import json

from application.notification import NotificationCenter, NotificationData
from autobahn.twisted.websocket import WebSocketServerProtocol
from autobahn.websocket import ConnectionDeny
from autobahn.exception import Disconnected

from .handler import ConnectionHandler
from .janus import JanusBackend
from .logger import log


SYLK_WS_PROTOCOL = 'sylkRTC-2'


class SylkWebSocketServerProtocol(WebSocketServerProtocol):
    janus_backend = JanusBackend()
    connection_handler = None

    notification_center = NotificationCenter()

    def onConnect(self, request):
        if SYLK_WS_PROTOCOL not in request.protocols:
            log.debug('Connection from {} request: {}'.format(self.peer, request))
            log.info('Rejecting connection from {}, client uses unsupported protocol: {}'.format(self.peer, ','.join(request.protocols)))
            raise ConnectionDeny(406, 'No compatible protocol specified')
        if not self.janus_backend.ready:
            log.warning('Rejecting connection from {}, Janus backend is not connected'.format(self.peer))
            raise ConnectionDeny(503, 'Backend is not connected')
        return SYLK_WS_PROTOCOL

    def onOpen(self):
        self.factory.connections.add(self)
        self.connection_handler = ConnectionHandler(self)
        self.connection_handler.start()
        self.connection_handler.log.info('websocket connected from: {address}'.format(address=self.peer))

    def onMessage(self, payload, is_binary):
        if is_binary:
            self.connection_handler.log.error('received invalid binary message')
            return
        self.notification_center.post_notification('WebRTCClientTrace', sender=self, data=NotificationData(direction='INCOMING', message=payload, peer=self.peer))
        try:
            data = json.loads(payload)
        except Exception as e:
            self.connection_handler.log.error('could not parse WebSocket payload: {exception!s}'.format(exception=e))
        else:
            self.connection_handler.handle_message(data)

    def onClose(self, clean, code, reason):
        if self.connection_handler is None:  # Connection was closed very early before onOpen was even called
            return
        self.connection_handler.log.info('websocket disconnected from {address}'.format(address=self.peer))
        self.factory.connections.discard(self)
        self.connection_handler.stop()
        self.connection_handler = None

    def sendMessage(self, payload, *args, **kw):
        self.notification_center.post_notification('WebRTCClientTrace', sender=self, data=NotificationData(direction='OUTGOING', message=payload, peer=self.peer))
        #log.info('Sending %s to web socket %s' % (payload, self.peer));
        try:
            super(SylkWebSocketServerProtocol, self).sendMessage(payload.encode(), *args, **kw)
        except Disconnected as e:
            pass

    def disconnect(self, code=1000, reason=''):
        self.sendClose(code, reason)