from enum import Enum
from dataclasses import dataclass
from typing import Optional, Any

class ResultError(Enum):
    """Classified error categories."""
    SUCCESS = "success"
    NOT_SUPPORTED = "NOT_SUPPORTED"
    INVALID_INPUT = "invalid_input"
    CONNECTION = "connection"
    DATABASE = "database"
    PERMISSION = "permission"
    SUBSCRIPTION = "subscription"
    NMCLI = "nmcli_issues"
    FIREWALL = "firewall"
    CLIENT_DNS = "client_dns"
    EXTERNAL_DNS = "external_dns"
    UNKNOWN = "unknown"

@dataclass
class Result():
    valid: bool
    error_type: ResultError = ResultError.SUCCESS
    data: Optional[Any] = None
    message: Optional[str] = None
    
    def user_message(self) -> str:
        """Human-readable error for the UI."""
        messages = {
            DBErrorType.SUCCESS: "Operation completed successfully.",
            DBErrorType.UNKNOWN: f"Error: {self.message}",
        }
        return messages.get(self.error_type, "Unknown error")