Siri control of web audio stream to HomePod

I have a simple set-up that I am using to pipe a web radio stream to HomePod, which allows me to listen to a particular radio station live, that is not available via TuneIn. It is based on Home Assistant Core, installed on a Raspberry Pi 4 running Raspbian Buster, with forked-daapd also installed as a service to provide the stream. I can currently start and stop it via the Home Assistant dashboard but would like to command it to start and stop with the HomePod’s Siri functionality.

To make it start, I would need to ensure that the stream is cued up on forked-daapd (though there is currently no other content), get it to play and switch the output to the HomePod. To stop, I guess the same in reverse. So that is multiple actions resulting from one command. Some of those actions are visible to the Apple Home app (via the HomeKit integration) but others are not.

1/ My first question is one of capability. I have been researching Home Assistant, its architecture and available integrations for a couple of evenings now but am not yet sure if this would even be possible. Before investing much more time, I am keen to understand if this ultimately possible. I am open to solutions that use components other than forked-daapd

2/ If it is possible, what elements of Home Assistant will I need to read-up on and master? Although I have read the architecture docs, I don’t think I will really understand what some of the terms, such as entities, scripts and automations mean until I start to use them. I would welcome some pointers

3/ Has this problem already been solved by someone else? It would be even better if I could use an existing solution as a starting point

Thanks

too complicated. using radio browser instead.
create a button to play radio to your homepod. then import this button to homekit. and you can control the button by siri.

here is the code

      radio:
        unique_id: "num0005"
        turn_on:

          service: media_player.play_media
          target:
            entity_id: media_player.hp
          data:
            media_content_id: http://stream.live.vc.bbcmedia.co.uk/bbc_world_service
            media_content_type: music
            announce: true
        turn_off:
          service: media_player.media_stop
          target:
            entity_id: media_player.hp

Thank you for replying to my question after all this time. I am still interested in resolving this and will give this a try