---

from abc import ABC, abstractmethod
from datetime import datetime
from queue import Empty, Queue
from threading import Thread, Event


class LoggerBase(ABC):
    @abstractmethod
    def log(self, source, message, task_id=None):
        pass

    @abstractmethod
    def stop(self):
        pass


class ThreadLoggerBase(LoggerBase):
    def __init__(self, log_file):
        self.log_file = log_file
        self.queue = Queue()
        self.stop_event = Event()
        self.thread = Thread(target=self.worker, daemon=False)
        self.thread.start()

    @abstractmethod
    def worker(self):
        pass

    def stop(self):
        self.stop_event.set()
        self.queue.join()
        self.thread.join()


class FileLogger(ThreadLoggerBase):
    def __init__(self, log_file="app.log"):
        super().__init__(log_file)

    def log(self, source, message, task_id=None):
        timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")

        if task_id is not None:
            line = f"[{timestamp}] [{source}] [task_id={task_id}] {message}"
        else:
            line = f"[{timestamp}] [{source}] {message}"

        self.queue.put(line)

    def worker(self):
        with open(self.log_file, "a", encoding="utf-8") as f:
            while not self.stop_event.is_set() or not self.queue.empty():
                try:
                    line = self.queue.get(timeout=0.1)
                except Empty:
                    continue

                try:
                    f.write(line + "\n")
                finally:
                    self.queue.task_done()