"""document summaries: documents.summary + chunks.is_summary

Revision ID: 0004
Revises: 0003
Create Date: 2026-08-25

Phase 30 (document-summaries story, A13 — two additive, reversible
columns, no table rework):

* ``documents.summary`` — TEXT, nullable. Natural-language summary of the
  document produced at import time by the aipi ``lite`` model (non-markdown
  A9 documents only). NULL for markdown docs and for documents imported
  before summaries existed (or whose summary generation failed — the
  fail-soft path still indexes the document without a summary).
* ``chunks.is_summary`` — BOOLEAN NOT NULL DEFAULT false. Marks the single
  extra summary chunk (position -1) that mirrors ``documents.summary`` into
  the embedding space, so hybrid search has a well-embedding
  natural-language target for badly-formatted raw text. The default keeps
  every pre-0004 row valid; the summary chunk flows through the unchanged
  A7 retrieval path (cosine ∪ FTS ∪ RRF) and the existing chunk→document
  mapping resolves a summary hit to its full source document.
"""
from __future__ import annotations

import sqlalchemy as sa

from alembic import op

revision = "0004"
down_revision = "0003"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column("documents", sa.Column("summary", sa.Text(), nullable=True))
    op.add_column(
        "chunks",
        sa.Column("is_summary", sa.Boolean(), nullable=False, server_default=sa.text("false")),
    )


def downgrade() -> None:
    op.drop_column("chunks", "is_summary")
    op.drop_column("documents", "summary")