Play Folder of Music Randomly

#include <RogueSD.h>
#include <RogueMP3.h>
#include <NewSoftSerial.h>

NewSoftSerial rmp3_serial(6, 7);

RogueMP3 rmp3(rmp3_serial);
RogueSD filecommands(rmp3_serial);

int numberOfSongs;
int lastSong;
char path[96];

const char *directory = "/XMAS";


void setup()
{
  Serial.begin(9600);

  Serial.println("Merry Xmas!");

  rmp3_serial.begin(9600);

  rmp3.sync();
  rmp3.stop();

  filecommands.sync();

  // mix up our random number generator
  randomSeed(analogRead(0));

  // get the number of songs available
  strcpy(path, directory);
  strcat(path, "/");
  strcat(path, "*.mp3");  // we have to do this because the IDE thinks that "/*" needs to be terminated everywhere

  numberOfSongs = filecommands.filecount(path);

  lastSong = -1;
}



void playNextSong()
{
  uint8_t s, i;
  char filename[80];
  char path[96];
  int nextSong = 0;

  if (numberOfSongs > 0)
  {
    // Select our next song randomly
    if (numberOfSongs > 2)
    {
      do
        nextSong = random(numberOfSongs);
      while (nextSong == lastSong);
    }
    else if (numberOfSongs == 2)
    {
      // we only have two songs
      if (lastSong == 0)
        nextSong = 1;
      else
        nextSong = 0;
    }

    // now, get our file name from file list

    filecommands.opendir(directory);

    for (i = 0; i <= nextSong; i++)
    {
      filecommands.readdir(filename, "*.mp3");
    }

    strcpy(path, directory);
    strcat(path, "/");
    strcat(path, filename);

    rmp3.playfile(path);

    Serial.print("Playing: ");
    Serial.println(path);

    lastSong = nextSong;
  }
  else
  {
    Serial.println("No files to play.");
  }
}


void loop()
{
  char c;
  uint8_t i;
  uint8_t lastvolume = 20;
  int16_t newtime;

  playbackinfo playinfo;

  char status = 'S';
  uint8_t playing = 1;
  uint8_t volume = 20;
  uint8_t boostOn = false;

  volume = rmp3.getvolume();  // this only gets the left volume
  
  playNextSong();

  while(1)
  {
    while(!Serial.available())
    {
      // we should do fancy stuff like flash lights on our Xmas tree here!
      // got lots of time!
      delay(200);

      status = rmp3.getplaybackstatus();
      playinfo = rmp3.getplaybackinfo();

      if (status == 'S' && playing)
        playNextSong();
    }
    
    // OOH!! got a character!
    c = Serial.read();

    switch(c)
    {
      case 'p':
        // pause
        if(status == 'D')
        {
          // fade in
          rmp3.playpause();
          rmp3.fade(volume, 400);
        }
        else if(status == 'P')
        {
          // fade out
          rmp3.fade(100, 400);
          rmp3.playpause();
        }
        else
        {
          // start playing
          playNextSong();
          playing = 1;
        }
        break;
      case 's':
        rmp3.stop();
        playing = 0;
        break;
      case 'n':
        playNextSong();
        playing = 1;
        break;

      case 'e':
        if(boostOn)
        {
          rmp3.setboost(0);
          boostOn = false;
        }
        else
        {
          rmp3.setboost(8, 6, 7, 3);
          boostOn = true;
        }
        break;
      
      case 'a':
        // jump back 5 seconds
        newtime = playinfo.position - 5;
        if (newtime < 0) newtime = 0;
        rmp3.jump(newtime);
        break;

      case 'd':
        // jump forward 5 seconds
        rmp3.jump(playinfo.position + 5);
        break;
        
      case 'k':
        if(volume < 254) volume++;
        if(status != 'D') rmp3.setvolume(volume);
        break;

      case 'i':
        if(volume > 0) volume--;
        if(status != 'D') rmp3.setvolume(volume);
        break;

    }
  }
}