import os
import json
import pytest
from app.core.render_engine import PythonRenderEngine
import numpy as np

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 _midi_track(instrument_id, fx_type=None):
    return {
        "id": "t1",
        "type": "MIDI",
        "instrument_id": instrument_id,
        "instrument_source": "vsti",
        "fx_type": fx_type,
        "volume_db": 0.0,
        "pan": 0.0,
        "mute": False,
        "items": [{
            "type": "MIDI_ITEM",
            "start_bar": 0.0,
            "duration_bars": 1.0,
            "clip_start_offset_bars": 0.0,
            "source_data": {
                "notes": [
                    {"pitch": 60, "velocity": 0.8, "start_beat": 0.0, "duration_beats": 1.0}
                ]
            },
        }],
    }


def test_render_session_vsti_bridge_unknown_instrument_falls_back(monkeypatch):
    """SF_RENDER_ENGINE=bridge: track VSTi đi vào native_render; instrument lạ
    (404) → fallback oscillator, không crash, không cần pedalboard."""
    from app.api.v1 import plugins as pl
    monkeypatch.setattr(pl.settings, "RENDER_ENGINE", "bridge")
    engine = PythonRenderEngine()
    session = {"tracks": [_midi_track("__no_such_plugin__")]}
    buf = engine.render_session_container(session, {}, 120.0, 4, 44100)
    assert buf.shape == (2, 44100)
    # oscillator sinh âm thật (non-silent)
    assert (buf != 0.0).any()


def test_render_session_vsti_non_bridge_engine_falls_back(monkeypatch):
    """Engine không phải bridge (vd 'pedalboard' cũ): VSTi → fallback oscillator (không crash)."""
    from app.api.v1 import plugins as pl
    monkeypatch.setattr(pl.settings, "RENDER_ENGINE", "pedalboard")
    engine = PythonRenderEngine()
    session = {"tracks": [_midi_track("__no_such_plugin__")]}
    buf = engine.render_session_container(session, {}, 120.0, 4, 44100)
    assert buf.shape == (2, 44100)


def test_render_session_fx_chorus_scipy_fallback():
    """FX chorus: fallback scipy (không pedalboard) không crash, thay đổi âm."""
    from app.api.v1 import plugins as pl
    pl.settings.RENDER_ENGINE = "bridge"
    engine = PythonRenderEngine()
    session = {"tracks": [_midi_track("__no_such_plugin__", fx_type="chorus")]}
    buf = engine.render_session_container(session, {}, 120.0, 4, 44100)
    assert buf.shape == (2, 44100)
    assert (buf != 0.0).any()


def test_render_session_fx_reverb_scipy_fallback():
    """FX reverb: fallback scipy (không pedalboard) không crash, thay đổi âm."""
    from app.api.v1 import plugins as pl
    pl.settings.RENDER_ENGINE = "bridge"
    engine = PythonRenderEngine()
    session = {"tracks": [_midi_track("__no_such_plugin__", fx_type="reverb")]}
    buf = engine.render_session_container(session, {}, 120.0, 4, 44100)
    assert buf.shape == (2, 44100)
    assert (buf != 0.0).any()


_BRIDGE_TEST_PATH = r"C:/Users/locpham/SonicForgeStudio/native_bridge/build/Release/daw_vst_bridge.exe"


def _peak(buf):
    return float(np.max(np.abs(buf)))


def test_render_track_fx_chain_gain_via_bridge(monkeypatch):
    """Track fx_chain (builtin gain +6dB) qua native_bridge → biên độ x2."""
    import numpy as np
    if not os.path.isfile(_BRIDGE_TEST_PATH):
        pytest.skip("bridge chưa build")
    monkeypatch.setenv("SF_BRIDGE_PATH", _BRIDGE_TEST_PATH)
    from app.api.v1 import plugins as pl
    monkeypatch.setattr(pl.settings, "RENDER_ENGINE", "bridge")
    engine = PythonRenderEngine()
    base = _midi_track("__no_such_plugin__")
    fx = _midi_track("__no_such_plugin__")
    fx["vst_fx_chain"] = [{"type": "builtin", "id": "gain", "params": {"db": 6.0}}]
    b0 = engine.render_session_container({"tracks": [base]}, {}, 120.0, 4, 44100)
    b1 = engine.render_session_container({"tracks": [fx]}, {}, 120.0, 4, 44100)
    assert _peak(b1) > 1.5 * _peak(b0)


def test_render_project_master_fx_chain_gain_via_bridge(monkeypatch, tmp_path):
    """Masterbus master.fx_chain (gain +6dB) qua native_bridge → peak x2."""
    import numpy as np
    if not os.path.isfile(_BRIDGE_TEST_PATH):
        pytest.skip("bridge chưa build")
    monkeypatch.setenv("SF_BRIDGE_PATH", _BRIDGE_TEST_PATH)
    from app.api.v1 import plugins as pl
    monkeypatch.setattr(pl.settings, "RENDER_ENGINE", "bridge")
    engine = PythonRenderEngine()

    def project(with_master):
        track = _midi_track("__no_such_plugin__")
        track["volume_db"] = -20.0  # tránh normalize (>1.0) làm hỏng tỉ lệ 2x
        proj = {
            "metadata": {"bpm": 120.0, "time_signature_numerator": 4},
            "main_session": {"length_bars": 1.0, "tracks": [track]},
            "section_store": {},
        }
        if with_master:
            proj["main_session"]["master"] = {
                "fx_chain": [{"type": "builtin", "id": "gain", "params": {"db": 6.0}}],
                "bypass": False,
            }
        return proj

    out0 = str(tmp_path / "no_master.wav")
    out1 = str(tmp_path / "with_master.wav")
    engine.render_project(project(False), out0)
    engine.render_project(project(True), out1)
    _, d0 = sf_read_peaks(out0)
    _, d1 = sf_read_peaks(out1)
    assert d1 > 1.5 * d0

import soundfile as _sf

def sf_read_peaks(path):
    import numpy as np
    data, _ = _sf.read(path, dtype="float32", always_2d=True)
    return data, float(np.max(np.abs(data)))