"""Playlist-Sound relationship model for managing sound order in playlists."""

from datetime import datetime
from typing import TYPE_CHECKING, Optional
from zoneinfo import ZoneInfo

from sqlalchemy import DateTime, ForeignKey, Integer, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import db

if TYPE_CHECKING:
    from app.models.playlist import Playlist
    from app.models.sound import Sound


class PlaylistSound(db.Model):
    """Model for playlist-sound relationships with ordering."""

    __tablename__ = "playlist_sound"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    playlist_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("playlist.id"), nullable=False
    )
    sound_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("sound.id"), nullable=False
    )
    order: Mapped[int] = mapped_column(Integer, nullable=False)
    added_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=lambda: datetime.now(tz=ZoneInfo("UTC")),
        nullable=False,
    )

    # Relationships
    playlist: Mapped["Playlist"] = relationship(
        "Playlist", back_populates="playlist_sounds"
    )
    sound: Mapped["Sound"] = relationship(
        "Sound", back_populates="playlist_sounds"
    )

    # Constraints
    __table_args__ = (
        UniqueConstraint(
            "playlist_id", "sound_id", name="unique_playlist_sound"
        ),
        UniqueConstraint("playlist_id", "order", name="unique_playlist_order"),
    )

    def __repr__(self) -> str:
        """String representation of the playlist-sound relationship."""
        return f"<PlaylistSound(playlist_id={self.playlist_id}, sound_id={self.sound_id}, order={self.order})>"

    def to_dict(self) -> dict:
        """Convert playlist-sound relationship to dictionary representation."""
        return {
            "id": self.id,
            "playlist_id": self.playlist_id,
            "sound_id": self.sound_id,
            "order": self.order,
            "added_at": self.added_at.isoformat() if self.added_at else None,
            "sound": self.sound.to_dict() if self.sound else None,
        }