import threading
import time


class APIRateLimiter:
    """API rate limiter"""
    
    def __init__(self, calls_per_second=2):
        self.min_interval = 1.0 / calls_per_second
        self.last_call = {}
        self.lock = threading.Lock()
    
    def wait(self, api_name):
        """Wait until API can be called"""
        with self.lock:
            current_time = time.time()
            if api_name in self.last_call:
                elapsed = current_time - self.last_call[api_name]
                if elapsed < self.min_interval:
                    time.sleep(self.min_interval - elapsed)
            self.last_call[api_name] = current_time