import datetime
from functools import wraps

from flask import g, jsonify, request

import jwt
from app.configs.default import SECRET_KEY
from flask_httpauth import HTTPTokenAuth, HTTPAuth

# 生成token,有效时间为 60*60 秒
from app.exts import db


def generate_auth_token(user_name, expiration=3600):
    reset_token = jwt.encode(
        {
            "user_name": user_name,
            "exp": datetime.datetime.now(tz=datetime.timezone.utc) + datetime.timedelta(seconds=expiration)
        },
        SECRET_KEY,
        algorithm="HS256"
    )
    return reset_token


# 重写 HTTPTokenAuth
class HTTPTokenAuthReReturn(HTTPTokenAuth):
    def __init__(self, scheme=None, realm=None, header=None):
        super().__init__(scheme, realm, header)

        # 重写default_auth_error, 或者也可以重新定义一个函数
        # def default_auth_error(status):
        #     return jsonify(data={}, message="token 错误！", code=status), status

        def default_auth_error(status, message):
            return jsonify(data={}, message=message, code=status), status

        # 如果重新定义函数的话，这里就传入新定义的函数名
        super().error_handler(default_auth_error)
        # 重写 login_required

    def login_required(self, f=None, role=None, optional=None):
        if f is not None and \
                (role is not None or optional is not None):  # pragma: no cover
            raise ValueError(
                'role and optional are the only supported arguments')

        def login_required_internal(f):
            @wraps(f)
            def decorated(*args, **kwargs):
                auth = self.get_auth()

                if request.method != 'OPTIONS':
                    password = self.get_auth_password(auth)

                    status = None  # 添加状态信息
                    message = None
                    user = self.authenticate(auth, password)
                    # 这里判断verify_token的返回值是否是这里的一员
                    if user in (False, None, 'BadSignature', 'SignatureExpired'):
                        status = 401
                        if user == 'BadSignature':
                            message = "Bad Signature"
                        elif user == 'SignatureExpired':
                            message = "Signature Expired"
                    elif not self.authorize(role, user, auth):
                        status = 403
                        message = "Forbidden"
                    if not optional and status:
                        # Clear TCP receive buffer of any pending data
                        request.data
                        try:
                            # 因为之前重写了default_auth_error所以多传入一个message
                            return self.auth_error_callback(status, message)
                        except TypeError:
                            return self.auth_error_callback()

                    g.flask_httpauth_user = user if user is not True \
                        else auth.username if auth else None
                return f(*args, **kwargs)

            return decorated

        if f:
            return login_required_internal(f)
        return login_required_internal


auth = HTTPTokenAuthReReturn(scheme="Bearer")


# 获取用户权限
@auth.get_user_roles
def get_user_roles(user):
    the_role = get_role_token(user["token"])
    return the_role.role_key


# 验证token
@auth.verify_token
def verify_token(token):
    try:
        print(token)
        data = jwt.decode(token, SECRET_KEY, algorithms=["HS256"])
        print(data)
    except jwt.ExpiredSignatureError:
        print("token过期")
        # 这里不用False，而是用自定义字符串
        return "SignatureExpired"
    except jwt.PyJWTError:
        print("token错误")
        # 这里不用False，而是用自定义字符串
        return "BadSignature"
    return True


# 解析token不加密部分
def token_parse(token):
    the_token = str.replace(str(token), 'Bearer ', '')
    decoded = jwt.decode(the_token, options={"verify_signature": False})
    return decoded


# 根据 username 获取角色
def get_role_username(username: str):
    return []


# 根据 username 获取角色
def get_role_token(token: str):
    user_info = token_parse(token)
    username = user_info["user_name"]
    the_role = get_role_username(username)
    return the_role