#include <stdio.h>

#define DSK_MAX_TRACKS 85
#define FDC_MAX_SECTORS	20
#define FDC_NUM_DRIVES 	4

typedef struct DISC_DRIVE_s {
  unsigned int write_protect;		// 0,1
  FILE *fd;
  unsigned int tracks;
  unsigned int track_table[85*2];	// max pocet stop
  int active_track;			// track, nebo -1
} DISC_DRIVE_t;


typedef struct FDContr_s {
  unsigned int motor;
  unsigned int track;
  unsigned int sector;
  unsigned int side;		// 0,1
  unsigned int status_reg;
  unsigned int hd;		// 0,1
  unsigned int int_enabled;	// 0,1
  DISC_DRIVE_t disc_drive[FDC_NUM_DRIVES];
} FDContr_t;

struct FDContr_s fdc;


int open_disk ( DISC_DRIVE_t *d_drive, char *dsk_filename) {
  int i;

  if ( ! ( d_drive->fd = fopen ( dsk_filename, "r" ) )) {
    perror ( "Can't open file." );
    return ( 1 );
  };

  d_drive->active_track=-1;
  
  fseek ( d_drive->fd, 0x30, SEEK_SET);
  
  d_drive->tracks = fgetc ( d_drive->fd );
  
  if ( d_drive->tracks > DSK_MAX_TRACKS ) {
    printf( "Error: DSK_MAX_TRACKS exceed!\n" );
    return ( 1 );
  };
  
//  printf("Track table:\n============\n");
  fseek ( d_drive->fd, 0x34, SEEK_SET);
  for ( i = 0; i < d_drive->tracks * 2; i++ ) {
    d_drive->track_table[i] = fgetc ( d_drive->fd );
    
    // bugfix: u HD disket je spatne uvedena Sharp stopa
    if ( i == 1 ) {
      if ( d_drive->track_table[i] == 0x18 ) {
        d_drive->track_table[i] = 0x11;
      };
    };
//    printf ("%i\n", d_drive->track_table[i] );
  };
//  printf("\n\n");
  return ( 0 );
};


void open_track( DISC_DRIVE_t *d_drive, unsigned int track, unsigned int side) {
  int i;
  long track_offset = 0;
  long sector_offset = 0;
  unsigned int sectors;
  int real_size;
  
  for ( i = 0; i < ((track * 2) + side); i++) {
    track_offset += d_drive->track_table[i] * 256;
//    printf ("o: %i (trk: %i)  = %X\n", i, d_drive->track_table[i], track_offset);
  };
  
  fseek ( d_drive->fd, track_offset + 0x0100 + 0x10, SEEK_SET);
  
  printf ( "Track: %02X, ", fgetc ( d_drive->fd ) );
  printf ( "side: %i, ", fgetc ( d_drive->fd ) );
  
  fseek ( d_drive->fd, track_offset + 0x0100 + 0x14, SEEK_SET);

  printf ( "sec_size: %i, ", fgetc ( d_drive->fd ) * 256 );
  sectors = fgetc ( d_drive->fd );
  printf ( "sectors: %i, ", sectors );

  // GAP#3 length ?
  // filler byte ?
  printf ( "GAP#3: %i, ", fgetc ( d_drive->fd ) );
  printf ( "filler: %i,", fgetc ( d_drive->fd ) );

  printf ( "T-offset: %X\n", track_offset + 0x0100 );

  
  fseek ( d_drive->fd, track_offset + 0x0100 + 0x18, SEEK_SET);
  for ( i = 1; i <= sectors; i++ ) {
    printf( "\ts_track: %i, ", fgetc ( d_drive->fd ) );
    printf( "s_side: %i, ", fgetc ( d_drive->fd ) );
    printf( "s_sector: %x, ", fgetc ( d_drive->fd ) );
    printf( "s_size: %i, ", fgetc ( d_drive->fd ) * 256 );
    printf( "FDCreg1: %i, ", fgetc ( d_drive->fd ) );
    printf( "FDCreg2: %i, ", fgetc ( d_drive->fd ) );
    real_size = fgetc ( d_drive->fd );
    real_size += fgetc ( d_drive->fd ) * 0x100;
    printf( "size: %i, ", real_size );
    printf( "offset: %X\n", track_offset + sector_offset + 0x0100 + 0x0100);
    sector_offset += real_size;
  };

};


int main(void) {
  int i;
  
  // resetovat fdc
  // otevrit disk a nacist info o stopach
  fdc.track = 0;
  fdc.sector = 0;
  fdc.side = 0;
  
  if ( open_disk( &fdc.disc_drive[ fdc.motor&0x03 ], "hryhd1.dsk" ) ) {
    return ( 1 );
  };

  printf ( "Tracks: %i\n",  fdc.disc_drive[ 0 ].tracks );
  
  for ( i = 0; i < fdc.disc_drive[ 0 ].tracks; i++ )  {
    open_track( &fdc.disc_drive[ 0 ], i, 0);
    open_track( &fdc.disc_drive[ 0 ], i, 1);
  };
  
  return ( 0 );
};