Originally from: https://github.com/bbcontrol/ha-snippets/blob/main/blueprints/single_button_dim_switch.yaml

single_button_dim_switch.yaml

# Originally from: https://github.com/bbcontrol/ha-snippets/blob/main/blueprints/single_button_dim_switch.yaml
blueprint:
  name: Single Button Dim Switch
  description: >-
    Switch a light on/off by pressing a button.
    Dim it up/down (depending on the current state) by holding the same button.
  domain: automation
  input:
    button:
      name: Push button
      description:
        Entity representing a physical push button (which restores its position
        when released). It must emit a square signal on press.
      selector:
        entity:
          domain: binary_sensor
    light:
      name: Light
      selector:
        entity:
          domain: light
    hold_threshold:
      name: Hold threshold
      description: Time to consider button is being held, instead of just pushed.
      default: 0.8
      selector:
        number:
          min: 0.05
          max: 10
          step: 0.05
          unit_of_measurement: s
    brightness_threshold:
      name: Brightness threshold
      description: If the light brightness is above this value,
        the light is going to dim down when holding the button.
      default: 130
      selector:
        number:
          min: 0
          max: 255
    brightness_step_pct:
      name: Brightness step
      description: Percentage brightness increase/decrease in each step.
      default: 20
      selector:
        number:
          min: 1
          max: 100
          unit_of_measurement: "%"
    transition_step_length:
      name: Transition length
      description: >-
        Lenght of brightness transition in each step.
        WARNING: may not be supported by all lights.
      default: 0
      selector:
        number:
          min: 0
          max: 5
          step: 0.01
          unit_of_measurement: s
    delay_step_length:
      name: Delay length
      description: >-
        Length of pause after each step.
        MUST be larger than Transition length.
      default: 0.2
      selector:
        number:
          min: 0.1
          max: 5
          step: 0.01
          unit_of_measurement: s

mode: single

trigger:
  - platform: state
    entity_id: !input button
    to: "on"

action:
  - variables:
      brightness_step_pct_positive: !input brightness_step_pct
  - variables:
      brightness_step_pct_negative: "{{ brightness_step_pct_positive|int * -1 }}"
      light: !input light
  - wait_for_trigger:
      - platform: state
        entity_id: !input button
        to: "off"
        from: "on"
    timeout: !input hold_threshold
    continue_on_timeout: true
  - choose:
      - conditions:
          # when no trigger came (button has not been switched back to
          # off state during timeout) = button is being held
          - condition: template
            value_template: "{{ wait.trigger == none }}"
        sequence:
          - choose:
              - conditions:
                  # when brightness level is high
                  - condition: numeric_state
                    entity_id: !input light
                    attribute: brightness
                    above: !input brightness_threshold
                sequence:
                  # dim down
                  - repeat:
                      while:
                        - condition: and
                          conditions:
                            - condition: state
                              entity_id: !input button
                              state: "on"
                            - condition: template
                              value_template: "{{ (state_attr(light, 'brightness') or 0) > 0 }}"
                      sequence:
                        - if:
                            - alias: If next step would not turn off the light
                              condition: template
                              value_template: "{{ (state_attr(light, 'brightness') or 0) > brightness_step_pct_positive }}"
                          then:
                            - service: light.turn_on
                              entity_id: !input light
                              data:
                                transition: !input transition_step_length
                                brightness_step_pct: "{{ brightness_step_pct_negative }}"
                          else:
                            - service: light.turn_off
                              entity_id: !input light
                              data:
                                transition: !input transition_step_length
                            - stop: Dimmed to zero
                        - delay: !input delay_step_length
            default:
              # otherwise, dim up
              - repeat:
                  while:
                    - condition: and
                      conditions:
                        - condition: state
                          entity_id: !input button
                          state: "on"
                        - condition: template
                          value_template: "{{ (state_attr(light, 'brightness') or 0) < 255 }}"
                  sequence:
                    - if:
                        - alias: If next step would not turn the light fully on
                          condition: template
                          value_template: "{{ (state_attr(light, 'brightness') or 0) + brightness_step_pct_positive < 255 }}"
                      then:
                        - service: light.turn_on
                          entity_id: !input light
                          data:
                            transition: !input transition_step_length
                            brightness_step_pct: "{{ brightness_step_pct_positive }}"
                      else:
                        - service: light.turn_on
                          entity_id: !input light
                          data:
                            transition: !input transition_step_length
                        - stop: Dimmed to max
                    - delay: !input delay_step_length

    # when trigger came (button has been released within timeout)
    default:
      - service: light.toggle
        entity_id: !input light
        data:
          transition: !input transition_step_length