'''
author:Ericam
description: 用于爬取b站视频链接
'''
import requests
import re
from lxml import etree
import time

'''
该函数用于解析爬取的网页。
提取出网页里视频的url链接以及对应的视频名。
'''
def getHref(url,page):
 try:
 req = requests.get(url,timeout=5,headers=headers)
 html = req.text
 data = etree.HTML(html)
 '''
 page-1://*[@id="all-list"]/div[1]/div[2]/ul[@class="video-list"]/li
 other://*[@id="all-list"]/div[1]/ul[@class="video-list"]/li
 '''
 pattern = '//*[@id="all-list"]/div[1]/div[2]/ul[contains(@class,"video-list")]/li' if page == 1 else '//*[@id="all-list"]/div[1]/ul[contains(@class,"video-list")]/li'
 vurlList = data.xpath(pattern)
 for li in vurlList:
  vurl = li.xpath(".//a/attribute::href")[0]
  title = li.xpath(".//a/attribute::title")[0]
  yield vurl,title
 except:
 print('第%d页爬取失败' % page)
 print('Unfortunitely -- An Unknow Error Happened, Please wait 3 seconds')
 time.sleep(3)

'''
该函数用于正则提取，将url内的BV号提取出来
'''
def getBv(href):
 pattern = re.compile('(BV.*"__main__":

 #头部伪装
 headers = {
 'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36 QIHU 360SE'
 }
 hrefList = []
 titleList = []
 #需要爬取多少页，自行进行修改，本代码测试1~2页
 for i in range(1,3): 
 url = "https://search.bilibili.com/all".format(i) #修改keyword后的关键字即可
 l = getHref(url,i)
 for vurl,title in l:
  hrefList.append(vurl)
  titleList.append(title)
 print("第{0}页爬取结束".format(i))
 time.sleep(2)
 
 print("---------------------------开始截取BV号-----------------------------")
 for i in range(len(hrefList)):
 hrefList[i] = getBv(hrefList[i])
 with open("bv.txt",'w',encoding='utf-8') as f:
 for i in range(len(hrefList)): 
  f.write(hrefList[i]+"\t"+titleList[i]+"\n")
 print("爬取结束")

'''
author:Ericam
description: 用于将下载下来的b站视频重命名，命名格式为bv号
'''
import os
import difflib

if __name__ == '__main__':
 
 bvpath = os.path.join("D:/","Coding","python","Python爬虫")
 os.chdir(bvpath)
 d = {}
 '''
 bvdownload.txt里存放bv号与title名
 若之前爬虫爬取了几千个，而唧唧只下载了几百个，便可以将这些已下载的bv和title复制到
 bvdownload.txt中，将已下载的视频进行改名
 '''
 with open("bvdownload.txt",'r',encoding='utf-8')as f:
 lines = f.readlines()
 for val in lines:
  val = val.strip("\n")
  data = val.split("\t")
  bv = data[0]
  title = data[1]
  d[title] = bv
 
 #视频存放位置
 path = 'F:/bilibili视频/'
 os.chdir(path)
 videoList = os.listdir()
 
 #开始进行模糊匹配
 for key in d:
 video = difflib.get_close_matches(key,videoList,1, cutoff=0.3)
 if len(video) == 0:
  continue
 video = video[0]
 #检查视频是否已存在,若存在则删除视频
 if os.path.isfile(d[key]+".mp4") and os.path.isfile(video):
  os.remove(video)
 else:
  if os.path.isfile(video):
  os.rename(video,d[key]+".mp4")
 print("重命名完成！")