import hashlib
import datetime

from django.db import models
from django.contrib.auth.models import User
# 引入内置信号
from django.db.models.signals import post_save
# 引入信号接收器的装饰器
from django.dispatch import receiver


# 用户信息
class Profile(models.Model):
    # 对应django自带的user
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
    # 电话
    phone = models.CharField(max_length=20, blank=True)
    # 个人简介
    bio = models.TextField(max_length=500, blank=True)
    # 头像
    avatar = models.ImageField(upload_to='avatar/%Y%m%d/', blank=True)

    def __str__(self):
        return 'user {}'.format(self.user.username)


# 设备表
class Devices(models.Model):
    # 对应django自带的User
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='devices')
    # 设备登录时间
    last_login_time = models.DateField(auto_now=True)
    # 设备码
    device_uid = models.CharField(max_length=100, default='233', blank=False, unique=True)
    # 登录凭证
    token = models.CharField(max_length=100, default='233', blank=False, unique=True)

    def gen_token(self):
        _token = self.device_uid + self.user.username + datetime.datetime.now().strftime("%Y%m%d%H%M%S")
        sha1 = hashlib.sha1()
        sha1.update(_token.encode())
        self.token = sha1.hexdigest()


# 信号接收函数，每当新建User实例的时候自动调用
@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    if created:
        Profile.objects.create(user=instance)


# 信号接收函数，每当更新User实例的时候自动调用
@receiver(post_save, sender=User)
def save_user_profile(sender, instance, **kwargs):
    instance.profile.save()