import queue
import threading
import time
from dataclasses import dataclass, field
from typing import Dict, List, Any, Optional
import uuid


@dataclass
class QueueItem:
    """代表队列中的一个评估请求"""
    id: str  # 唯一标识符
    input_data: Dict[str, Any]  # 输入数据
    status: str = "queued"  # 状态：queued, processing, completed, error
    result: Optional[Dict[str, Any]] = None  # 评估结果
    created_at: float = field(default_factory=time.time)  # 创建时间
    started_at: Optional[float] = None  # 开始处理时间
    completed_at: Optional[float] = None  # 完成时间


class QueueManager:
    """管理代码评估请求队列"""
    
    def __init__(self):
        self.queue = queue.Queue()  # 请求队列
        self.queue_items = {}  # 存储所有队列项，以ID为键
        self.processing_thread = None  # 处理线程
        self.running = False  # 是否正在运行
        self.evaluator = None  # 评估器，将在开始时设置
    
    def set_evaluator(self, evaluator_func):
        """设置评估函数
        
        Args:
            evaluator_func: 评估函数，接受输入数据并返回结果
        """
        self.evaluator = evaluator_func
    
    def enqueue(self, input_data):
        """添加新的评估请求到队列
        
        Args:
            input_data: 输入数据，包含要评估的代码
            
        Returns:
            str: 请求的唯一ID
        """
        item_id = str(uuid.uuid4())
        queue_item = QueueItem(id=item_id, input_data=input_data)
        self.queue_items[item_id] = queue_item
        self.queue.put(item_id)
        
        # 如果处理线程未运行，则启动它
        if not self.running:
            self.start_processing()
            
        return item_id
    
    def start_processing(self):
        """启动队列处理线程"""
        if self.processing_thread is None or not self.processing_thread.is_alive():
            self.running = True
            self.processing_thread = threading.Thread(target=self._process_queue)
            self.processing_thread.daemon = True
            self.processing_thread.start()
    
    def stop_processing(self):
        """停止队列处理"""
        self.running = False
        if self.processing_thread and self.processing_thread.is_alive():
            self.processing_thread.join(timeout=1.0)
    
    def _process_queue(self):
        """处理队列中的请求（在单独的线程中运行）"""
        while self.running:
            try:
                # 尝试从队列获取一个项目，如果队列为空，等待1秒后重试
                try:
                    item_id = self.queue.get(timeout=1.0)
                except queue.Empty:
                    continue
                
                # 获取队列项并更新状态
                queue_item = self.queue_items[item_id]
                queue_item.status = "processing"
                queue_item.started_at = time.time()
                
                # 处理请求
                try:
                    if self.evaluator:
                        result = self.evaluator(queue_item.input_data)
                        queue_item.result = result
                        queue_item.status = "completed"
                    else:
                        queue_item.status = "error"
                        queue_item.result = {"status": "Error", "error": "No evaluator function set"}
                except Exception as e:
                    queue_item.status = "error"
                    queue_item.result = {"status": "Exception", "error": str(e)}
                
                # 更新完成时间
                queue_item.completed_at = time.time()
                
                # 标记任务为完成
                self.queue.task_done()
                
            except Exception as e:
                print(f"Error in queue processing: {e}")
                time.sleep(1)  # 防止过度CPU使用
    
    def get_queue_status(self):
        """获取队列状态信息
        
        Returns:
            dict: 包含队列状态的字典
        """
        queued = 0
        processing = 0
        completed = 0
        error = 0
        
        # 统计各状态的数量
        for item in self.queue_items.values():
            if item.status == "queued":
                queued += 1
            elif item.status == "processing":
                processing += 1
            elif item.status == "completed":
                completed += 1
            elif item.status == "error":
                error += 1
        
        # 获取队列中的项目，仅包括等待和处理中的
        queue_items = []
        for item in self.queue_items.values():
            if item.status in ["queued", "processing"]:
                queue_items.append({
                    "id": item.id,
                    "status": item.status,
                    "created_at": item.created_at,
                    "started_at": item.started_at,
                })
        
        # 按创建时间排序
        queue_items.sort(key=lambda x: x["created_at"])
        
        return {
            "stats": {
                "queued": queued,
                "processing": processing,
                "completed": completed,
                "error": error,
                "total": len(self.queue_items)
            },
            "queue_items": queue_items
        }
    
    def get_result(self, item_id):
        """获取特定请求的结果
        
        Args:
            item_id: 请求的唯一ID
            
        Returns:
            dict: 请求的状态和结果
        """
        if item_id in self.queue_items:
            item = self.queue_items[item_id]
            return {
                "id": item.id,
                "status": item.status,
                "result": item.result,
                "created_at": item.created_at,
                "started_at": item.started_at,
                "completed_at": item.completed_at
            }
        return {"status": "not_found", "error": "Request ID not found"}
    
    def clean_completed(self, max_age=3600):
        """清理完成的请求
        
        Args:
            max_age: 最大保留时间（秒），默认为1小时
        """
        current_time = time.time()
        to_remove = []
        
        for item_id, item in self.queue_items.items():
            if item.status in ["completed", "error"]:
                if item.completed_at and (current_time - item.completed_at) > max_age:
                    to_remove.append(item_id)
        
        for item_id in to_remove:
            del self.queue_items[item_id]