from perfkit import sqlstats
from perfkit.sqlstats import explain_candidates, v3_functions, is_explainable, pick_params


def row(q, total=1.0):
    return {"query": q, "total_exec_time": total}


def test_v3_functions_extracts_names():
    assert v3_functions("SELECT * FROM v3.v_sheet_rows($1, $2)") == ["v_sheet_rows"]
    assert v3_functions("select v3.upd_cell($1,$2)") == ["upd_cell"]
    assert v3_functions("SELECT 1") == []


def test_is_explainable_select_and_read_functions():
    assert is_explainable("SELECT * FROM v3.v_sheet_rows($1)")
    assert is_explainable("  select a from t where id = $1")
    assert is_explainable("WITH x AS (SELECT 1) SELECT * FROM x")


def test_is_explainable_rejects_dml_and_writers():
    assert not is_explainable("UPDATE t SET a = $1")
    assert not is_explainable("INSERT INTO t VALUES ($1)")
    assert not is_explainable("DELETE FROM t")
    assert not is_explainable("SELECT * FROM v3.add_line($1)")
    assert not is_explainable("SELECT v3.upd_cell($1, $2)")
    assert not is_explainable("SELECT v3.del_line($1)")
    assert not is_explainable("SELECT * FROM t FOR UPDATE")
    assert not is_explainable("SELECT set_config('a', $1, false)")
    assert not is_explainable("SELECT pg_stat_statements_reset()")
    assert not is_explainable("EXPLAIN SELECT 1")


def test_explain_candidates_top5_by_total_in_order():
    rows = [row("UPDATE t SET a=$1", 100)] + [row(f"SELECT {i} FROM t WHERE a=$1", i) for i in range(10)]
    got = explain_candidates(rows, n=5)
    assert [r["total_exec_time"] for r in got] == [9, 8, 7, 6, 5]


def test_pick_params_uses_sample_when_given():
    assert pick_params("SELECT $1, $2", {"SELECT $1, $2": [1, "a"]}) == [1, "a"]
    assert pick_params("SELECT $1", {}) is None


def test_dump_out_dir_passed_to_dump(monkeypatch, tmp_path):
    """--out: sql_top.json/explain пишутся в отдельный каталог шага (run-all), сетевой лог читается из run_dir."""
    seen = {}

    async def fake(run_dir, top, out_dir):
        seen.update(run_dir=run_dir, top=top, out_dir=out_dir)
        return {"explained": 0, "skipped": 0}

    monkeypatch.setattr(sqlstats, "_dump", fake)
    out = tmp_path / "sql" / "scroll"
    assert sqlstats.main(["dump", str(tmp_path), "--top", "7", "--out", str(out)]) == 0
    assert seen == {"run_dir": tmp_path, "top": 7, "out_dir": out}
    assert out.is_dir()


def test_dump_without_out_writes_to_run_dir(monkeypatch, tmp_path):
    seen = {}

    async def fake(run_dir, top, out_dir):
        seen.update(out_dir=out_dir)
        return {"explained": 0, "skipped": 0}

    monkeypatch.setattr(sqlstats, "_dump", fake)
    assert sqlstats.main(["dump", str(tmp_path)]) == 0
    assert seen["out_dir"] == tmp_path