Add comprehensive error handling and debugging for signup issues

- Enhanced login endpoint with detailed logging for debugging JWT token issues
- Added explicit is_google_user and email_verified flags during registration
- Added test endpoints for JWT token creation verification
- Added debug endpoint to check user authentication status
- Improved error handling and logging throughout authentication flow
- Better validation for password vs Google OAuth users

Debug endpoints added:
- POST /auth/test-token - Test JWT token creation
- GET /auth/debug/user/{email} - Check user authentication status

This will help identify why JWT tokens are not being returned during signin.

app/routes/auth.py

@@ -23,6 +23,46 @@ async def test_auth():
     }
 
 
+@router.post("/test-token")
+async def test_token_creation():
+    """Test endpoint to verify JWT token creation is working"""
+    try:
+        test_token = create_access_token(data={"sub": "test@example.com"})
+        return {
+            "message": "Token creation successful",
+            "token_length": len(test_token),
+            "token_preview": test_token[:50] + "..." if len(test_token) > 50 else test_token
+        }
+    except Exception as e:
+        logger.error(f"Token creation test failed: {e}")
+        return {
+            "message": "Token creation failed",
+            "error": str(e)
+        }
+
+
+@router.get("/debug/user/{email}")
+async def debug_user_status(email: str, db: Session = Depends(get_db)):
+    """Debug endpoint to check user status - REMOVE IN PRODUCTION"""
+    try:
+        db_user = db.query(User).filter(User.email == email).first()
+        if not db_user:
+            return {"message": "User not found", "email": email}
+        
+        return {
+            "email": db_user.email,
+            "has_password_hash": db_user.password_hash is not None,
+            "password_hash_length": len(db_user.password_hash) if db_user.password_hash else 0,
+            "is_google_user": db_user.is_google_user,
+            "email_verified": db_user.email_verified,
+            "can_login_with_password": db_user.can_login_with_password(),
+            "created_at": str(db_user.created_at),
+            "google_id": db_user.google_id
+        }
+    except Exception as e:
+        return {"error": str(e)}
+
+
 class UserCreate(BaseModel):
     email: EmailStr
     password: str
@@ -63,15 +103,19 @@ async def register(user: UserCreate, db: Session = Depends(get_db)):
         
         # Hash password and create user
         hashed_password = get_password_hash(user.password)
+        logger.info(f"Password hashed successfully for user: {user.email}")
+        
         db_user = User(
             email=user.email,
-            password_hash=hashed_password
+            password_hash=hashed_password,
+            is_google_user=False,  # Explicitly set for password users
+            email_verified=False   # Email not verified for regular registration
         )
         db.add(db_user)
         db.commit()
         db.refresh(db_user)
         
-        logger.info(f"User registered successfully: {user.email}")
+        logger.info(f"User registered successfully: {user.email}, can_login_with_password: {db_user.can_login_with_password()}")
         return UserResponse(
             id=db_user.id,
             email=db_user.email,
@@ -91,35 +135,55 @@ async def register(user: UserCreate, db: Session = Depends(get_db)):
 
 @router.post("/login", response_model=Token)
 async def login(user: UserLogin, db: Session = Depends(get_db)):
-    db_user = db.query(User).filter(User.email == user.email).first()
+    try:
+        logger.info(f"Login attempt for email: {user.email}")
         
-    # Check if user exists
+        db_user = db.query(User).filter(User.email == user.email).first()
-    if not db_user:
+        
+        # Check if user exists
+        if not db_user:
+            logger.warning(f"Login failed - user not found: {user.email}")
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Incorrect email or password",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        
+        logger.info(f"User found: {user.email}, is_google_user: {db_user.is_google_user}, has_password: {db_user.password_hash is not None}")
+        
+        # Check if user can login with password
+        if not db_user.can_login_with_password():
+            logger.warning(f"Login failed - Google user attempted password login: {user.email}")
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="This account uses Google sign-in. Please use Google to login.",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        
+        # Verify password
+        if not verify_password(user.password, db_user.password_hash):
+            logger.warning(f"Login failed - incorrect password: {user.email}")
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Incorrect email or password",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        
+        # Create token
+        access_token = create_access_token(data={"sub": db_user.email})
+        logger.info(f"Login successful for user: {user.email}")
+        
+        return {"access_token": access_token, "token_type": "bearer"}
+        
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Login error for {user.email}: {str(e)}")
         raise HTTPException(
-            status_code=status.HTTP_401_UNAUTHORIZED,
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="Incorrect email or password",
+            detail="Internal server error during login"
-            headers={"WWW-Authenticate": "Bearer"},
         )
 
-    # Check if user can login with password
-    if not db_user.can_login_with_password():
-        raise HTTPException(
-            status_code=status.HTTP_401_UNAUTHORIZED,
-            detail="This account uses Google sign-in. Please use Google to login.",
-            headers={"WWW-Authenticate": "Bearer"},
-        )
-    
-    # Verify password
-    if not verify_password(user.password, db_user.password_hash):
-        raise HTTPException(
-            status_code=status.HTTP_401_UNAUTHORIZED,
-            detail="Incorrect email or password",
-            headers={"WWW-Authenticate": "Bearer"},
-        )
-    
-    access_token = create_access_token(data={"sub": db_user.email})
-    return {"access_token": access_token, "token_type": "bearer"}
-
 
 # Google OAuth Models
 class GoogleTokenLogin(BaseModel):