Fix volume control for Frontier Silicon media players (#32040)

* Fixed volume control for Frontier Silicon media players.

* Removed unnecessary else which caused pylint test to fail.

* Removed whitespace on empty line.

* Tweaks from on springstan's suggestions and other fixes

* Apply suggestions from code review

Co-Authored-By: springstan <46536646+springstan@users.noreply.github.com>

* Comment to explain why 1 is subtracted from volume_Steps

Also reformatted using black after code review changes.

* Split up the set volume functions into steps rather than all in-line as suggested.

* Renamed _volume_steps to _max_volume.

* Prevent asnyc_update from failing if we can't get the volume steps

Co-authored-by: springstan <46536646+springstan@users.noreply.github.com>

homeassistant/components/frontier_silicon/media_player.py

@@ -112,6 +112,8 @@ class AFSAPIDevice(MediaPlayerDevice):
         self._source = None
         self._source_list = None
         self._media_image_url = None
+        self._max_volume = None
+        self._volume_level = None
 
     # Properties
     @property
@@ -181,6 +183,11 @@ class AFSAPIDevice(MediaPlayerDevice):
         """Image url of current playing media."""
         return self._media_image_url
 
+    @property
+    def volume_level(self):
+        """Volume level of the media player (0..1)."""
+        return self._volume_level
+
     async def async_update(self):
         """Get the latest date and update device state."""
         fs_device = self.fs_device
@@ -191,6 +198,12 @@ class AFSAPIDevice(MediaPlayerDevice):
         if not self._source_list:
             self._source_list = await fs_device.get_mode_list()
 
+        # The API seems to include 'zero' in the number of steps (e.g. if the range is
+        # 0-40 then get_volume_steps returns 41) subtract one to get the max volume.
+        # If call to get_volume fails set to 0 and try again next time.
+        if not self._max_volume:
+            self._max_volume = int(await fs_device.get_volume_steps() or 1) - 1
+
         if await fs_device.get_power():
             status = await fs_device.get_play_status()
             self._state = {
@@ -214,6 +227,11 @@ class AFSAPIDevice(MediaPlayerDevice):
             self._source = await fs_device.get_mode()
             self._mute = await fs_device.get_mute()
             self._media_image_url = await fs_device.get_play_graphic()
+
+            volume = await self.fs_device.get_volume()
+
+            # Prevent division by zero if max_volume not known yet
+            self._volume_level = float(volume or 0) / (self._max_volume or 1)
         else:
             self._title = None
             self._artist = None
@@ -223,6 +241,8 @@ class AFSAPIDevice(MediaPlayerDevice):
             self._mute = None
             self._media_image_url = None
 
+            self._volume_level = None
+
     # Management actions
     # power control
     async def async_turn_on(self):
@@ -274,16 +294,20 @@ class AFSAPIDevice(MediaPlayerDevice):
     async def async_volume_up(self):
         """Send volume up command."""
         volume = await self.fs_device.get_volume()
-        await self.fs_device.set_volume(volume + 1)
+        volume = int(volume or 0) + 1
+        await self.fs_device.set_volume(min(volume, self._max_volume))
 
     async def async_volume_down(self):
         """Send volume down command."""
         volume = await self.fs_device.get_volume()
-        await self.fs_device.set_volume(volume - 1)
+        volume = int(volume or 0) - 1
+        await self.fs_device.set_volume(max(volume, 0))
 
     async def async_set_volume_level(self, volume):
         """Set volume command."""
-        await self.fs_device.set_volume(int(volume * 20))
+        if self._max_volume:  # Can't do anything sensible if not set
+            volume = int(volume * self._max_volume)
+            await self.fs_device.set_volume(volume)
 
     async def async_select_source(self, source):
         """Select input source."""