Add improved scene support to the light integration (#27182)

* light reproduce state

* Add types

* Fix linting error

* Add tests

* Improve test

* Fix failing tests

* Another try

* avoid repetition

* simplified if

* Remove attributes that are no attributes

homeassistant/components/light/reproduce_state.py

@@ -0,0 +1,94 @@
+"""Reproduce an Light state."""
+import asyncio
+import logging
+from types import MappingProxyType
+from typing import Iterable, Optional
+
+from homeassistant.const import (
+    ATTR_ENTITY_ID,
+    STATE_ON,
+    STATE_OFF,
+    SERVICE_TURN_OFF,
+    SERVICE_TURN_ON,
+)
+from homeassistant.core import Context, State
+from homeassistant.helpers.typing import HomeAssistantType
+
+from . import (
+    DOMAIN,
+    ATTR_BRIGHTNESS,
+    ATTR_COLOR_TEMP,
+    ATTR_EFFECT,
+    ATTR_HS_COLOR,
+    ATTR_RGB_COLOR,
+    ATTR_WHITE_VALUE,
+    ATTR_XY_COLOR,
+)
+
+_LOGGER = logging.getLogger(__name__)
+
+VALID_STATES = {STATE_ON, STATE_OFF}
+ATTR_GROUP = [ATTR_BRIGHTNESS, ATTR_EFFECT, ATTR_WHITE_VALUE]
+COLOR_GROUP = [ATTR_COLOR_TEMP, ATTR_HS_COLOR, ATTR_RGB_COLOR, ATTR_XY_COLOR]
+
+
+async def _async_reproduce_state(
+    hass: HomeAssistantType, state: State, context: Optional[Context] = None
+) -> None:
+    """Reproduce a single state."""
+    cur_state = hass.states.get(state.entity_id)
+
+    if cur_state is None:
+        _LOGGER.warning("Unable to find entity %s", state.entity_id)
+        return
+
+    if state.state not in VALID_STATES:
+        _LOGGER.warning(
+            "Invalid state specified for %s: %s", state.entity_id, state.state
+        )
+        return
+
+    # Return if we are already at the right state.
+    if cur_state.state == state.state and all(
+        check_attr_equal(cur_state.attributes, state.attributes, attr)
+        for attr in ATTR_GROUP + COLOR_GROUP
+    ):
+        return
+
+    service_data = {ATTR_ENTITY_ID: state.entity_id}
+
+    if state.state == STATE_ON:
+        service = SERVICE_TURN_ON
+        for attr in ATTR_GROUP:
+            # All attributes that are not colors
+            if attr in state.attributes:
+                service_data[attr] = state.attributes[attr]
+
+        for color_attr in COLOR_GROUP:
+            # Choose the first color that is specified
+            if color_attr in state.attributes:
+                service_data[color_attr] = state.attributes[color_attr]
+                break
+
+    elif state.state == STATE_OFF:
+        service = SERVICE_TURN_OFF
+
+    await hass.services.async_call(
+        DOMAIN, service, service_data, context=context, blocking=True
+    )
+
+
+async def async_reproduce_states(
+    hass: HomeAssistantType, states: Iterable[State], context: Optional[Context] = None
+) -> None:
+    """Reproduce Light states."""
+    await asyncio.gather(
+        *(_async_reproduce_state(hass, state, context) for state in states)
+    )
+
+
+def check_attr_equal(
+    attr1: MappingProxyType, attr2: MappingProxyType, attr_str: str
+) -> bool:
+    """Return true if the given attributes are equal."""
+    return attr1.get(attr_str) == attr2.get(attr_str)