"""Golden test T13 — NativeMixer mirror server render pipeline.

So sanh output native mixer (native_mixer_test.exe) voi reference dung chinh
code path cua server `render_project`:
- track gain/pan: cong thuc render_engine.py (10^(dB/20), constant-power pan)
- master limiter: app.core.mastering_engine.apply_mastering (module limiter)
  + hard clip [-1,1] nhu render_project sau apply_mastering

Yeu cau: |RMS| va |peak| sai lech < 0.1 dB moi case, moi kenh.

Chay:  python native_host/tests/test_native_mixer_golden.py
(tu repo root; can native_mixer_test.exe da build + numpy/scipy)
"""
import os
import subprocess
import sys

import numpy as np

ROOT = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
EXE = os.path.join(ROOT, "native_host", "tests", "native_mixer_test.exe")
SR = 44100

sys.path.insert(0, ROOT)
from app.core.mastering_engine import apply_mastering  # noqa: E402


def make_signal(n=SR):
    t = np.arange(n) / SR
    sig = (
        np.sin(2 * np.pi * 220 * t)
        + 0.5 * np.sin(2 * np.pi * 440 * t + 0.3)
        + 0.3 * np.sin(2 * np.pi * 880 * t + 1.1)
    )
    env = np.minimum(1.0, t * 20.0) * np.exp(-t * 0.8)
    sig *= env
    rng = np.random.default_rng(1234)
    sig = sig + rng.standard_normal(n) * 0.05
    # spike de limiter clip ro rang
    for i in range(0, n, 22050):
        sig[i] += 3.0
    return np.stack([sig, np.roll(sig, 100)])


def ref_process(x, gain_db, pan, lim_active, th_db):
    y = x * (10.0 ** (gain_db / 20.0))
    if pan != 0.0:
        theta = ((np.clip(pan, -1.0, 1.0) + 1.0) / 2.0) * (np.pi / 2.0)
        y = y.copy()
        y[0, :] *= np.cos(theta)
        y[1, :] *= np.sin(theta)
    if lim_active:
        settings = {
            "masterConnected": True,
            "isBypassed": False,
            "chain": [{"type": "limiter", "active": True}],
            "limActive": True,
            "limThreshold": th_db,
        }
        y = apply_mastering(y, settings, SR)
        np.clip(y, -1.0, 1.0, out=y)
    return y


def run_native(x, gain_db, pan, lim_active, th_db, tmp):
    inp = os.path.join(tmp, "in.raw")
    outp = os.path.join(tmp, "out.raw")
    with open(inp, "wb") as f:
        f.write(x.T.astype(np.float32).tobytes())
    args = [EXE, inp, outp, str(gain_db), str(pan), str(int(lim_active)), str(th_db)]
    subprocess.run(args, check=True)
    return np.fromfile(outp, dtype=np.float32).reshape(-1, 2).T


def db_rms_peak(y):
    rms = 20.0 * np.log10(np.sqrt(np.mean(y * y, axis=1)) + 1e-12)
    peak = 20.0 * np.log10(np.max(np.abs(y), axis=1) + 1e-12)
    return rms, peak


def main():
    if not os.path.exists(EXE):
        print(f"FAIL: {EXE} not found (build native_mixer_test.exe truoc)")
        return 1
    import tempfile

    x = make_signal()
    cases = [
        (0.0, 0.0, False, -1.0),   # identity (limiter off)
        (6.0, -0.5, False, -1.0),  # gain/pan, khong limiter
        (6.0, -0.5, True, -3.0),
        (-9.0, 0.8, True, -6.0),
        (12.0, 0.0, True, 0.0),
    ]
    worst = 0.0
    with tempfile.TemporaryDirectory() as tmp:
        for i, (g, p, la, th) in enumerate(cases):
            native = run_native(x, g, p, la, th, tmp)
            ref = ref_process(x, g, p, la, th)
            nr, npk = db_rms_peak(native)
            rr, rpk = db_rms_peak(ref)
            dr = np.max(np.abs(nr - rr))
            dp = np.max(np.abs(npk - rpk))
            worst = max(worst, dr, dp)
            status = "OK " if (dr < 0.1 and dp < 0.1) else "FAIL"
            print(f"case {i} gain={g} pan={p} lim={int(la)} th={th}: "
                  f"RMS diff={dr:.4f} dB peak diff={dp:.4f} dB [{status}]")
            if dr >= 0.1 or dp >= 0.1:
                print(f"  native rms={nr} peak={npk}")
                print(f"  ref    rms={rr} peak={rpk}")
    print(f"worst diff: {worst:.4f} dB (< 0.1 -> PASS)")
    return 0 if worst < 0.1 else 1


if __name__ == "__main__":
    sys.exit(main())