var Functions = {
  remove_unique_id: function(short_id) {
  	db.collection("unique_ids").update({"_id": "unique_ids"}, {$pull: {unique_ids: short_id}}, function(err, docs) {});
  },

  remove_name_from_db: function(guid, name) {
  	db.collection("user_names").update({"_id": "all_names"}, {$pull: {names: name}}, function(err, updated) {
  		db.collection("user_names").remove({"guid": guid}, function(err, removed) {	});
  	});
  },

  remove_from_array: function(array, element){
  	if(Functions.contains(array, element)){
  		var index = array.indexOf(element);
  		if(index != -1)
  		array.splice(index, 1);
  	}
  },

  get_short_id: function(seed, minlen, socket) {
		var len = minlen;
		var id = Functions.rndName(seed, minlen, socket);

		db.collection("unique_ids").update({"_id": "unique_ids"}, {$addToSet: {unique_ids: id}}, {upsert: true}, function(err, updated) {
			if(updated.nModified == 1) {
				short_id = id;
				socket.join(short_id);
				socket.emit("id", short_id);
			} else {
				Functions.get_short_id(Functions.rndName(String(len)+id, len + 0.1, socket));
			}
		});
	},

  uniqueID: function(seed, minlen){
  	var len = minlen;
  	var id = Functions.rndName(seed, minlen);

  	db.collection("unique_ids").update({"_id": "unique_ids"}, {$addToSet: {unique_ids: id}}, function(err, updated) {
  		if(updated.nModified == 1) {
  			return id;
  		} else {
  			return Functions.uniqueID(Functions.rndName(String(len)+id, len + 0.1));
  		}
  	});
  },

  check_inlist: function(coll, guid, socket, offline)
  {
  	if(!offline && coll != undefined){
  		db.collection("connected_users").update({"_id": coll}, {$addToSet:{users: guid}}, {upsert: true}, function(err, updated) {
  			if(updated.nModified > 0) {
  				db.collection("connected_users").find({"_id": coll}, function(err, new_doc) {
  					db.collection("frontpage_lists").update({"_id": coll}, {$set: {"viewers": new_doc[0].users.length}}, function(){
  						io.to(coll).emit("viewers", new_doc[0].users.length);
  						db.collection("user_names").find({"guid": guid}, function(err, docs) {
  							if(docs.length == 1) {
  								socket.broadcast.to(coll).emit('chat', {from: docs[0].name, msg: " joined"});
  							}
  						});

  						db.collection("connected_users").update({"_id": "total_users"}, {$inc: {total_users: 1}}, function(err, docs){});
  					});
  				});
  			}
  		});

  	} else {
  		db.collection("connected_users").update({"_id": coll}, {$addToSet: {users: guid}}, function(err, docs){});
  		db.collection("connected_users").update({"_id": "total_users"}, {$inc: {total_users: 1}}, function(err, docs) {});
  	}
  },

  rndName: function(seed, len) {
  	var vowels = ['a', 'e', 'i', 'o', 'u'];
  	consts =  ['b', 'c', 'd', 'f', 'g', 'h', 'j', 'k', 'l', 'm', 'n', 'p', 'r', 's', 't', 'v', 'w', 'x', 'y'];
  	len = Math.floor(len);
  	word = '';
  	is_vowel = false;
  	var arr;
  	for (var i = 0; i < len; i++) {
  		if (is_vowel) arr = vowels;
  		else arr = consts;
  		is_vowel = !is_vowel;
  		word += arr[(seed[i%seed.length].charCodeAt()+i) % (arr.length-1)];
  	}
  	return word;
  },

  decrypt_string: function(socket_id, pw){
  	try {
  		var input = pw.split("$");
  		pw = input[0];
  		var testKey = ((new Buffer(socket_id).toString('base64')) + (new Buffer(socket_id).toString('base64'))).substring(0,32);
  		var keyNew = (new Buffer(testKey)).toString('base64');
  		var encrypted = CryptoJS.enc.Base64.parse(pw);
  		var key = CryptoJS.enc.Base64.parse(keyNew);
  		var iv = CryptoJS.enc.Base64.parse(input[1]);
  		var decrypted = CryptoJS.enc.Utf8.stringify(
  			CryptoJS.AES.decrypt({
  				ciphertext: encrypted
  			},
      	key,
       // edit: changed to Pkcs5
      	{
  				mode: CryptoJS.mode.CBC,
  				padding: CryptoJS.pad.Pkcs7,
  				iv: iv,
  			}));
  			return decrypted;
  	} catch(e) {
  		return "";
  	}
  },

  get_time: function()
  {
  	var d = new Date();
  	var time = Math.floor(d.getTime() / 1000);
  	return time;
  },

  contains: function(a, obj) {
  	try{
  		var i = a.length;
  		while (i--) {
  			if (a[i] === obj) {
  				return true;
  			}
  		}
  		return false;
  	}catch(e){
  		return false;
  	}
  },

  hash_pass: function(adminpass) {
  	return crypto.createHash('sha256').update(adminpass).digest('base64');
  }

}

module.exports = Functions;