#include "ata.h"
#include <string.h>

//internal function to print integers on the LCD
void lcd_int(DWRD d);

// these have no tight latency requirements and can use the system exclusively
void
nextTrack()     //goto next track
{
  if(cur_mp3>=(mp3count-1))
    return;
  clear();
  find_next();
  cur_mp3++;
  disp_file();
}

void
prevTrack()     //goto previous track
{
  if(cur_mp3==0)
    return;
  clear();
  find_prev();
  cur_mp3--;
  disp_file();
//debug code to print out the sector the track is located at
//  lcd_gotoxy(0,0);
//  lcd_int(play_sect);
//  lcd_putsf("      ");
}

// these routines below have tight latency requirements

void
requestNextSector1()    //first part of the sector request
{
  disp_file();
  if(play_length>=track_length)
    nextTrack();
  ATAPI_prep_sector1();
  play_sect++;
}

BOOL
requestNextSector2()    //second part of the sector request
{
  return ATAPI_prep_sector2(play_sect);
}

int
fetchSomeData(char * dest)  //read a portion of the sector data from the CDROM
{
  //since we can't access external RAM we have to read into the xfer_buf...
  xfer_data(xfer_buf, DATA_BLOCK_SIZE>>1);
  //...then transfer to the real destination
  memcpy(dest, xfer_buf, DATA_BLOCK_SIZE);

//debug statements to print out the first bits of the MP3 to check that the right
//stuff has been read from the right place
//  lcd_clear();
//  lcd_int(dest[0]);
//  lcd_putchar('-');
//  lcd_int(dest[1]);
//  lcd_putchar('-');
//  lcd_int(dest[2]);
//  lcd_putchar('-');
//  lcd_int(dest[3]);
//  while(1);
  play_length += DATA_BLOCK_SIZE;
  return DATA_BLOCK_SIZE;
} // returns # of bytes read


BYTE
isntmp3()
{
/*
debug statements to print out info from the file table: 
 
  lcd_clear();
  lcd_putchar(sec_buf[cur_offs+sec_buf[cur_offs+32]+20]);
  lcd_putchar(sec_buf[cur_offs+sec_buf[cur_offs+32]+22]);
  lcd_putchar(sec_buf[cur_offs+sec_buf[cur_offs+32]+24]);
  lcd_putchar(sec_buf[cur_offs+sec_buf[cur_offs+32]+26]);
  lcd_putchar(sec_buf[cur_offs+34]);
  lcd_putchar(sec_buf[cur_offs+36]);
  lcd_putchar(sec_buf[cur_offs+38]);
  lcd_putchar(sec_buf[cur_offs+40]);
  lcd_putchar(sec_buf[cur_offs+42]);
  lcd_putchar(sec_buf[cur_offs+44]);
  lcd_putchar(sec_buf[cur_offs+46]);
  lcd_putchar(sec_buf[cur_offs+48]);
  delay_ms(1000);
*/
  //check that this file entry is a file and has the .MP3 extension
  return ((sec_buf[cur_offs+25]&2) ||
         (sec_buf[cur_offs+sec_buf[cur_offs+32]+28] != '3') ||
         ((sec_buf[cur_offs+sec_buf[cur_offs+32]+26] != 'P') &&
          (sec_buf[cur_offs+sec_buf[cur_offs+32]+26] != 'p')) ||
         ((sec_buf[cur_offs+sec_buf[cur_offs+32]+24] != 'M') &&
          (sec_buf[cur_offs+sec_buf[cur_offs+32]+24] != 'm')) ||
         (sec_buf[cur_offs+sec_buf[cur_offs+32]+22] != '.'));
}  

//print an integer to the LCD
void
lcd_int(DWRD d)
{
  if(d>9)
    lcd_int(d/10);

  lcd_putchar((BYTE)((d%10) + '0'));
}

//print an integer to the serial port
void
sio_int(DWRD d)
{
  if(d>9)
    sio_int(d/10);

  while(!(USR&32));
  UDR = (BYTE)((d%10) + '0');
}

//get a sector from the 
void
get_sec(DWRD s)
{
  //if we aren't in CD_REQUEST state, do the follow to get there
  switch(cd_state)
  {
    case CD_WAIT1:
      while(!requestNextSector2());
    case CD_WAIT2:
      while(!ATAPI_sect_ready());
    case CD_READ:
      while(cd_ctr < BUF_BLOCK_SIZE)
        cd_ctr += fetchSomeData(buf+producer+cd_ctr);
    default:
  }
//  do {
//  CDerror = FALSE;
  ATAPI_prep_sector(s);      //prepare the sector
  ATAPI_wait_for_sect();     //wait for it to come back
  xfer_data(sec_buf, 1024);  //transfer the data
//  }
//  while(CDerror);
}

BYTE
find_next()      //goto the next sector
{
  DWRD old1;
  WORD old2;
  old1 = cur_sect;
  old2 = cur_offs;
  
