from alive_progress import alive_bar
import math
import requests
import os


class Download():
    def __init__(self, urlPath=None):
        self.urlPath = urlPath
        self.filename = urlPath.split('/')[-1]
        self.header = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36'
        }

    def download(self):
        self.header['Range'] = 'bytes=%s-%s' % (self.fileSize, self.totalSize)
        self.result = requests.get(url=self.urlPath, headers=self.header, stream=True)


    def progress(self):
        with alive_bar(total=math.ceil((self.totalSize - self.fileSize) / 1024), title=self.filename, title_length=10, force_tty=True) as bar:
            with open(self.filename, 'wb') as f:
                for i in self.result.iter_content(chunk_size=1024):
                    f.write(i)
                    bar()

    def checkPath(self):
        self.totalSize = int(requests.head(url=self.urlPath, headers=self.header).headers['Content-Length'])
        if os.path.exists(self.filename):
            self.fileSize = os.path.getsize(self.filename)
            if self.fileSize < self.totalSize:
                print(f'文件{self.filename}断点续传中')
            else:
                print('文件已存在')
                return ''
        else:
            self.fileSize = 0

    def run(self):
        self.checkPath()
        self.download()
        self.progress()

if __name__ == '__main__':
    with open('./url.txt','r') as f:
        urls = f.read().splitlines()
        for url in urls:
            if not url:
                continue
            s = Download(urlPath=url)
            s.run()