import pytest
from engine.signal import SignalEngine

@pytest.fixture
def engine():
    return SignalEngine()

def test_compute_score_default_weights(engine):
    score = engine.compute_score(80, 60, 70, 50)
    assert score == 72.0

def test_classify_buy(engine):
    assert engine.classify(75) == "BUY"

def test_classify_hold(engine):
    assert engine.classify(55) == "HOLD"

def test_classify_sell(engine):
    assert engine.classify(30) == "SELL"

def test_custom_weights(engine):
    engine.set_weights({"technical": 0.4, "news": 0.3, "social": 0.2, "ai": 0.1})
    score = engine.compute_score(80, 60, 70, 50)
    assert score == 69.0

def test_weights_must_sum_to_one(engine):
    with pytest.raises(ValueError):
        engine.set_weights({"technical": 0.5, "news": 0.3, "social": 0.1, "ai": 0.2})

def test_rank_coins(engine):
    coins = {
        "BTC": {"technical": 80, "news": 70, "social": 60, "ai": 75},
        "ETH": {"technical": 90, "news": 80, "social": 70, "ai": 85},
        "DOGE": {"technical": 30, "news": 25, "social": 40, "ai": 20},
    }
    ranked = engine.rank_coins(coins)
    assert ranked[0]["symbol"] == "ETH"
    assert ranked[-1]["symbol"] == "DOGE"
    assert ranked[-1]["signal"] == "SELL"