blueprint:
  name: Sonoff TRVZB External Setpoint
  description: |
    Control multiple TRV (Thermostatic Radiator Valve) valves using a single external temperature sensor.
    Compatible with both Zigbee2MQTT and ZHA integrations.

    Features:
    - Directly sets external temperature on TRV (no offset calculation)
    - Automatically switches TRV to external sensor mode if needed
    - Automatic 2-hour update to prevent TRV fail-safe mode
    - Rate limiting to preserve battery life and reduce Zigbee traffic
  domain: automation
  input:
    external_temperature_sensor:
      name: External Temperature Sensor
      description: The external temperature sensor (e.g., SNZB-02) to use as the reference
      selector:
        entity:
          filter:
            - domain: sensor
              device_class: temperature
    target_trvs:
      name: Target TRV Valves (Sonoff TRVZB)
      description: Select one or more Sonoff TRVZB valves to control with the external sensor
      selector:
        target:
          entity:
            - domain: climate
          device:
            - manufacturer: SONOFF
              model: TRVZB
    update_interval:
      name: Minimum Update Interval
      description: Minimum time between updates on sensor changes to avoid battery drain (in seconds)
      default: 300
      selector:
        number:
          min: 60
          max: 3600
          unit_of_measurement: seconds
          mode: slider

mode: restart

trigger:
  - platform: state
    entity_id: !input external_temperature_sensor
    id: sensor_change
  - platform: time_pattern
    hours: "/2"
    id: failsafe_prevention

variables:
  external_sensor: !input external_temperature_sensor
  target_valves: !input target_trvs
  min_interval: !input update_interval

condition:
  - alias: Check external sensor is available
    condition: template
    value_template: "{{ states(external_sensor) not in ['unknown', 'unavailable'] }}"
  - alias: Determine if update should proceed
    condition: or
    conditions:
      # Always update every 2 hours to prevent fail-safe mode
      - alias: 2-hour failsafe update (bypass rate limiter)
        condition: trigger
        id: failsafe_prevention
      # For sensor changes, respect the rate limiter
      - alias: Sensor change with rate limiting
        condition: and
        conditions:
          - alias: Triggered by sensor change
            condition: trigger
            id: sensor_change
          - alias: Rate limiter check (minimum interval elapsed)
            condition: template
            value_template: >
              {{ this.attributes.last_triggered is none or
                 (now() - this.attributes.last_triggered).total_seconds() >= min_interval }}

action:
  - alias: Process each TRV valve
    repeat:
      for_each: "{{ target_valves.entity_id }}"
      sequence:
        - variables:
            trv_entity: "{{ repeat.item }}"
            trv_device_id: "{{ device_id(trv_entity) }}"
            trv_external_temperature_input: >
              {{ expand(device_entities(trv_device_id))
                 | selectattr('entity_id', 'search', 'external_temperature_input')
                 | map(attribute='entity_id')
                 | list
                 | first | default('') }}
            trv_sensor_select: >
              {{ expand(device_entities(trv_device_id))
                 | selectattr('entity_id', 'search', 'temperature_sensor_select')
                 | map(attribute='entity_id')
                 | list
                 | first | default('') }}
        # Step 1: Ensure TRV is set to use "external" temperature sensor (slot 1)
        - alias: Switch TRV to external mode if needed
          choose:
            - conditions:
                - alias: Check if sensor select exists and is not set to external
                  condition: template
                  value_template: >
                    {{ trv_sensor_select != '' and
                       states(trv_sensor_select) != 'external' }}
              sequence:
                - alias: Set TRV temperature sensor to external (slot 1)
                  service: select.select_option
                  target:
                    entity_id: "{{ trv_sensor_select }}"
                  data:
                    option: external
        # Step 2: Set the external temperature value
        - alias: Check if external temperature input entity exists
          condition: template
          value_template: "{{ trv_external_temperature_input != '' }}"
        - alias: Write external temperature value to TRV
          service: number.set_value
          target:
            entity_id: "{{ trv_external_temperature_input }}"
          data:
            value: "{{ states(external_sensor) | float }}"