from django.db import models
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.urls import reverse
from django.utils import timezone


class Board(models.Model):
    # The short URL name for the board
    url = models.CharField(max_length=255, null=False, blank=False, unique=True)
    # Human-readable name for the board
    name = models.CharField(max_length=255, null=False, blank=False)

    @property
    def threads(self):
        return Post.objects.filter(board=self, op=None)


class Post(models.Model):
    # Board that this post was made on
    board = models.ForeignKey("Board", on_delete=models.CASCADE)
    # Thread that this is a part of
    op = models.ForeignKey(
        "self", null=True, on_delete=models.CASCADE, related_name="all_replies"
    )
    # Post that this is replying to
    reply = models.ForeignKey(
        "self", null=True, on_delete=models.CASCADE, related_name="replies"
    )
    # User's supplied name for this post
    name = models.CharField(max_length=255, null=True, blank=True)
    # User's supplied subject for this post
    subject = models.CharField(max_length=255, null=True, blank=True)
    # Text of this post
    text = models.TextField(max_length=10000, null=False, blank=True)
    # The IP address of the user that made this post
    ip = models.GenericIPAddressField()
    # Creation time
    created = models.DateTimeField(auto_now_add=True)
    # Last bump time
    last_bump = models.DateTimeField(auto_now_add=True)

    # TODO : images

    def get_absolute_url(self):
        if self.op is None:
            return reverse(
                "board:post_detail", kwargs={"url": self.board.url, "id": self.id}
            )
        else:
            return (
                reverse(
                    "board:post_detail",
                    kwargs={"url": self.board.url, "id": self.op.id},
                )
                + f"#p{self.id}"
            )


@receiver(post_save, sender=Post)
def post_created(sender, instance, created, **kwargs):
    if created and instance.op:
        instance.op.last_bump = timezone.now()
        instance.op.save()