import heapq
import threading
import time

from llm_server.llm.generator import generator
from llm_server.routes.stats import generation_elapsed, generation_elapsed_lock


class PriorityQueue:
    def __init__(self):
        self._queue = []
        self._index = 0
        self._cv = threading.Condition()

    def put(self, item, priority):
        event = DataEvent()
        with self._cv:
            heapq.heappush(self._queue, (-priority, self._index, item, event))
            self._index += 1
            self._cv.notify()
        return event

    def get(self):
        with self._cv:
            while len(self._queue) == 0:
                self._cv.wait()
            return heapq.heappop(self._queue)

    def __len__(self):
        return len(self._queue)


priority_queue = PriorityQueue()


class DataEvent(threading.Event):
    def __init__(self):
        super().__init__()
        self.data = None


def worker():
    while True:
        priority, index, (request_json_body, client_ip, token, parameters), event = priority_queue.get()
        start_time = time.time()
        success, response, error_msg = generator(request_json_body)

        end_time = time.time()
        elapsed_time = end_time - start_time
        with generation_elapsed_lock:
            generation_elapsed.append((end_time, elapsed_time))

        event.data = (success, response, error_msg)
        event.set()


def start_workers(num_workers: int):
    for _ in range(num_workers):
        threading.Thread(target=worker).start()