var recursive = require('recursive-readdir');
var mongoose = require('mongoose');
var path = require('path');
var mm = require('musicmetadata')
var FileQueue = require('filequeue')
var fq = new FileQueue(1024)  // max number of open files. Beyond this limit, EMFILE exception will occur
var Promise = require('promise')

var musicSchema = mongoose.Schema({
  path : {type : String, required: true},
  genre : {type: String, required: true},
  img: { data: Buffer, contentType: String }
});

var fromToSchema = mongoose.Schema({
    from : {type : String, required: true},
    to : {type: String, required: true},
    number : {type : Number, required: true, default: 0}
})

var genreSchema = mongoose.Schema({
    genre : {type : String, required: true},
    number : {type : Number, required: true, default: 0}
})

console.log('Db initializing')
Music = mongoose.model("Music", musicSchema);
FromTo = mongoose.model("FromTo", fromToSchema);
Genre = mongoose.model("Genre", genreSchema);

var authExt = ['.mp3', '.ogg'];

mongoose.connect("mongodb://localhost/musicalBase", function(){
  Music.count(function(err, count)
  {
      console.log('Number of music files ' + count)
      if (count === 0 || ISDEBUG)
      {
        console.log('db reset')
        dbReset();
      }
  });
});

function dbReset()
{
  mongoose.connection.db.dropDatabase();

  recursive('musicFiles', function (err, files) {
    if (err)
    {
      console.log('Error during files reading - ' + err)
      return;
    }

    files = files.filter(function(file)
    {
      var ext = path.extname(file);
      return authExt.contains(ext);
    })

    // use of promises in order to be able to check when all the files are processed
    var promises = [];
    files.forEach(function(file)
    {
      var p = new Promise(function(resolve, reject)
      {
        var filePath = file.split('\\').splice(1).join('/');
        mm(fq.createReadStream(file), function(err, metadata)
        {
          var music = new Music
          music.path = htmlEncode(filePath)
          music.genre = (metadata.genre != null && metadata.genre != '' ? metadata.genre : '(empty)')
          if (metadata.picture.length > 0)
          {
            music.img.data = metadata.picture[0].data
            music.img.contentType = 'image/' + metadata.picture[0].format
          }

          music.save(function(err, musicFile)
          {
            if (err)
            {
              reject('Error during mongoDb music file save ' + filePath + ' - ' + err);
            }
            else
            {
              resolve(filePath)
            }
          });
        });
      });
      promises.push(p);
    });

    Promise.all(promises).then(function(valeur) {
      console.log("Db init completed");
    }, function(raison) {
      console.log(raison)
    });

  });
}