from django.conf import settings
from django.db import models


class Collection(models.Model):
    """A user-created collection of documents."""
    name = models.CharField(max_length=300)
    description = models.TextField(blank=True, default="")
    cover = models.ImageField(upload_to="collection_covers/", blank=True, null=True)
    documents = models.ManyToManyField(
        "documents.Document",
        related_name="collections",
        blank=True,
    )
    is_public = models.BooleanField(default=False)
    owner = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="collections",
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "collections_collection"
        ordering = ["-updated_at"]

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

    @property
    def document_count(self) -> int:
        return self.documents.count()

    @property
    def cover_url(self) -> str | None:
        if self.cover:
            return self.cover.url
        return None