1 files changed, 108 insertions, 0 deletions
diff --git a/client/stt.py b/client/stt.py
index aeaae0b..543a322 100644
--- a/client/stt.py
+++ b/client/stt.py
@@ -307,6 +307,114 @@ class GoogleSTT(AbstractSTTEngine):
         return diagnose.check_network_connection()
 
 
+class AttSTT(AbstractSTTEngine):
+    """
+    Speech-To-Text implementation which relies on the AT&T Speech API.
+
+    This implementation requires an AT&T app_key/app_secret to be present in
+    profile.yml. Please sign up at http://developer.att.com/apis/speech and
+    create a new app. You can then take the app_key/app_secret and put it into
+    your profile.yml:
+        ...
+        stt_engine: att
+        att-stt:
+          app_key:    4xxzd6abcdefghijklmnopqrstuvwxyz
+          app_secret: 6o5jgiabcdefghijklmnopqrstuvwxyz
+    """
+
+    SLUG = "att"
+
+    def __init__(self, app_key, app_secret):
+        self._logger = logging.getLogger(__name__)
+        self._token = None
+        self.app_key = app_key
+        self.app_secret = app_secret
+
+    @classmethod
+    def get_config(cls):
+        # FIXME: Replace this as soon as we have a config module
+        config = {}
+        # Try to get AT&T app_key/app_secret from config
+        profile_path = jasperpath.config('profile.yml')
+        if os.path.exists(profile_path):
+            with open(profile_path, 'r') as f:
+                profile = yaml.safe_load(f)
+                if 'att-stt' in profile:
+                    if 'app_key' in profile['att-stt']:
+                        config['app_key'] = profile['att-stt']['app_key']
+                    if 'app_secret' in profile['att-stt']:
+                        config['app_secret'] = profile['att-stt']['app_secret']
+        return config
+
+    @property
+    def token(self):
+        if not self._token:
+            headers = {'content-type': 'application/x-www-form-urlencoded',
+                       'accept': 'application/json'}
+            payload = {'client_id': self.app_key,
+                       'client_secret': self.app_secret,
+                       'scope': 'SPEECH',
+                       'grant_type': 'client_credentials'}
+            r = requests.post('https://api.att.com/oauth/token',
+                              data=payload,
+                              headers=headers)
+            self._token = r.json()['access_token']
+        return self._token
+
+    def transcribe(self, fp):
+        data = fp.read()
+        r = self._get_response(data)
+        if r.status_code == requests.codes['unauthorized']:
+            # Request token invalid, retry once with a new token
+            self._logger.warning('OAuth access token invalid, generating a ' +
+                                 'new one and retrying...')
+            self._token = None
+            r = self._get_response(data)
+        try:
+            r.raise_for_status()
+        except requests.exceptions.HTTPError:
+            self._logger.critical('Request failed with response: %r',
+                                  r.text,
+                                  exc_info=True)
+            return []
+        except requests.exceptions.RequestException:
+            self._logger.critical('Request failed.', exc_info=True)
+            return []
+        else:
+            try:
+                recognition = r.json()['Recognition']
+                if recognition['Status'] != 'OK':
+                    raise ValueError(recognition['Status'])
+                results = [(x['Hypothesis'], x['Confidence'])
+                           for x in recognition['NBest']]
+            except ValueError as e:
+                self._logger.debug('Recognition failed with status: %s',
+                                   e.args[0])
+                return []
+            except KeyError:
+                self._logger.critical('Cannot parse response.',
+                                      exc_info=True)
+                return []
+            else:
+                results = [x[0].upper() for x in sorted(results,
+                                                        key=lambda x: x[1],
+                                                        reverse=True)]
+                self._logger.info('Recognized: %r', results)
+                return results
+
+    def _get_response(self, data):
+        headers = {'authorization': 'Bearer %s' % self.token,
+                   'accept': 'application/json',
+                   'content-type': 'audio/wav'}
+        return requests.post('https://api.att.com/speech/v3/speechToText',
+                             data=data,
+                             headers=headers)
+
+    @classmethod
+    def is_available(cls):
+        return diagnose.check_network_connection()
+
+
 def get_engine_by_slug(slug=None):
     """
     Returns: