v2.3.2: add Google Gemini provider with OAuth support

- Two presets: API Key and OAuth modes
- OAuth Login button: full Google OAuth2 flow with auto-refresh
- Auto-refreshes expired access tokens using refresh_token
- Gemini OpenAI-compatible endpoint works with existing proxy
- Models: gemini-2.5-flash, gemini-2.5-pro, gemini-2.0-flash, etc.

src/translate-proxy.py

@@ -79,11 +79,47 @@ PORT = CONFIG["port"]
 BACKEND = CONFIG["backend_type"]
 TARGET_URL = CONFIG["target_url"].rstrip("/")
 API_KEY = CONFIG["api_key"]
+OAUTH_PROVIDER = CONFIG.get("oauth_provider", "")
 MODELS = CONFIG["models"]
 CC_VERSION = CONFIG.get("cc_version", "")
 REASONING_ENABLED = CONFIG.get("reasoning_enabled", True)
 REASONING_EFFORT = CONFIG.get("reasoning_effort", "medium")
 
+def _refresh_oauth_token():
+    if OAUTH_PROVIDER != "google":
+        return API_KEY
+    token_path = os.path.join(os.path.expanduser("~"), ".cache", "codex-proxy", "google-oauth-token.json")
+    if not os.path.exists(token_path):
+        return API_KEY
+    try:
+        with open(token_path) as f:
+            tokens = json.load(f)
+        if tokens.get("expires_at", 0) > time.time() + 60:
+            return tokens.get("access_token", API_KEY)
+        client_id = tokens.get("client_id", "")
+        client_secret = tokens.get("client_secret", "")
+        refresh_token = tokens.get("refresh_token", "")
+        if not all([client_id, client_secret, refresh_token]):
+            return tokens.get("access_token", API_KEY)
+        print("[oauth] refreshing Google access token...", file=sys.stderr)
+        data = urllib.parse.urlencode({
+            "client_id": client_id, "client_secret": client_secret,
+            "refresh_token": refresh_token, "grant_type": "refresh_token",
+        }).encode()
+        req = urllib.request.Request("https://oauth2.googleapis.com/token", data=data,
+                                     headers={"Content-Type": "application/x-www-form-urlencoded"})
+        resp = urllib.request.urlopen(req, timeout=30)
+        new_tokens = json.loads(resp.read())
+        tokens["access_token"] = new_tokens.get("access_token", tokens.get("access_token"))
+        tokens["expires_at"] = time.time() + new_tokens.get("expires_in", 3600)
+        with open(token_path, "w") as f:
+            json.dump(tokens, f, indent=2)
+        print("[oauth] token refreshed OK", file=sys.stderr)
+        return tokens["access_token"]
+    except Exception as e:
+        print(f"[oauth] refresh failed: {e}", file=sys.stderr)
+        return API_KEY
+
 # ═══════════════════════════════════════════════════════════════════
 # Shared helpers
 # ═══════════════════════════════════════════════════════════════════
@@ -1000,9 +1036,10 @@ class Handler(http.server.BaseHTTPRequestHandler):
             chat_body["reasoning_effort"] = REASONING_EFFORT
 
         target = upstream_target(TARGET_URL, "/chat/completions")
+        effective_key = _refresh_oauth_token()
         fwd = forwarded_headers(self.headers, {
             "Content-Type": "application/json",
-            "Authorization": f"Bearer {API_KEY}",
+            "Authorization": f"Bearer {effective_key}",
         }, browser_ua=True)
         print(f"[translate-proxy] POST {target} model={model} stream={stream} items={len(input_data) if isinstance(input_data,list) else 1} ua={fwd.get('User-Agent','')[:50]}", file=sys.stderr)