from django.conf import settings
from django.db import models
from django.urls import reverse
from django.utils import timezone
from django.utils.text import slugify

from core.models import TimeStampedModel, UUIDPrimaryKeyModel


class Post(UUIDPrimaryKeyModel, TimeStampedModel):
    title = models.CharField(max_length=200)
    slug = models.SlugField(max_length=220, unique=True)
    excerpt = models.TextField(blank=True)
    body = models.TextField()
    is_published = models.BooleanField(default=False)
    published_at = models.DateTimeField(null=True, blank=True)
    author = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="blog_posts",
    )

    class Meta:
        ordering = ["-published_at", "-created_at"]

    def __str__(self) -> str:
        return self.title

    def get_absolute_url(self) -> str:
        return reverse("blog:detail", kwargs={"slug": self.slug})

    def save(self, *args, **kwargs):
        if not self.slug:
            base = slugify(self.title)[:200] or "post"
            slug = base
            n = 2
            while Post.objects.filter(slug=slug).exclude(pk=self.pk).exists():
                slug = f"{base}-{n}"
                n += 1
            self.slug = slug
        if self.is_published and self.published_at is None:
            self.published_at = timezone.now()
        super().save(*args, **kwargs)