Add custom exceptions handling

app/exceptions/auth.py

@@ -0,0 +1,95 @@
+# app/exceptions/auth.py
+"""
+Authentication and authorization specific exceptions.
+"""
+
+from typing import Any, Dict, Optional
+from .base import AuthenticationException, AuthorizationException
+
+
+class InvalidCredentialsException(AuthenticationException):
+    """Raised when login credentials are invalid."""
+
+    def __init__(self, message: str = "Invalid username or password"):
+        super().__init__(
+            message=message,
+            error_code="INVALID_CREDENTIALS",
+        )
+
+
+class TokenExpiredException(AuthenticationException):
+    """Raised when JWT token has expired."""
+
+    def __init__(self, message: str = "Token has expired"):
+        super().__init__(
+            message=message,
+            error_code="TOKEN_EXPIRED",
+        )
+
+
+class InvalidTokenException(AuthenticationException):
+    """Raised when JWT token is invalid or malformed."""
+
+    def __init__(self, message: str = "Invalid token"):
+        super().__init__(
+            message=message,
+            error_code="INVALID_TOKEN",
+        )
+
+
+class InsufficientPermissionsException(AuthorizationException):
+    """Raised when user lacks required permissions for an action."""
+
+    def __init__(
+            self,
+            message: str = "Insufficient permissions for this action",
+            required_permission: Optional[str] = None,
+    ):
+        details = {}
+        if required_permission:
+            details["required_permission"] = required_permission
+
+        super().__init__(
+            message=message,
+            error_code="INSUFFICIENT_PERMISSIONS",
+            details=details,
+        )
+
+
+class UserNotActiveException(AuthorizationException):
+    """Raised when user account is not active."""
+
+    def __init__(self, message: str = "User account is not active"):
+        super().__init__(
+            message=message,
+            error_code="USER_NOT_ACTIVE",
+        )
+
+
+class AdminRequiredException(AuthorizationException):
+    """Raised when admin privileges are required."""
+
+    def __init__(self, message: str = "Admin privileges required"):
+        super().__init__(
+            message=message,
+            error_code="ADMIN_REQUIRED",
+        )
+
+
+class UserAlreadyExistsException(AuthenticationException):
+    """Raised when trying to register with existing username/email."""
+
+    def __init__(
+            self,
+            message: str = "User already exists",
+            field: Optional[str] = None,
+    ):
+        details = {}
+        if field:
+            details["field"] = field
+
+        super().__init__(
+            message=message,
+            error_code="USER_ALREADY_EXISTS",
+            details=details,
+        )