import asyncio
import json
import uuid
from dataclasses import dataclass, field
from typing import Optional


@dataclass
class TaskState:
    """单个提取任务的状态"""

    task_id: str = ""
    is_running: bool = False
    cancel_event: asyncio.Event = field(default_factory=asyncio.Event)
    progress: dict = field(default_factory=lambda: {
        "percent": 0,
        "status": "idle",
        "current_file": "",
        "action": "",
        "files_total": 0,
        "files_completed": 0,
        "stories_found": 0,
        "phase": "",
        "phase_percent": 0,
        "phase_detail": "",
    })
    _queue: asyncio.Queue = field(default_factory=asyncio.Queue)

    def update(self, **kwargs):
        """更新进度，同时推送到 SSE 队列"""
        self.progress.update(kwargs)
        try:
            self._queue.put_nowait(self.progress.copy())
        except asyncio.QueueFull:
            pass

    async def get_update(self) -> dict:
        """SSE 消费端：等待新的进度更新"""
        return await self._queue.get()

    def reset(self):
        """重置状态"""
        self.is_running = False
        self.cancel_event = asyncio.Event()
        self.progress = {
            "percent": 0,
            "status": "idle",
            "current_file": "",
            "action": "",
            "files_total": 0,
            "files_completed": 0,
            "stories_found": 0,
            "phase": "",
            "phase_percent": 0,
            "phase_detail": "",
        }
        self._queue = asyncio.Queue()


class TaskManager:
    """多任务管理器：支持多个用户同时提取"""

    def __init__(self):
        self._tasks: dict[str, TaskState] = {}

    def create_task(self) -> TaskState:
        """创建新任务"""
        task_id = uuid.uuid4().hex[:12]
        state = TaskState(task_id=task_id)
        self._tasks[task_id] = state
        return state

    def get_task(self, task_id: str) -> Optional[TaskState]:
        """获取任务状态"""
        return self._tasks.get(task_id)

    def remove_task(self, task_id: str):
        """清理已完成的任务"""
        self._tasks.pop(task_id, None)

    def cleanup_old_tasks(self):
        """清理所有非运行中的任务"""
        to_remove = [
            tid for tid, state in self._tasks.items()
            if not state.is_running
        ]
        for tid in to_remove:
            self._tasks.pop(tid, None)


# 全局任务管理器
task_manager = TaskManager()

# 向后兼容：默认任务（单用户场景）
extraction_state = TaskState()