blueprint:
  name: Sonos · Join to master
  domain: script
  input:
    join_player:
      name: Sonos player to join to master
      selector:
        device:
          integration: media_player

sequence:
  - service: sonos.join
    entity_id: !input join_player
    data_template:
      master: >-
        {% if is_state('binary_sensor.sonos_is_living_room_master', 'on') %}
          media_player.living_room
        {% else %}
          media_player.master_bedroom
        {% endif %}