# -*- coding: utf-8 -*-
"""
    unionpay.oauth
    ~~~~~~~~~~~~~~~

    This module provides OAuth2 library for unionpay

    :copyright: (c) 2014 by messense.
    :license: MIT, see LICENSE for more details.
"""
from __future__ import absolute_import, unicode_literals

import requests
import six

from apilib.systypes import StrEnum
from apilib.utils_string import get_random_string
import time
from Crypto.Hash import SHA256

from library import to_binary, to_text

try:
    import simplejson as json
except ImportError:
    import json  # NOQA


class UnionPayOAuth(object):
    """ 云闪付平台 OAuth 网页授权
    """
    class Scope(StrEnum):
        SNSAPI_BASE = 'snsapi_base'
        SNSAPI_UNION_LOGIN = 'snsapi_union_login'

    API_BASE_URL = 'https://open.95516.com/'
    OAUTH_BASE_URL = 'https://open.95516.com/s/open/html/oauth.html'

    def __str__(self):
        _repr = '{kclass}(appid: {appid})'.format(
            kclass = self.__class__.__name__,
            appid = self.app_id)

        if six.PY2:
            return to_binary(_repr)
        else:
            return to_text(_repr)

    def __repr__(self):
        return str(self)

    def __init__(self, app_id, secret):
        self.app_id = app_id
        self.secret = secret

    def _request(self, method, url_or_endpoint, **kwargs):
        if not url_or_endpoint.startswith(('http://', 'https://')):
            url = '{base}{endpoint}'.format(
                base = self.API_BASE_URL,
                endpoint = url_or_endpoint
            )
        else:
            url = url_or_endpoint

        if isinstance(kwargs.get('data', ''), dict):
            body = json.dumps(kwargs['data'], ensure_ascii = False)
            body = body.encode('utf-8')
            kwargs['data'] = body

        kwargs['timeout'] = kwargs.get('timeout', 15)

        with requests.sessions.Session() as session:
            res = session.request(
                method = method,
                url = url,
                **kwargs
            )
            try:
                res.raise_for_status()
            except requests.RequestException as reqe:
                return {'errmsg':u'网络异常'}
            result = json.loads(res.content.decode('utf-8', 'ignore'), strict = False)

            if 'msg' in result and result['errcode'] != 0:
                return result

    def _get(self, url, **kwargs):
        return self._request(
            method = 'get',
            url_or_endpoint = url,
            **kwargs
        )

    def get_oauth_token(self, auth_code):
        """获取 access_token

        :param auth_code: 授权完成跳转回来后 URL 中的 code 参数
        :return: JSON 数据包
        """
        #先计算出随机字符串
        nonceStr = get_random_string(16)
        timestamp = time.time()
        rawStr = 'appId=%s&secret=%s&nonceStr=%s&timestamp=%s'(self.app_id,self.secret,nonceStr,timestamp)
        digest = SHA256.new()
        signature = digest.update(rawStr)
        res = self._get(
            'open/access/1.0/backendToken',
            params = {
                'appId': self.app_id,
                'nonceStr': nonceStr,
                'timestamp': timestamp,
                'signature': signature
            }
        )
        return res

    def get_user_info(self, token = None, code = None, lang = 'zh_CN'):
        res = self._get(
            'open/access/1.0/backendToken',
            params = {
                'appId': self.app_id,
                'backendToken': token,
                'code': code,
                'grantType': 'authorization_code'
            }
        )
        return res

    def authorize_url(self, redirect_uri, scope):
        pass