"""Schema-level guarantees: the cascade, and the one hole the cascade leaves."""

import sys
from pathlib import Path

SCRIPTS = Path(__file__).parent.parent / "scripts"
sys.path.insert(0, str(SCRIPTS))

import wiki_store as store
from wiki_db import EMBEDDING_DIMS

NOW = "2026-09-09T12:00:00+00:00"


def _seed_file(conn, source_id, path, chunk_texts):
    store.upsert_source(conn, source_id, "workspace")
    store.upsert_file(conn, source_id, path, "T", ["t"], ["H"], "sha", 10, 1.0, NOW)
    store.replace_chunks(conn, source_id, path, [(f"{path} > s", t) for t in chunk_texts])
    for row in store.pending_chunks(conn, 100):
        store.store_embedding(conn, row["id"], [0.1] * EMBEDDING_DIMS, NOW)


def test_delete_file_leaves_no_orphan_vectors(tmp_path):
    """The FK cascade reaches chunks and chunks_fts but never vec0 — deletes must be explicit."""
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        _seed_file(conn, "ws", "a.md", ["alpha text", "beta text"])
        _seed_file(conn, "ws", "b.md", ["gamma text"])

    with store.connection(db_path) as conn:
        assert store.index_stats(conn) == {"files": 2, "chunks": 3, "vectors": 3, "pending": 0}

    with store.transaction(db_path) as conn:
        store.delete_file(conn, "ws", "a.md")

    with store.connection(db_path) as conn:
        assert store.index_stats(conn) == {"files": 1, "chunks": 1, "vectors": 1, "pending": 0}
        assert store.orphan_vector_ids(conn) == []
        assert store.bm25_ranked_ids(conn, "alpha", 10) == []
        assert len(store.bm25_ranked_ids(conn, "gamma", 10)) == 1


def test_replace_chunks_drops_old_vectors(tmp_path):
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        _seed_file(conn, "ws", "a.md", ["alpha text", "beta text", "delta text"])

    with store.transaction(db_path) as conn:
        store.replace_chunks(conn, "ws", "a.md", [("a.md > s", "only one now")])

    with store.connection(db_path) as conn:
        assert store.index_stats(conn) == {"files": 1, "chunks": 1, "vectors": 0, "pending": 1}
        assert store.orphan_vector_ids(conn) == []
        assert store.bm25_ranked_ids(conn, "alpha", 10) == []


def test_delete_by_path_does_not_touch_other_source(tmp_path):
    """The key is (source_id, path); a path-only delete would eat a foreign source's chunks."""
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        _seed_file(conn, "ws", "notes.md", ["shared name one"])
        _seed_file(conn, "git", "notes.md", ["shared name two"])

    with store.transaction(db_path) as conn:
        store.delete_file(conn, "ws", "notes.md")

    with store.connection(db_path) as conn:
        assert store.index_stats(conn)["chunks"] == 1
        assert store.orphan_vector_ids(conn) == []
        remaining = list(conn.execute("SELECT source_id FROM chunks"))
        assert remaining[0]["source_id"] == "git"


def test_embedded_at_update_keeps_fts_row(tmp_path):
    """Step 4b flips embedded_at on unchanged text; the WHEN guard must keep FTS intact."""
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        store.upsert_source(conn, "ws", "workspace")
        store.upsert_file(conn, "ws", "a.md", "T", [], [], "sha", 10, 1.0, NOW)
        store.replace_chunks(conn, "ws", "a.md", [("a.md", "zaloha dat na disk")])

    with store.connection(db_path) as conn:
        assert len(store.bm25_ranked_ids(conn, "zaloha", 10)) == 1

    with store.transaction(db_path) as conn:
        pending = store.pending_chunks(conn, 10)
        store.store_embedding(conn, pending[0]["id"], [0.2] * EMBEDDING_DIMS, NOW)

    with store.connection(db_path) as conn:
        assert len(store.bm25_ranked_ids(conn, "zaloha", 10)) == 1
        assert store.index_stats(conn) == {"files": 1, "chunks": 1, "vectors": 1, "pending": 0}


def test_fts_folds_czech_diacritics(tmp_path):
    """remove_diacritics 2 is what makes `zaloha` find `záloha`."""
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        store.upsert_source(conn, "ws", "workspace")
        store.upsert_file(conn, "ws", "a.md", "T", [], [], "sha", 10, 1.0, NOW)
        store.replace_chunks(conn, "ws", "a.md", [("a.md", "zálohování dat probíhá denně")])

    with store.connection(db_path) as conn:
        assert len(store.bm25_ranked_ids(conn, "zaloh*", 10)) == 1
        assert len(store.bm25_ranked_ids(conn, "záloh*", 10)) == 1


def test_meta_roundtrip_and_rollback(tmp_path):
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        store.write_meta(conn, {"embedding_model": "qwen3-embedding:0.6b", "embedding_dims": "1024"})

    with store.connection(db_path) as conn:
        assert store.read_meta(conn)["embedding_dims"] == "1024"

    try:
        with store.transaction(db_path) as conn:
            store.write_meta(conn, {"embedding_dims": "768"})
            raise RuntimeError("boom")
    except RuntimeError:
        pass

    with store.connection(db_path) as conn:
        assert store.read_meta(conn)["embedding_dims"] == "1024"


def test_toc_filters_by_tag(tmp_path):
    db_path = tmp_path / "index.sqlite"
    with store.transaction(db_path) as conn:
        store.upsert_source(conn, "travel", "git")
        store.upsert_file(conn, "travel", "japan/metro.md", "Metro", ["transit"], [], "s", 1, 1.0, NOW)
        store.upsert_file(conn, "travel", "alps/gear.md", "Gear", ["gear", "safety"], [], "s", 1, 1.0, NOW)

    with store.connection(db_path) as conn:
        assert [r["path"] for r in store.list_toc_files(conn, tag="gear")] == ["alps/gear.md"]
        assert len(store.list_toc_files(conn, source_id="travel")) == 2
        assert store.list_toc_files(conn, source_id="nope") == []