"""Tests cho tools/autosample_vsti.py — SF2 writer tự-sinh phải là RIFF/sfbk
hợp lệ mà sf2utils parse được (không cần VSTi/pedalboard)."""
import os
import numpy as np
import pytest

from tools.autosample_vsti import write_sf2

sf2utils = pytest.importorskip("sf2utils.sf2parse")


def _sine(note, sr=44100, dur=0.2):
    t = np.arange(int(sr * dur)) / sr
    f = 440.0 * 2 ** ((note - 69) / 12)
    return (np.sin(2 * np.pi * f * t) * 20000).astype(np.int16)


def test_write_sf2_valid_structure(tmp_path):
    out = str(tmp_path / "test.sf2")
    samples = [{"note": n, "frames": _sine(n)} for n in (60, 62, 64)]
    write_sf2(out, samples, sample_rate=44100, name="Test")
    assert os.path.getsize(out) > 100
    with open(out, "rb") as f:
        head = f.read(12)
    assert head[:4] == b"RIFF"
    assert head[8:12] == b"sfbk"
    with open(out, "rb") as f:
        sf2 = sf2utils.Sf2File(f)
    real_samples = [s for s in sf2.samples if s.end > s.start]
    assert len(real_samples) == 3
    assert len(sf2.presets) == 2  # preset + terminator
    assert sf2.presets[0].bank == 0
    assert sf2.presets[0].preset == 0
    assert sf2.presets[0].name == "Test"
    for s in real_samples:
        assert s.end - s.start == 8820
        assert s.sample_rate == 44100


def test_write_sf2_rejects_empty(tmp_path):
    with pytest.raises(ValueError):
        write_sf2(str(tmp_path / "empty.sf2"), [])


def test_write_sf2_odd_name_no_corruption(tmp_path, caplog):
    """INFO text chunk chan — ten le (vd "Nexus") khong duoc lam mat can
    (sf2utils khong skip pad byte cua odd-size chunk)."""
    import logging
    out = str(tmp_path / "odd.sf2")
    write_sf2(out, [{"note": 60, "frames": _sine(60)}], 44100, name="Nexus")
    with caplog.at_level(logging.WARNING):
        with open(out, "rb") as f:
            sf2 = sf2utils.Sf2File(f)
    assert len([s for s in sf2.samples if s.end > s.start]) == 1
    assert not any("corrupted" in r.message for r in caplog.records)