"""
homeassistant.components.media_player.plex
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Provides an interface to the Plex API.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/media_player.plex/
"""
import os
import json
import logging
from datetime import timedelta
from urllib.parse import urlparse

from homeassistant.loader import get_component
import homeassistant.util as util
from homeassistant.components.media_player import (
    MediaPlayerDevice, SUPPORT_PAUSE, SUPPORT_PREVIOUS_TRACK,
    SUPPORT_NEXT_TRACK, MEDIA_TYPE_TVSHOW, MEDIA_TYPE_VIDEO)
from homeassistant.const import (
    DEVICE_DEFAULT_NAME, STATE_IDLE, STATE_PLAYING,
    STATE_PAUSED, STATE_OFF, STATE_UNKNOWN)

REQUIREMENTS = ['plexapi==1.1.0']
MIN_TIME_BETWEEN_SCANS = timedelta(seconds=10)
MIN_TIME_BETWEEN_FORCED_SCANS = timedelta(seconds=1)

PLEX_CONFIG_FILE = 'plex.conf'

# Map ip to request id for configuring
_CONFIGURING = {}
_LOGGER = logging.getLogger(__name__)

SUPPORT_PLEX = SUPPORT_PAUSE | SUPPORT_PREVIOUS_TRACK | SUPPORT_NEXT_TRACK


def config_from_file(filename, config=None):
    ''' Small configuration file management function'''
    if config:
        # We're writing configuration
        try:
            with open(filename, 'w') as fdesc:
                fdesc.write(json.dumps(config))
        except IOError as error:
            _LOGGER.error('Saving config file failed: %s', error)
            return False
        return True
    else:
        # We're reading config
        if os.path.isfile(filename):
            try:
                with open(filename, 'r') as fdesc:
                    return json.loads(fdesc.read())
            except IOError as error:
                _LOGGER.error('Reading config file failed: %s', error)
                # This won't work yet
                return False
        else:
            return {}


# pylint: disable=abstract-method, unused-argument
def setup_platform(hass, config, add_devices_callback, discovery_info=None):
    """ Sets up the plex platform. """

    config = config_from_file(hass.config.path(PLEX_CONFIG_FILE))
    if len(config):
        # Setup a configured PlexServer
        host, token = config.popitem()
        token = token['token']
    # Via discovery
    elif discovery_info is not None:
        # Parse discovery data
        host = urlparse(discovery_info[1]).netloc
        _LOGGER.info('Discovered PLEX server: %s', host)

        if host in _CONFIGURING:
            return
        token = None
    else:
        return

    setup_plexserver(host, token, hass, add_devices_callback)


# pylint: disable=too-many-branches
def setup_plexserver(host, token, hass, add_devices_callback):
    ''' Setup a plexserver based on host parameter'''
    import plexapi.server
    import plexapi.exceptions

    try:
        plexserver = plexapi.server.PlexServer('http://%s' % host, token)
    except (plexapi.exceptions.BadRequest,
            plexapi.exceptions.Unauthorized,
            plexapi.exceptions.NotFound) as error:
        _LOGGER.info(error)
        # No token or wrong token
        request_configuration(host, hass, add_devices_callback)
        return

    # If we came here and configuring this host, mark as done
    if host in _CONFIGURING:
        request_id = _CONFIGURING.pop(host)
        configurator = get_component('configurator')
        configurator.request_done(request_id)
        _LOGGER.info('Discovery configuration done!')

    # Save config
    if not config_from_file(
            hass.config.path(PLEX_CONFIG_FILE),
            {host: {'token': token}}):
        _LOGGER.error('failed to save config file')

    _LOGGER.info('Connected to: htts://%s', host)

    plex_clients = {}
    plex_sessions = {}

    @util.Throttle(MIN_TIME_BETWEEN_SCANS, MIN_TIME_BETWEEN_FORCED_SCANS)
    def update_devices():
        """ Updates the devices objects. """
        try:
            devices = plexserver.clients()
        except plexapi.exceptions.BadRequest:
            _LOGGER.exception("Error listing plex devices")
            return

        new_plex_clients = []
        for device in devices:
            # For now, let's allow all deviceClass types
            if device.deviceClass in ['badClient']:
                continue

            if device.machineIdentifier not in plex_clients:
                new_client = PlexClient(device, plex_sessions, update_devices,
                                        update_sessions)
                plex_clients[device.machineIdentifier] = new_client
                new_plex_clients.append(new_client)
            else:
                plex_clients[device.machineIdentifier].set_device(device)

        if new_plex_clients:
            add_devices_callback(new_plex_clients)

    @util.Throttle(MIN_TIME_BETWEEN_SCANS, MIN_TIME_BETWEEN_FORCED_SCANS)
    def update_sessions():
        """ Updates the sessions objects. """
        try:
            sessions = plexserver.sessions()
        except plexapi.exceptions.BadRequest:
            _LOGGER.exception("Error listing plex sessions")
            return

        plex_sessions.clear()
        for session in sessions:
            plex_sessions[session.player.machineIdentifier] = session

    update_devices()
    update_sessions()


def request_configuration(host, hass, add_devices_callback):
    """ Request configuration steps from the user. """
    configurator = get_component('configurator')

    # We got an error if this method is called while we are configuring
    if host in _CONFIGURING:
        configurator.notify_errors(
            _CONFIGURING[host], "Failed to register, please try again.")

        return

    def plex_configuration_callback(data):
        """ Actions to do when our configuration callback is called. """
        setup_plexserver(host, data.get('token'), hass, add_devices_callback)

    _CONFIGURING[host] = configurator.request_config(
        hass, "Plex Media Server", plex_configuration_callback,
        description=('Enter the X-Plex-Token'),
        description_image="/static/images/config_plex_mediaserver.png",
        submit_caption="Confirm",
        fields=[{'id': 'token', 'name': 'X-Plex-Token', 'type': ''}]
    )


class PlexClient(MediaPlayerDevice):
    """ Represents a Plex device. """

    # pylint: disable=too-many-public-methods, attribute-defined-outside-init
    def __init__(self, device, plex_sessions, update_devices, update_sessions):
        self.plex_sessions = plex_sessions
        self.update_devices = update_devices
        self.update_sessions = update_sessions
        self.set_device(device)

    def set_device(self, device):
        """ Sets the device property. """
        self.device = device

    @property
    def unique_id(self):
        """ Returns the id of this plex client """
        return "{}.{}".format(
            self.__class__, self.device.machineIdentifier or self.device.name)

    @property
    def name(self):
        """ Returns the name of the device. """
        return self.device.name or DEVICE_DEFAULT_NAME

    @property
    def session(self):
        """ Returns the session, if any. """
        if self.device.machineIdentifier not in self.plex_sessions:
            return None

        return self.plex_sessions[self.device.machineIdentifier]

    @property
    def state(self):
        """ Returns the state of the device. """
        if self.session:
            state = self.session.player.state
            if state == 'playing':
                return STATE_PLAYING
            elif state == 'paused':
                return STATE_PAUSED
        # This is nasty. Need to find a way to determine alive
        elif self.device:
            return STATE_IDLE
        else:
            return STATE_OFF

        return STATE_UNKNOWN