"""documents image columns: is_image + image_path (phase 122, task 02)

Revision ID: 0022
Revises: 0021
Create Date: 2026-09-24

Phase 122 (standalone images become first-class documents — task 02,
storage only):

* ``documents.is_image`` — BOOLEAN NOT NULL, server default
  ``false``: True iff the doc is a standalone image (LOCKED A3) whose
  ``content``/``summary`` is the CHAT model's vision description — the
  ONLY embedded text (the embedding model never sees pixels). The
  server default makes EVERY pre-phase-122 row a text doc without a
  backfill.
* ``documents.image_path`` — TEXT NULLABLE: the absolute path of the
  image's persistent copy in ``settings.image_dir`` (``<doc-id>.<ext>``
  — the copy must outlive the source file: uploads are replaced on
  every upload, git checkouts are re-cloned). NULL for text docs.

One additive, fully reversible migration (A13); no other schema
change. The walk filter, the binary index path, and the prune guard
are importer code (task 02) — this revision only carries the columns.
"""
from __future__ import annotations

import sqlalchemy as sa

from alembic import op

revision = "0022"
down_revision = "0021"
branch_labels = None
depends_on = None


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


def downgrade() -> None:
    # Both columns are the only 0022 artefacts — dropping them leaves
    # 0021's schema byte-identical (A13, fully reversible).
    op.drop_column("documents", "image_path")
    op.drop_column("documents", "is_image")