"""drop rulebook subscriptions and per-project suppressions

Revision ID: 0101
Revises: 0100
Create Date: 2026-09-15

Milestone 414. A rule lives in a rulebook topic, where it is GLOBAL, or on one
project, and retrieval reads that home directly (step 1). Subscriptions were
the last thing that pretended a rulebook reached some projects and not others,
and after milestone 394 they changed nothing a session received — only what a
project's rule LISTING showed. Operator, 2026-09-15: "we have global and
project scoped rules, we don't need the subscriptions now."

WHAT GOES

  - ``project_rulebook_subscriptions`` (migration 0058).
  - ``project_rule_suppressions`` and ``project_topic_suppressions``. They let a
    project mute rules from a rulebook it subscribed to. With no subscription
    there is nothing to mute; a project that departs from a global rule writes
    a project rule with an ``overrides`` relation, which says why.
  - The ``subscribe_rulebooks`` key inside ``projects.inception.choices``, and
    the ``exclude_always_on_rulebooks`` key milestone 394 left behind in the
    same place. Both describe decisions that can no longer be made; a stored
    record carrying them would be read back as a choice the product offers.

IRREVERSIBLE, AND THE DOWNGRADE SAYS SO

The downgrade recreates the three tables empty. Which projects subscribed to
which rulebooks, and what they muted, is in what this drops. Restore a backup
taken before this ran if the prior state matters.
"""
import sqlalchemy as sa
from alembic import op

revision = "0101"
down_revision = "0100"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.drop_table("project_topic_suppressions")
    op.drop_table("project_rule_suppressions")
    op.drop_table("project_rulebook_subscriptions")
    op.execute(
        """
        UPDATE projects
        SET inception = jsonb_set(
            inception, '{choices}',
            (inception->'choices') - 'subscribe_rulebooks' - 'exclude_always_on_rulebooks'
        )
        WHERE inception IS NOT NULL
          AND jsonb_typeof(inception->'choices') = 'object'
        """
    )


def _join_table(name: str, other: str, other_table: str) -> None:
    op.create_table(
        name,
        sa.Column(
            "project_id", sa.BigInteger(),
            sa.ForeignKey("projects.id", ondelete="CASCADE"),
            primary_key=True, nullable=False,
        ),
        sa.Column(
            other, sa.BigInteger(),
            sa.ForeignKey(f"{other_table}.id", ondelete="CASCADE"),
            primary_key=True, nullable=False,
        ),
        sa.Column(
            "created_at", sa.DateTime(timezone=True),
            server_default=sa.text("now()"), nullable=True,
        ),
    )


def downgrade() -> None:
    """Structure only. See the module docstring — the rows are gone."""
    _join_table("project_rulebook_subscriptions", "rulebook_id", "rulebooks")
    _join_table("project_rule_suppressions", "rule_id", "rules")
    _join_table("project_topic_suppressions", "topic_id", "rulebook_topics")