media_player: add Denon remote support

.coveragerc

@@ -47,6 +47,7 @@ omit =
     homeassistant/components/light/hue.py
     homeassistant/components/light/limitlessled.py
     homeassistant/components/media_player/cast.py
+    homeassistant/components/media_player/denon.py
     homeassistant/components/media_player/kodi.py
     homeassistant/components/media_player/mpd.py
     homeassistant/components/media_player/squeezebox.py

homeassistant/components/media_player/denon.py

@@ -0,0 +1,192 @@
+"""
+homeassistant.components.media_player.denon
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Provides an interface to Denon Network Receivers.
+Developed for a Denon DRA-N5, see
+http://www.denon.co.uk/chg/product/compactsystems/networkmusicsystems/ceolpiccolo
+
+A few notes:
+    - As long as this module is active and connected, the receiver does
+      not seem to accept additional telnet connections.
+
+    - Be careful with the volume. 50% or even 100% are very loud.
+
+    - To be able to wake up the receiver, activate the "remote" setting
+      in the receiver's settings.
+
+    - Play and pause are supported, toggling is not possible.
+
+    - Seeking cannot be implemented as the UI sends absolute positions.
+      Only seeking via simulated button presses is possible.
+
+Configuration:
+
+To use your Denon you will need to add something like the following to
+your config/configuration.yaml:
+
+media_player:
+  platform: denon
+  name: Music station
+  host: 192.168.0.123
+
+Variables:
+
+host
+*Required
+The ip of the player. Example: 192.168.0.123
+
+name
+*Optional
+The name of the device.
+"""
+import telnetlib
+import logging
+
+from homeassistant.components.media_player import (
+    MediaPlayerDevice, SUPPORT_PAUSE, SUPPORT_VOLUME_SET,
+    SUPPORT_VOLUME_MUTE, SUPPORT_PREVIOUS_TRACK, SUPPORT_NEXT_TRACK,
+    SUPPORT_TURN_ON, SUPPORT_TURN_OFF,
+    DOMAIN)
+from homeassistant.const import (
+    CONF_HOST, STATE_OFF, STATE_IDLE, STATE_UNKNOWN)
+
+_LOGGER = logging.getLogger(__name__)
+
+SUPPORT_DENON = SUPPORT_PAUSE | SUPPORT_VOLUME_SET | SUPPORT_VOLUME_MUTE | \
+    SUPPORT_PREVIOUS_TRACK | SUPPORT_NEXT_TRACK | \
+    SUPPORT_TURN_ON | SUPPORT_TURN_OFF
+
+
+# pylint: disable=unused-argument
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """ Sets up the Denon platform. """
+    if not config.get(CONF_HOST):
+        _LOGGER.error(
+            "Missing required configuration items in %s: %s",
+            DOMAIN,
+            CONF_HOST)
+        return False
+
+    add_devices([
+        DenonDevice(
+            config.get('name', 'Music station'),
+            config.get('host'))
+    ])
+
+    return True
+
+
+class DenonDevice(MediaPlayerDevice):
+    """ Represents a Denon device. """
+
+    # pylint: disable=too-many-public-methods
+
+    def __init__(self, name, host):
+        self._name = name
+        self._host = host
+        self._telnet = telnetlib.Telnet(self._host)
+
+    def query(self, message):
+        """ Send request and await response from server """
+        try:
+            # unspecified command, should be ignored
+            self._telnet.write("?".encode('UTF-8') + b'\r')
+        except (EOFError, BrokenPipeError, ConnectionResetError):
+            self._telnet.open(self._host)
+
+        _LOGGER.error(self._telnet.read_very_eager())  # skip
+
+        _LOGGER.error(message)
+        self._telnet.write(message.encode('ASCII') + b'\r')
+        # timeout 200ms, defined by protocol
+        resp = self._telnet.read_until(b'\r', timeout=0.2)\
+            .decode('UTF-8').strip()
+
+        if message == "PW?":
+            # workaround; PW? sends also SISTATUS
+            _LOGGER.error(self._telnet.read_until(b'\r', timeout=0.2))
+        _LOGGER.error(resp)
+        return resp
+
+    @property
+    def name(self):
+        """ Returns the name of the device. """
+        return self._name
+
+    @property
+    def state(self):
+        """ Returns the state of the device. """
+        pwstate = self.query('PW?')
+        if pwstate == "PWSTANDBY":
+            return STATE_OFF
+        if pwstate == "PWON":
+            return STATE_IDLE
+
+        return STATE_UNKNOWN
+
+    @property
+    def volume_level(self):
+        """ Volume level of the media player (0..1). """
+        return int(self.query('MV?')[len('MV'):]) / 60
+
+    @property
+    def is_volume_muted(self):
+        """ Boolean if volume is currently muted. """
+        return self.query('MU?') == "MUON"
+
+    @property
+    def media_title(self):
+        """ Current media source. """
+        return self.query('SI?')[len('SI'):]
+
+    @property
+    def supported_media_commands(self):
+        """ Flags of media commands that are supported. """
+        return SUPPORT_DENON
+
+    def turn_off(self):
+        """ turn_off media player. """
+        self.query('PWSTANDBY')
+
+    def volume_up(self):
+        """ volume_up media player. """
+        self.query('MVUP')
+
+    def volume_down(self):
+        """ volume_down media player. """
+        self.query('MVDOWN')
+
+    def set_volume_level(self, volume):
+        """ set volume level, range 0..1. """
+        # 60dB max
+        self.query('MV' + str(round(volume * 60)).zfill(2))
+
+    def mute_volume(self, mute):
+        """ mute (true) or unmute (false) media player. """
+        self.query('MU' + ('ON' if mute else 'OFF'))
+
+    def media_play_pause(self):
+        """ media_play_pause media player. """
+        raise NotImplementedError()
+
+    def media_play(self):
+        """ media_play media player. """
+        self.query('NS9A')
+
+    def media_pause(self):
+        """ media_pause media player. """
+        self.query('NS9B')
+
+    def media_next_track(self):
+        """ Send next track command. """
+        self.query('NS9D')
+
+    def media_previous_track(self):
+        self.query('NS9E')
+
+    def media_seek(self, position):
+        raise NotImplementedError()
+
+    def turn_on(self):
+        """ turn the media player on. """
+        self.query('PWON')