import os
import shutil
import sqlite3
import tempfile

import pytest

import backend.db as db_mod


@pytest.fixture
def drift_db_dir():
    # Persistent temp dir; on Windows the global WAL connection can outlive the
    # test frame, so we avoid TemporaryDirectory's immediate rmtree race and clean
    # up best-effort after the handle is released.
    tmp = tempfile.mkdtemp(prefix="slab_drift_")
    yield tmp
    db_mod._reset_for_tests()
    shutil.rmtree(tmp, ignore_errors=True)



def _setup_temp_db_with_m2_schema(tmp_dir: str) -> str:
    db_path = os.path.join(tmp_dir, "test.db")
    # M2-era settings shape: NO `value` column (this is the drift signature).
    # Use a raw connection (DELETE journal) exactly as an old M2 db would be on disk.
    conn = sqlite3.connect(db_path)
    conn.execute("CREATE TABLE settings (key TEXT PRIMARY KEY, value_enc BLOB, updated_at TEXT)")
    conn.execute("INSERT INTO settings (key, value_enc, updated_at) VALUES ('woo_wp_username', X'00', '2026-01-01')")
    conn.commit()
    conn.close()
    # Force any journal sidecars to merge before the WAL-mode factory opens the file.
    for suffix in ("-journal", "-wal", "-shm"):
        try:
            os.remove(db_path + suffix)
        except OSError:
            pass
    return db_path


def test_drift_detection_and_rebuild(monkeypatch, drift_db_dir):
    db_path = _setup_temp_db_with_m2_schema(drift_db_dir)
    monkeypatch.setenv("SLAB_DB_PATH", db_path)
    # init_db must detect pre-M3 drift and rebuild to the M3 settings shape
    conn = db_mod.init_db()
    cur = conn.execute("SELECT version FROM schema_version").fetchone()
    assert cur is not None
    assert cur[0] == 1
    info = conn.execute("PRAGMA table_info(settings)").fetchall()
    cols = {row[1] for row in info}
    assert "value" in cols
    assert "value_enc" in cols
    # M2 rows are disposable (M3 supersedes M2 on this dev volume)
    rows = conn.execute("SELECT key FROM settings").fetchall()
    assert rows == []