import numpy as np

from localizer.config import ExtractionConfig
from localizer.extraction import extract_hrir
from fixtures import synth_brir, SAMPLE_RATE


def test_extracts_target_length():
    cfg = ExtractionConfig()
    brir = synth_brir(30.0)
    hrir = extract_hrir(brir, cfg)
    expected = int(round(cfg.hrir_duration * SAMPLE_RATE))
    assert hrir.num_samples == expected  # 6 ms window


def test_removes_leading_silence():
    brir = synth_brir(0.0, leading_silence=200)
    hrir = extract_hrir(brir)
    # After trimming, energy should be concentrated near the start, not delayed by 200.
    env = np.abs(hrir.left) + np.abs(hrir.right)
    onset = int(np.argmax(env))
    assert onset < 64


def test_preserves_lateral_energy_asymmetry():
    # Source on the left: left channel should carry more energy than the right.
    brir = synth_brir(60.0)
    hrir = extract_hrir(brir)
    assert np.sum(hrir.left ** 2) > np.sum(hrir.right ** 2)