from django.db import models
from django.utils import timezone
from django.contrib.auth.models import User
from markdown import Markdown


class Category(models.Model):
    """文章分类"""
    # 分类名称
    title = models.CharField(max_length=100)
    created = models.DateTimeField(default=timezone.now)

    class Meta:
        ordering = ['-created']

    def __str__(self):
        return self.title


class Tag(models.Model):
    """文章标签"""
    text = models.CharField(max_length=30)

    class Meta:
        ordering = ['-id']

    def __str__(self):
        return self.text


# 博客文章 model
class Article(models.Model):
    class Meta:
        # 按创建时间降序排列
        ordering = ['-created']

    # 作者
    author = models.ForeignKey(
        User,
        null=True,
        on_delete=models.CASCADE,
        related_name='articles'
        )

    # 分类
    category = models.ForeignKey(
        Category,
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name='articles'
    )

    # 标签
    # 一篇文章可以有多个tag，一个tag可以属于多篇文章
    tags = models.ManyToManyField(
        Tag,
        blank=True,
        related_name='articles',
    )

    # 标题
    title = models.CharField(max_length=100)
    # 正文
    body = models.TextField()
    # 创建时间
    created = models.DateTimeField(default=timezone.now)
    # 更新时间
    updated = models.DateTimeField(auto_now=True)

    def __str__(self):
        return self.title

    # 新增方法,将body转换为带html标签的正文
    def get_md(self):
        md = Markdown(
            extensions=[
                'markdown.extensions.extra',
                'markdown.extensions.codehilite',
                'markdown.extensions.toc',
            ]
        )
        md_body = md.convert(self.body)
        return md_body, md.toc