"""BoardImage database model - junction table for boards and images."""

from datetime import datetime, timezone
from typing import TYPE_CHECKING
from uuid import UUID, uuid4

from sqlalchemy import DateTime, ForeignKey, Integer
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.dialects.postgresql import UUID as PGUUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database.base import Base

if TYPE_CHECKING:
    from app.database.models.board import Board
    from app.database.models.group import Group
    from app.database.models.image import Image


class BoardImage(Base):
    """
    BoardImage model - junction table connecting boards and images.

    Stores position, transformations, and z-order for each image on a board.
    """

    __tablename__ = "board_images"

    id: Mapped[UUID] = mapped_column(PGUUID(as_uuid=True), primary_key=True, default=uuid4)
    board_id: Mapped[UUID] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("boards.id", ondelete="CASCADE"), nullable=False
    )
    image_id: Mapped[UUID] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("images.id", ondelete="CASCADE"), nullable=False
    )

    position: Mapped[dict] = mapped_column(JSONB, nullable=False)
    transformations: Mapped[dict] = mapped_column(
        JSONB,
        nullable=False,
        default=lambda: {
            "scale": 1.0,
            "rotation": 0,
            "opacity": 1.0,
            "flipped_h": False,
            "flipped_v": False,
            "greyscale": False,
        },
    )
    z_order: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    group_id: Mapped[UUID | None] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("groups.id", ondelete="SET NULL"), nullable=True
    )

    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, nullable=False, default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc)
    )

    # Relationships
    board: Mapped["Board"] = relationship("Board", back_populates="board_images")
    image: Mapped["Image"] = relationship("Image", back_populates="board_images")
    group: Mapped["Group | None"] = relationship("Group", back_populates="board_images")

    def __repr__(self) -> str:
        """String representation of BoardImage."""
        return f"<BoardImage(id={self.id}, board_id={self.board_id}, image_id={self.image_id})>"