import time
import datetime
import jwt
import hashlib
from os import path
from django.conf import settings
from rest_framework.response import Response
from django.contrib.auth.models import User


def generate_token(user):
    """
     :param user: 用户对象
     :return: 生成的token
    """
    payload = {
        'user_id': user.id,
        'username': user.username,
        'exp': datetime.datetime.utcnow() + datetime.timedelta(weeks=1)  # token过期时间 1week
    }
    token = jwt.encode(payload=payload, key=settings.SECRET_KEY, algorithm='HS256')
    return token


def decode_token_exp_time(token):
    try:
        res_dict = jwt.decode(token, settings.SECRET_KEY, algorithms=['HS256'])
        exp = res_dict.get('exp')
        exp_time = time.ctime(exp)
        return exp_time
    except Exception as e:
        return None


def update_tp_querydict(querydict):
    new_querydict = dict()
    if 'record_time' in querydict:
        new_querydict['record_time__icontains'] = ''.join(querydict.pop('record_time'))
    if 'police_id' in querydict:
        new_querydict['police_id__icontains'] = ''.join(querydict.pop('police_id'))
    if 'event_type' in querydict:
        new_querydict['event_type__icontains'] = ''.join(querydict.pop('event_type'))
    if 'start_time' in querydict:
        new_querydict['record_time__gte'] = ''.join(querydict.pop('start_time'))
    if 'end_time' in querydict:
        new_querydict['record_time__lte'] = datetime.datetime.strptime(''.join(querydict.pop('end_time')), "%Y-%m-%d") + datetime.timedelta(days=1)
    if 'violation' in querydict:
        if ''.join(querydict.get('violation')) == '1':
            new_querydict['is_violation'] = True
        elif ''.join(querydict.get('violation')) == '0':
            new_querydict['is_violation'] = False
    if 'violation_type' in querydict:
        new_querydict['ai_analysis__icontains'] = ''.join(querydict.pop('violation_type'))
    return new_querydict


def get_file_hash(filename):
    if path.isfile(filename) is False:
        return

    # make a hash object
    h_sha256 = hashlib.sha256()

    # open file for reading in binary mode
    with open(filename, "rb") as file:
        # read file in chunks and update hash
        chunk = 0
        while chunk != b"":
            chunk = file.read(1024)
            h_sha256.update(chunk)

    # return the hex digest
    return h_sha256.hexdigest()