( blocknum ).textlines() )
    { ocrdes->ocr_errno = OCRAD_bad_argument; return 0; }
  const Textline & textline =
    ocrdes->textpage->textblock( blocknum ).textline( linenum );
  ocrdes->text.clear();
  if( !ocrdes->control.utf8 )
    for( int i = 0; i < textline.characters(); ++i )
      ocrdes->text += textline.character( i ).byte_result();
  else
    for( int i = 0; i < textline.characters(); ++i )
      ocrdes->text += textline.character( i ).utf8_result();
  ocrdes->text += '\n';
  return ocrdes->text.c_str();
  }


int OCRAD_result_first_character( OCRAD_Descriptor * const ocrdes )
  {
  if( !verify_descriptor( ocrdes, true ) ) return -1;
  int ch = 0;
  if( ocrdes->textpage->textblocks() > 0 &&
      ocrdes->textpage->textblock( 0 ).textlines() > 0 )
    {
    const Character & character =
      ocrdes->textpage->textblock( 0 ).textline( 0 ).character( 0 );
    if( character.guesses() )
      {
      if( !ocrdes->control.utf8 )
        ch = UCS::map_to_byte( character.guess( 0 ).code );
      else
        ch = character.guess( 0 ).code;
      }
    }
  return ch;
  }