#!/usr/bin/env python3
"""
SonicMaster Mastering Wrapper for HAIM Dataset
================================================
AI mastering using SonicMaster (https://arxiv.org/abs/2508.03448).
Wraps the SonicMaster inference pipeline for easy single-file or batch mastering.

Usage:
    # Single file mastering
    python sonic_master.py --input track.wav --output mastered.wav

    # With custom prompt
    python sonic_master.py --input track.wav --output mastered.wav \
        --prompt "Apply warm mastering with balanced EQ and gentle compression"

    # Auto mode (no text prompt)
    python sonic_master.py --input track.wav --output mastered.wav --auto

    # Batch mastering
    python sonic_master.py --input_dir /path/to/tracks --output_dir /path/to/output
"""

import argparse
import os
import sys
from pathlib import Path

# Add SonicMaster repo to path
SONIC_MASTER_DIR = Path(__file__).parent / "SonicMaster"
sys.path.insert(0, str(SONIC_MASTER_DIR))

DEFAULT_CKPT = SONIC_MASTER_DIR / "checkpoints" / "model.safetensors"
DEFAULT_CONFIG = SONIC_MASTER_DIR / "configs" / "tangoflux_config.yaml"
DEFAULT_PROMPT = "Apply professional mastering with balanced EQ, gentle compression, and optimal loudness"


def parse_args():
    p = argparse.ArgumentParser(
        description="SonicMaster AI Mastering for HAIM Dataset",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog=__doc__,
    )
    # Input/output
    p.add_argument("--input", type=str, help="Path to input audio file.")
    p.add_argument("--output", type=str, help="Path to output audio file.")
    p.add_argument("--input_dir", type=str, help="Directory of input audio files (batch mode).")
    p.add_argument("--output_dir", type=str, help="Directory for output audio files (batch mode).")

    # Mastering control
    p.add_argument("--prompt", type=str, default=DEFAULT_PROMPT,
                   help="Text prompt guiding the mastering.")
    p.add_argument("--auto", action="store_true",
                   help="Auto mode: use default restoration prompt.")

    # Model paths
    p.add_argument("--ckpt", type=str, default=str(DEFAULT_CKPT),
                   help="Path to model.safetensors.")
    p.add_argument("--config", type=str, default=str(DEFAULT_CONFIG),
                   help="Path to tangoflux_config.yaml.")

    # Inference params
    p.add_argument("--fs", type=int, default=44100)
    p.add_argument("--chunk_duration", type=int, default=30)
    p.add_argument("--overlap_duration", type=int, default=10)
    p.add_argument("--num_inference_steps", type=int, default=10)
    p.add_argument("--guidance_scale", type=float, default=1.0)
    p.add_argument("--seed", type=int, default=0)

    return p.parse_args()


def load_model(ckpt_path, config_path, device):
    """Load SonicMaster model and VAE."""
    import torch
    import yaml
    from safetensors.torch import load_file
    from diffusers import AutoencoderOobleck
    from model import TangoFlux

    with open(config_path, "r") as f:
        cfg = yaml.safe_load(f)

    model = TangoFlux(config=cfg["model"])
    weights = load_file(str(ckpt_path))
    model.load_state_dict(weights, strict=False)
    model.to(device).half().eval()

    for p in model.text_encoder.parameters():
        p.requires_grad = False
    model.text_encoder.eval()

    hf_token = os.getenv("HF_TOKEN") or os.getenv("HUGGINGFACE_TOKEN")
    # VAE stays fp32 for audio quality — memory managed per-chunk
    vae = AutoencoderOobleck.from_pretrained(
        "stabilityai/stable-audio-open-1.0", subfolder="vae",
        use_auth_token=hf_token,
    ).to(device)
    vae.eval()

    return model, vae


@__import__('torch').no_grad()
def master_single(model, vae, input_path, output_path, prompt, args, device):
    """Master a single audio file."""
    import torch
    import torchaudio
    import soundfile as sf

    fs = args.fs
    chunk_size = args.chunk_duration * fs
    overlap = args.overlap_duration * fs
    stride = chunk_size - overlap

    # Load and standardize (keep on CPU)
    audio, sr = torchaudio.load(str(input_path))
    if audio.shape[0] == 1:
        audio = audio.repeat(2, 1)
    elif audio.shape[0] > 2:
        audio = audio[:2, :]
    if sr != fs:
        audio = torchaudio.functional.resample(audio, sr, fs)

    T = audio.shape[1]

    # Chunk on CPU
    chunks = []
    start = 0
    while start < T:
        end = min(start + chunk_size, T)
        ch = audio[:, start:end]
        if ch.shape[1] < chunk_size:
            ch = torch.nn.functional.pad(ch, (0, chunk_size - ch.shape[1]))
        chunks.append(ch)
        start += stride

    # Process each chunk: encode -> infer -> decode, one at a time
    decoded_chunks = []
    prev_cond = None

    for i, ch in enumerate(chunks):
        torch.cuda.empty_cache()

