app/models/link.py

"""Author RAG Chatbot SaaS — Link and Audit Log Models."""

from datetime import datetime

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

from app.models.base import Base, TimestampMixin, generate_uuid


class Link(Base, TimestampMixin):
    """Purchase and external links for a specific book."""

    __tablename__ = "links"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=generate_uuid)
    author_id: Mapped[str] = mapped_column(
        String(36), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
    )
    book_id: Mapped[str] = mapped_column(
        String(36), ForeignKey("books.id", ondelete="CASCADE"), nullable=False, index=True
    )
    purchase_url: Mapped[str | None] = mapped_column(String(2000), nullable=True)
    preview_url: Mapped[str | None] = mapped_column(String(2000), nullable=True)
    sample_chapter_url: Mapped[str | None] = mapped_column(String(2000), nullable=True)
    author_bio_url: Mapped[str | None] = mapped_column(String(2000), nullable=True)
    newsletter_url: Mapped[str | None] = mapped_column(String(2000), nullable=True)
    discount_code: Mapped[str | None] = mapped_column(String(50), nullable=True)

    # URL health tracking
    purchase_url_ok: Mapped[bool | None] = mapped_column(nullable=True)
    preview_url_ok: Mapped[bool | None] = mapped_column(nullable=True)
    last_health_check: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    # Relationships
    book: Mapped["Book"] = relationship("Book", back_populates="links")

    def __repr__(self) -> str:
        return f"<Link book={self.book_id} purchase={self.purchase_url}>"


class AuditLog(Base):
    """Immutable audit log — append-only, no updates or deletes ever."""

    __tablename__ = "audit_logs"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=generate_uuid)
    timestamp: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    actor_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    actor_email: Mapped[str] = mapped_column(String(255), nullable=False)
    action: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    target_type: Mapped[str | None] = mapped_column(String(50), nullable=True)
    target_id: Mapped[str | None] = mapped_column(String(36), nullable=True)
    details: Mapped[str | None] = mapped_column(Text, nullable=True)  # JSON string
    ip_address_hash: Mapped[str | None] = mapped_column(String(64), nullable=True)  # Hashed

    def __repr__(self) -> str:
        return f"<AuditLog actor={self.actor_email} action={self.action} at={self.timestamp}>"