"""Database models for YouTube feed storage."""

from datetime import datetime
from typing import List

from sqlalchemy import String, DateTime, ForeignKey, Index
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship


class Base(DeclarativeBase):
    """Base class for all database models."""
    pass


class Channel(Base):
    """YouTube channel model."""

    __tablename__ = "channels"

    id: Mapped[int] = mapped_column(primary_key=True)
    channel_id: Mapped[str] = mapped_column(String(50), unique=True, nullable=False, index=True)
    title: Mapped[str] = mapped_column(String(200), nullable=False)
    link: Mapped[str] = mapped_column(String(500), nullable=False)
    last_fetched: Mapped[datetime] = mapped_column(DateTime, nullable=False, default=datetime.utcnow)

    # Relationship to video entries
    videos: Mapped[List["VideoEntry"]] = relationship("VideoEntry", back_populates="channel", cascade="all, delete-orphan")

    def __repr__(self) -> str:
        return f"<Channel(id={self.id}, channel_id='{self.channel_id}', title='{self.title}')>"


class VideoEntry(Base):
    """YouTube video entry model."""

    __tablename__ = "video_entries"

    id: Mapped[int] = mapped_column(primary_key=True)
    channel_id: Mapped[int] = mapped_column(ForeignKey("channels.id"), nullable=False)
    title: Mapped[str] = mapped_column(String(500), nullable=False)
    link: Mapped[str] = mapped_column(String(500), unique=True, nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, default=datetime.utcnow)

    # Relationship to channel
    channel: Mapped["Channel"] = relationship("Channel", back_populates="videos")

    # Index for faster queries
    __table_args__ = (
        Index('idx_channel_created', 'channel_id', 'created_at'),
    )

    def __repr__(self) -> str:
        return f"<VideoEntry(id={self.id}, title='{self.title}', link='{self.link}')>"

    def to_dict(self) -> dict:
        """Convert to dictionary for API responses."""
        return {
            "id": self.id,
            "title": self.title,
            "link": self.link,
            "created_at": self.created_at.isoformat()
        }