Add OpenExchangeRates sensor (#2356)

* Create openexchangerates.py

* Create OpenExchangeRates Sensor

* Add openexchangerate sensor

* Update openexchangerates.py

* Added params dict

* Update openexchangerates.py

* Update openexchangerates.py

* Update openexchangerates.py

* Update openexchangerates.py

* Added API key validation

* Update openexchangerates.py

.coveragerc

@@ -187,6 +187,7 @@ omit =
     homeassistant/components/sensor/nzbget.py
     homeassistant/components/sensor/onewire.py
     homeassistant/components/sensor/openweathermap.py
+    homeassistant/components/sensor/openexchangerates.py
     homeassistant/components/sensor/plex.py
     homeassistant/components/sensor/rest.py
     homeassistant/components/sensor/sabnzbd.py

homeassistant/components/sensor/openexchangerates.py

@@ -0,0 +1,100 @@
+"""Support for openexchangerates.org exchange rates service."""
+from datetime import timedelta
+import logging
+import requests
+from homeassistant.helpers.entity import Entity
+from homeassistant.util import Throttle
+from homeassistant.const import CONF_API_KEY
+
+_RESOURCE = 'https://openexchangerates.org/api/latest.json'
+_LOGGER = logging.getLogger(__name__)
+# Return cached results if last scan was less then this time ago.
+MIN_TIME_BETWEEN_UPDATES = timedelta(minutes=100)
+CONF_BASE = 'base'
+CONF_QUOTE = 'quote'
+CONF_NAME = 'name'
+DEFAULT_NAME = 'Exchange Rate Sensor'
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Setup the Openexchangerates sensor."""
+    payload = config.get('payload', None)
+    rest = OpenexchangeratesData(
+        _RESOURCE,
+        config.get(CONF_API_KEY),
+        config.get(CONF_BASE, 'USD'),
+        config.get(CONF_QUOTE),
+        payload
+    )
+    response = requests.get(_RESOURCE, params={'base': config.get(CONF_BASE,
+                                                                  'USD'),
+                                               'app_id':
+                                               config.get(CONF_API_KEY)},
+                            timeout=10)
+    if response.status_code != 200:
+        _LOGGER.error("Check your OpenExchangeRates API")
+        return False
+    rest.update()
+    add_devices([OpenexchangeratesSensor(rest, config.get(CONF_NAME,
+                                                          DEFAULT_NAME),
+                                         config.get(CONF_QUOTE))])
+
+
+class OpenexchangeratesSensor(Entity):
+    """Implementing the Openexchangerates sensor."""
+
+    def __init__(self, rest, name, quote):
+        """Initialize the sensor."""
+        self.rest = rest
+        self._name = name
+        self._quote = quote
+        self.update()
+
+    @property
+    def name(self):
+        """Return the name of the sensor."""
+        return self._name
+
+    @property
+    def state(self):
+        """Return the state of the sensor."""
+        return self._state
+
+    @property
+    def device_state_attributes(self):
+        """Return other attributes of the sensor."""
+        return self.rest.data
+
+    def update(self):
+        """Update current conditions."""
+        self.rest.update()
+        value = self.rest.data
+        self._state = round(value[str(self._quote)], 4)
+
+
+# pylint: disable=too-few-public-methods
+class OpenexchangeratesData(object):
+    """Get data from Openexchangerates.org."""
+
+    # pylint: disable=too-many-arguments
+    def __init__(self, resource, api_key, base, quote, data):
+        """Initialize the data object."""
+        self._resource = resource
+        self._api_key = api_key
+        self._base = base
+        self._quote = quote
+        self.data = None
+
+    @Throttle(MIN_TIME_BETWEEN_UPDATES)
+    def update(self):
+        """Get the latest data from openexchangerates."""
+        try:
+            result = requests.get(self._resource, params={'base': self._base,
+                                                          'app_id':
+                                                          self._api_key},
+                                  timeout=10)
+            self.data = result.json()['rates']
+        except requests.exceptions.HTTPError:
+            _LOGGER.error("Check Openexchangerates API Key")
+            self.data = None
+            return False