#include <stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <fcntl.h>

#include <errno.h>

#include <sys/stat.h>

#include "cdi.h"

#define CDI_V2 0x80000004

#define CDI_V3 0x80000005

static char track_start_marker[20] = { 0,0,1,0,0,0,255,255,255,255,

                                       0,0,1,0,0,0,255,255,255,255 };

struct cdi_trailer {

    uint32_t cdi_version;

    uint32_t header_offset;

};

struct cdi_track {

    int file_posn;

    int length; /* bytes */

    int pregap; /* sectors */

    int mode;

    int sector_size;

    int session;

    struct cdi_track *next;

};

struct cdi_handle {

    int fd;

    uint16_t num_sessions;

    struct cdi_track *tracks;

};

struct cdi_track_data {

    char unknown[0x19];

    uint32_t pregap_length;

    uint32_t length;

    char unknown2[6];

    uint32_t mode;

    char unknown3[0x0c];

    uint32_t start_lba;

    uint32_t total_length;

    char unknown4[0x10];

    uint32_t sector_size;

    char unknown5[0x1D];

} __attribute__((packed));

cdi_t cdi_open( char *filename )

{

#define BAIL( x, ... ) { fprintf( stderr, x, __VA_ARGS__ ); if( fd != -1 ) close(fd); return NULL; }

    struct stat st;

    int fd = -1, i,j, tmp;

    int posn = 0, hdr;

    long len;

    struct cdi_trailer trail;

    struct cdi_handle cdi;

    uint16_t tracks;

    uint32_t new_fmt;

    char tmpc;

    char marker[20];

    fd = open( filename, O_RDONLY );

    if( fd == -1 )

        BAIL( "Unable to open file: %s (%s)\n", filename, strerror(errno) );

    fstat( fd, &st );

    if( st.st_size < 8 )

        BAIL( "File is too small to be a valid CDI image: %s\n", filename );

    len = lseek( fd, -8, SEEK_END );

    read( fd, &trail, sizeof(trail) );

    if( trail.header_offset > st.st_size ||

        trail.header_offset == 0 )

        BAIL( "Not a valid CDI image: %s\n", filename );

    if( trail.cdi_version == CDI_V2 ) trail.cdi_version = 2;

    else if( trail.cdi_version == CDI_V3 ) trail.cdi_version = 3;

    else BAIL( "Unknown CDI version code %08x in %s\n", trail.cdi_version,

               filename );

    lseek( fd, trail.header_offset, SEEK_SET );

    read( fd, &cdi.num_sessions, 2 );

    printf( "CDI version: %d\n", trail.cdi_version );

    printf( "Sessions: %d\n\n", cdi.num_sessions );

    for( i=0; i< cdi.num_sessions; i++ ) {        

        read( fd, &tracks, 2 );

        printf( "Session %d - %d tracks:\n", i+1, tracks );

        for( j=0; j<tracks; j++ ) {

            struct cdi_track_data trk;

            read( fd, &new_fmt, 4 );

            if( new_fmt != 0 ) { /* Additional data 3.00.780+ ?? */

                printf( "Note: CDI image has 3.00.780+ flag set\n" );

                lseek( fd, 8, SEEK_CUR );

            }

            read( fd, marker, 20 );

            if( memcmp( marker, track_start_marker, 20) != 0 )

                BAIL( "Track start marker not found, error reading cdi\n",NULL );

            read( fd, &tmp, 4 );

            printf( "Unknown 4 bytes: %08x\n", tmp );

            read( fd, &tmpc, 1 );

            lseek( fd, (int)tmpc, SEEK_CUR ); /* skip over the filename */

            read( fd, &trk, sizeof(trk) );

            switch( trk.sector_size ) {

                case 0: trk.sector_size = 2048; hdr=0; break;

                case 1: trk.sector_size = 2336; hdr=8; break;

                case 2:

                    trk.sector_size = 2352;

                    if( trk.mode == 2 ) hdr=24;

                    else hdr=16;

                    break;

                default: BAIL( "Unknown sector size: %d\n", trk.sector_size );

            }

            posn += hdr;

            len = trk.length*trk.sector_size;

            printf( "  Track %d\n", j+1 );

            printf( "    Pregap: %08x\n", trk.pregap_length );

            printf( "    Length: %08x\n", trk.length );

            printf( "    Mode: %d\n", trk.mode );

            printf( "    Sector size: %d\n", trk.sector_size );

            printf( "    Start LBA: %08x\n", trk.start_lba );

            printf( "    Total length: %08x\n", trk.total_length );

            printf( "   ---\n" );

            printf( "    File position: %08x\n", posn+trk.pregap_length*trk.sector_size );

            printf( "    File length: %d\n", len );

            posn += trk.total_length*trk.sector_size;

            lseek( fd, 12, SEEK_CUR );

            if( new_fmt )

                lseek( fd, 78, SEEK_CUR );

            tmp = lseek( fd, 0, SEEK_CUR );

            printf( "(Header offset: %x)\n", tmp - trail.header_offset );

        }

    }

    return NULL;

#undef BAIL(x, ...)

}

int main(int argc, char *argv[] )

{

    int i;

    for( i=1; i<argc; i++ ) {

        cdi_open(argv[i]);

    }

    return 0;

}