import asyncio
from datetime import datetime


class BatchLimiter:
    def __init__(self, max_requests, period):
        self.max_requests = max_requests
        self.period = period
        self.current_requests = 0
        self.start_time = None
        self.lock = asyncio.Lock()

    async def acquire(self):
        async with self.lock:
            if self.current_requests == 0:
                self.start_time = datetime.now()

            if self.current_requests < self.max_requests:
                self.current_requests += 1
                return

            elapsed_time = (datetime.now() - self.start_time).total_seconds()
            if elapsed_time < self.period:
                await asyncio.sleep(self.period - elapsed_time)
                self.current_requests = 1
                self.start_time = datetime.now()
            else:
                self.current_requests = 1
                self.start_time = datetime.now()