#include  <fstream>
#include  <iostream>
#include  <cstdlib>
#include  <cstring>
  using namespace  std;

#include  "FixedLen.h"

void InsertIndex( char* ISBN, int offset ) {
  fstream  index, temp;
  int      number, length, result;
  char     str[256], buffer[1024];
  bool     found = false, duplicate = false;

  index.open( "index.txt", fstream::out | fstream::in );
  index.read( str, 6 );
  if ( ( number = atoi( str ) ) == 0 ) {
    index.seekp( 12, fstream::beg );
    index << ISBN << '|' << FixedLen( offset, str, 5 ) << endl;
    index.seekp( 0, fstream::beg );
    index << FixedLen( 1, str, 6 );
    index.close( );
    return;
  }

  temp.open( "temp.txt", fstream::out );
  temp << FixedLen( number+1, str, 6 );
  index.read( str, 6 );
  length = atoi( str );
  temp.write( str, 6 );
  for ( int i = 0;  i < number && !found;  i++ ) {
    index.read( str, length );
    if ( ( result = strncmp( ISBN, str, 10 ) ) > 0 )
      temp.write( str, length );
    else {
      if ( result == 0 )  duplicate = true;
      temp << ISBN << '|' << FixedLen( offset, buffer, 5 ) << endl;
      temp.write( str, length );
      do {
        index.read( buffer, 1024 );
        length = index.gcount( );
        temp.write( buffer, length );
      } while ( !index.eof( ) );
    found = true;
   }
  }

  if ( !found )
    temp << ISBN << '|' << FixedLen( offset, buffer, 5 ) << endl;
  if ( duplicate )
    cout << "\n\nDuplicate ISBN: " << ISBN << "\n\n";
  system( "mv temp.txt index.txt" );
  index.close( );
  temp.close ( );
}