from PyQt4 import QtCore
from traceback import *
from clSong import Song
from traceback import print_exc
from misc import *
import mpd

class Monty(QtCore.QObject):
	"""The Monty class offers another layer above pympd, with usefull events."""
	_client=None	# MPD client
	_listeners=None	# array of listeners: { event: (listeners)* }

	# cached objects
	_curLib=None
	_curPlaylist=None
	_curSong=None

	# objects used for comparison with previous value
	_curSongID=None
	_curTime=None
	_curState=None
	_curVolume=None

	_timerID=None

	events={
		'onSongChange':'oldSongID, newSongID',
		'onTimeChange':'oldTime, newTime',
		'onStateChange':'oldState, newState',
		'onVolumeChange':'oldVolume, newVolume',
		'onConnect':'',
		'onDisconnect':'',
		'onReady':'',	# when connected, and initialisation is ready
	}

	def __init__(self):
		QtCore.QObject.__init__(self)
		self._client=None
		self._listeners={}
		
		self._curSongID=-1
		self._curTime=-1
		self._curState=-1
		self._curVolume=-1
		self._curLib=[]
		self._curPlaylist=[]

		for event in self.events:
			self._listeners[event]=[]

	def connect(self, host, port):
		"""Connect to MPD@$host:$port. Returns true at success, false otherwise."""
		if self._client:
			return
		self._client = mpd.MPDClient()
		try:
			self._client.connect(host, port)
		except:
			self._client=None
			return False
		
		self._raiseEvent('onConnect', None)
		try:
			self._updateLib()
			self._updatePlaylist()
			self._updateCurrentSong()
			self._timerID=self.startTimer(300)
		except Exception:
			print_exc()
		self._raiseEvent('onStateChange', {'oldState':'stop', 'newState':self.getStatus()['state']})
		self._raiseEvent('onReady', None)
		doEvents()
		return True

	def disconnect(self):
		"""Disconnect from MPD."""
		if self._client:
			self._client.close()
			self._client.disconnect()
			self._client=None
			# don't kill timer, as it'll happen in timerEvent
	
	def isConnected(self):
		"""Returns true if we're connected to MPD, false otherwise."""
		return self._client!=None

	def listPlaylist(self):
		"""Returns the current playlist."""
		if self.isConnected()==False:
			return None
		return self._curPlaylist

	def listLibrary(self):
		"""Returns the library."""
		if self.isConnected()==False:
			return None
		return self._curLib

	def getCurrentSong(self):
		"""Returns the current playing song."""
		if self.isConnected()==False:
			return None
		return self._curSong
		

	def getStatus(self):
		"""Returns the status."""
		try:
			if self.isConnected()==False:
				return None
			ret=self._retrieve(self._client.status)
			if 'time' in ret:
				len=int(ret['time'][ret['time'].find(':')+1:])
				cur=int(ret['time'][:ret['time'].find(':')])
				ret['length']=len
				ret['time']=cur
			return ret
		except Exception, d:
			print_exc()
			return None
	
	_retrMutex=QtCore.QMutex()
	def _retrieve(self, method):
		"""Makes sure only one call is made at a time to MPD."""
		self._retrMutex.lock()
		try:
			ret=method()
		except:
			self._retrMutex.unlock()
			raise

		self._retrMutex.unlock()
		return ret

	def play(self, id):
		"""Play song with ID $id."""
		if id!=None:
			self._client.playid(id)
		else:
			self._client.playid()
	
	def pause(self):
		"""Pause playing."""
		self._client.pause(1)
	def resume(self):
		"""Resume playing."""
		self._client.pause(0)
	def next(self):
		"""Move on to the next song in the playlist."""
		self._client.next()
	def previous(self):
		"""Move back to the previous song in the playlist."""
		self._client.previous()
	def stop(self):
		"""Stop playing."""
		self._client.stop()

	def seek(self, time):
		"""Move the current playing time to $time."""
		self._client.seekid(self._curSongID, time)
	
	def deleteFromPlaylist(self, list):
		"""Remove all songIDs in $list from the playlist."""
		self._client.command_list_ok_begin()
		for id in list:
			self._client.deleteid(id)
		self._client.command_list_end()
		self._updatePlaylist()
	
	def addToPlaylist(self, paths):
		"""Add all files in $paths to the current playlist."""
		self._client.command_list_ok_begin()
		for path in paths:
			self._client.add(path)
		self._client.command_list_end()
		self._updatePlaylist()

	def setVolume(self, volume):
		"""Set volumne to $volume."""
		self._client.setvol(volume)

	
	def addListener(self, event, callback):
		"""Add $callback to the listeners for $event."""
		if not(event in self.events):
			raise Exception("Unknown event "+event)

		self._listeners[event].append(callback)


	def _updateLib(self):
		"""Update the library."""
		self._curLib=self._arrayToSongArray(self._retrieve(self._client.listallinfo))
		id=0
		for song in self._curLib:
			song._data['id']=id
			id+=1
	def _updatePlaylist(self):
		"""Update the playlist."""
		self._curPlaylist=self._arrayToSongArray(self._retrieve(self._client.playlistinfo))
	def _arrayToSongArray(self, array):
		"""Convert an array to an array of Songs."""
		return map(lambda entry: Song(entry)
			, filter(lambda entry: not('directory' in entry), array)
			)
	def _updateCurrentSong(self):
		"""Update the current song."""
		self._curSong=self._retrieve(self._client.currentsong)
		if self._curSong==None:
			return
		self._curSong=Song(self._curSong)

	def _raiseEvent(self, event, params):
		"""Call all listeners for $event with parameters $params."""
		if not(event in self.events):
			raise Exception("Unknown raised event "+event)

		for listener in self._listeners[event]:
			listener(params)
	
	def timerEvent(self, event):
		"Check for changes since last check."
		try:
			self._updateCurrentSong()
			status=self.getStatus()
		except:
			self._curSong=None

		song=self._curSong
		if song==None or status==None:
			self._client=None
			self._raiseEvent('onDisconnect', None)
			self.killTimer(self._timerID)
			return
		
		" check if song has changed"
		if song.getID()>=0:
			curID=song.getID()
			if curID!=self._curSongID:
				self._raiseEvent('onSongChange', {'oldSongID':self._curSongID, 'newSongID':curID})
				self._curSongID=curID

		" check if the time has changed"
		if 'time' in status:
			curTime=status['time']
			if curTime!=self._curTime:
				self._raiseEvent('onTimeChange', {'oldTime':self._curTime, 'newTime':curTime})
				self._curTime=curTime

		" check if the playing state has changed"
		if 'state' in status:
			curState=status['state']
			if curState!=self._curState:
				self._raiseEvent('onStateChange', {'oldState':self._curState, 'newState':curState})
				self._curState=curState

		" check if the volume has changed"
		if 'state' in status:
			curVolume=int(status['volume'])
			if curVolume!=self._curVolume:
				self._raiseEvent('onVolumeChange', {'oldVolume':self._curVolume, 'newVolume':curVolume})
				self._curVolume=curVolume

monty=Monty()