import os
import pickle
import requests
import bs4
import concurrent.futures

from .Logger import Logger


class ProxyHandler:
	PROXY_FILE_NAME = 'temp/proxy.bin'

	def __init__(self):
		if not os.path.exists('temp'):
			os.makedirs('temp')

		self.proxies = []
		self.check_url = ''

	def check_proxy(self, proxy, top_url):
		try:
			resp = requests.get(top_url, proxies=proxy, timeout=2)
		except:
			proxy['alive'] = False
		else:
			if resp.status_code != 200:
				proxy['alive'] = False

	def check_proxy_all(self, proxies, check_url):
		Logger.log('checking proxies for {}'.format(check_url))

		worker_cnt = 16
		pool = concurrent.futures.ThreadPoolExecutor(worker_cnt)
		[pool.submit(self.check_proxy, proxy, check_url) for proxy in proxies]
		pool.shutdown()

	def has_file(self):
		return os.path.exists(self.PROXY_FILE_NAME)

	def load_proxy(self):
		with open(self.PROXY_FILE_NAME, 'rb') as f:
			proxies = pickle.load(f)

		return proxies

	def crawl_proxy(self):
		proxies = []

		resp = requests.get('https://www.us-proxy.org')
		soup = bs4.BeautifulSoup(resp.text, 'lxml')
		table = soup.select('table.table')
		trs = table[0].select('tr')
		for tr in trs[1:]:
			tds = tr.select('td')
			if len(tds) < 2:
				continue

			ip, port = tds[0].text, tds[1].text
			proxies.append(
				{
					'alive': True,
					'http': '{}:{}'.format(ip, port),
					'https': '{}:{}'.format(ip, port),
				}
			)

		self.check_proxy_all(proxies, self.check_url)
		alive_proxies = [proxy for proxy in proxies if proxy['alive']]
		Logger.log('proxies checking end: available : {}'.format(len(alive_proxies)))

		with open(self.PROXY_FILE_NAME, 'wb') as f:
			pickle.dump(alive_proxies, f)

		return alive_proxies

	def get_proxy(self):
		if len(self.proxies) <= 0:
			if self.has_file():
				self.proxies = self.load_proxy()
			else:
				self.proxies = self.crawl_proxy()

		for proxy in self.proxies:
			if proxy['alive']:
				return proxy

		return None

	def set_proxy_dead(self, proxy):
		proxy['alive'] = False
		for proxy in self.proxies:
			if proxy['alive']:
				with open(self.PROXY_FILE_NAME, 'wb') as f:
					pickle.dump(self.proxies, f)
				return

		os.remove(self.PROXY_FILE_NAME)
		self.proxies = []