import numpy as np
import pytest

from rhythma_engine import RhythmaModulationEngine


def test_render_session_returns_normalized_layered_audio():
    engine = RhythmaModulationEngine()
    profile = {
        "tone_center": 396.0,
        "pattern": "calm",
        "modulation_type": "sine",
        "brightness": 0.25,
        "density": 0.45,
        "shimmer": 0.12,
        "breath_rate": 0.08,
    }

    audio = engine.render_session(profile, duration=4)

    assert len(audio) == engine.sample_rate * 4
    assert np.max(np.abs(audio)) <= 0.9 + 1e-9
    assert np.max(np.abs(audio[:400])) < np.max(np.abs(audio[2000:2400]))
    assert np.max(np.abs(audio[-400:])) < np.max(np.abs(audio[2000:2400]))


def test_render_session_is_not_identical_to_single_layer_base_wave():
    engine = RhythmaModulationEngine()
    profile = {
        "tone_center": 639.0,
        "pattern": "focused",
        "modulation_type": "sine",
        "brightness": 0.4,
        "density": 0.35,
        "shimmer": 0.18,
        "breath_rate": 0.12,
    }

    session_audio = engine.render_session(profile, duration=3)
    legacy_audio = engine.generate_modulated_wave(3)

    assert not np.allclose(session_audio[:2000], legacy_audio[:2000])


def test_render_session_keeps_breath_layer_pulse_shaped():
    engine = RhythmaModulationEngine()
    pulse_profile = {
        "tone_center": 528.0,
        "pattern": "relaxed",
        "modulation_type": "pulse",
        "brightness": 0.3,
        "density": 0.4,
        "shimmer": 0.15,
        "breath_rate": 0.1,
    }
    chirp_profile = dict(pulse_profile, modulation_type="chirp")

    pulse_audio = engine.render_session(pulse_profile, duration=2)
    chirp_audio = engine.render_session(chirp_profile, duration=2)

    assert np.allclose(pulse_audio, chirp_audio)


@pytest.mark.parametrize("duration", [0, -1, 0.5 / RhythmaModulationEngine.SAMPLE_RATE])
def test_render_session_rejects_invalid_duration(duration):
    engine = RhythmaModulationEngine()
    profile = {
        "tone_center": 528.0,
        "pattern": "calm",
        "modulation_type": "sine",
        "brightness": 0.2,
        "density": 0.3,
        "shimmer": 0.1,
        "breath_rate": 0.08,
    }

    with pytest.raises(ValueError, match="duration must produce at least one sample"):
        engine.render_session(profile, duration=duration)