[Home Assistant] If/Then Script

configuration.yaml

http:
  ...
  trusted_networks:
    - 127.0.0.1

rest_command:
  ha_rest_api:
    url: "http://localhost:8123/api/services/{{ service|replace('.', '/') }}"
    method: post
    content_type: application/json
    payload: "{{ data|tojson }}"

script:
  if_then:
    alias: "If Then"
    sequence:
      - condition: template
        value_template: "{{ if }}"
      - service: rest_command.ha_rest_api
        data_template:
          service: "{{ service }}"
          data: "{{ data }}"

automation:
  - alias: "If/Then Test"
    trigger:
      - platform: state
        entity_id: fan.dummy_fan
        to: 'on'
    action:
      - service: script.if_then
        data_template:
          if: "{{ is_state('light.dummy_light_1', 'on') }}"
          service: persistent_notification.create
          data:
            message: "Testing..."