from datetime import date

from sqlalchemy import Date, ForeignKey, String, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from ..core.db import Base


class Channel(Base):
    __tablename__ = "channels"
    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str] = mapped_column(String(128))
    playlists: Mapped[list["Playlist"]] = relationship(back_populates="channel")
    videos: Mapped[list["Video"]] = relationship(back_populates="channel")


class Playlist(Base):
    __tablename__ = "playlists"
    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str] = mapped_column(String(128))

    channel_id: Mapped[int] = mapped_column(ForeignKey("channels.id"))
    channel: Mapped[Channel] = relationship(back_populates="playlists")

    videos: Mapped[list["Video"]] = relationship(back_populates="playlist")


class Video(Base):
    __tablename__ = "videos"
    __table_args__ = (
        UniqueConstraint("channel_id", "filename", name="uq_video_channel_filename"),
    )

    id: Mapped[int] = mapped_column(primary_key=True)
    filename: Mapped[str] = mapped_column(String(255))
    path: Mapped[str] = mapped_column(String(1024))
    preview_path: Mapped[str] = mapped_column(String(1024))

    playlist_id: Mapped[int | None] = mapped_column(ForeignKey("playlists.id"))
    playlist: Mapped[Playlist | None] = relationship(back_populates="videos")

    channel_id: Mapped[int] = mapped_column(ForeignKey("channels.id"))
    channel: Mapped[Channel] = relationship(back_populates="videos")

    title: Mapped[str | None] = mapped_column(String(256), nullable=True)
    date: Mapped[date | None] = mapped_column(Date, nullable=True)