controllers.py

import hashlib
import json
import tempfile
import threading
from enum import Enum
from pathlib import Path
from typing import Any
from typing import List
from typing import Optional
from typing import Tuple

import pychromecast
from pychromecast.config import APP_BACKDROP as BACKDROP_APP_ID
from pychromecast.config import APP_DASHCAST as DASHCAST_APP_ID
from pychromecast.config import APP_MEDIA_RECEIVER as MEDIA_RECEIVER_APP_ID
from pychromecast.config import APP_YOUTUBE as YOUTUBE_APP_ID
from pychromecast.controllers.dashcast import DashCastController as PyChromecastDashCastController
from pychromecast.controllers.youtube import YouTubeController

from . import __version__
from .error import AppSelectionError
from .error import CastError
from .error import ControllerError
from .error import ListenerError
from .error import StateFileError
from .stream_info import StreamInfo
from .util import echo_warning
from .util import is_ipaddress

GOOGLE_MEDIA_NAMESPACE = "urn:x-cast:com.google.cast.media"
DEFAULT_PORT = 8009
VALID_STATE_EVENTS = ["UNKNOWN", "IDLE", "BUFFERING", "PLAYING", "PAUSED"]
CLOUD_APP_ID = "38579375"


class App:
    def __init__(self, app_name, app_id, supported_device_types):
        self.name = app_name
        self.id = app_id
        self.supported_device_types = supported_device_types


class CCInfo:
    def __init__(self, ip, port, manufacturer, model_name, cast_type):
        self.ip = ip
        self.port = port
        self.manufacturer = manufacturer
        self.model_name = model_name
        self.cast_type = cast_type

    @property
    def all_info(self):
        return self.__dict__


DEFAULT_APP = App(app_name="default", app_id=MEDIA_RECEIVER_APP_ID, supported_device_types=["cast", "audio", "group"])
APPS = [
    DEFAULT_APP,
    App(app_name="youtube", app_id=YOUTUBE_APP_ID, supported_device_types=["cast"]),
    App(app_name="dashcast", app_id=DASHCAST_APP_ID, supported_device_types=["cast", "audio"]),
]


def get_chromecasts() -> List[pychromecast.Chromecast]:
    devices = pychromecast.get_chromecasts()
    devices.sort(key=lambda cc: cc.name)
    return devices


def get_chromecast(device_name: Optional[str]) -> Optional[pychromecast.Chromecast]:
    devices = get_chromecasts()
    if not devices:
        return None

    if device_name:
        try:
            return next(cc for cc in devices if cc.name == device_name)
        except StopIteration:
            return None
    else:
        return devices[0]


def get_chromecast_with_ip(device_ip: str, port: int = DEFAULT_PORT) -> Optional[pychromecast.Chromecast]:
    try:
        # tries = 1 is necessary in order to stop pychromecast engaging
        # in a retry behaviour when ip is correct, but port is wrong.
        return pychromecast.Chromecast(device_ip, port=port, tries=1)
    except pychromecast.error.ChromecastConnectionError:
        return None


def get_cast(device: Optional[str] = None) -> Tuple[pychromecast.Chromecast, CCInfo]:
    """
    Attempt to connect with requested device (or any device if none has been specified).

    :param device: Can be an ip-address or a name.
    :type device: str
    :returns: Chromecast object for use in a CastController,
              and CCInfo object for use in setup_cast and StreamInfo
    :rtype: (pychromecast.Chromecast, CCInfo)
    """

    cast = None

    if device and is_ipaddress(device):
        cast = get_chromecast_with_ip(device, DEFAULT_PORT)
        if not cast:
            msg = "No device found at {}".format(device)
            raise CastError(msg)
        cc_info = CCInfo(cast.host, cast.port, None, None, cast.cast_type)
    else:
        cache = Cache()
        maybe_cc_info = cache.get_data(device)

        if maybe_cc_info:
            # Get the Chromecast from the CCInfo IP/port.
            cast = get_chromecast_with_ip(maybe_cc_info.ip, maybe_cc_info.port)
            cc_info = maybe_cc_info

        if not cast:
            cast = get_chromecast(device)
            if not cast:
                msg = 'Specified device "{}" not found'.format(device) if device else "No devices found"
                raise CastError(msg)
            cc_info = CCInfo(cast.host, cast.port, cast.device.manufacturer, cast.model_name, cast.cast_type)
            cache.set_data(cast.name, cc_info)

