import functools
import time

from flask import request
from itsdangerous import TimedJSONWebSignatureSerializer as Serializer, BadSignature, SignatureExpired

from common.rsa import decrypt_data
from user.user_db import FIND_FID_IN_RATING_RECORD


def create_token(param):
    """
    创建token
    Parameters:
        param: 传入参数，用于创建token
    Returns:
        token: 用户访问令牌
    """
    secret_key = '0FTuOi^#Afx1@2@F'
    token_expire = 14400
    s = Serializer(secret_key, expires_in=token_expire)
    token = '' + s.dumps(param).decode('ascii')
    return token


def verify_token(func):
    """
    校验token
    """
    secret_key = '0FTuOi^#Afx1@2@F'

    @functools.wraps(func)
    def internal(*args, **kwargs):
        # 检查token
        try:
            token = request.headers.get('token')
            s = Serializer(secret_key)
            cid = s.loads(token)['cid']
        except TypeError:
            return {"info": "参数错误"}, 401
        except KeyError:
            return {"info": "参数错误"}, 401
        except BadSignature:
            return {"info": "token错误"}, 401
        except SignatureExpired:
            return {"info": "token过期"}, 401
        # 通过以上检查 返回原函数
        return func(*args, **kwargs, cid=cid)

    # 返回包装函数结果
    return internal


def check_block(func):
    """
    检查滑块是否通过

    注: 前端发送的滑块校验码是rsa加密的时间戳，若时间戳间隔小于3秒则校验通过
    """

    @functools.wraps(func)
    def internal(*args, **kwargs):
        try:
            verify_code = decrypt_data(encrypt_msg=request.headers.get('block'))
            if (time.time() - float(verify_code)/1000) > 3:
                return {"info": "滑块校验失败"}, 400
        except TypeError:
            return {"info": "缺少滑块验证"}, 400
        except ValueError:
            return {"info": "滑块验证异常"}, 400
        return func(*args, **kwargs)
    return internal


def verify_report_view_auth(func):
    """
    检查是否具有报告查看权限
    """
    @functools.wraps(func)
    def internal(*args, **kwargs):

        file_id = request.args.get('file_id')

        records = FIND_FID_IN_RATING_RECORD(kwargs['cid'])

        if not records:
            return {"info": "没有找到文件"}, 404

        file_id_pool = list()
        for record in records:
            for a_file_id in list(record.values()):
                file_id_pool.append(a_file_id)

        if file_id not in file_id_pool:
            return {"info": "没有文件访问权限"}, 401

        return func(*args, **kwargs)
    return internal