"""Group database model."""

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

from sqlalchemy import DateTime, ForeignKey, String, Text
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.board_image import BoardImage


class Group(Base):
    """
    Group model for organizing images with labels and annotations.

    Groups contain multiple images that can be moved together and have
    shared visual indicators (color, annotation text).
    """

    __tablename__ = "groups"

    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
    )
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    color: Mapped[str] = mapped_column(String(7), nullable=False)  # Hex color #RRGGBB
    annotation: Mapped[str | None] = mapped_column(Text, 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="groups")
    board_images: Mapped[list["BoardImage"]] = relationship("BoardImage", back_populates="group")

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