Added a new sensor to read data from the efergy energy monitor

homeassistant/components/sensor/efergy.py

@@ -0,0 +1,138 @@
+"""
+homeassistant.components.sensor.efergy
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Monitors home energy use as measured by an efergy
+engage hub using its (unofficial, undocumented) API.
+
+Configuration:
+
+To use the efergy sensor you will need to add something
+like the following to your config/configuration.yaml
+
+sensor:
+  platform: efergy
+  app_token: APP_TOKEN
+  utc_offset: UTC_OFFSET
+  monitored_variables:
+    - type: instant_readings
+    - type: budget
+    - type: cost
+      period: day
+      currency: $
+
+Variables:
+
+api_key
+*Required
+To get a new App Token, log in to your efergy account, go
+to the Settings page, click on App tokens, and click "Add token".
+
+utc_offset
+*Required for some variables
+Some variables (currently only the daily_cost) require that the
+negative number of minutes your timezone is ahead/behind UTC time.
+
+monitored_variables
+*Required
+An array specifying the variables to monitor.
+
+period
+*Optional
+Some variables take a period argument. Valid options are "day",
+1"week", "month", and "year"
+
+currency
+*Optional
+This is used to display the cost/period as the unit when monitoring the
+cost.  It should correspond to the actual currency used in your dashboard.
+"""
+import logging
+from requests import get
+
+from homeassistant.helpers.entity import Entity
+
+_LOGGER = logging.getLogger(__name__)
+_RESOURCE = 'https://engage.efergy.com/mobile_proxy/'
+SENSOR_TYPES = {
+    'instant_readings': ['Energy Usage', 'kW'],
+    'budget': ['Energy Budget', ''],
+    'cost': ['Energy Cost', ''],
+}
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """ Sets up the efergy sensor. """
+    app_token = config.get("app_token")
+    if not app_token:
+        _LOGGER.error(
+            "Configuration Error"
+            "Please make sure you have configured your app token")
+        return None
+    utc_offset = str(config.get("utc_offset"))
+    dev = []
+    for variable in config['monitored_variables']:
+        if 'period' not in variable:
+            variable['period'] = ''
+        if 'currency' not in variable:
+            variable['currency'] = ''
+        if variable['type'] not in SENSOR_TYPES:
+            _LOGGER.error('Sensor type: "%s" does not exist', variable)
+        else:
+            dev.append(EfergySensor(variable['type'], app_token, utc_offset,
+                                    variable['period'], variable['currency']))
+
+    add_devices(dev)
+
+
+# pylint: disable=too-many-instance-attributes
+class EfergySensor(Entity):
+    """ Implements an Efergy sensor. """
+
+    # pylint: disable=too-many-arguments
+    def __init__(self, sensor_type, app_token, utc_offset, period, currency):
+        self._name = SENSOR_TYPES[sensor_type][0]
+        self.type = sensor_type
+        self.app_token = app_token
+        self.utc_offset = utc_offset
+        self._state = None
+        self.period = period
+        self.currency = currency
+        if self.type == 'cost':
+            self._unit_of_measurement = self.currency + '/' + self.period
+        else:
+            self._unit_of_measurement = SENSOR_TYPES[sensor_type][1]
+
+    @property
+    def name(self):
+        """ Returns the name. """
+        return self._name
+
+    @property
+    def state(self):
+        """ Returns the state of the device. """
+        return self._state
+
+    @property
+    def unit_of_measurement(self):
+        """ Unit of measurement of this entity, if any. """
+        return self._unit_of_measurement
+
+    def update(self):
+        """ Gets the efergy monitor data from the web service """
+        if self.type == 'instant_readings':
+            url_string = _RESOURCE + 'getInstant?token=' + self.app_token
+            response = get(url_string)
+            self._state = response.json()['reading'] / 1000
+        elif self.type == 'budget':
+            url_string = _RESOURCE + 'getBudget?token=' + self.app_token
+            response = get(url_string)
+            self._state = response.json()['status']
+        elif self.type == 'cost':
+            url_string = _RESOURCE + 'getCost?token=' + self.app_token \
+                + '&offset=' + self.utc_offset + '&period=' \
+                + self.period
+            response = get(url_string)
+            self._state = response.json()['sum']
+        else:
+            self._state = 'Unknown'