#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <unistd.h>

// Global variables
#define true  1
#define false 0

#define MAX_PATH 2048

#define ERR_GENERIC   0L
#define ERR_OPENIMAGE 0x01
#define ERR_SAVETRACK 0x02
#define ERR_READIMAGE 0x03
#define ERR_SAVEIMAGE 0x04
#define ERR_PATH      0x05

void error_exit(long errcode, char *string)
{

  char errmessage[256];

  if (errcode != ERR_GENERIC)
    printf("\n%s: %s\n", string, strerror(errno));  // string is used as Filename

    switch(errcode)
    {
      case ERR_OPENIMAGE:
        strcpy(errmessage, "File not found\n\nYou may have typed a wrong name or path to source CDI image");
        break;
      case ERR_SAVETRACK:
        strcpy(errmessage, "Could not save track");
        break;
      case ERR_READIMAGE:
        strcpy(errmessage, "Error reading image");
        break;
      case ERR_PATH:
        strcpy(errmessage, "Could not find destination path");
        break;
      case ERR_GENERIC:
      default: strcpy(errmessage, string);          // string is used as Error message
    }

    printf(errmessage);
    exit(EXIT_FAILURE);
}

// Main function
void convertlba(char *lptr,unsigned int lba)
{
  int minutes=lba / (75 * 60);
  lptr[0] = minutes;
  lba -= minutes * (75 * 60);
  int seconds=(lba / 75);
  lptr[1] = seconds;
  lba -= seconds * (75);
  lptr[2] = lba;
}
unsigned int convertmsf(int min, int sec, int fra)
{
  unsigned int lba = min * 60;
  lba += sec;
  lba *= 75;
  lba += fra;
  return lba;
}

int main( int argc, char **argv )
{
  char filename[MAX_PATH];
  FILE *fcue,*fsource,*fdest;

 if (argc >= 2)
   {
     strcpy(filename, argv[1]);
     printf("Searching file: '%s'\n",filename);

     fcue = fopen(filename,"r");
     if (fcue == NULL)
     {
       if (errno == ENOENT)  // "No such file or directory"
       {
         strcat(filename, ".cue");
         printf("Not found. Trying '%s' instead...\n",filename);
         fcue = fopen(filename,"r");
       }
     }
     if (fcue == NULL) error_exit(ERR_OPENIMAGE, filename);
     errno = 0;
     printf("Found cue file. Opening...\n");

     char buff[2048];
     const char* result = NULL;
     while (result == NULL)
     {
       if (fgets(buff, 2047, fcue) == NULL)
         error_exit(ERR_OPENIMAGE, filename);
       result = strstr(buff, "FILE");
     }
     result = strstr(result, "\"");
     if (result == NULL)
       error_exit(ERR_OPENIMAGE, filename);
     result++;
     const char* result2 = strstr(result, "\"");
     if (result2 == NULL)
       error_exit(ERR_OPENIMAGE, filename);
     strncpy(filename,result,result2-result);
     filename[result2-result] = '\0';
     printf("Found. Trying '%s'...\n",filename);

     fsource = fopen(filename,"rb");
     if (fsource == NULL)
     {
       if (errno == ENOENT)  // "No such file or directory"
       {
         strcat(filename, ".bin");
         printf("Not found. Trying '%s' instead...\n",filename);
         fsource = fopen(filename,"rb");
       }
     }
     if (fsource == NULL) error_exit(ERR_OPENIMAGE, filename);

     errno = 0;
     printf("Found image file. Copying...\n");

     strcat(filename, ".cdi");
     fdest = fopen(filename,"wb");

     size_t buffsize = 2048;
     while (buffsize == 2048)
     {
       buffsize = fread(buff, 1, 2048, fsource);
       for (int i=0;i<buffsize;i+=2)
       {
         char tmp=buff[i];
         buff[i]=buff[i+1];
         buff[i+1]=tmp;
       }
       fwrite(buff, 1, buffsize, fdest);
     }
     long seekpos = ftell(fsource);
     long endlba = seekpos / (2532); // 588*4
     printf("Found End Lba 0x%x...\n", endlba);
     fclose(fsource);
     printf("Processing cue file...\n");
     result = NULL;
     long nextlba = 0;
     long lba = 0;
     long tracks = 0;
     long track = 0;
     long index = 0;
     seekpos = ftell(fcue);
     while (fgets(buff, 2047, fcue) != NULL)
     {
         result = strstr(buff, "TRACK");
         if (result != NULL)
         {
           track = atoi(result + 6);
           printf("Found track %d...\n", track);
           tracks++;
         }
     }
     long pregap[127];
     long startlba[127];


     fseek(fcue,seekpos,SEEK_SET);
     while (fgets(buff, 2047, fcue) != NULL)
     {
       result = strstr(buff, "TRACK");
       if (result != NULL)
       {
         track = atoi(result + 6);
         printf("Processing track %d...\n", track);
         pregap[track] = -1;
       }
       result = strstr(buff, "INDEX");
       if (result != NULL)
       {
         index = atoi(result += 6);
         printf("Found index %d...\n", index);
         long min = atoi(result += 3);
         long sec = atoi(result += 3);
         long fra = atoi(result += 3);
         printf("Found index start %d %d %d...\n", min, sec, fra);
         lba = convertmsf(min, sec, fra);
         if (index == 0)
           pregap[track] = lba;
         else
           startlba[track] = lba;
       }
     }
     fclose(fcue);

