var taglib=require('taglib');
// create table songs (id int not null auto_increment, artist varchar(300), title varchar(300) , album varchar(300), added_on DATE, filename varchar(300) not null, transcoded varchar(300), primary key ( id));
// ALTER TABLE songs ADD CONSTRAINT constr_fname UNIQUE (filename);
var connection = require('mysql').createConnection({
  user: 'music',
  password: 'music',
  database: 'music',
  socketPath: '/var/run/mysqld/mysqld.sock'
});

connection.connect();

var validExtensions = [ "mp3","aac","flac","alac","ogg","m4a" ]; //3289 songs in 37sec

function endsWith(str, suffix) { return str.indexOf(suffix, str.length - suffix.length) !== -1; }

function validMusicFile(path){
	for (ext in validExtensions)
		if (endsWith(path, validExtensions[ext]))
			return true;
	return false;
}

function tags(path) {
	var empty = {'artist': '', 'title': '', 'album': ''};
	try {
		var tag = taglib.tagSync(path);
		if(!tag.isEmpty())
			return { 'artist': tag.artist, 'title': tag.title, 'album': tag.album}; 
		else
			return empty;
	} catch (ex) {
		return empty;
	}
}

var fs = require('fs');
var path = require('path');
var walk = function(dir, done) {
  var results = [];
  fs.readdir(dir, function(err, list) {
    if (err) return done(err);
    var pending = list.length;
    if (!pending) return done(null, results);
    list.forEach(function(file) {
      file = path.resolve(dir, file);
      fs.stat(file, function(err, stat) {
        if (stat && stat.isDirectory()) {
          walk(file, function(err, res) {
            results = results.concat(res);
            if (!--pending) done(null, results);
          });
        } else {
		  if (validMusicFile(file))
	          results.push(file);
          if (!--pending) done(null, results);
        }
      });
    });
  });
};


var populate = function(path) { //"/storage/samba/Music"
	var query = 'INSERT INTO songs(filename,artist,title,album,added_on) values ? on duplicate key update artist=artist,title=title,album=album';
	var res = [];
	var now = {};
	walk(path, function(err, results) {
		if (err) throw err;
		for( r in results) {
			var s = [];
			var meta = tags(results[r]); 
			s.push(results[r]);
			s.push(meta.artist);
			s.push(meta.title);
			s.push(meta.album);
			res.push(s);
		}
	
		connection.query(query, [res], function(err, result) {
			if (err) throw err;
			console.log("Finished");
			//connection.end();
		});
	});

}

var pathFromID = function(id, callback){
	var query = 'select filename from songs where id=? limit 1';
	connection.query(query, id, function(err, result) {
		if(result.length==1)
		callback(result[0].filename);	
		//connection.end();
	});

};

var getArtist= function(artist, callback){
	var query = 'select * from songs where artist like ?';
	connection.query(query, "%"+artist+"%", function(err, result) {
		callback(result);	
		//connection.end();
	});

};

var getArtists=function(callback){
	var query = 'select distinct(artist) from songs order by artist';
	connection.query(query, function(err, result) {
		callback(result);	
	});
};
var getAlbums=function(callback){
	var query = 'select artist,album from songs group by album order by artist';
	connection.query(query, function(err, result) {
		callback(result);	
	});
};

module.exports.pathFromID=pathFromID;
module.exports.getArtist=getArtist;
module.exports.getArtists=getArtists;
module.exports.getAlbums=getAlbums;
module.exports.populate=populate;

//populate("/storage/samba/Music");