"""
任務管理系統 - 支持提交-輪詢模式
"""

import uuid
import asyncio
import logging
from datetime import datetime, timedelta
from typing import Optional, Dict, Any
from enum import Enum
from dataclasses import dataclass, asdict

logger = logging.getLogger(__name__)


class TaskStatus(Enum):
    """任務狀態"""
    PENDING = "pending"          # 等待處理
    PROCESSING = "processing"    # 處理中
    READY = "ready"              # 完成
    FAILED = "failed"            # 失敗


@dataclass
class CaptchaTask:
    """驗證碼任務"""
    task_id: str
    url: str
    sitekey: str
    status: str = TaskStatus.PENDING.value
    token: Optional[str] = None
    error: Optional[str] = None
    created_at: str = None
    updated_at: str = None
    expires_at: str = None
    timeout: int = 30000
    
    def __post_init__(self):
        if self.created_at is None:
            self.created_at = datetime.utcnow().isoformat()
        if self.updated_at is None:
            self.updated_at = datetime.utcnow().isoformat()
        if self.expires_at is None:
            # 默認 30 分鐘過期
            self.expires_at = (datetime.utcnow() + timedelta(minutes=30)).isoformat()
    
    def to_dict(self) -> Dict[str, Any]:
        """轉換為字典"""
        return asdict(self)
    
    def is_expired(self) -> bool:
        """檢查是否過期"""
        return datetime.fromisoformat(self.expires_at) < datetime.utcnow()
    
    def set_processing(self):
        """設置為處理中"""
        self.status = TaskStatus.PROCESSING.value
        self.updated_at = datetime.utcnow().isoformat()
    
    def set_ready(self, token: str):
        """設置為完成"""
        self.status = TaskStatus.READY.value
        self.token = token
        self.updated_at = datetime.utcnow().isoformat()
    
    def set_failed(self, error: str):
        """設置為失敗"""
        self.status = TaskStatus.FAILED.value
        self.error = error
        self.updated_at = datetime.utcnow().isoformat()


class TaskManager:
    """任務管理器"""
    
    def __init__(self, cleanup_interval: int = 300):
        """
        初始化任務管理器
        
        參數:
        - cleanup_interval: 清理過期任務的間隔（秒）
        """
        self.tasks: Dict[str, CaptchaTask] = {}
        self.cleanup_interval = cleanup_interval
        self._cleanup_task = None
    
    async def start(self):
        """啟動任務管理器"""
        self._cleanup_task = asyncio.create_task(self._cleanup_loop())
        logger.info("任務管理器已啟動")
    
    async def stop(self):
        """停止任務管理器"""
        if self._cleanup_task:
            self._cleanup_task.cancel()
        logger.info("任務管理器已停止")
    
    async def _cleanup_loop(self):
        """定期清理過期任務"""
        while True:
            try:
                await asyncio.sleep(self.cleanup_interval)
                self._cleanup_expired_tasks()
            except asyncio.CancelledError:
                break
            except Exception as e:
                logger.error(f"清理任務失敗: {str(e)}")
    
    def _cleanup_expired_tasks(self):
        """清理過期任務"""
        expired_ids = [
            task_id for task_id, task in self.tasks.items()
            if task.is_expired()
        ]
        
        for task_id in expired_ids:
            del self.tasks[task_id]
            logger.info(f"已清理過期任務: {task_id}")
    
    def create_task(self, url: str, sitekey: str, timeout: int = 30000) -> str:
        """
        創建新任務
        
        參數:
        - url: 網頁 URL
        - sitekey: Turnstile sitekey
        - timeout: 超時時間（毫秒）
        
        返回:
        - task_id: 任務 ID
        """
        task_id = str(uuid.uuid4())
        task = CaptchaTask(
            task_id=task_id,
            url=url,
            sitekey=sitekey,
            timeout=timeout
        )
        self.tasks[task_id] = task
        logger.info(f"已創建任務: {task_id}")
        return task_id
    
    def get_task(self, task_id: str) -> Optional[CaptchaTask]:
        """
        獲取任務
        
        參數:
        - task_id: 任務 ID
        
        返回:
        - 任務對象或 None
        """
        return self.tasks.get(task_id)
    
    def update_task_status(self, task_id: str, status: TaskStatus, **kwargs):
        """
        更新任務狀態
        
        參數:
        - task_id: 任務 ID
        - status: 新狀態
        - kwargs: 其他更新字段（token, error 等）
        """
        task = self.get_task(task_id)
        if not task:
            logger.warning(f"任務不存在: {task_id}")
            return
        
        task.status = status.value
        task.updated_at = datetime.utcnow().isoformat()
        
        if status == TaskStatus.READY and 'token' in kwargs:
            task.token = kwargs['token']
        elif status == TaskStatus.FAILED and 'error' in kwargs:
            task.error = kwargs['error']
        
        logger.info(f"已更新任務狀態: {task_id} -> {status.value}")
    
    def get_pending_tasks(self, limit: int = 10) -> list:
        """
        獲取待處理任務
        
        參數:
        - limit: 最多返回任務數
        
        返回:
        - 待處理任務列表
        """
        pending = [
            task for task in self.tasks.values()
            if task.status == TaskStatus.PENDING.value and not task.is_expired()
        ]
        return pending[:limit]
    
    def get_task_stats(self) -> Dict[str, Any]:
        """
        獲取任務統計信息
        
        返回:
        - 統計信息字典
        """
        stats = {
            "total": len(self.tasks),
            "pending": sum(1 for t in self.tasks.values() if t.status == TaskStatus.PENDING.value),
            "processing": sum(1 for t in self.tasks.values() if t.status == TaskStatus.PROCESSING.value),
            "ready": sum(1 for t in self.tasks.values() if t.status == TaskStatus.READY.value),
            "failed": sum(1 for t in self.tasks.values() if t.status == TaskStatus.FAILED.value),
        }
        return stats
    
    def delete_task(self, task_id: str) -> bool:
        """
        刪除任務
        
        參數:
        - task_id: 任務 ID
        
        返回:
        - 是否成功刪除
        """
        if task_id in self.tasks:
            del self.tasks[task_id]
            logger.info(f"已刪除任務: {task_id}")
            return True
        return False


# 全局任務管理器實例
task_manager = TaskManager()