import uuid

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


class Bookmark(models.Model):
    """A saved location in a book that the user can return to."""

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="bookmarks",
        db_index=True,
    )
    book = models.ForeignKey(
        "books.Book",
        on_delete=models.CASCADE,
        related_name="bookmarks",
        db_index=True,
    )
    page = models.PositiveIntegerField()
    location_text = models.TextField(
        blank=True,
        default="",
        help_text="The selected passage text at this location",
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "annotations_bookmark"
        verbose_name = "Bookmark"
        verbose_name_plural = "Bookmarks"
        ordering = ["-created_at"]
        constraints = [
            models.UniqueConstraint(
                fields=["user", "book", "page"],
                name="uq_bookmark_user_book_page",
            )
        ]

    def __str__(self) -> str:
        return f"{self.user} @ {self.book} p.{self.page}"


class Note(models.Model):
    """A user-written note attached to a specific location in a book."""

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="notes",
        db_index=True,
    )
    book = models.ForeignKey(
        "books.Book",
        on_delete=models.CASCADE,
        related_name="notes",
        db_index=True,
    )
    page = models.PositiveIntegerField()
    location_text = models.TextField(
        blank=True,
        default="",
        help_text="The selected passage text this note refers to",
    )
    content = models.TextField(
        help_text="The note body content"
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "annotations_note"
        verbose_name = "Note"
        verbose_name_plural = "Notes"
        ordering = ["-created_at"]

    def __str__(self) -> str:
        preview = self.content[:50]
        return f"{self.user} @ {self.book} p.{self.page}: {preview}"