        # Encode on GPU with autocast for memory savings
        ch_gpu = ch.unsqueeze(0).to(device)
        with torch.amp.autocast('cuda'):
            z = vae.encode(ch_gpu).latent_dist.mode()
        del ch_gpu
        torch.cuda.empty_cache()

        # Inference (transformer is fp16)
        z_in = z.half().transpose(1, 2)
        del z
        result_latent = model.inference_flow(
            z_in, prompt,
            audiocond_latents=prev_cond,
            num_inference_steps=args.num_inference_steps,
            timesteps=None,
            guidance_scale=args.guidance_scale,
            duration=args.chunk_duration,
            seed=args.seed,
            disable_progress=True,
            num_samples_per_prompt=1,
            callback_on_step_end=None,
            solver="Euler",
        )
        del z_in
        torch.cuda.empty_cache()

        # Decode back to waveform (fp32 VAE for quality)
        with torch.amp.autocast('cuda'):
            wav = vae.decode(result_latent.float().transpose(2, 1)).sample.cpu()
        wav = torch.clamp(wav, -1.0, 1.0)
        decoded_chunks.append(wav)

        # Carry conditioning for next chunk
        if i < len(chunks) - 1:
            last = wav[:, :, -overlap:].to(device)
            with torch.amp.autocast('cuda'):
                prev_cond = vae.encode(last).latent_dist.mode().transpose(1, 2).half()
            del last
            torch.cuda.empty_cache()

        del result_latent

    # Crossfade stitch (all on CPU, fp32)
    final = decoded_chunks[0]
    for i in range(1, len(decoded_chunks)):
        prev = final[:, :, -overlap:]
        curr = decoded_chunks[i][:, :, :overlap]
        alpha = torch.linspace(1.0, 0.0, steps=overlap).view(1, 1, -1)
        blended = prev * alpha + curr * (1.0 - alpha)
        final = torch.cat(
            [final[:, :, :-overlap], blended, decoded_chunks[i][:, :, overlap:]],
            dim=2,
        )

    # Trim to original length
    final = final[:, :, :T]

    # Save
    out_path = Path(output_path)
    out_path.parent.mkdir(parents=True, exist_ok=True)
    data = final.squeeze(0).float().numpy().T
    sf.write(str(out_path), data, fs)
    return True


def main():
    import torch
    from time import time

    args = parse_args()
    device = "cuda" if torch.cuda.is_available() else "cpu"
    torch.backends.cuda.matmul.allow_tf32 = True
    torch.backends.cudnn.allow_tf32 = True

    # Validate args
    single_mode = args.input and args.output
    batch_mode = args.input_dir and args.output_dir
    if not single_mode and not batch_mode:
        print("Error: provide --input/--output for single mode or --input_dir/--output_dir for batch mode.")
        sys.exit(1)

    prompt = args.prompt
    if args.auto:
        prompt = "Restore and enhance audio quality"

    # Load model once
    print(f"Loading SonicMaster model from {args.ckpt}...")
    t0 = time()
    model, vae = load_model(args.ckpt, args.config, device)
    print(f"Model loaded in {time()-t0:.1f}s (device={device})")

    if single_mode:
        print(f"Mastering: {args.input}")
        print(f"Prompt: {prompt}")
        t0 = time()
        master_single(model, vae, args.input, args.output, prompt, args, device)
        print(f"Done: {args.output} ({time()-t0:.1f}s)")

    elif batch_mode:
        import json as _json
        input_dir = Path(args.input_dir)
        output_dir = Path(args.output_dir)
        output_dir.mkdir(parents=True, exist_ok=True)

        audio_exts = {'.wav', '.flac', '.mp3', '.ogg'}
        files = sorted([f for f in input_dir.iterdir() if f.suffix.lower() in audio_exts])
        print(f"Found {len(files)} audio files in {input_dir}")

        meta_path = output_dir / "metadata.jsonl"
        meta_f = open(meta_path, "a", encoding="utf-8")

        for i, f in enumerate(files, 1):
            out_file = output_dir / f"{f.stem}_mastered.wav"
            if out_file.exists():
                print(f"[{i}/{len(files)}] Skip (exists): {out_file.name}")
                continue
            print(f"[{i}/{len(files)}] Mastering: {f.name}")
            t0 = time()
            try:
                master_single(model, vae, str(f), str(out_file), prompt, args, device)
                elapsed = time() - t0
                meta = {
                    "track_id": f.stem,
                    "filename": out_file.name,
                    "input_source": f.name,
                    "method": "sonicmaster",
                    "prompt": prompt,
                    "elapsed_sec": round(elapsed, 1),
                }
                # Per-track JSON
                with open(output_dir / f"{f.stem}_mastered.json", "w", encoding="utf-8") as jf:
                    _json.dump(meta, jf, ensure_ascii=False, indent=2)
                meta_f.write(_json.dumps(meta, ensure_ascii=False) + "\n")
                meta_f.flush()
                print(f"  -> {out_file.name} ({elapsed:.1f}s)")
            except Exception as e:
                print(f"  -> FAILED: {e}")

        meta_f.close()


if __name__ == "__main__":
    main()