"""workplan projection retirement (STATE-WP-0083-T03)

A forge-derived projection must be able to say that a record no longer derives
from the forge. It cannot say so by deleting the row: progress events, tasks,
decisions and review contracts reference workplans with ON DELETE RESTRICT, and
those hub-native records must survive (ADR-010 decision 4, ADR-012 decision 7 as
amended 2026-08-25).

Nor can it say so through `status`. A workplan that is `archived` was closed by
its owner; one that no longer derives is a different fact, and overloading the
same field would destroy the distinction exactly where it matters.

Revision ID: d1a2b3c4e5f6
Revises: c9e5a1b3d7f2
"""
from alembic import op
import sqlalchemy as sa

revision = "d1a2b3c4e5f6"
down_revision = "c9e5a1b3d7f2"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column(
        "workplans",
        sa.Column("projection_retired_at", sa.DateTime(timezone=True), nullable=True),
    )
    op.add_column(
        "workplans",
        sa.Column("projection_retired_reason", sa.String(length=255), nullable=True),
    )
    op.add_column(
        "workplans",
        sa.Column("derived_from_commit", sa.String(length=40), nullable=True),
    )
    op.create_index(
        "ix_workplans_projection_retired_at",
        "workplans",
        ["projection_retired_at"],
    )


def downgrade() -> None:
    op.drop_index("ix_workplans_projection_retired_at", table_name="workplans")
    op.drop_column("workplans", "derived_from_commit")
    op.drop_column("workplans", "projection_retired_reason")
    op.drop_column("workplans", "projection_retired_at")