from __future__ import annotations

import pytest

from app.engine.indicators import atr, ema, macd, roc, rolling_std, rsi, sma
from app.schemas import Candle


def candle(high: float, low: float, close: float, open_: float | None = None) -> Candle:
    return Candle(
        ts=0,
        open=open_ if open_ is not None else close,
        high=high,
        low=low,
        close=close,
        volume=1,
    )


def test_sma() -> None:
    assert sma([1, 2, 3, 4, 5], 3) == [None, None, 2.0, 3.0, 4.0]


def test_ema() -> None:
    assert ema([1, 2, 3, 4, 5], 3) == [None, None, 2.0, 3.0, 4.0]


def test_rsi_monotonic_is_100() -> None:
    values = [float(i) for i in range(1, 20)]
    assert rsi(values, 14)[-1] == pytest.approx(100.0)


def test_atr_flat_market_is_zero() -> None:
    candles = [candle(100, 100, 100) for _ in range(20)]
    assert atr(candles, 5)[-1] == pytest.approx(0.0)


def test_rolling_std() -> None:
    result = rolling_std([1, 1, 1, 1], 2)
    assert result[-1] == pytest.approx(0.0)


def test_roc() -> None:
    values = [100.0, 110.0, 121.0, 100.0]
    out = roc(values, 2)
    assert out[0] is None and out[1] is None
    assert out[2] == pytest.approx(0.21)
    assert out[3] == pytest.approx(-0.09090909, rel=1e-4)


def test_macd_shapes_and_crossover_sign() -> None:
    rising = [float(i) for i in range(1, 80)]
    macd_line, signal_line, histogram = macd(rising, 12, 26, 9)
    assert len(macd_line) == len(rising)
    assert macd_line[-1] is not None and signal_line[-1] is not None
    # In a steady uptrend MACD is positive (but can be below its signal after lag).
    assert macd_line[-1] > 0
    assert histogram[-1] == pytest.approx(macd_line[-1] - signal_line[-1])

    falling = [float(i) for i in range(80, 0, -1)]
    macd_falling, _, _ = macd(falling, 12, 26, 9)
    assert macd_falling[-1] < 0