Add custom TokenError exception and refactor token handling for impro…

…ved clarity

jwt_helper.py

@@ -10,8 +10,21 @@
 REFRESH_TOKEN_EXPIRY = timedelta(days=30)
 
 
+class TokenError(Exception):
+    """
+    Custom exception for token-related errors.
+    """
+
+    def __init__(self, message, status_code):
+        super().__init__(message)
+        self.status_code = status_code
+        self.message = message
+
+
 def generate_access_token(player_id: int) -> str:
-    """Generate a JWT token for a user."""
+    """
+    Generate a short-lived JWT access token for a user.
+    """
     payload = {
         "player_id": player_id,
         "exp": datetime.now(timezone.utc) + ACCESS_TOKEN_EXPIRY,  # Expiration
@@ -21,7 +34,9 @@ def generate_access_token(player_id: int) -> str:
 
 
 def generate_refresh_token(player_id: int) -> str:
-    """Generate a long-lived refresh token."""
+    """
+    Generate a long-lived refresh token for a user.
+    """
     payload = {
         "player_id": player_id,
         "exp": datetime.now(timezone.utc) + REFRESH_TOKEN_EXPIRY,
@@ -30,35 +45,41 @@ def generate_refresh_token(player_id: int) -> str:
     return jwt.encode(payload, SECRET_KEY, algorithm="HS256")
 
 
-def verify_token(token: str) -> dict | None:
-    """Verify a JWT token and return the payload."""
-    token = request.headers.get("Authorization")
-
-    if not token or not token.startswith("Bearer "):
-        return jsonify(message="Token is missing or improperly formatted"), 401
+def extract_token_from_header() -> str:
+    """
+    Extract the Bearer token from the Authorization header.
+    """
+    auth_header = request.headers.get("Authorization")
+    if not auth_header or not auth_header.startswith("Bearer "):
+        raise TokenError("Token is missing or improperly formatted", 401)
+    return auth_header.split("Bearer ")[1]
 
-    token = token.split("Bearer ")[1]
 
+def verify_token(token: str) -> dict:
+    """
+    Verify and decode a JWT token.
+    """
     try:
         return jwt.decode(token, SECRET_KEY, algorithms=["HS256"])
     except jwt.ExpiredSignatureError:
-        return None  # Token expired
+        raise TokenError("Token has expired", 401)
     except jwt.InvalidTokenError:
-        return None  # Invalid token
+        raise TokenError("Invalid token", 401)
 
 
 def token_required(f):
+    """
+    Decorator to protect routes by requiring a valid token.
+    """
+
     @wraps(f)
     def decorated(*args, **kwargs):
-        token = request.headers.get("Authorization")
-        if not token:
-            return jsonify(message="Token is missing"), 401
-
-        decoded = verify_token(token)
-        if not decoded:
-            return jsonify(message="Token is invalid or expired"), 401
-
-        request.player_id = decoded["player_id"]  # Attach user ID to the request
-        return f(*args, **kwargs)
+        try:
+            token = extract_token_from_header()
+            decoded = verify_token(token)
+            request.player_id = decoded["player_id"]
+            return f(*args, **kwargs)
+        except TokenError as e:
+            return jsonify(message=e.message), e.status_code
 
     return decorated

routes/authentication.py

@@ -8,7 +8,13 @@
 from pymysql import MySQLError
 
 from db import get_db_connection
-from jwt_helper import generate_access_token, generate_refresh_token, verify_token
+from jwt_helper import (
+    generate_access_token,
+    generate_refresh_token,
+    verify_token,
+    extract_token_from_header,
+    TokenError,
+)
 
 load_dotenv()
 
@@ -110,23 +116,12 @@ def login():
 
 @authentication_blueprint.route("/refresh", methods=["POST"])
 def refresh_token():
-    auth_header = request.headers.get("Authorization")
-
-    if not auth_header or not auth_header.startswith("Bearer "):
-        return (
-            jsonify(message="Refresh token is required in the Authorization header"),
-            400,
-        )
-
-    refresh_token = auth_header.split("Bearer ")[1]
-
     try:
-        decoded = verify_token(refresh_token)
+        token = extract_token_from_header()
+        decoded = verify_token(token)
         player_id = decoded["player_id"]
 
         new_access_token = generate_access_token(player_id)
         return jsonify(access_token=new_access_token), 200
-    except jwt.ExpiredSignatureError:
-        return jsonify(message="Refresh token has expired, please log in again"), 401
-    except jwt.InvalidTokenError:
-        return jsonify(message="Invalid refresh token"), 401
+    except TokenError as e:
+        return jsonify(message=e.message), e.status_code