//  get_sec(cur_sect);

  do
  {
    cur_offs += sec_buf[cur_offs]; //skip file info
    
    /* do we need a new sector? */
    if((cur_offs >= 2048) || (sec_buf[cur_offs] == 0))
    {
      cur_sect++;
      if(cur_sect > (root_dir+root_size-1))
      {
        cur_sect = old1;
        cur_offs = old2;
        get_sec(cur_sect);
        return 0;
      }
      get_sec(cur_sect);
      cur_offs = 0;
    }
  }
  while(isntmp3());
  sec = 0;
  play_sect = *(DWRD*)(sec_buf+cur_offs+2);      //extract first sector of file
  play_length = 0;
  track_length = *(DWRD*)(sec_buf+cur_offs+10);  //extract file length
  scroll = 0;
  scroll_dir = 0;
  if((sec_buf[cur_offs+32]-12)<=48)    //is the name so long that we need to scroll?
    scroll_max = 0;
  else
    scroll_max = sec_buf[cur_offs+32]-12-48;
  return 1;
}

BYTE
find_prev()
{
  DWRD old1;
  WORD old2;
  WORD last_offs;
  WORD prev_offs;
  old1 = cur_sect;
  old2 = cur_offs;

//  get_sec(cur_sect);

  do
  {
    /* do we need a new sector? */
    while(cur_offs == 0)
    {
      if(cur_sect == root_dir)
      {
        cur_sect = old1;
        cur_offs = old2;
        get_sec(cur_sect);
        return 0;
      }
      cur_sect--;
      cur_offs = 0;
      get_sec(cur_sect);
      last_offs = 0;
      
      //find last MP3
      while((cur_offs < 2048) && sec_buf[cur_offs])
      {
        if(!isntmp3())
          last_offs = cur_offs;
        cur_offs += sec_buf[cur_offs];
      }
      
      cur_offs = last_offs;
    }

    prev_offs = cur_offs;
    cur_offs = last_offs = 0;
      
    //search back to the MP3 that was just before the last one
    while(cur_offs != prev_offs)
    {
      if(!isntmp3())
        last_offs = cur_offs;
      cur_offs += sec_buf[cur_offs];
    }
      
    cur_offs = last_offs;
  }
  while(isntmp3());
  sec = 0;
  play_sect = *(DWRD*)(sec_buf+cur_offs+2);       //extract first sector of file
  play_length = 0;
  track_length = *(DWRD*)(sec_buf+cur_offs+10);   //extract track length from file
  scroll = 0;
  scroll_dir = 0;
  if((sec_buf[cur_offs+32]-12)<=48)   //do we need to scroll the track title?
    scroll_max = 0;
  else
    scroll_max = sec_buf[cur_offs+32]-12-48;
  return 1;
}

void
disp_file()  //display file track name and info
{
  WORD i;
  lcd_clear();
  for(i=0; (i<(sec_buf[cur_offs+32]-12)) && (i<48); i += 2)
    lcd_putchar(sec_buf[i+cur_offs+34+scroll]);
  lcd_gotoxy(0,1);
  lcd_putsf("Track ");
  lcd_int(cur_mp3+1);
  lcd_putchar('/');
  lcd_int(mp3count);
  lcd_gotoxy(14,1);
  lcd_putsf("Time ");
  lcd_int(sec/2003);
  lcd_putchar(':');
  lcd_putchar((BYTE)('0' + ((sec/334)%6)));  
  lcd_putchar((BYTE)('0' + ((sec*10/334)%10)));
}

void
process_root()
{
  DWRD old1;
  WORD old2;
  old1 = cur_sect;
  old2 = cur_offs;
  
  get_sec(cur_sect);

  //go through finding all MP3 files
  while(find_next())
    mp3count++;
    
  //start over
  cur_sect = old1;
  cur_offs = old2;
  get_sec(cur_sect);
  find_next();

  //display MP3 files
  lcd_clear();
  lcd_int(mp3count);
  lcd_putsf(" MP3 files found");
  
  if(mp3count==0)
  {
    lcd_putsf("\nSorry, nothing to play");
    while(1);
  }
  
  delay_ms(1000);
  
  disp_file();
/*  

debug routines to go through tracks by button presses

  while(1)
  {
    if((PINF.0==0) && (cur_mp3<(mp3count-1)))
    {
      //next track
      find_next();
      cur_mp3++;
      disp_file();
      delay_ms(100);
      while(PINF.0==0);
      delay_ms(100);      
    }
    if((PINF.1==0) && cur_mp3)
    {
      //prev track
      find_prev();
      cur_mp3--;
      disp_file();
      delay_ms(100);
      while(PINF.1==0);
      delay_ms(100);      
    }
  }  */
}

void
initCD()
{
  DWRD vol_desc=16;
  
  //clear it
  lcd_clear(); 
  //write a constant string from flash
  lcd_putsf("MP3 CD SuperJukeBox V1.0");
  lcd_putsf("    Reading CD-ROM..    ");
  ATA_init();
  //         012345678901234567890123
  
  do
  {
    get_sec(vol_desc);
    if((sec_buf[88] == 0x25) && (sec_buf[89] == 0x2F) && (sec_buf[40] == 0))
    {
      //printf("JOLIET volume descriptor found at sector %ld\n",vol_desc);
      root_dir = *(DWRD*)(sec_buf+158);
      root_size = *(DWRD*)(sec_buf+166);
      root_size >>= 11;
      //printf("root dir at sector %ld is %ld sectors long\n", root_dir, root_size);
      cur_sect = root_dir;
      cur_offs = 0;
      
      //once we find the root, go there and process it
      process_root();
      return;
    }
    vol_desc++;
  }                
  while(sec_buf[0] != 0xFF);

  lcd_clear();
  lcd_putsf("ERROR:\n");
  lcd_putsf("JOLIET volume not found");
  while(1);
}