#80: Support for Alexa/Echo assistant

docs/source/conf.py

@@ -226,6 +226,8 @@ autodoc_mock_imports = ['googlesamples.assistant.grpc.audio_helpers',
                         'pwm3901',
                         'PIL',
                         'croniter',
+                        'pyaudio',
+                        'avs',
                         ]
 
 sys.path.insert(0, os.path.abspath('../..'))

docs/source/platypush/plugins/assistant.alexa.rst

@@ -0,0 +1,6 @@
+``platypush.plugins.assistant.alexa``
+=====================================
+
+.. automodule:: platypush.plugins.assistant.alexa
+    :members:
+

platypush/plugins/assistant/echo/__init__.py

@@ -0,0 +1,123 @@
+"""
+.. moduleauthor:: Fabio Manganiello <blacklight86@gmail.com>
+"""
+
+import os
+
+from avs.auth import auth
+from avs.alexa import Alexa
+from avs.config import DEFAULT_CONFIG_FILE
+from avs.mic import Audio
+
+from platypush.context import get_bus
+from platypush.plugins import action
+from platypush.plugins.assistant import AssistantPlugin
+
+from platypush.message.event.assistant import ConversationStartEvent, \
+    ConversationEndEvent, SpeechRecognizedEvent, VolumeChangedEvent, \
+    ResponseEvent
+
+
+class AssistantEchoPlugin(AssistantPlugin):
+    """
+    Amazon Echo/Alexa assistant plugin.
+
+    In order to activate the Echo service on your device follow these steps:
+
+        1. Install avs (``pip install avs``)
+        2. Run the ``alexa-auth`` script. A local webservice will start on port 3000
+        3. If a browser instance doesn't open automatically then head to http://localhost:3000
+        4. Log in to your Amazon account
+        5. The required credentials will be stored to ~/.avs.json
+
+    Triggers:
+
+        * :class:`platypush.message.event.assistant.ConversationStartEvent`
+            when a new conversation starts
+        * :class:`platypush.message.event.assistant.SpeechRecognizedEvent`
+            when a new voice command is recognized
+        * :class:`platypush.message.event.assistant.ConversationEndEvent`
+            when a new conversation ends
+
+    Requires:
+
+        * **avs** (``pip install avs``)
+    """
+
+    def __init__(self, avs_config_file=DEFAULT_CONFIG_FILE, **kwargs):
+        """
+        :param avs_config_file: AVS credentials file - default: ~/.avs.json. If the file doesn't exist then
+            an instance of the AVS authentication service will be spawned. You can login through an Amazon
+            account either in the spawned browser window, if available, or by opening http://your-ip:3000
+            in the browser on another machine.
+        """
+        super().__init__(**kwargs)
+
+        if not avs_config_file or not os.path.isfile(avs_config_file):
+            auth(None, avs_config_file)
+            self.logger.warning('Amazon Echo assistant credentials not configured. Open http://localhost:3000 ' +
+                                'to authenticate this client')
+
+        self.audio = Audio()
+        self.alexa = Alexa(avs_config_file)
+        self._ready = False
+
+        self.alexa.state_listener.on_ready = self._on_ready()
+        self.alexa.state_listener.on_listening = self._on_listening()
+        self.alexa.state_listener.on_speaking = self._on_speaking()
+        self.alexa.state_listener.on_finished = self._on_finished()
+        self.alexa.state_listener.on_disconnected = self._on_disconnected()
+
+        self.audio.link(self.alexa)
+        self.alexa.start()
+
+    def _on_ready(self):
+        def _callback():
+            self._ready = True
+        return _callback
+
+    @staticmethod
+    def _on_listening():
+        def _callback():
+            get_bus().post(ConversationStartEvent())
+        return _callback
+
+    @staticmethod
+    def _on_speaking():
+        def _callback():
+            # AVS doesn't provide a way to access the response text
+            get_bus().post(ResponseEvent(response_text=''))
+        return _callback
+
+    @staticmethod
+    def _on_finished():
+        def _callback():
+            get_bus().post(ConversationEndEvent())
+        return _callback
+
+    def _on_disconnected(self):
+        def _callback():
+            self._ready = False
+        return _callback
+
+    @action
+    def start_conversation(self):
+        """
+        Programmatically start a conversation with the assistant
+        """
+        if not self._ready:
+            raise RuntimeError('Echo assistant not ready')
+
+        self.audio.start()
+        self.alexa.listen()
+
+    @action
+    def stop_conversation(self):
+        """
+        Programmatically stop a running conversation with the assistant
+        """
+        self.audio.stop()
+        self._on_finished()()
+
+
+# vim:sw=4:ts=4:et: