"""Play media on a device by sending an URL."""

import logging
import asyncio
import plistlib

from pyatv import exceptions


_LOGGER = logging.getLogger(__name__)

# This is the default port. It is also included in the Bonjour service
# _airplay._tcp, so it might be a good idea to get it from there in the
# future.
AIRPLAY_PORT = 7000

TIMEOUT = 10


# TODO: Use net.HttpSession instead of ClientSession
# pylint: disable=too-few-public-methods
class AirPlayPlayer:
    """This class helps with playing media from an URL."""

    def __init__(self, loop, session, address, port=7000):
        """Initialize a new AirPlay instance."""
        self.loop = loop
        self.address = address
        self.session = session
        self.port = port

    async def play_url(self, url, position=0):
        """Play media from an URL on the device."""
        headers = {'User-Agent': 'MediaControl/1.0',
                   'Content-Type': 'application/x-apple-binary-plist'}
        body = {'Content-Location': url, 'Start-Position': position}

        address = self._url(self.port, 'play')
        _LOGGER.debug('AirPlay %s to %s', url, address)

        resp = None
        try:
            # pylint: disable=no-member
            resp = await self.session.post(
                address, headers=headers,
                data=plistlib.dumps(body, fmt=plistlib.FMT_BINARY),
                timeout=TIMEOUT)
            await self._wait_for_media_to_end()
        finally:
            if resp is not None:
                resp.close()

    def _url(self, port, command):
        return 'http://{0}:{1}/{2}'.format(self.address, port, command)

    # Poll playback-info to find out if something is playing. It might take
    # some time until the media starts playing, give it 5 seconds (attempts)
    async def _wait_for_media_to_end(self):
        address = self._url(self.port, 'playback-info')
        attempts = 5
        video_started = False
        while True:
            info = None
            try:
                info = await self.session.get(address)
                data = await info.content.read()

                if info.status == 403:
                    raise exceptions.NoCredentialsError(
                        'device authentication required')

                _LOGGER.debug('Playback-info (%d): %s', info.status, data)

                parsed = plistlib.loads(data)

                # duration is only available if something is playing
                if 'duration' in parsed:
                    video_started = True
                    attempts = -1
                else:
                    video_started = False
                    if attempts >= 0:
                        attempts -= 1

                if not video_started and attempts < 0:
                    _LOGGER.debug('media playback ended')
                    break

            finally:
                if info is not None:
                    info.close()

            await asyncio.sleep(1, loop=self.loop)
