"""
全局请求速率限制器
确保代理每秒不超过5次请求
"""
import time
import threading
from collections import deque


class RateLimiter:
    """
    令牌桶算法实现的速率限制器
    """
    def __init__(self, max_requests_per_second: int = 5):
        """
        初始化速率限制器
        
        Args:
            max_requests_per_second: 每秒最大请求数
        """
        self.max_requests = max_requests_per_second
        self.requests = deque()
        self.lock = threading.RLock()
    
    def acquire(self):
        """
        获取请求权限，如果需要则等待
        """
        with self.lock:
            now = time.time()
            
            # 清理超过1秒的请求记录
            while self.requests and now - self.requests[0] >= 1.0:
                self.requests.popleft()
            
            # 如果当前请求数已达上限，等待
            if len(self.requests) >= self.max_requests:
                # 计算需要等待的时间
                wait_time = 1.0 - (now - self.requests[0])
                if wait_time > 0:
                    time.sleep(wait_time)
                    return self.acquire()  # 递归调用以重新检查
            
            # 记录这次请求
            self.requests.append(now)
    
    def can_make_request(self) -> bool:
        """
        检查是否可以立即发起请求（非阻塞）
        """
        with self.lock:
            now = time.time()
            
            # 清理超过1秒的请求记录
            while self.requests and now - self.requests[0] >= 1.0:
                self.requests.popleft()
            
            return len(self.requests) < self.max_requests


# 全局速率限制器实例
global_rate_limiter = RateLimiter(max_requests_per_second=5)


def wait_for_request():
    """
    等待直到可以发起请求
    """
    global_rate_limiter.acquire()


def can_request_now() -> bool:
    """
    检查是否可以立即发起请求
    """
    return global_rate_limiter.can_make_request()