#!/usr/bin/python3

import urllib.parse
import urllib.request
import urllib.response
import logging
import re
import argparse

logger = logging.getLogger('login_manager')

def generate_post_data(username: str, password: str):
    '''
    Generate bytes to send to through HTTP POST, an example from browser:

    DDDDD=2021020000&upass=Bistu000000&R1=0&R2=&R3=0&R6=0&para=00&0MKKey=123456&buttonClicked=&redirect_url=&err_flag=&username=&password=&user=&cmd=&Login=
    '''

    data_template = {
        'DDDDD': None,
        'upass': None,
        'R1': 0,
        'R2': '',
        'R3': 0,
        'R6': 0,
        'para': 00,
        '0MKKey': 123456,
        'buttonClicked': '',
        'redirect_url': '',
        'err_flag': '',
        'username': '',
        'password': '',
        'user': '',
        'cmd': '',
        'Login': ''
    }

    data_template['DDDDD'] = username
    data_template['upass'] = password

    # login_manager.generate_post_data_hook(data_template)

    logger.debug('the generated post data is %s', str(data_template))

    return bytes(urllib.parse.urlencode(data_template), 'utf-8')

def login(username: str, password: str, host: str = '10.1.206.13'):
    '''
    There are some other host, the known are:

    - 10.1.206.3 (default)
    - 192.168.211.3
    '''
    headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8',
        'Accept-Language': 'en-US,zh-CN;q=0.5',
        'Accept-Encoding': 'gzip, deflate'
    }
    post_data = generate_post_data(username, password)

    login_url = f'http://{host}/a70.htm'
    logger.debug('the dest url is: %s', login_url)
    logger.debug('the headers is: %s', str(headers))
    logger.debug('the encoded post data is %s', str(post_data))

    req = urllib.request.Request(url=login_url, data=post_data, headers=headers, method='POST')

    logger.info('sending the login request...')

    with urllib.request.urlopen(req) as response:
        response_body = response.read().decode('gbk')

        html_title = re.search('<title>(.*)</title>', response_body)[1]

        logger.info('http_status: %d', response.status)
        logger.info('title_of_response_html: %s', html_title)
        logger.info('login_state: %s', 'success' if html_title == '认证成功页' else 'fail')

def logout(host: str = '10.1.206.13'):
    '''
    param host: see login host
    '''

    logout_url = f'http://{host}/F.htm'
    req = urllib.request.Request(url=logout_url)

    logger.info('sending the logout request...')

    with urllib.request.urlopen(req) as response:
        response_body = response.read().decode('gbk')

        html_title = re.search('<title>(.*)</title>', response_body)[1]

        logger.info('http_status: %d', response.status)
        logger.info('title_of_response_html: %s', html_title)
        logger.info('logout_state: %s', 'success' if html_title == '信息页' else 'fail')

    #@staticmethod
    #def generate_post_data_hook(post_data: dict) -> None:
    #    username = post_data['DDDDD']
    #    username += '@bistu'
    #    post_data['DDDDD'] = username


def load_auth_info(path: str):
    with open(path, 'r', encoding='utf-8') as file:
        username = file.readline().strip()
        password = file.readline().strip()

        host = file.readline().strip()
        if host == '':
            host = None

        return username, password, host

def main():
    logging.basicConfig(level=logging.DEBUG)
    logger = logging.getLogger('main')

    parser = argparse.ArgumentParser()
    parser.description = 'login or logout bistu wifi'
    parser.epilog = 'the config file format(without quote): "{username}\\n{password}". The "\\n" is a newline charactor'

    parser.add_argument('-u', '--username', nargs='?',
                        type=str, help='username you use to login bistu wifi, logout if not provided')
    parser.add_argument('-p', '--password', nargs='?',
                        type=str, help='password you use to login bistu wifi, logout if not provided')
    parser.add_argument('--host', nargs='?', default=None,
                        type=str, help='host to send login/logout request to, default use 10.1.206.13')
    parser.add_argument('-o', '--logout', nargs='?', type=bool, default=False,
                        help='logout bistu wifi')
    parser.add_argument('-c', '--config', nargs='?', type=str,
                        help='load info(username, password, host) from config file')

    args = parser.parse_args()

    logger.debug('parse argument: username= %s', args.username)
    logger.debug('parse argument: password= %s', args.password)
    logger.debug('parse argument: host= %s', args.host)
    logger.debug('parse argument: logout= %s', args.logout)

    if args.config is not None:
        username, password, host = load_auth_info(args.config)

        if host is None:
            login(username, password)
        else:
            login(username, password, host)

    elif args.username is not None and args.password is not None:
        if args.host is None:
            login(args.username, args.password)
        else:
            login(args.username, args.password, args.host)

    elif args.logout:
        if args.host is None:
            logout()
        else:
            logout(args.host)
    else:
        parser.print_help()


if __name__ == '__main__':
    main()