"""MITRE ATT&CK reference tables.

Read-mostly. Hard delete (no soft-delete) — replaced by the periodic sync job.
A technique can map to multiple tactics (kill_chain_phases in STIX) hence the
M2M `technique_tactics` join. Sub-techniques inherit their parent's tactics
through the parent technique.
"""

from __future__ import annotations

import uuid

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

from app.db.base import Base
from app.db.mixins import TimestampMixin, UuidPkMixin


class MitreTactic(Base, UuidPkMixin, TimestampMixin):
    __tablename__ = "mitre_tactics"

    external_id: Mapped[str] = mapped_column(String(16), unique=True, nullable=False)
    short_name: Mapped[str] = mapped_column(String(80), nullable=False)
    name: Mapped[str] = mapped_column(String(120), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    url: Mapped[str | None] = mapped_column(String(512), nullable=True)

    techniques: Mapped[list["MitreTechnique"]] = relationship(
        secondary="mitre_technique_tactics",
        back_populates="tactics",
    )


class MitreTechnique(Base, UuidPkMixin, TimestampMixin):
    __tablename__ = "mitre_techniques"

    external_id: Mapped[str] = mapped_column(String(16), unique=True, nullable=False)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    url: Mapped[str | None] = mapped_column(String(512), nullable=True)

    tactics: Mapped[list[MitreTactic]] = relationship(
        secondary="mitre_technique_tactics",
        back_populates="techniques",
        lazy="selectin",
    )
    subtechniques: Mapped[list["MitreSubtechnique"]] = relationship(
        back_populates="technique",
        cascade="all, delete-orphan",
    )

    __table_args__ = (Index("ix_mitre_techniques_name", "name"),)


class MitreSubtechnique(Base, UuidPkMixin, TimestampMixin):
    __tablename__ = "mitre_subtechniques"

    external_id: Mapped[str] = mapped_column(String(16), unique=True, nullable=False)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    url: Mapped[str | None] = mapped_column(String(512), nullable=True)
    technique_id: Mapped[uuid.UUID] = mapped_column(
        Uuid(as_uuid=True), ForeignKey("mitre_techniques.id", ondelete="CASCADE"), nullable=False
    )

    technique: Mapped[MitreTechnique] = relationship(back_populates="subtechniques")

    __table_args__ = (Index("ix_mitre_subtechniques_technique_id", "technique_id"),)


class MitreTechniqueTactic(Base):
    """Many-to-many: a technique can serve several tactics (STIX kill_chain_phases)."""

    __tablename__ = "mitre_technique_tactics"

    technique_id: Mapped[uuid.UUID] = mapped_column(
        Uuid(as_uuid=True),
        ForeignKey("mitre_techniques.id", ondelete="CASCADE"),
        primary_key=True,
    )
    tactic_id: Mapped[uuid.UUID] = mapped_column(
        Uuid(as_uuid=True),
        ForeignKey("mitre_tactics.id", ondelete="CASCADE"),
        primary_key=True,
    )