Add Swisscom Internet-Box device tracker (#4123)

* Add Swisscom Internet-Box device tracker

* Add Swisscom device tracker to .coveragerc

* Add timeout to requests
Fix formatting and add missing comments to pass the lint test

* Remove authentication which was not required

I realised that there was no need to be authenticated to get the
connected devices. Thanks Swisscom :/

* Moving config to a PLATFORM_SCHEMA and using voluptuous

.coveragerc

@@ -150,6 +150,7 @@ omit =
     homeassistant/components/device_tracker/netgear.py
     homeassistant/components/device_tracker/nmap_tracker.py
     homeassistant/components/device_tracker/snmp.py
+    homeassistant/components/device_tracker/swisscom.py
     homeassistant/components/device_tracker/thomson.py
     homeassistant/components/device_tracker/tomato.py
     homeassistant/components/device_tracker/tplink.py

homeassistant/components/device_tracker/swisscom.py

@@ -0,0 +1,109 @@
+"""
+Support for Swisscom routers (Internet-Box).
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/device_tracker.swisscom/
+"""
+import logging
+import threading
+from datetime import timedelta
+
+import requests
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.components.device_tracker import DOMAIN, PLATFORM_SCHEMA
+from homeassistant.const import CONF_HOST
+from homeassistant.util import Throttle
+
+# Return cached results if last scan was less then this time ago.
+MIN_TIME_BETWEEN_SCANS = timedelta(seconds=5)
+
+_LOGGER = logging.getLogger(__name__)
+
+DEFAULT_IP = '192.168.1.1'
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Optional(CONF_HOST, default=DEFAULT_IP): cv.string
+})
+
+
+def get_scanner(hass, config):
+    """Return the Swisscom device scanner."""
+    scanner = SwisscomDeviceScanner(config[DOMAIN])
+
+    return scanner if scanner.success_init else None
+
+
+class SwisscomDeviceScanner(object):
+    """This class queries a router running Swisscom Internet-Box firmware."""
+
+    def __init__(self, config):
+        """Initialize the scanner."""
+        self.host = config[CONF_HOST]
+
+        self.lock = threading.Lock()
+
+        self.last_results = {}
+
+        # Test the router is accessible.
+        data = self.get_swisscom_data()
+        self.success_init = data is not None
+
+    def scan_devices(self):
+        """Scan for new devices and return a list with found device IDs."""
+        self._update_info()
+        return [client['mac'] for client in self.last_results]
+
+    def get_device_name(self, device):
+        """Return the name of the given device or None if we don't know."""
+        if not self.last_results:
+            return None
+        for client in self.last_results:
+            if client['mac'] == device:
+                return client['host']
+        return None
+
+    @Throttle(MIN_TIME_BETWEEN_SCANS)
+    def _update_info(self):
+        """Ensure the information from the Swisscom router is up to date.
+
+        Return boolean if scanning successful.
+        """
+        if not self.success_init:
+            return False
+
+        with self.lock:
+            _LOGGER.info("Loading data from Swisscom Internet Box")
+            data = self.get_swisscom_data()
+            if not data:
+                return False
+
+            active_clients = [client for client in data.values() if
+                              client['status']]
+            self.last_results = active_clients
+            return True
+
+    def get_swisscom_data(self):
+        """Retrieve data from Swisscom and return parsed result."""
+        request = requests.post('http://' + self.host + '/ws', headers={
+            'Content-Type': 'application/x-sah-ws-4-call+json'
+            },
+                                data="""{"service":"Devices",
+                                    "method":"get",
+                                    "parameters":
+                                    {"expression":"lan and not self"}}""",
+                                timeout=10)
+
+        devices = {}
+        for device in request.json()['status']:
+            try:
+                devices[device['Key']] = {
+                    'ip': device['IPAddress'],
+                    'mac': device['PhysAddress'],
+                    'host': device['Name'],
+                    'status': device['Active']
+                    }
+            except (KeyError, requests.exceptions.RequestException):
+                pass
+        return devices