     char val[128];
     int i;
     for (i=1;i<128;i++) val[i]=0;
     val[0] = 1;
     fwrite(val, 1, 2, fdest); // sessions
     val[0] = tracks & 0xFF;
     val[1] = (tracks >> 8) & 0xFF;
     fwrite(val, 1, 2, fdest); // tracks
     for (track=1;track<=tracks;track++)
     {
       if (pregap[track] == -1)
         pregap[track] = startlba[track];
     }
     for (track=1;track<=tracks;track++)
     {
       printf("Writing track %d...\n", track);
       if (track + 1 <= tracks)
         nextlba = pregap[track+1];
       else
         nextlba = endlba;
       val[0]=0;
       val[1]=0;
       val[2]=0;
       val[3]=0;
       fwrite(val, 1, 4, fdest); // pretrack = 0 4-bytes for no extra data
       char TRACK_START_MARK[10] = { 0, 0, 0x01, 0, 0, 0, 0xFF, 0xFF, 0xFF, 0xFF };
       fwrite(TRACK_START_MARK, 1, 10, fdest);
       fwrite(TRACK_START_MARK, 1, 10, fdest);
       val[0]=0x06; // ??
       val[1]=0x02; // ??
       val[2]=0x90; // ??
       val[3]=0x0B; // ??
       fwrite(val, 1, 4, fdest); // pre-filelength??
       val[0]=38;
       fwrite(val, 1, 1, fdest); // filename must be <256 long
       char FILENAME_TXT[39] = "E:\\Directory01234567890123\\filename.cdi";
       fwrite(FILENAME_TXT, 1, 38, fdest); // filename just hard coding; not used
       val[0]=0;
       val[1]=0;
       val[2]=0;
       val[3]=0;
       val[11]=0x02; // ??
       val[22]=0x80; // indicates 8 extra bytes
       val[23]=0x40; // ??
       val[24]=0x7E; // ??
       val[25]=0x05; // ??
       val[29]=0x98; // ??
       val[31]=0x02; // ??
       fwrite(val, 1, 33, fdest); // ??
       for (i=1;i<128;i++) val[i]=0;
       lba = startlba[track] - pregap[track];
       val[0] = lba & 0xFF;
       val[1] = (lba >> 8) & 0xFF;
       val[2] = (lba >> 16) & 0xFF;
       val[3] = (lba >> 24) & 0xFF;
       printf("PreGap 0x%x...\n", lba);
       fwrite(val, 1, 4, fdest); // pregap
       lba = nextlba - startlba[track];
       val[0] = lba & 0xFF;
       val[1] = (lba >> 8) & 0xFF;
       val[2] = (lba >> 16) & 0xFF;
       val[3] = (lba >> 24) & 0xFF;
       printf("Length 0x%x...\n", lba);
       fwrite(val, 1, 4, fdest); // pregap
       for (i=0;i<4;i++) val[i]=0;
       fwrite(val, 1, 6, fdest); // ??
       fwrite(val, 1, 4, fdest); // mode = 0 = Audio
       fwrite(val, 1, 12, fdest); // ??
       lba = pregap[track];
       val[0] = lba & 0xFF;
       val[1] = (lba >> 8) & 0xFF;
       val[2] = (lba >> 16) & 0xFF;
       val[3] = (lba >> 24) & 0xFF;
       printf("Start LBA 0x%x...\n", lba);
       fwrite(val, 1, 4, fdest); // start lba
       lba = nextlba - pregap[track];
       val[0] = lba & 0xFF;
       val[1] = (lba >> 8) & 0xFF;
       val[2] = (lba >> 16) & 0xFF;
       val[3] = (lba >> 24) & 0xFF;
       printf("Total Length 0x%x...\n", lba);
       fwrite(val, 1, 4, fdest); // total length
       for (i=0;i<4;i++) val[i]=0;
       fwrite(val, 1, 16, fdest); // ??
       val[0] = 2;
       fwrite(val, 1, 4, fdest); // sector size = 2 = 2352
       val[0] = 0;
       val[5] = lba & 0xFF;
       val[6] = (lba >> 8) & 0xFF;
       val[7] = (lba >> 16) & 0xFF;
       val[8] = (lba >> 24) & 0xFF;
       for (i=30;i<38;i++) val[i]=0xFF; // indicates 78 more bytes
       fwrite(val, 1, 38, fdest); // ??
       for (i=0;i<127;i++) val[i]=0x0;
       val[0] = 0x01; // ??
       val[4] = 0x80; // ??
       val[8] = 0x02; // ??
       val[12] = 0x10; // ??
       val[16] = 0x44; // ??
       val[17] = 0xAC; // ??
       for (i=62;i<66;i++) val[i]=0xFF;
       fwrite(val, 1, 78, fdest); // ??
     }
     val[0] = 6;
     val[3] = 0x80;
     fwrite(val, 1, 4, fdest); // CDI V 3.5
     lba = 2 + 2 + (tracks * (4 + 10 + 10 + 4 + 1 + 38 + 33 + 4 + 4 + 6 + 4 + 12 + 4 + 4 + 16 + 4 + 38 + 78)) + 4 + 4;
     val[0] = lba & 0xFF;
     val[1] = (lba >> 8) & 0xFF;
     val[2] = (lba >> 16) & 0xFF;
     val[3] = (lba >> 24) & 0xFF;
     fwrite(val, 1, 4, fdest); // Header start offset

     fclose(fdest);

   }

   return 0;
}