"""Integration: migration 0002 (hybrid retrieval) schema contract.

Asserts the state the migration must leave on the live schema:
``chunks.tsv`` as a stored generated tsvector, its GIN index, and the
nullable ``query_log.fts_hits`` column (pre-0002 rows stay NULL, so it
must accept NULL and an int). Requires ``podman compose up -d db``.
"""
from __future__ import annotations

from sqlalchemy import text


def test_migration_0002_schema_contract(db) -> None:
    tsv_col = db.execute(
        text(
            "SELECT count(*) FROM information_schema.columns"
            " WHERE table_name = 'chunks' AND column_name = 'tsv'"
        )
    ).scalar()
    assert tsv_col == 1, "chunks.tsv (stored tsvector) is missing"

    gin = db.execute(
        text(
            "SELECT count(*) FROM pg_indexes"
            " WHERE tablename = 'chunks' AND indexdef ILIKE '%USING gin%'"
            " AND indexdef ILIKE '%tsv%'"
        )
    ).scalar()
    assert gin == 1, "GIN index on chunks.tsv is missing"

    fts = db.execute(
        text(
            "SELECT is_nullable = 'YES' FROM information_schema.columns"
            " WHERE table_name = 'query_log' AND column_name = 'fts_hits'"
        )
    ).scalar()
    assert fts is True, "query_log.fts_hits must exist and be nullable (pre-0002 rows)"


def test_tsv_is_generated_and_lexically_queryable(db) -> None:
    """The tsvector is generated from ``content`` (not maintained by app
    code) and answers a tsquery — the retrieval path's lexical branch."""
    doc_id = db.execute(text("SELECT gen_random_uuid()")).scalar()
    try:
        db.execute(
            text(
                "INSERT INTO documents (id, source, path, full_path, title, content,"
                " content_hash, indexed_at) VALUES"
                " (:id, 'mig_test', 't.md', '/t.md', 'T', 'kafkabridge routes here',"
                " repeat('0', 64), now())"
            ),
            {"id": doc_id},
        )
        db.execute(
            text(
                "INSERT INTO chunks (id, document_id, position, content) VALUES"
                " (gen_random_uuid(), :id, 0, 'kafkabridge routes here')"
            ),
            {"id": doc_id},
        )
        db.commit()
        hit = db.execute(
            text(
                "SELECT count(*) FROM chunks"
                " WHERE tsv @@ to_tsquery('english', 'kafkabridge')"
            )
        ).scalar()
        assert hit == 1
    finally:
        db.execute(text("DELETE FROM chunks WHERE document_id = :id"), {"id": doc_id})
        db.execute(text("DELETE FROM documents WHERE id = :id"), {"id": doc_id})
        db.commit()