Home Assistant Light Control Pattern

livingroom_lights_alone_off.yaml

- alias: 'Livingroom lights alone off'
  trigger:
    - platform: state
      entity_id: binary_sensor.hallway_motion
      to: 'on'
    - platform: state
      entity_id: binary_sensor.bedroom_motion
      to: 'on'
  condition:
    condition: and
    conditions:
      - condition: numeric_state
        entity_id: sensor.people_present
        above: 0
        below: 2
      - condition: state
        entity_id: binary_sensor.livingroom_motion
        state: 'off'
        for:
          seconds: 10
      - condition: state
        entity_id: input_select.livingroom_light_mode
        state: 'auto'
  action:
    - service: light.turn_off
      data:
        entity_id:
          - group.livingroom_lights

livingroom_lights_brightness_adjust.yaml

- alias: 'Adjust living room lights brightness'
  trigger:
    - platform: time
      minutes: '/1'
      seconds: 00
    - platform: state
      entity_id: media_player.tv
  condition:
    condition: and
    conditions:
      - condition: state
        entity_id: input_select.livingroom_light_mode
        state: 'auto'
      - condition: state
        entity_id: group.livingroom_lights
        state: 'on'
  action:
    - service: light.turn_on
      data_template:
        brightness_pct: >
          {{ states.sensor.target_brightness_livingroom.state|int}}
        entity_id:
          - group.livingroom_lights

livingroom_lights_off_at_night.yaml

- alias: 'Livingroom lights off at night'
  trigger:
    - platform: state
      entity_id: binary_sensor.livingroom_motion
      to: 'off'
      for:
        seconds: 30
  condition:
      - condition: and
        conditions:
          - condition: state
            entity_id: input_select.livingroom_light_mode
            state: 'auto'
          - condition: state
            entity_id: input_boolean.bedtime
            state: 'on'
  action:
    - service: light.turn_off
      data:
        entity_id:
          - group.livingroom_lights

livingroom_lights_presence_off.yaml

- alias: 'Livingroom lights presence off'
  trigger:
    - platform: state
      entity_id: binary_sensor.livingroom_motion
      to: 'off'
      for:
        minutes: 20
    - platform: state
      entity_id: binary_sensor.livingroom_motion
      to: 'off'
      for:
        minutes: 2
  condition:
    condition: and
    conditions:
      - condition: state
        entity_id: input_select.livingroom_light_mode
        state: 'auto'
      - condition: state
        entity_id: input_boolean.bedtime
        state: 'off'
      - condition: or
        conditions:
          - condition: and
            conditions:
              - condition: state
                entity_id: binary_sensor.livingroom_motion
                state: 'off'
                for:
                  minutes: 20
          - condition: and
            conditions:
              - condition: state
                entity_id: binary_sensor.livingroom_motion
                state: 'off'
                for:
                  minutes: 2
              - condition: template
                value_template: "{{ (as_timestamp(now())-as_timestamp(states.group.livingroom_lights.last_changed)) <= 300 }}"
  action:
    - service: light.turn_off
      data:
        entity_id:
          - group.livingroom_lights

livingroom_lights_presence_on.yaml

- alias: 'Living room lights presence on'
  trigger:
    - platform: state
      entity_id: binary_sensor.livingroom_motion
      to: 'on'
  condition:
    - condition: and
      conditions:
        - condition: state
          entity_id: group.livingroom_lights
          state: 'off'
        - condition: state
          entity_id: input_select.livingroom_light_mode
          state: 'auto'
  action:
    - service: light.turn_on
      data_template:
        brightness_pct: >
          {{ states.sensor.target_brightness_livingroom.state|int}}
        entity_id:
          - group.livingroom_lights

livingroom_lights_switch_off.yaml

- alias: 'Livingroom lights switch off'
  trigger:
    - platform: state
      entity_id: input_select.livingroom_light_mode
      to: 'off'
  action:
    - service: light.turn_off
      data:
        entity_id:
          - group.livingroom_lights

livingroom_lights_switch_on.yaml

- alias: 'Living room lights switch on'
  trigger:
    - platform: state
      entity_id: input_select.livingroom_light_mode
      to: 'on'
  action:
    - service: light.turn_on
      data_template:
        brightness_pct: 100
        entity_id:
          - group.livingroom_lights

target_brightness.yaml

- platform: template
  sensors:
    target_brightness_outside:
      friendly_name: "Target brightness outside"
      unit_of_measurement: "%"
      value_template: >
        {%  set bedtime_value = 10 %}
        {%  set maximum = 100 %}
        {%  set a = -0.0037 %}
        {%  set c = 0 %}
        {%  set n = 100-c %}
        {%  set minimum = 20 %}
        {%  set i = states('sensor.light_intensity') | float %}
        {%  set p = n*e**(a*i)+c %}
        {% if is_state('input_boolean.bedtime','on') %}
          {{ bedtime_value | int }}
        {% else %}
          {%if p < minimum %}
            0
          {% elif p > maximum %}
            {{ maximum }}
          {% else %}
            {{ p | int}}
          {% endif %}
        {% endif%}
    target_brightness_inside:
      friendly_name: "Target brightness inside"
      unit_of_measurement: "%"
      value_template: >
        {%  set bedtime_value = 10 %}
        {%  set maximum = 100 %}
        {%  set a = -0.0037 %}
        {%  set c = 20 %}
        {%  set n = 100-c %}
        {%  set minimum = 20 %}
        {%  set i = states('sensor.light_intensity') | float %}
        {%  set p = n*e**(a*i)+c %}
        {% if is_state('input_boolean.bedtime','on') %}
          {{ bedtime_value | int }}
        {% else %}
          {%if p < minimum %}
            0
          {% elif p > maximum %}
            {{ maximum }}
          {% else %}
            {{ p | int}}
          {% endif %}
        {% endif%}
    target_brightness_livingroom:
      friendly_name: "Target brightness livingroom"
      unit_of_measurement: "%"
      value_template: >
        {% if is_state('media_player.tv','playing') or (as_timestamp(now())-as_timestamp(states.media_player.tv.last_changed)) < 60 %}
              {% if states('sensor.target_brightness_outside') | int >= 20 %}
              20
              {% else %}
              0
              {% endif %}
        {% else %}
        {{ states.sensor.target_brightness_outside.state }}
        {% endif %}

sensor.light_intensity is the output of a BH1750 light sensor (in lux). Now what the templates are supposed to do is map this to a target brightness for lights between 0 and 100%. The exponential function it's using (p = ne**(ai)+c) doesn't have any physical background (that I know of) but simply was a pretty good fit for my needs. Parameters can be tweaked as needed of course. There is a second variant ("target_brightness_inside") where the light is always set to 20% more by setting c to 20 (since it's used in rooms that don't have windows).
Finally, there is some logic that limits the values to between 0 and 100% and not more than that and sets it to a fixed value of 10% for the night when someone is walking around in the middle of the night.
I hope that helps.