from datetime import datetime, timedelta

from sqlalchemy import DateTime, Integer, String, and_, or_
from sqlalchemy.orm import Mapped, Session, mapped_column

from app.database import Base


class HTMLFile(Base):
    __tablename__ = "html_files"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, index=True)
    unique_id: Mapped[str] = mapped_column(
        String(32),
        unique=True,
        index=True,
        nullable=False,
    )
    filename: Mapped[str] = mapped_column(String(255), nullable=False)
    title: Mapped[str | None] = mapped_column(String(120), nullable=True)
    source: Mapped[str | None] = mapped_column(String(80), nullable=True)
    request_id: Mapped[str | None] = mapped_column(String(120), nullable=True)
    size_bytes: Mapped[int | None] = mapped_column(Integer, nullable=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=datetime.utcnow,
        nullable=False,
    )
    expires_at: Mapped[datetime | None] = mapped_column(
        DateTime,
        nullable=True,
        index=True,
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=datetime.utcnow,
        onupdate=datetime.utcnow,
        nullable=False,
    )

    @classmethod
    def list_expired_records(
        cls,
        db: Session,
        default_retention_days: int,
    ) -> list["HTMLFile"]:
        now = datetime.utcnow()
        fallback_cutoff = now - timedelta(days=default_retention_days)
        return (
            db.query(cls)
            .filter(
                or_(
                    cls.expires_at < now,
                    and_(
                        cls.expires_at.is_(None),
                        cls.created_at < fallback_cutoff,
                    ),
                )
            )
            .all()
        )

    def resolved_expires_at(self, default_retention_days: int) -> datetime:
        if self.expires_at is not None:
            return self.expires_at

        return self.created_at + timedelta(days=default_retention_days)