#
# Script to manage a light using standard controls from a Lutron Pico Remote
# This will translate the standard button meanings on a Pico to any light controlled
# by Home Assistant.
# The "favourite" button is presumed to be 50% brightness (but can be overriden).
# Expected data packet is: { new_state: X, entity_id: entity_id, fav_brightness: [0-100] }
#     new_state: REQUIRED. The pico value that triggered the event.
#     entity_id: REQUIRED. The entity_id of the light to control
#     fav_brightness: OPTIONAL. What brightness percentage to set when the favourite button is pressed (int 1 - 100).
#
# Example call from automations.yaml:
# trigger:
#    - platform: state
#      entity_id: sensor.PICO_REMOTE_ID
#      from: '0'
# action:
#  - data_template:
#      entity_id: light.LIGHT_TO_CONTROL_ID
#      new_state: "{{ trigger.to_state.state }}"
#    service: python_script.pico_light_switch_std
#
# Note: In order to work best with LIFX bulbs, pressing ON has two modes. If the bulb is not already on, then
#       ON will turn on the light at the previously set brightness. However, if the light is already on, then
#       ON will set brightness to maximum (255)
#

# Function Definitions
def get_fav_brightness(data):
    try:
        fav_percent = int(data.get('fav_brightness', 50))
        return int(255 * fav_percent / 100)
    except ValueError:
        return 50

# Init
BUTTON_ON    = 1
BUTTON_FAV   = 2
BUTTON_OFF   = 4
BUTTON_RAISE = 8
BUTTON_LOWER = 16
button_values = [BUTTON_ON, BUTTON_FAV, BUTTON_OFF, BUTTON_RAISE, BUTTON_LOWER]
BRIGHTNESS_STEP = 5 # Brightness value to step up/down
BRIGHTNESS_MAX = 255

entity_id = data.get('entity_id')
button = int(data.get('new_state'))
brightness = None
action = 'turn_on' # Most buttons require turning on
action_data = { "entity_id" : entity_id }

# Validation
valid = True
if entity_id is None:
    logger.warning("No entity ID provided to pico_light_switch_std script")
    valid = False
if button is None or button not in button_values:
    logger.warning("Invalid or missing new_state value provided to pico_light_switch_std script")
    valid = False

if valid:
    try:
        cur_entity_state = hass.states.get(entity_id)
        cur_brightness = cur_entity_state.attributes['brightness']
    except KeyError:
        cur_brightness = 0

    logger.debug("Payload received: {}".format(data))
    logger.debug("Current brightness: {}".format(cur_brightness))

    # Build Service Call Payload
    if button == BUTTON_OFF:
        action = 'turn_off'
    elif button == BUTTON_RAISE:
        brightness = cur_brightness + BRIGHTNESS_STEP
        if brightness > 255: brightness = 255 # sigh: apparantly min/max fn's are not considered "safe"
    elif button == BUTTON_LOWER:
        brightness = cur_brightness - BRIGHTNESS_STEP
        if brightness < 0: brightness = 0
    elif button == BUTTON_FAV:
        brightness = get_fav_brightness(data)
    elif button == BUTTON_ON:
        if cur_entity_state.state == 'on':
            brightness = BRIGHTNESS_MAX

    if brightness is not None:
        action_data['brightness'] = brightness

    # Make service call to light
    logger.info("Making '%s' call with payload: %s", action, action_data)
    hass.services.call('light', action, action_data)