New sensor viaggiatreno. (#10522)

* New sensor viaggiatreno.

I've messed up the previous PR so here it is in a new one.
Should include also all corrections from @pvizeli

* fixes from PR 10522

* fixed import order

* requested changes from MartinHjelmare

.coveragerc

@@ -583,6 +583,7 @@ omit =
     homeassistant/components/sensor/upnp.py
     homeassistant/components/sensor/ups.py
     homeassistant/components/sensor/vasttrafik.py
+    homeassistant/components/sensor/viaggiatreno.py
     homeassistant/components/sensor/waqi.py
     homeassistant/components/sensor/whois.py
     homeassistant/components/sensor/worldtidesinfo.py

homeassistant/components/sensor/viaggiatreno.py

@@ -0,0 +1,187 @@
+"""
+Support for information about the Italian train system using ViaggiaTreno API.
+
+For more details about this platform please refer to the documentation at
+https://home-assistant.io/components/sensor.viaggiatreno
+"""
+import logging
+
+import asyncio
+import async_timeout
+import aiohttp
+
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.components.sensor import PLATFORM_SCHEMA
+from homeassistant.const import ATTR_ATTRIBUTION
+from homeassistant.helpers.entity import Entity
+
+_LOGGER = logging.getLogger(__name__)
+
+CONF_ATTRIBUTION = "Powered by ViaggiaTreno Data"
+VIAGGIATRENO_ENDPOINT = ("http://www.viaggiatreno.it/viaggiatrenonew/"
+                         "resteasy/viaggiatreno/andamentoTreno/"
+                         "{station_id}/{train_id}")
+
+REQUEST_TIMEOUT = 5  # seconds
+ICON = 'mdi:train'
+MONITORED_INFO = [
+    'categoria',
+    'compOrarioArrivoZeroEffettivo',
+    'compOrarioPartenzaZeroEffettivo',
+    'destinazione',
+    'numeroTreno',
+    'orarioArrivo',
+    'orarioPartenza',
+    'origine',
+    'subTitle',
+    ]
+
+DEFAULT_NAME = "Train {}"
+
+CONF_NAME = 'train_name'
+CONF_STATION_ID = 'station_id'
+CONF_STATION_NAME = 'station_name'
+CONF_TRAIN_ID = 'train_id'
+
+ARRIVED_STRING = 'Arrived'
+CANCELLED_STRING = 'Cancelled'
+NOT_DEPARTED_STRING = "Not departed yet"
+NO_INFORMATION_STRING = "No information for this train now"
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Required(CONF_TRAIN_ID): cv.string,
+    vol.Required(CONF_STATION_ID): cv.string,
+    vol.Optional(CONF_NAME): cv.string,
+    })
+
+
+@asyncio.coroutine
+def async_setup_platform(hass, config,
+                         async_add_devices, discovery_info=None):
+    """Setup the ViaggiaTreno platform."""
+    train_id = config.get(CONF_TRAIN_ID)
+    station_id = config.get(CONF_STATION_ID)
+    name = config.get(CONF_NAME)
+    if not name:
+        name = DEFAULT_NAME.format(train_id)
+    async_add_devices([ViaggiaTrenoSensor(train_id, station_id, name)])
+
+
+@asyncio.coroutine
+def async_http_request(hass, uri):
+    """Perform actual request."""
+    try:
+        session = hass.helpers.aiohttp_client.async_get_clientsession(hass)
+        with async_timeout.timeout(REQUEST_TIMEOUT, loop=hass.loop):
+            req = yield from session.get(uri)
+        if req.status != 200:
+            return {'error': req.status}
+        else:
+            json_response = yield from req.json()
+            return json_response
+    except (asyncio.TimeoutError, aiohttp.ClientError) as exc:
+        _LOGGER.error("Cannot connect to ViaggiaTreno API endpoint: %s", exc)
+    except ValueError:
+        _LOGGER.error("Received non-JSON data from ViaggiaTreno API endpoint")
+
+
+class ViaggiaTrenoSensor(Entity):
+    """Implementation of a ViaggiaTreno sensor."""
+
+    def __init__(self, train_id, station_id, name):
+        """Initialize the sensor."""
+        self._state = None
+        self._attributes = {}
+        self._unit = ''
+        self._icon = ICON
+        self._station_id = station_id
+        self._name = name
+
+        self.uri = VIAGGIATRENO_ENDPOINT.format(
+            station_id=station_id,
+            train_id=train_id)
+
+    @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 icon(self):
+        """Icon to use in the frontend, if any."""
+        return self._icon
+
+    @property
+    def unit_of_measurement(self):
+        """Return the unit of measurement."""
+        return self._unit
+
+    @property
+    def device_state_attributes(self):
+        """Return extra attributes."""
+        self._attributes[ATTR_ATTRIBUTION] = CONF_ATTRIBUTION
+        return self._attributes
+
+    @staticmethod
+    def has_departed(data):
+        """Check if the train has actually departed."""
+        try:
+            first_station = data['fermate'][0]
+            if data['oraUltimoRilevamento'] or first_station['effettiva']:
+                return True
+        except ValueError:
+            _LOGGER.error("Cannot fetch first station: %s", data)
+        return False
+
+    @staticmethod
+    def has_arrived(data):
+        """Check if the train has already arrived."""
+        last_station = data['fermate'][-1]
+        if not last_station['effettiva']:
+            return False
+        return True
+
+    @staticmethod
+    def is_cancelled(data):
+        """Check if the train is cancelled."""
+        if data['tipoTreno'] == 'ST' and data['provvedimento'] == 1:
+            return True
+        return False
+
+    @asyncio.coroutine
+    def async_update(self):
+        """Update state."""
+        uri = self.uri
+        res = yield from async_http_request(self.hass, uri)
+        if res.get('error', ''):
+            if res['error'] == 204:
+                self._state = NO_INFORMATION_STRING
+                self._unit = ''
+            else:
+                self._state = "Error: {}".format(res['error'])
+                self._unit = ''
+        else:
+            for i in MONITORED_INFO:
+                self._attributes[i] = res[i]
+
+            if self.is_cancelled(res):
+                self._state = CANCELLED_STRING
+                self._icon = 'mdi:cancel'
+                self._unit = ''
+            elif not self.has_departed(res):
+                self._state = NOT_DEPARTED_STRING
+                self._unit = ''
+            elif self.has_arrived(res):
+                self._state = ARRIVED_STRING
+                self._unit = ''
+            else:
+                self._state = res.get('ritardo')
+                self._unit = 'min'
+                self._icon = ICON