Update auth.py

auth.py

@@ -1,5 +1,6 @@
+# auth.py
 from fastapi import APIRouter, Request, HTTPException
-from fastapi.responses import RedirectResponse
+from fastapi.responses import RedirectResponse, JSONResponse
 from google_auth_oauthlib.flow import Flow
 from dotenv import load_dotenv
 import os
@@ -9,19 +10,13 @@ router = APIRouter()
 
 CLIENT_ID = os.getenv("GOOGLE_CLIENT_ID")
 CLIENT_SECRET = os.getenv("GOOGLE_CLIENT_SECRET")
-ENV_REDIRECT_URI = os.getenv("REDIRECT_URI")  # optional override
+ENV_REDIRECT_URI = os.getenv("REDIRECT_URI")  # optional
 
 SCOPES = ["https://www.googleapis.com/auth/calendar"]
 
 def build_redirect_uri(request: Request) -> str:
-    """
-    Prefer env REDIRECT_URI if set.
-    Otherwise, derive from request with proxy headers so it works on HF + local.
-    """
     if ENV_REDIRECT_URI:
         return ENV_REDIRECT_URI.strip().rstrip("/")
-
-    # Respect reverse proxy headers (HF Spaces)
     proto = request.headers.get("x-forwarded-proto") or request.url.scheme
     host = request.headers.get("x-forwarded-host") or request.headers.get("host") or request.url.hostname
     return f"{proto}://{host}/auth/callback".rstrip("/")
@@ -45,8 +40,6 @@ def login(request: Request):
     redirect_uri = build_redirect_uri(request)
     flow = build_flow(redirect_uri)
     flow.redirect_uri = redirect_uri
-
-    # IMPORTANT: offline access so we get refresh_token
     auth_url, _ = flow.authorization_url(
         prompt="consent",
         include_granted_scopes="true",
@@ -54,23 +47,61 @@ def login(request: Request):
     )
     return RedirectResponse(auth_url)
 
-@router.get("/auth/callback")
+# accept GET/POST and trailing slash
+@router.api_route("/auth/callback", methods=["GET", "POST"])
+@router.api_route("/auth/callback/", methods=["GET", "POST"])
 async def auth_callback(request: Request):
+    # try query first
     code = request.query_params.get("code")
-    if not code:
-        raise HTTPException(status_code=400, detail="Missing code")
+    # also accept POST (some proxies can end up posting back)
+    if not code and request.method == "POST":
+        try:
+            form = await request.form()
+            code = form.get("code")
+        except Exception:
+            code = None
 
     redirect_uri = build_redirect_uri(request)
     flow = build_flow(redirect_uri)
     flow.redirect_uri = redirect_uri
 
+    if not code:
+        # Return diagnostics so we can see what arrived
+        return JSONResponse(
+            status_code=400,
+            content={
+                "detail": "Missing code",
+                "method": request.method,
+                "url": str(request.url),
+                "query": dict(request.query_params),
+                "headers": {
+                    "x-forwarded-proto": request.headers.get("x-forwarded-proto"),
+                    "x-forwarded-host": request.headers.get("x-forwarded-host"),
+                    "host": request.headers.get("host"),
+                },
+                "derived_redirect_uri": redirect_uri,
+            },
+        )
+
     try:
         flow.fetch_token(code=code)
-        credentials = flow.credentials
+        cred = flow.credentials
         return {
-            "access_token": credentials.token,
-            "refresh_token": credentials.refresh_token,
-            "expiry": credentials.expiry.isoformat() if credentials.expiry else None,
+            "access_token": cred.token,
+            "refresh_token": cred.refresh_token,
+            "expiry": cred.expiry.isoformat() if cred.expiry else None,
         }
     except Exception as e:
         raise HTTPException(status_code=500, detail=f"Failed to fetch token: {e}")
+
+@router.get("/auth/debug")
+def auth_debug(request: Request):
+    return {
+        "derived_redirect_uri": build_redirect_uri(request),
+        "request_url": str(request.url),
+        "headers": {
+            "x-forwarded-proto": request.headers.get("x-forwarded-proto"),
+            "x-forwarded-host": request.headers.get("x-forwarded-host"),
+            "host": request.headers.get("host"),
+        },
+    }