Backend changes for customize config panel. (#9134)

* Backend changes for customize config panel.

* Backend changes for customize config panel.

* Add customize.yaml to default config

* Precreate customize.yaml

* Add tests

homeassistant/components/config/customize.py

@@ -0,0 +1,39 @@
+"""Provide configuration end points for Customize."""
+import asyncio
+
+from homeassistant.components.config import EditKeyBasedConfigView
+from homeassistant.components import async_reload_core_config
+from homeassistant.config import DATA_CUSTOMIZE
+
+import homeassistant.helpers.config_validation as cv
+
+CONFIG_PATH = 'customize.yaml'
+
+
+@asyncio.coroutine
+def async_setup(hass):
+    """Set up the Customize config API."""
+    hass.http.register_view(CustomizeConfigView(
+        'customize', 'config', CONFIG_PATH, cv.entity_id, dict,
+        post_write_hook=async_reload_core_config
+    ))
+
+    return True
+
+
+class CustomizeConfigView(EditKeyBasedConfigView):
+    """Configure a list of entries."""
+
+    def _get_value(self, hass, data, config_key):
+        """Get value."""
+        customize = hass.data.get(DATA_CUSTOMIZE, {}).get(config_key) or {}
+        return {'global': customize, 'local': data.get(config_key, {})}
+
+    def _write_value(self, hass, data, config_key, new_value):
+        """Set value."""
+        data[config_key] = new_value
+
+        state = hass.states.get(config_key)
+        state_attributes = dict(state.attributes)
+        state_attributes.update(new_value)
+        hass.states.async_set(config_key, state.state, state_attributes)