__author__ = '行简'

import sys, os

import struct

class WxapkgFile(object):

    nameLen = 0

    name = ""

    offset = 0

    size = 0

def main(dir_path):

    with open(dir_path, "rb") as f:

        root = os.path.dirname(os.path.realpath(f.name))

        name = os.path.basename(f.name) + '_dir'

        if len(sys.argv) > 2:

            name = sys.argv[2]

        firstMark = struct.unpack('B', f.read(1))[0]

        print('first header mark = {}'.format(firstMark))

        info1 = struct.unpack('>L', f.read(4))[0]

        print('info1 = {}'.format(info1))

        indexInfoLength = struct.unpack('>L', f.read(4))[0]

        print('indexInfoLength = {}'.format(indexInfoLength))

        bodyInfoLength = struct.unpack('>L', f.read(4))[0]

        print('bodyInfoLength = {}'.format(bodyInfoLength))

        lastMark = struct.unpack('B', f.read(1))[0]

        print('last header mark = {}'.format(lastMark))

        if firstMark != 0xBE or lastMark != 0xED:

            print('its not a wxapkg file!!!!!')

            f.close()

            exit()

        fileCount = struct.unpack('>L', f.read(4))[0]

        print('fileCount = {}'.format(fileCount))

        fileList = []

        for i in range(fileCount):

            data = WxapkgFile()

            data.nameLen = struct.unpack('>L', f.read(4))[0]

            data.name = f.read(data.nameLen)

            data.offset = struct.unpack('>L', f.read(4))[0]

            data.size = struct.unpack('>L', f.read(4))[0]

            print('readFile = {} at Offset = {}'.format(str(data.name, encoding = "utf-8"), data.offset))

            fileList.append(data)

        for d in fileList:

            d.name = '/' + name + str(d.name, encoding = "utf-8")

            path = root + os.path.dirname(d.name)

            if not os.path.exists(path):

                os.makedirs(path)

            w = open(root + d.name, 'wb')

            f.seek(d.offset)

            w.write(f.read(d.size))

            w.close()

            print('writeFile = {}{}'.format(root, d.name))

        f.close()

if __name__ == '__main__':

    dir_path = r'xxxx'  

    main(dir_path)