Got a little help from CGPT so it might not be perfect, but this seems to work from my limited testing:
triggers:
- trigger: state
entity_id:
- input_boolean.ups_power
conditions: []
actions:
- choose:
- conditions:
- condition: state
entity_id: input_boolean.ups_power
state:
- "on"
sequence:
- action: scene.create
data:
scene_id: light_states_backup
snapshot_entities: |
{{ states.light | map(attribute='entity_id') | list }}
- conditions:
- condition: state
entity_id: input_boolean.ups_power
state:
- "off"
sequence:
- action: scene.turn_on
target:
entity_id: scene.light_states_backup
data: {}
- delay:
hours: 0
minutes: 0
seconds: 10
milliseconds: 0
- action: scene.delete
data:
entity_id: scene.light_states_backup
mode: single
I've only tested it by toggling the UPS boolean manually and not actually cutting the power, so I'm probably going to need to add a delay, or a retry loop or something to make sure the scene applies consistently but so far so good! Thanks for the inspiration.
That first line is what CGPT helped me with. I wanted something that I don't need to modify when I add or remove lights, so this just gets everything. Ideally I'd just get the lights that don't have the power restore feature but most of my lights go via Hue and that doesn't expose the feature to HA at all.
The input_boolean is a thing I already had setup. The UPS fires a webhook event when it goes in and out of battery mode and there's a separate automation that switches the helper based on those.