"""Implementation of a threaded version of a scraper."""

from typing import List, Callable
from multiprocessing import cpu_count, Lock
from multiprocessing.pool import ThreadPool

from scrapthechan.scraper import Scraper
from scrapthechan.fileinfo import FileInfo


__all__ = ["ThreadedScraper"]


class ThreadedScraper(Scraper):
	def __init__(self, save_directory: str, files: List[FileInfo],
		download_progress_callback: Callable[[int], None] = None) -> None:
		super().__init__(save_directory, files, download_progress_callback)
		self._files_downloaded = 0
		self._files_downloaded_mutex = Lock()

	def run(self):
		pool = ThreadPool(cpu_count() * 2)
		pool.map(self._thread_run, self._files)
		pool.close()
		pool.join()

	def _thread_run(self, f: FileInfo):
		if not self._progress_callback is None:
			with self._files_downloaded_mutex:
				self._files_downloaded += 1
				self._progress_callback(self._files_downloaded)
		self._download_file(f)