import os
import json
import pytest
from app.core.render_engine import PythonRenderEngine

def test_render_engine_init():
    engine = PythonRenderEngine()
    assert engine.sample_rate == 44100

def test_bars_to_samples():
    engine = PythonRenderEngine()
    samples = engine.bars_to_samples(4.0, 120.0, 4)
    assert samples == 352800

def test_render_session_container_empty():
    engine = PythonRenderEngine()
    session = {"tracks": []}
    buf = engine.render_session_container(session, {}, 120.0, 4, 1000)
    assert buf.shape == (2, 1000)
    assert (buf == 0.0).all()

def test_render_project_bit_depth(tmp_path):
    """bit_depth 24/32 → WAV PCM_24/PCM_32; mặc định vẫn PCM_16."""
    import soundfile as sf
    engine = PythonRenderEngine()
    project = {
        "metadata": {"bpm": 120, "time_signature_numerator": 4},
        "main_session": {"length_bars": 1.0, "tracks": []},
        "section_store": {},
    }
    for bd, subtype in [(16, "PCM_16"), (24, "PCM_24"), (32, "PCM_32")]:
        out = str(tmp_path / f"render_{bd}.wav")
        engine.render_project(project, out, bit_depth=bd)
        assert sf.info(out).subtype == subtype

def _default_mastering():
    return {
        "masterConnected": True, "isBypassed": False,
        "eqActive": True, "eqLowGain": 1.5, "eqMid1Gain": -1.0, "eqMid2Gain": 2.0, "eqHighGain": 1.8,
        "imagerActive": True, "w1": 0, "w2": 115, "w3": 135, "w4": 150,
        "maximizerActive": True, "maxGain": 5.4, "maxUpward": 2.0, "maxSoftClip": 15, "ceiling": -0.1,
        "compActive": False, "compThreshold": -16, "compRatio": 3, "compMakeup": 2,
        "limActive": False, "limThreshold": -1.0,
        "excActive": False, "excDrive": 30,
        "rebalActive": False, "rebalMid": 0, "rebalSide": 0,
        "chain": [
            {"id": "mod_eq", "type": "eq", "active": True},
            {"id": "mod_imager", "type": "imager", "active": True},
            {"id": "mod_maximizer", "type": "maximizer", "active": True},
        ],
    }

def test_apply_mastering_engine_gates_and_ceiling():
    """apply_mastering: gate masterConnected/isBypassed/chain rỗng → copy;
    chain mặc định → khác input, peak ≤ ceiling (hard clip của Maximizer)."""
    import numpy as np
    from app.core.mastering_engine import apply_mastering
    sr = 44100
    t = np.arange(sr // 5) / sr
    buf = np.stack([np.sin(2 * np.pi * 220 * t) * 0.9,
                    np.sin(2 * np.pi * 220 * t + 0.5) * 0.8]).astype(np.float32)
    s = _default_mastering()
    assert np.array_equal(apply_mastering(buf, None, sr), buf)
    assert np.array_equal(apply_mastering(buf, {**s, "masterConnected": False}, sr), buf)
    assert np.array_equal(apply_mastering(buf, {**s, "isBypassed": True}, sr), buf)
    assert np.array_equal(apply_mastering(buf, {**s, "chain": []}, sr), buf)
    out = apply_mastering(buf, s, sr)
    assert out.shape == buf.shape and not np.array_equal(out, buf)
    assert np.max(np.abs(out)) <= 10 ** (-0.1 / 20) + 1e-6  # ceiling -0.1 dB

def test_render_project_mastering(tmp_path):
    """render_project: có mastering_settings → WAV khác bản không mastering,
    peak ≤ 1.0 (hard clip sau mastering như WAV encoder client)."""
    import numpy as np
    import soundfile as sf
    from app.config import settings
    engine = PythonRenderEngine()
    # 1s 440Hz tone làm nguồn audio thật (project rỗng = silence → mastering
    # của silence = silence, không test được gì)
    sr = engine.sample_rate
    t = np.arange(sr) / sr
    tone = (0.9 * np.sin(2 * np.pi * 440 * t)).astype(np.float32)
    src_path = os.path.join(settings.UPLOADS_DIR, "mastering_test_tone.wav")
    sf.write(src_path, tone, sr)
    try:
        project = {
            "metadata": {"bpm": 120, "time_signature_numerator": 4},
            "main_session": {
                "length_bars": 4.0,
                "tracks": [{
                    "type": "AUDIO", "volume_db": 0.0, "pan": 0.0, "mute": False,
                    "items": [{
                        "type": "AUDIO_ITEM", "start_bar": 0.0, "duration_bars": 4.0,
                        "clip_start_offset_bars": 0.0,
                        "source_data": {"audio_file_url": "/static/audio/uploads/mastering_test_tone.wav", "gain": 1.0},
                    }],
                }],
            },
            "section_store": {},
        }
        out_plain = str(tmp_path / "plain.wav")
        engine.render_project(project, out_plain, bit_depth=16)
        plain, _ = sf.read(out_plain, dtype="float32")
        assert np.max(np.abs(plain)) > 0.01

        out_mast = str(tmp_path / "mastered.wav")
        engine.render_project({**project, "mastering_settings": _default_mastering()},
                              out_mast, bit_depth=16)
        mast, _ = sf.read(out_mast, dtype="float32")
        assert not np.array_equal(mast, plain)
        assert np.max(np.abs(mast)) <= 1.0 + 1e-6
    finally:
        try:
            os.remove(src_path)
        except OSError:
            pass