Do not clear the configured OAuth Client ID on a token mismatch (#712)

README.md

@@ -11,17 +11,20 @@ Watch your favorite gaming streams on Kodi.
 LOGIN
 ----------------
 
-1. Go to __Settings - Login - Login (device code)__
-2. Visit [twitch.tv/activate](https://www.twitch.tv/activate) on any device, sign in, and enter the code shown in Kodi
-
-The add-on stores the tokens and refreshes them automatically. Automatic refresh
-requires a public Client ID — the bundled Client ID cannot refresh tokens, so you
-will be asked to log in again once the token expires. To enable automatic refresh:
+Set up your own Client ID first, then log in — in that order. The bundled Client ID
+cannot refresh tokens (Twitch treats it as a confidential client), so with it you have
+to log in again every time the token expires.
 
 1. Register your own application at [dev.twitch.tv/console/apps](https://dev.twitch.tv/console/apps)
    (OAuth Redirect URL: `http://localhost`, Client Type: __Public__)
 2. Enter its Client ID in __Settings - Developer - OAuth Client ID__
-3. Log in again via __Settings - Login - Login (device code)__
+3. Go to __Settings - Login - Login (device code)__
+4. Visit [twitch.tv/activate](https://www.twitch.tv/activate) on any device, sign in, and enter the code shown in Kodi
+
+The add-on stores the tokens and refreshes them automatically from then on.
+
+If you logged in before entering your Client ID, simply log in again (step 3) — the
+previous token belongs to the bundled Client ID and cannot be refreshed.
 
 AD-FREE PLAYBACK (TURBO / SUBSCRIPTIONS)
 ----------------

resources/lib/twitch_addon/addon/api.py

@@ -93,27 +93,28 @@ def valid_token(self, client_id, token, scopes):  # client_id, token used for un
                 else:
                     return False
             else:
-                matches_default = token_check['client_id'] == utils.get_client_id(default=True)
-                log_utils.log('Error: OAuth Client-ID mismatch', log_utils.LOGERROR)
-                if matches_default:
-                    _ = kodi.Dialog().ok(
-                        i18n('oauth_token'),
-                        '[CR]'.join([i18n('client_id_mismatch'), i18n('ok_to_resolve')])
-                    )
-                    utils.clear_client_id()
-                    self.client_id = utils.get_client_id(default=True)
-                    self.queries.CLIENT_ID = self.client_id
-                    self.client = oauth.clients.MobileClient(self.client_id, self.client_secret)
-                else:
-                    _ = kodi.Dialog().ok(
-                        i18n('oauth_token'),
-                        '[CR]'.join([
-                            i18n('client_id_mismatch'),
-                            i18n('get_new_oauth_token') %
-                            (i18n('settings'), i18n('login'), i18n('device_login'))
-                        ])
-                    )
-                    return False
+                # The stored token belongs to a different Client-ID than the configured one. The
+                # configured Client-ID is the user's deliberate setting, so the stale token is what
+                # has to go -- discard it and ask for a new login.
+                #
+                # Do NOT clear the configured Client-ID here (as this used to do when the token
+                # matched the bundled one). Following the README, a user logs in first and enters
+                # their own Client-ID afterwards, which lands exactly in this branch: clearing the
+                # setting sent them back to the bundled Client-ID, which is confidential and cannot
+                # refresh, so every subsequent login died again an hour later -- and re-entering the
+                # Client-ID triggered the very same wipe. See issue #712.
+                log_utils.log('Error: OAuth Client-ID mismatch, discarding the stored token',
+                              log_utils.LOGERROR)
+                utils.clear_oauth_tokens()
+                _ = kodi.Dialog().ok(
+                    i18n('oauth_token'),
+                    '[CR]'.join([
+                        i18n('client_id_mismatch'),
+                        i18n('get_new_oauth_token') %
+                        (i18n('settings'), i18n('login'), i18n('device_login'))
+                    ])
+                )
+                return False
 
     @cache.cache_method(cache_limit=1)
     def valid_private_token(self, client_id, token):  # client_id used for unique caching only

resources/lib/twitch_addon/addon/strings.py

@@ -108,7 +108,6 @@
     'items': 30214,
     'duration': 30215,
     'curated': 30216,
-    'ok_to_resolve': 30217,
     'search_id_url_description': 30218,
     'authorize_url_fail': 30220,
     'unknown': 30221,

resources/lib/twitch_addon/addon/utils.py

@@ -174,10 +174,6 @@ def get_private_client_id():
     return kodi.decode_utf8(settings_id)
 
 
-def clear_client_id():
-    kodi.set_setting('oauth_clientid', '')
-
-
 def get_oauth_token(token_only=True, required=False):
     oauth_token = _read_oauth_store().get('access', '')
     if not oauth_token or not oauth_token.strip():

resources/lib/twitch_addon/service.py

@@ -19,7 +19,8 @@
 
 from .addon.common import kodi, log_utils
 from .addon.constants import Keys
-from .addon.utils import i18n, get_stamp_diff, get_vodcast_color, ensure_valid_token
+from .addon.utils import (i18n, get_stamp_diff, get_vodcast_color, ensure_valid_token,
+                          get_client_id, get_oauth_token, clear_oauth_tokens)
 from .addon.player import TwitchPlayer
 from .addon import api, cache
 
@@ -202,10 +203,43 @@ def stopped(self):
         return self._stopped.is_set()
 
 
+class SettingsMonitor(xbmc.Monitor):
+    """Discards the stored OAuth token as soon as the configured Client-ID changes.
+
+    A token is only valid for the Client-ID it was issued for. Without this, entering a
+    Client-ID *after* logging in leaves a stale token behind that surfaces much later, on
+    the next API call, as a "Client id mismatch" dialog -- the trap behind issue #712.
+    Dropping the token right here makes the order of "log in" and "set Client-ID"
+    irrelevant: whichever comes last, the user simply logs in once more.
+
+    Note on re-entrancy: clearing the store mirrors the empty values back into the Kodi
+    settings, which fires onSettingsChanged again. Updating self._client_id *before*
+    clearing makes that second call a no-op.
+    """
+
+    def __init__(self):
+        xbmc.Monitor.__init__(self)
+        self._client_id = get_client_id()
+
+    def onSettingsChanged(self):
+        client_id = get_client_id()
+        if client_id == self._client_id:
+            return
+        self._client_id = client_id
+        if not get_oauth_token(token_only=True, required=False):
+            return  # no token stored -> nothing to invalidate
+        clear_oauth_tokens()
+        log_utils.log('OAuth: Client-ID changed, discarded the token issued for the previous one',
+                      log_utils.LOGNOTICE)
+        kodi.notify(header=i18n('client_id_mismatch'),
+                    msg=i18n('get_new_oauth_token') % (i18n('settings'), i18n('login'), i18n('device_login')),
+                    duration=7000)
+
+
 def run():
     log_utils.log('Service: Start', log_utils.LOGNOTICE)
 
-    monitor = xbmc.Monitor()
+    monitor = SettingsMonitor()
 
     check_adaptive()