    cast.wait()
    return (cast, cc_info)


def get_app(id_or_name: str, cast_type: Optional[str] = None, strict: bool = False, show_warning: bool = False) -> App:
    try:
        app = next(a for a in APPS if id_or_name in [a.id, a.name])
    except StopIteration:
        if strict:
            raise AppSelectionError("App not found (strict is set)")
        else:
            return DEFAULT_APP

    if app.name == "default":
        return app

    if not cast_type:
        raise AppSelectionError("Cast type is needed for app selection")
    elif cast_type not in app.supported_device_types:
        msg = "The {} app is not available for this device".format(app.name.capitalize())
        if strict:
            raise AppSelectionError("{} (strict is set)".format(msg))
        elif show_warning:
            echo_warning(msg)
        return DEFAULT_APP
    else:
        return app


# I'm not sure it serves any purpose to have get_app and get_controller
# as two separate functions. I'll probably merge them at some point.
def get_controller(cast, app, action=None, prep=None) -> "CastController":
    controller = {"youtube": YoutubeCastController, "dashcast": DashCastController}.get(app.name, DefaultCastController)
    if action and action not in dir(controller):
        raise ControllerError("This action is not supported by the {} controller".format(app.name))
    return controller(cast, app, prep=prep)


def setup_cast(device_name, video_url=None, controller=None, ytdl_options=None, action=None, prep=None):
    cast, cc_info = get_cast(device_name)
    cast_type = cc_info.cast_type
    stream = StreamInfo(video_url, device_info=cc_info, ytdl_options=ytdl_options) if video_url else None

    if controller:
        app = get_app(controller, cast_type, strict=True)
    elif prep == "app":
        if stream:
            if stream.is_local_file:
                app = get_app("default")
            else:
                app = get_app(stream.extractor, cast_type, show_warning=True)
        else:
            app = get_app("default")
    else:
        # cast.app_id can be None, in the case of an inactive audio device.
        if cast.app_id:
            app = get_app(cast.app_id, cast_type)
        else:
            app = get_app("default")

    cast_controller = get_controller(cast, app, action=action, prep=prep)
    return (cast_controller, stream) if stream else cast_controller


class CattStore:
    def __init__(self, store_path):
        self.store_path = store_path

    def _create_store_dir(self):
        try:
            self.store_path.parent.mkdir()
        except FileExistsError:
            pass

    def _read_store(self):
        with self.store_path.open() as store:
            return json.load(store)

    def _write_store(self, data):
        with self.store_path.open("w") as store:
            json.dump(data, store)

    def get_data(self, *args):
        raise NotImplementedError

    def set_data(self, *args) -> None:
        raise NotImplementedError

    def clear(self):
        try:
            self.store_path.unlink()
            self.store_path.parent.rmdir()
        except FileNotFoundError:
            pass


class Cache(CattStore):
    def __init__(self):
        vhash = hashlib.sha1(__version__.encode()).hexdigest()[:8]
        cache_path = Path(tempfile.gettempdir(), "catt_{}_cache".format(vhash), "chromecast_hosts")
        super(Cache, self).__init__(cache_path)
        self._create_store_dir()

        if not self.store_path.is_file():
            devices = get_chromecasts()
            cache_data = {
                d.name: CCInfo(d.host, d.port, d.device.manufacturer, d.model_name, d.cast_type).all_info
                for d in devices
            }
            self._write_store(cache_data)

    def get_data(self, name: Optional[str]) -> Optional[CCInfo]:  # type: ignore
        data = self._read_store()
        # In the case that cache has been initialized with no cc's on the
        # network, we need to ensure auto-discovery.
        if not data:
            return None
        if name:
            fetched = data.get(name)
        else:
            # When the user does not specify a device, we need to make an attempt
            # to consistently return the same IP, thus the alphabetical sorting.
            fetched = data[min(data, key=str)]
        return CCInfo(**fetched) if fetched else None

    def set_data(self, name: str, device_entry: CCInfo) -> None:  # type: ignore
        data = self._read_store()
        data[name] = device_entry.all_info
        self._write_store(data)


class StateMode(Enum):
    READ = 1
    CONF = 2
    ARBI = 3


class CastState(CattStore):
    def __init__(self, state_path: Path, mode: StateMode) -> None:
        super(CastState, self).__init__(state_path)
        if mode == StateMode.CONF:
            self._create_store_dir()
            if not self.store_path.is_file():
                self._write_store({})
        elif mode == StateMode.ARBI:
            self._write_store({})

    def get_data(self, name: str) -> str:  # type: ignore
        try:
            data = self._read_store()
            if set(next(iter(data.values())).keys()) != set(["controller", "data"]):
                raise ValueError
        except (json.decoder.JSONDecodeError, ValueError, StopIteration, AttributeError):
            raise StateFileError
        if name:
            return data.get(name)
        else:
            return next(iter(data.values()))

    def set_data(self, name: str, value: str) -> None:  # type: ignore
        data = self._read_store()
        data[name] = value
        self._write_store(data)


class CastStatusListener:
    def __init__(self, app_id, active_app_id=None):
        self.app_id = app_id
        self.app_ready = threading.Event()
        if (active_app_id and app_id == active_app_id) and app_id != DASHCAST_APP_ID:
            self.app_ready.set()

    def new_cast_status(self, status):
        if self._is_app_ready(status):
            self.app_ready.set()
        else:
            self.app_ready.clear()

    def _is_app_ready(self, status):
        if status.app_id == self.app_id == DASHCAST_APP_ID:
            # DashCast is an exception and therefore needs special treatment.
            # Whenever it's loaded, it's initial status is "Application is starting",
            # as shown here: https://github.com/stestagg/dashcast/blob/master/receiver.html#L163
            # While in that status, it's still not ready to start receiving nor loading URLs
            # Therefore we must wait until its status change to "Application ready"
            # https://github.com/stestagg/dashcast/blob/master/receiver.html#L143
            #
            # If one does not wait for the status to become "Application ready",
            # casting the URL will trigger a race condition as the URL may arrive before the
            # "Application ready" status. In this case, casting will not work.
            # One simple way to confirm changes is to uncomment the line below
            # print(status.status_text)
            return status.status_text == "Application ready"
        return status.app_id == self.app_id


class MediaStatusListener:
    def __init__(self, current_state, states, invert=False, fail=False):
        if any(s not in VALID_STATE_EVENTS for s in states):
            raise ListenerError("Invalid state(s)")
        if invert:
            self._states_waited_for = [s for s in VALID_STATE_EVENTS if s not in states]
        else:
            self._states_waited_for = states

        self._state_event = threading.Event()
        self._current_state = current_state
        if self._current_state in self._states_waited_for:
            if fail:
                raise ListenerError("Condition is already met (fail is set)")
            else:
                self._state_event.set()

    def new_media_status(self, status):
        self._current_state = status.player_state
        if self._current_state in self._states_waited_for:
            self._state_event.set()
        else:
            self._state_event.clear()

    def wait_for_states(self, timeout=None):
        return self._state_event.wait(timeout=timeout)


class SimpleListener:
    def __init__(self):
        self._status_received = threading.Event()

    def new_media_status(self, status):
        self._status_received.set()

    def block_until_status_received(self):
        self._status_received.wait()


class CastController:
    def __init__(self, cast: pychromecast.Chromecast, app: App, prep: Optional[str] = None) -> None:
        self._cast = cast
        self.name = app.name
        self.info_type = None
        self.save_capability = None
        self.playlist_capability = None

        self._cast_listener = CastStatusListener(app.id, self._cast.app_id)
        self._cast.register_status_listener(self._cast_listener)

        try:
            self._cast.register_handler(self._controller)  # type: ignore
        except AttributeError:
            self._controller = self._cast.media_controller

        if prep == "app":
            self.prep_app()
        elif prep == "control":
            self.prep_control()
        elif prep == "info":
            self.prep_info()

    def prep_app(self):
        """Make sure desired chromecast app is running."""

        if not self._cast_listener.app_ready.is_set():
            self._cast.start_app(self._cast_listener.app_id)
            self._cast_listener.app_ready.wait()

    def prep_control(self):
        """Make sure chromecast is not inactive or idle."""

        self._check_inactive()
        self._update_status()
        if self._is_idle:
            raise CastError("Nothing is currently playing")

    def prep_info(self):
        """Make sure chromecast is not inactive."""

        self._check_inactive()
        self._update_status()

    def _check_inactive(self):
        if self._cast.app_id == BACKDROP_APP_ID or not self._cast.app_id:
            raise CastError("Chromecast is inactive")

    def _update_status(self):
        # Under rare circumstances, a lot of fields are not populated in the updated status.
        # This causes unexpected results in the is_idle logic of this class (among others).
        # An extra update appears to weed out these incomplete statuses.
        def update():
            listener = SimpleListener()
            self._cast.media_controller.register_status_listener(listener)
            self._cast.media_controller.update_status()
            listener.block_until_status_received()

        if not self._supports_google_media_namespace:
            # This namespace needs to be supported, in order for listeners to work.
            # So far only Dashcast appears to be affected.
            return
        update()
        status = self._cast.media_controller.status
        if status.current_time and not status.content_id:
            update()

    @property
    def cc_name(self):
        return self._cast.device.friendly_name

    @property
    def info(self):
        status = self._cast.media_controller.status.__dict__
        # Values in media_controller.status for the keys "volume_level" and "volume_muted"
        # are always the same, regardless of actual state, so we discard those by
        # overwriting them with the values from system status.
        status.update(self._cast.status._asdict())
        return status

    @property
    def media_info(self):
        status = self._cast.media_controller.status
        return {
            "title": status.title,
            "content_id": status.content_id,
            "current_time": status.current_time if self._is_seekable else None,
            "thumb": status.images[0].url if status.images else None,
        }

    @property
    def cast_info(self):
        status = self._cast.media_controller.status
        cinfo = self.media_info

        if self._is_seekable:
            duration, current = status.duration, status.current_time
            remaining = duration - current
            progress = int((1.0 * current / duration) * 100)
            cinfo.update({"duration": duration, "remaining": remaining, "progress": progress})

        if self._is_audiovideo:
            cinfo.update({"player_state": status.player_state})

        cinfo.update({"volume_level": str(int(round(self._cast.status.volume_level, 2) * 100))})
        return cinfo

    @property
    def is_streaming_local_file(self):
        status = self._cast.media_controller.status
        return status.content_id.endswith("?loaded_from_catt")

    @property
    def _supports_google_media_namespace(self):
        return GOOGLE_MEDIA_NAMESPACE in self._cast.status.namespaces

    @property
    def _is_seekable(self):
        status = self._cast.media_controller.status
        return status.duration and status.stream_type == "BUFFERED"

    @property
    def _is_audiovideo(self):
        status = self._cast.media_controller.status
        content_type = status.content_type.split("/")[0] if status.content_type else None
        # We can't check against valid types, as some custom apps employ
        # a different scheme (like "application/dash+xml").
        return content_type != "image" if content_type else False

    @property
    def _is_idle(self):
        status = self._cast.media_controller.status
        # Dashcast (and maybe others) does not support the google media namespace, and thus
        # "player_state" will be "UNKNOWN" for such apps, regardless of state.
        return status.player_state in ["UNKNOWN", "IDLE"] and self._supports_google_media_namespace

    def volume(self, level: float) -> None:
        self._cast.set_volume(level)

    def volumeup(self, delta: float) -> None:
        self._cast.volume_up(delta)

    def volumedown(self, delta: float) -> None:
        self._cast.volume_down(delta)

    def kill(self, idle_only=False, force=False):
        """
        Kills current Chromecast session.

        :param idle_only: If set, session is only killed if the active Chromecast app
                          is idle. Use to avoid killing an active streaming session
                          when catt fails with certain invalid actions (such as trying
                          to cast an empty playlist).
        :type idle_only: bool
        :param force: If set, a dummy chromecast app is launched before killing the session.
                      This is a workaround for some devices that do not respond to this
                      command under certain circumstances.
        :type force: bool
        """

        if idle_only and not self._is_idle:
            return
        # The Google cloud app which is launched by the workaround is functionally
        # identical to the Default Media Receiver.
        if force:
            listener = CastStatusListener(CLOUD_APP_ID)
            self._cast.register_status_listener(listener)
            self._cast.start_app(CLOUD_APP_ID)
            listener.app_ready.wait()
        self._cast.quit_app()


class MediaControllerMixin:
    _is_seekable = None  # type: Any
    _cast = None  # type: pychromecast.Chromecast

    def play(self):
        self._cast.media_controller.play()

    def pause(self):
        self._cast.media_controller.pause()

