"""
Task state management for Sanguo Orchestrator
Defines Task state machine and transitions
"""
import enum
from dataclasses import dataclass
from typing import Any


class TaskState(enum.Enum):
    """Task execution states"""
    PENDING = "pending"
    RUNNING = "running"
    DONE = "done"
    FAILED = "failed"


@dataclass
class Task:
    """Represents a task in the orchestrator"""
    task_id: str
    task_type: str
    status: TaskState = TaskState.PENDING
    result_id: int | None = None
    raw_result: Any = None  # in-memory result object (e.g. FactorReport for factor tasks)
    error_msg: str | None = None
    stage: str = ""  # Current stage (数据加载/算因子/回测中...)

    def start(self):
        """Transition from PENDING to RUNNING"""
        if self.status != TaskState.PENDING:
            raise ValueError(f"不能从 {self.status.name} 启动")
        self.status = TaskState.RUNNING

    def complete(self, result_id: int):
        """Transition to DONE with result"""
        self.status = TaskState.DONE
        self.result_id = result_id

    def fail(self, error_msg: str):
        """Transition to FAILED with error message"""
        self.status = TaskState.FAILED
        self.error_msg = error_msg