from django.conf.global_settings import MEDIA_ROOT
from django.db import models
import os


def user_directory_path(instance, filename):
    ext = filename.split('.').pop()
    filename = '{0}{1}.{2}'.format(instance.username, instance.phone, ext)
    return os.path.join("avatar", filename) # 系统路径分隔符差异，增强代码重用性


# Create your models here.
class User(models.Model):
    """
    用户表
    """
    id = models.AutoField(verbose_name="id", primary_key=True, unique=True)
    username = models.CharField(max_length=50, unique=True, verbose_name="用户名", null=True, blank=True)
    pwd = models.CharField(max_length=1000, verbose_name="密码", null=True, blank=True)
    email = models.EmailField(max_length=100, verbose_name="电子邮件")
    phone = models.CharField(max_length=11, verbose_name="手机", null=True, blank=True)
    create_time = models.DateTimeField(verbose_name="注册时间")
    avatar = models.ImageField(verbose_name="头像", upload_to=user_directory_path)
    last_login_time = models.DateTimeField(verbose_name="最后登录时间", auto_now=True)

    def __str__(self):
        return self.username

    class Meta:
        verbose_name = '用户表'

    # 这里定义一个方法，作用是当用户注册时没有上传照片，模板中调用 [ModelName].[ImageFieldName].url 时赋予一个默认路径
    def avatar_url(self):
        if self.avatar and hasattr(self.avatar, 'url'):
            return self.avatar.url
        else:
            return '/media/avatar/default.jpg'