    def play_toggle(self):
        state = self._cast.media_controller.status.player_state
        if state == "PAUSED":
            self.play()
        elif state in ["BUFFERING", "PLAYING"]:
            self.pause()
        else:
            raise ValueError("Invalid or undefined state type")

    def seek(self, seconds: int) -> None:
        if self._is_seekable:
            self._cast.media_controller.seek(seconds)
        else:
            raise CastError("Stream is not seekable")

    def rewind(self, seconds: int) -> None:
        pos = self._cast.media_controller.status.current_time
        self.seek(pos - seconds)

    def ffwd(self, seconds: int) -> None:
        pos = self._cast.media_controller.status.current_time
        self.seek(pos + seconds)

    def skip(self):
        if self._is_seekable:
            self._cast.media_controller.skip()
        else:
            raise CastError("Stream is not skippable")


class PlaybackBaseMixin:
    _cast = None  # type: pychromecast.Chromecast

    def play_media_url(self, video_url: str, **kwargs) -> None:
        raise NotImplementedError

    def play_media_id(self, video_id: str) -> None:
        raise NotImplementedError

    def play_playlist(self, playlist_id: str, video_id: str) -> None:
        raise NotImplementedError

    def wait_for(self, states: list, invert: bool = False, fail: bool = False, timeout: Optional[int] = None) -> bool:
        media_listener = MediaStatusListener(
            self._cast.media_controller.status.player_state, states, invert=invert, fail=fail
        )
        self._cast.media_controller.register_status_listener(media_listener)

        try:
            return media_listener.wait_for_states(timeout=timeout)
        except pychromecast.error.UnsupportedNamespace:
            raise CastError("Chromecast app operation was interrupted")

    def restore(self, data):
        raise NotImplementedError


class DefaultCastController(CastController, MediaControllerMixin, PlaybackBaseMixin):
    def __init__(self, cast, app, prep=None):
        super(DefaultCastController, self).__init__(cast, app, prep=prep)
        self.info_type = "url"
        self.save_capability = "complete" if (self._is_seekable and self._cast.app_id == DEFAULT_APP.id) else None

    def play_media_url(self, video_url, **kwargs):
        content_type = kwargs.get("content_type") or "video/mp4"
        self._controller.play_media(
            video_url,
            content_type,
            current_time=kwargs.get("current_time"),
            title=kwargs.get("title"),
            thumb=kwargs.get("thumb"),
            subtitles=kwargs.get("subtitles"),
        )
        self._controller.block_until_active()

    def restore(self, data):
        self.play_media_url(
            data["content_id"], current_time=data["current_time"], title=data["title"], thumb=data["thumb"]
        )


class DashCastController(CastController):
    def __init__(self, cast, app, prep=None):
        self._controller = PyChromecastDashCastController()
        super(DashCastController, self).__init__(cast, app, prep=prep)

    def load_url(self, url, **kwargs):
        self._controller.load_url(url, force=True)

    def prep_app(self):
        """Make sure desired chromecast app is running."""

        # We must force the launch of the DashCast app because it, by design,
        # becomes unresponsive after a website is loaded.
        self._cast.start_app(self._cast_listener.app_id, force_launch=True)
        self._cast_listener.app_ready.wait()


class YoutubeCastController(CastController, MediaControllerMixin, PlaybackBaseMixin):
    def __init__(self, cast, app, prep=None):
        self._controller = YouTubeController()
        super(YoutubeCastController, self).__init__(cast, app, prep=prep)
        self.info_type = "id"
        self.save_capability = "partial"
        self.playlist_capability = "complete"

    def play_media_id(self, video_id):
        self._controller.play_video(video_id)

    def play_playlist(self, playlist_id, video_id):
        self.clear()
        self._controller.play_video(video_id, playlist_id)

    def add(self, video_id):
        # You can't add videos to the queue while the app is buffering.
        self.wait_for(["BUFFERING"], invert=True)
        self._controller.add_to_queue(video_id)

    def add_next(self, video_id):
        self.wait_for(["BUFFERING"], invert=True)
        self._controller.play_next(video_id)

    def remove(self, video_id):
        self.wait_for(["BUFFERING"], invert=True)
        self._controller.remove_video(video_id)

    def clear(self):
        self._controller.clear_playlist()

    def restore(self, data):
        self.play_media_id(data["content_id"])
        self.wait_for(["PLAYING"])
        self.seek(data["current_time"])