Initial Configuration Push

deps/pychromecast/discovery.py

@@ -0,0 +1,90 @@
+"""Discovers Chromecasts on the network using mDNS/zeroconf."""
+import time
+from uuid import UUID
+
+import six
+from zeroconf import ServiceBrowser, Zeroconf
+
+DISCOVER_TIMEOUT = 5
+
+
+class CastListener(object):
+    """Zeroconf Cast Services collection."""
+    def __init__(self):
+        self.services = {}
+
+    @property
+    def count(self):
+        """Number of discovered cast services."""
+        return len(self.services)
+
+    @property
+    def devices(self):
+        """List of tuples (ip, host) for each discovered device."""
+        return list(self.services.values())
+
+    # pylint: disable=unused-argument
+    def remove_service(self, zconf, typ, name):
+        """ Remove a service from the collection. """
+        self.services.pop(name, None)
+
+    def add_service(self, zconf, typ, name):
+        """ Add a service to the collection. """
+        service = None
+        tries = 0
+        while service is None and tries < 4:
+            try:
+                service = zconf.get_service_info(typ, name)
+            except IOError:
+                # If the zerconf fails to receive the necesarry data we abort
+                # adding the service
+                break
+            tries += 1
+
+        if not service:
+            return
+
+        def get_value(key):
+            """Retrieve value and decode for Python 2/3."""
+            value = service.properties.get(key.encode('utf-8'))
+
+            if value is None or isinstance(value, six.text_type):
+                return value
+            return value.decode('utf-8')
+
+        ips = zconf.cache.entries_with_name(service.server.lower())
+        host = repr(ips[0]) if ips else service.server
+
+        model_name = get_value('md')
+        uuid = get_value('id')
+        friendly_name = get_value('fn')
+
+        if uuid:
+            uuid = UUID(uuid)
+
+        self.services[name] = (host, service.port, uuid, model_name,
+                               friendly_name)
+
+
+def discover_chromecasts(max_devices=None, timeout=DISCOVER_TIMEOUT):
+    """ Discover chromecasts on the network. """
+    try:
+        zconf = Zeroconf()
+        listener = CastListener()
+        browser = ServiceBrowser(zconf, "_googlecast._tcp.local.", listener)
+
+        if max_devices is None:
+            time.sleep(timeout)
+            return listener.devices
+
+        else:
+            start = time.time()
+
+            while (time.time() - start < timeout and
+                   listener.count < max_devices):
+                time.sleep(.1)
+
+            return listener.devices
+    finally:
+        browser.cancel()
+        zconf.close()