import datetime

from sqlalchemy import create_engine, text

from src.postgres_history import PostgresHistory


def test_history_returns_station_series_in_chronological_order(tmp_path):
    engine = create_engine(f"sqlite:///{tmp_path / 'history.db'}")
    with engine.begin() as connection:
        connection.execute(text("CREATE TABLE stations (id INTEGER PRIMARY KEY, station_code TEXT)"))
        connection.execute(
            text(
                "CREATE TABLE water_measurements ("
                "timestamp DATETIME, station_id INTEGER, water_level REAL, "
                "discharge REAL, discharge_percent REAL)"
            )
        )
        connection.execute(text("INSERT INTO stations VALUES (1, 'P.1'), (2, 'P.20')"))
        connection.execute(
            text(
                "INSERT INTO water_measurements VALUES "
                "('2026-08-09 13:00:00', 1, 3.2, 110.0, 40.0),"
                "('2026-08-09 14:00:00', 1, 3.4, 120.0, 42.0),"
                "('2026-08-09 14:00:00', 2, 2.1, 30.0, 15.0)"
            )
        )

    history = PostgresHistory(engine=engine).station_history(
        "P.1",
        start=datetime.datetime(2026, 8, 9, 12),
        end=datetime.datetime(2026, 8, 9, 15),
        limit=100,
    )

    assert [row["timestamp"].hour for row in history] == [13, 14]
    assert [row["discharge"] for row in history] == [110.0, 120.0]
    assert all(row["station_code"] == "P.1" for row in history)


def test_history_rejects_excessive_limit():
    history = PostgresHistory.__new__(PostgresHistory)

    try:
        history.station_history("P.1", datetime.datetime.now(), datetime.datetime.now(), 100001)
    except ValueError as error:
        assert "limit" in str(error)
    else:
        raise AssertionError("Expected excessive history limit to be rejected")