import threading
from concurrent.futures import ThreadPoolExecutor, wait

from crawler.spiders import SearchEngine, VisitDomain, SyncData
from crawler.utils import err_details


class BreadthCrawler(SearchEngine, VisitDomain):

    def __init__(self, workers=1, **kwargs):
        SyncData(**kwargs)
        SearchEngine.__init__(self, **kwargs)
        VisitDomain.__init__(self, **kwargs)
        self._workers = workers

    def start(self):
        threading.Thread(
            target=self.load_engines,
            name='MainSearchEngine'
        ).start()
        with ThreadPoolExecutor(max_workers=self._workers) as executor:
            futures = []
            for _ in range(1, self._workers + 1):
                f = executor.submit(self.search_domains)
                f.add_done_callback(err_details)
                futures.append(f)
            wait(futures)
        print('寻源任务结束')