"""PostAttachment — a non-art file preserved from a post.

Art images become ImageRecords; everything else a post contained
(archives, .exe, .pdf, ...) is captured here so nothing is lost.
post_id is nullable (set only when an adjacent sidecar yields a Post);
artist_id mirrors the canonical attribution model (FC-2d-vii-c). Both
FKs are SET NULL so deleting a Post/Artist never deletes the preserved
binary row.
"""

from datetime import datetime

from sqlalchemy import (
    BigInteger,
    DateTime,
    ForeignKey,
    Integer,
    String,
    Text,
    func,
)
from sqlalchemy.orm import Mapped, mapped_column

from .base import Base


class PostAttachment(Base):
    __tablename__ = "post_attachment"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    post_id: Mapped[int | None] = mapped_column(
        ForeignKey("post.id", ondelete="SET NULL"), nullable=True, index=True
    )
    artist_id: Mapped[int | None] = mapped_column(
        ForeignKey("artist.id", ondelete="SET NULL"), nullable=True, index=True
    )
    sha256: Mapped[str] = mapped_column(
        String(64), nullable=False, unique=True, index=True
    )
    path: Mapped[str] = mapped_column(Text, nullable=False)
    original_filename: Mapped[str] = mapped_column(Text, nullable=False)
    ext: Mapped[str] = mapped_column(String(32), nullable=False)
    mime: Mapped[str | None] = mapped_column(String(128), nullable=True)
    size_bytes: Mapped[int] = mapped_column(BigInteger, nullable=False)
    captured_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )