app.py

"""ACE-Step 1.5 XL (CPU) - Gradio frontend + CLI for ace-server GGUF inference"""

import os
import sys
import time
import json
import argparse
import tempfile
import subprocess
import shutil
import requests
import logging

from train_engine import (
    preprocess_audio,
    train_lora_generator,
    cancel_training,
    get_trained_loras as _get_trained_loras_engine,
)

logger = logging.getLogger(__name__)

# ---------------------------------------------------------------------------
# Configurable limits (edit here, not buried in code)
# ---------------------------------------------------------------------------

MAX_AUDIO_DURATION = 240     # seconds, cap per audio file for training
MAX_TRAINING_TIME = 28800    # 8 hours hard training timeout (seconds)
MAX_AUDIO_FILES = 50         # max number of training audio files per run

# ---------------------------------------------------------------------------
# Paths & constants
# ---------------------------------------------------------------------------

ACE_SERVER = os.environ.get("ACE_SERVER", "http://127.0.0.1:8085")
OUTPUT_DIR = os.environ.get("ACE_OUTPUT_DIR", "/app/outputs")
os.makedirs(OUTPUT_DIR, exist_ok=True)

ACE_CHECKPOINT_DIR = os.environ.get("ACE_CHECKPOINT_DIR", "/app/checkpoints")
ACE_SOURCE_DIR = "/app/ace-step-source"
ACE_HF_MODEL = "ACE-Step/Ace-Step1.5"
ADAPTER_DIR = os.environ.get("ACE_ADAPTER_DIR", "/app/adapters")
MODELS_DIR = os.environ.get("ACE_MODELS_DIR", "/app/models")

ACE_SERVER_BIN = "/app/ace-server"

# HF repo for on-demand GGUF downloads
GGUF_HF_REPO = "Serveurperso/ACE-Step-1.5-GGUF"

# ---------------------------------------------------------------------------
# ace-server helpers
# ---------------------------------------------------------------------------

def _server_ok():
    try:
        return requests.get(f"{ACE_SERVER}/health", timeout=5).status_code == 200
    except Exception:
        return False


def _get_props():
    """Fetch server properties (models, adapters)."""
    try:
        r = requests.get(f"{ACE_SERVER}/props", timeout=10)
        if r.status_code == 200:
            return r.json()
    except Exception:
        pass
    return {}


def _poll_job(job_id, timeout=600, progress_cb=None):
    """Poll a job until done/error/timeout. Returns (status, elapsed)."""
    t0 = time.time()
    while time.time() - t0 < timeout:
        try:
            r = requests.get(f"{ACE_SERVER}/job", params={"id": job_id}, timeout=10)
            data = r.json()
            status = data.get("status", "unknown")
            if progress_cb:
                progress_cb(status, data)
            if status in ("done", "error"):
                return status, time.time() - t0
        except Exception:
            pass
        time.sleep(2)
    return "timeout", time.time() - t0


def _fetch_result(job_id, timeout=60):
    """Fetch result bytes/json for a completed job."""
    r = requests.get(
        f"{ACE_SERVER}/job",
        params={"id": job_id, "result": 1},
        timeout=timeout,
    )
    return r


def _run_pipeline(caption, lyrics, bpm, duration, seed, steps, output_format,
                  adapter=None, lm_model=None, progress_cb=None):
    """Run full LM -> synth pipeline. Returns (audio_path, status_msg) or raises."""
    t0 = time.time()

    # -- Build LM request --
    req = {"caption": caption or "upbeat electronic dance music"}
    req["lyrics"] = lyrics if lyrics and lyrics.strip() else "[Instrumental]"

    if bpm and int(bpm) > 0:
        req["bpm"] = int(bpm)
    if duration and float(duration) > 0:
        req["duration"] = min(float(duration), 300)
    if seed is not None and int(seed) >= 0:
        req["seed"] = int(seed)
    if steps and int(steps) > 0:
        req["inference_steps"] = int(steps)
    if adapter:
        req["adapter"] = adapter
    if lm_model:
        req["model"] = lm_model

    fmt = output_format if output_format in ("wav", "mp3") else "mp3"
    synth_fmt = "wav16" if fmt == "wav" else "mp3"
    suffix = f".{fmt}"

    # -- LM phase --
    if progress_cb:
        progress_cb("lm_submit", None)
    r = requests.post(f"{ACE_SERVER}/lm", json=req, timeout=30)
    if r.status_code != 200:
        raise RuntimeError(f"LM submit failed: {r.status_code} {r.text}")
    lm_job_id = r.json().get("id")

    if progress_cb:
        progress_cb("lm_poll", {"job_id": lm_job_id})
    lm_status, lm_elapsed = _poll_job(lm_job_id, timeout=900)
    if lm_status != "done":
        raise RuntimeError(f"LM {lm_status} after {lm_elapsed:.0f}s")

    # Fetch LM result
    r = _fetch_result(lm_job_id)
    lm_results = r.json()
    if not isinstance(lm_results, list) or len(lm_results) == 0:
        raise RuntimeError(f"LM returned no results: {lm_results}")
    synth_request = lm_results[0]

    # -- Synth phase --
    synth_request["output_format"] = synth_fmt
    if adapter:
        synth_request["adapter"] = adapter
        synth_request["synth_model"] = "acestep-v15-turbo-Q4_K_M.gguf"
    if progress_cb:
        progress_cb("synth_submit", None)
    r = requests.post(f"{ACE_SERVER}/synth", json=synth_request, timeout=30)
    if r.status_code != 200:
        raise RuntimeError(f"Synth submit failed: {r.status_code} {r.text}")
    synth_job_id = r.json().get("id")

    if progress_cb:
        progress_cb("synth_poll", {"job_id": synth_job_id})
    synth_status, synth_elapsed = _poll_job(synth_job_id, timeout=600)
    if synth_status != "done":
        raise RuntimeError(f"Synth {synth_status} after {synth_elapsed:.0f}s")

    # Fetch audio
    if progress_cb:
        progress_cb("fetch", None)
    r = _fetch_result(synth_job_id, timeout=60)
    if r.status_code != 200:
        raise RuntimeError(f"Audio fetch failed: {r.status_code}")

    tmp = tempfile.NamedTemporaryFile(suffix=suffix, dir=OUTPUT_DIR, delete=False)
    tmp.write(r.content)
    tmp.close()

    elapsed = time.time() - t0
    msg = f"Done in {elapsed:.0f}s | {duration}s audio, {steps} steps, {fmt}"
    return tmp.name, msg


# ---------------------------------------------------------------------------
# LM model scanning & on-demand download
# ---------------------------------------------------------------------------

DEFAULT_LM = "acestep-5Hz-lm-1.7B-Q8_0.gguf"

AVAILABLE_LM_MODELS = [
    "acestep-5Hz-lm-1.7B-Q8_0.gguf",
    "acestep-5Hz-lm-0.6B-Q8_0.gguf",
    "acestep-5Hz-lm-4B-Q5_K_M.gguf",
]

def _scan_lm_models():
    """Return LM model choices. Installed shown as-is, others need download."""
    installed = set()
    if os.path.isdir(MODELS_DIR):
        for f in os.listdir(MODELS_DIR):
            if "-lm-" in f and f.endswith(".gguf"):
                installed.add(f)
    choices = []
    for m in AVAILABLE_LM_MODELS:
        if m in installed:
            choices.append(m)
        else:
            choices.append(f"{m} [not installed]")
    return choices


def _download_lm_model(filename):
    """Download a GGUF LM model from HF if not already present."""
    dest = os.path.join(MODELS_DIR, filename)
    if os.path.isfile(dest):
        return dest
    try:
        from huggingface_hub import hf_hub_download
        path = hf_hub_download(
            repo_id=GGUF_HF_REPO,
            filename=filename,
            local_dir=MODELS_DIR,
        )
        return path
    except Exception as exc:
        logger.error("Failed to download %s: %s", filename, exc)
        return None


# ---------------------------------------------------------------------------
# LoRA listing for UI dropdowns
# ---------------------------------------------------------------------------

def _list_lora_choices():
    """Return list of LoRA choices for dropdown, including 'None'."""
    choices = ["None (no LoRA)"]
    if os.path.isdir(ADAPTER_DIR):
        for d in os.listdir(ADAPTER_DIR):
            if os.path.isdir(os.path.join(ADAPTER_DIR, d)):
                choices.append(d)
    return choices


# ---------------------------------------------------------------------------
# ace-server stop/start helpers
# ---------------------------------------------------------------------------

_ace_proc = None

def _stop_ace_server():
    """Stop ace-server process."""
    global _ace_proc
    logger.info("[ace-server] Stopping...")
    if _ace_proc and _ace_proc.poll() is None:
        _ace_proc.terminate()
        try:
            _ace_proc.wait(timeout=10)
        except subprocess.TimeoutExpired:
            _ace_proc.kill()
        _ace_proc = None
        logger.info("[ace-server] Stopped (tracked PID)")
    else:
        try:
            subprocess.run(["pkill", "ace-server"],
                           stderr=subprocess.DEVNULL, stdout=subprocess.DEVNULL,
                           timeout=10)
            logger.info("[ace-server] Stopped (pkill)")
        except Exception:
            pass
    time.sleep(1)


def _start_ace_server():
    """Start ace-server in background and wait for health."""
    global _ace_proc
    logger.info("[ace-server] Starting with --adapters %s", ADAPTER_DIR)
    try:
        _ace_proc = subprocess.Popen(
            [ACE_SERVER_BIN, "--host", "127.0.0.1", "--port", "8085",
             "--models", MODELS_DIR, "--adapters", ADAPTER_DIR, "--max-batch", "1"],
        )
    except Exception as exc:
        logger.error("[ace-server] Failed to start: %s", exc)
        return False

    for _ in range(30):
        if _server_ok():
            logger.info("[ace-server] Healthy")
            return True
        time.sleep(2)
    logger.error("[ace-server] Health check timeout")
    return False


# ---------------------------------------------------------------------------
# CLI mode
# ---------------------------------------------------------------------------

def cli_main():
    parser = argparse.ArgumentParser(
        description="ACE-Step 1.5 XL (CPU) - CLI inference via ace-server",
    )
    parser.add_argument("caption", nargs="?", default="upbeat electronic dance music",
                        help="Music description / caption")
    parser.add_argument("--lyrics", "-l", default="[Instrumental]",
                        help="Lyrics text (use '[Instrumental]' for no vocals)")
    parser.add_argument("--bpm", type=int, default=120, help="Beats per minute")
    parser.add_argument("--duration", "-d", type=float, default=10,
                        help="Duration in seconds (max 300)")
    parser.add_argument("--steps", "-s", type=int, default=8,
                        help="Inference steps (1-32)")
    parser.add_argument("--seed", type=int, default=-1,
                        help="Random seed (-1 for random)")
    parser.add_argument("--format", "-f", choices=["wav", "mp3"], default="wav",
                        help="Output audio format")
    parser.add_argument("--adapter", "-a", default=None,
                        help="LoRA adapter name")
    parser.add_argument("-o", "--output", default=None,
                        help="Output file path (default: auto in outputs dir)")
    parser.add_argument("--server", default=None,
                        help="ace-server URL (default: http://127.0.0.1:8085)")

    args = parser.parse_args()

    if args.server:
        global ACE_SERVER
        ACE_SERVER = args.server

    if not _server_ok():
        print(f"ERROR: ace-server not reachable at {ACE_SERVER}", file=sys.stderr)
        sys.exit(1)

    seed = args.seed if args.seed >= 0 else None

    def cli_progress(phase, data):
        phases = {
            "lm_submit": "Submitting LM job...",
            "lm_poll": f"LM generating (job {data['job_id']})..." if data else "LM generating...",
            "synth_submit": "Submitting synth job...",
            "synth_poll": f"Synthesizing (job {data['job_id']})..." if data else "Synthesizing...",
            "fetch": "Fetching audio...",
        }
        msg = phases.get(phase, phase)
        print(f"  [{phase}] {msg}")

    print(f"ACE-Step CLI | caption: {args.caption}")
    print(f"  lyrics: {args.lyrics} | bpm: {args.bpm} | duration: {args.duration}s "
          f"| steps: {args.steps} | seed: {args.seed} | format: {args.format}")

    try:
        audio_path, status = _run_pipeline(
            caption=args.caption,
            lyrics=args.lyrics,
            bpm=args.bpm,
            duration=args.duration,
            seed=seed,
            steps=args.steps,
            output_format=args.format,
            adapter=args.adapter,
            progress_cb=cli_progress,
        )
    except RuntimeError as e:
        print(f"ERROR: {e}", file=sys.stderr)
        sys.exit(1)

    # Move to requested output path if specified
    if args.output:
        out_dir = os.path.dirname(os.path.abspath(args.output))
        os.makedirs(out_dir, exist_ok=True)
        shutil.move(audio_path, args.output)
        audio_path = args.output

    print(f"  {status}")
    print(f"  Output: {audio_path}")


# ---------------------------------------------------------------------------
# Gradio UI mode
# ---------------------------------------------------------------------------

def gradio_main():
    import gradio as gr
    import gc

    # -- Persistent training log buffer (survives across yields) --
    _train_log_lines = []

    # -- Generate tab handler --
    def generate_music(caption, lyrics, instrumental, bpm, duration, seed,
                       steps, lora_select, lm_model_select,
                       progress=gr.Progress(track_tqdm=True)):
        if not _server_ok():
            return None, "ace-server not running. Check logs."

        if instrumental or not lyrics or lyrics.strip() == "":
            lyrics = "[Instrumental]"

        actual_seed = None if seed is None or int(seed) < 0 else int(seed)
        adapter = None if lora_select == "None (no LoRA)" else lora_select
        lm_model_file = lm_model_select.replace(" [not installed]", "") if lm_model_select else None
        if lm_model_file and "[not installed]" in (lm_model_select or ""):
            _download_lm_model(lm_model_file)
        lm_model = lm_model_file

        progress_map = {
            "lm_submit": (0.05, "Submitting LM job..."),
            "lm_poll": (0.10, "LM generating..."),
            "synth_submit": (0.40, "Submitting synth job..."),
            "synth_poll": (0.50, "Synthesizing audio..."),
            "fetch": (0.90, "Fetching audio..."),
        }

        def gr_progress(phase, data):
            pct, desc = progress_map.get(phase, (0.5, phase))
            if data and "job_id" in data:
                desc += f" (job {data['job_id']})"
            progress(pct, desc=desc)

        try:
            audio_path, status = _run_pipeline(
                caption=caption,
                lyrics=lyrics,
                bpm=bpm,
                duration=duration,
                seed=actual_seed,
                steps=steps,
                output_format="mp3",
                adapter=adapter,
                lm_model=lm_model,
                progress_cb=gr_progress,
            )
            return audio_path, status
        except RuntimeError as e:
            return None, str(e)
        except Exception as e:
            return None, f"Unexpected error: {e}"

    # -- Server info helper --
    def get_server_status():
        if not _server_ok():
            return "ace-server: OFFLINE"
        props = _get_props()
        lines = ["ace-server: ONLINE"]
        if props:
            lines.append(json.dumps(props, indent=2))
        return "\n".join(lines)

    # -- Training generator (direct integration, no subprocess) --
    def train_lora_ui(audio_files, lora_name, epochs, lr, rank):
        """Generator that yields (train_log, train_btn_update, cancel_btn_update)."""
        import gc as _gc

        _train_log_lines.clear()
        train_start = time.time()

        def _log(msg):
            _train_log_lines.append(msg)

        def _log_text():
            return "\n".join(_train_log_lines)

        # -- Validation --
        if not audio_files:
            _log("[FAIL] No audio files uploaded.")
            yield _log_text(), gr.update(visible=True), gr.update(visible=False)
            return

        if len(audio_files) > MAX_AUDIO_FILES:
            _log(f"[FAIL] Too many files ({len(audio_files)}). Max: {MAX_AUDIO_FILES}")
            yield _log_text(), gr.update(visible=True), gr.update(visible=False)
            return

        lora_name = (lora_name or "").strip() or "my-lora"
        # Sanitize: alphanumeric, dash, underscore only
        lora_name = "".join(c if c.isalnum() or c in "-_" else "-" for c in lora_name)

        epochs = max(1, min(int(epochs), 10))
        lr = float(lr)
        rank = max(1, min(int(rank), 64))

        work_dir = os.path.join(OUTPUT_DIR, "train_workspace", lora_name)
        os.makedirs(work_dir, exist_ok=True)
        audio_dir = os.path.join(work_dir, "audio_input")
        os.makedirs(audio_dir, exist_ok=True)
        adapter_out = os.path.join(ADAPTER_DIR, lora_name)
        os.makedirs(adapter_out, exist_ok=True)

        # Copy uploaded audio files
        _log(f"[INFO] Preparing {len(audio_files)} audio files...")
        yield _log_text(), gr.update(visible=False), gr.update(visible=True)

        for f in audio_files:
            src = f.name if hasattr(f, "name") else str(f)
            shutil.copy2(src, os.path.join(audio_dir, os.path.basename(src)))

        _log(f"[INFO] LoRA: '{lora_name}' | Files: {len(audio_files)} | "
             f"Epochs: {epochs} | LR: {lr} | Rank: {rank}")
        yield _log_text(), gr.update(visible=False), gr.update(visible=True)

        # Stop ace-server before training (frees memory)
        _log("[INFO] Stopping ace-server for training...")
        yield _log_text(), gr.update(visible=False), gr.update(visible=True)
        _stop_ace_server()
        _gc.collect()

        try:
            # -- Phase 1: Preprocessing --
            _log("[Step 1/2] Preprocessing audio...")
            yield _log_text(), gr.update(visible=False), gr.update(visible=True)

            preprocessed_dir = os.path.join(work_dir, "preprocessed_tensors")

            def preprocess_progress(current, total, desc):
                _log(f"  {desc} ({current}/{total})")

            result = preprocess_audio(
                audio_dir=audio_dir,
                output_dir=preprocessed_dir,
                checkpoint_dir=ACE_CHECKPOINT_DIR,
                device="cpu",
                variant="turbo",
                max_duration=float(MAX_AUDIO_DURATION),
                progress_callback=preprocess_progress,
                cancel_check=lambda: False,
            )
            yield _log_text(), gr.update(visible=False), gr.update(visible=True)

            processed = result.get("processed", 0)
            failed = result.get("failed", 0)
            total = result.get("total", 0)
            _log(f"[OK] Preprocessed: {processed}/{total} (failed: {failed})")
            yield _log_text(), gr.update(visible=False), gr.update(visible=True)

            if processed == 0:
                _log("[FAIL] No files preprocessed successfully. Cannot train.")
                yield _log_text(), gr.update(visible=True), gr.update(visible=False)
                return

            _gc.collect()

            # -- Phase 2: Training --
            _log("[Step 2/2] Training LoRA...")
            yield _log_text(), gr.update(visible=False), gr.update(visible=True)

            for msg in train_lora_generator(
                dataset_dir=preprocessed_dir,
                output_dir=adapter_out,
                checkpoint_dir=ACE_CHECKPOINT_DIR,
                epochs=epochs,
                lr=lr,
                rank=rank,
                alpha=rank * 2,
                dropout=0.0,
                batch_size=1,
                gradient_accumulation_steps=4,
                warmup_steps=100,
                weight_decay=0.01,
                max_grad_norm=1.0,
                save_every_n_epochs=max(1, epochs // 2),
                seed=42,
                variant="turbo",
                device="cpu",
                log_every=5,
            ):
                # Timeout check
                elapsed = time.time() - train_start
                if elapsed > MAX_TRAINING_TIME:
                    _log(f"[WARN] Training timed out after {int(elapsed)}s")
                    cancel_training()
                    break

                _log(msg)
                yield _log_text(), gr.update(visible=False), gr.update(visible=True)

                if msg.strip() == "[DONE]":
                    break

            _log(f"[INFO] Total time: {time.time() - train_start:.0f}s")
            yield _log_text(), gr.update(visible=False), gr.update(visible=True)

        except Exception as exc:
            _log(f"[FAIL] Training error: {exc}")
            import traceback
            _log(traceback.format_exc())
            yield _log_text(), gr.update(visible=True), gr.update(visible=False)

        finally:
            # Always restart ace-server
            _log("[INFO] Restarting ace-server...")
            yield _log_text(), gr.update(visible=False), gr.update(visible=True)
            _gc.collect()
            ok = _start_ace_server()
            if ok:
                _log("[OK] ace-server restarted successfully")
            else:
                _log("[WARN] ace-server may not have restarted -- check logs")
            yield _log_text(), gr.update(visible=True), gr.update(visible=False)

    # -- Cancel handler --
    def _on_cancel():
        cancel_training()
        logger.info("Cancel requested by user")
        return "Cancelling after current epoch... please wait"

    # -- Check log handler --
    def _check_log():
        if _train_log_lines:
            return "\n".join(_train_log_lines)
        return "No training log available."

    # -- Build LM model choices --
    def _lm_model_choices():
        return _scan_lm_models()

    # -- Build UI --
    CSS = """
    .compact-row { gap: 8px !important; }
    .status-box textarea { font-family: monospace; font-size: 13px; }
    """

    with gr.Blocks(title="ACE-Step 1.5 XL (CPU)", css=CSS) as demo:

        with gr.Tabs():
            # ============================================================
            # Tab 1: Generate Music
            # ============================================================
            with gr.Tab("Generate Music"):
                gr.Markdown(
                    "**[ACE-Step 1.5 XL (CPU)](https://github.com/ace-step/ACE-Step-1.5)** "
                    "GGUF Q4_K_M via "
                    "[acestep.cpp](https://github.com/ServeurpersoCom/acestep.cpp)"
                )

                with gr.Row(elem_classes="compact-row"):
                    with gr.Column(scale=2):
                        caption = gr.Textbox(
                            label="Music Description",
                            lines=2,
                            value="upbeat electronic dance music, energetic synth leads",
                        )
                        lyrics = gr.Textbox(
                            label="Lyrics",
                            lines=3,
                            value="[Instrumental]",
                            placeholder="Enter lyrics or [Instrumental] for no vocals",
                        )
                    with gr.Column(scale=1):
                        audio_out = gr.Audio(label="Output", type="filepath")
                        status = gr.Textbox(
                            label="Status",
                            interactive=False,
                            lines=2,
                            elem_classes="status-box",
                        )

                with gr.Row(elem_classes="compact-row"):
                    instrumental = gr.Checkbox(label="Instrumental", value=True, scale=1)
                    bpm = gr.Number(label="BPM", value=120, minimum=0, maximum=300, scale=1)
                    duration = gr.Slider(
                        label="Duration (s)", minimum=10, maximum=120,
                        value=10, step=5, scale=1,
                    )
                    steps = gr.Slider(
                        label="Steps", minimum=1, maximum=32,
                        value=8, step=1, scale=1,
                    )
                    seed = gr.Number(label="Seed (-1=random)", value=-1, scale=1)

                with gr.Row(elem_classes="compact-row"):
                    lora_select = gr.Dropdown(
                        label="LoRA", choices=_list_lora_choices(),
                        value="None (no LoRA)", scale=1,
                        allow_custom_value=True,
                    )
                    lm_model_select = gr.Dropdown(
                        label="LM Model", choices=_lm_model_choices(),
                        value=DEFAULT_LM, scale=1,
                    )

                with gr.Row(elem_classes="compact-row"):
                    gen_btn = gr.Button("Generate Music", variant="primary", scale=2)
                    status_btn = gr.Button("Server Status", scale=1)

                gen_btn.click(
                    fn=generate_music,
                    inputs=[caption, lyrics, instrumental, bpm, duration,
                            seed, steps, lora_select, lm_model_select],
                    outputs=[audio_out, status],
                    api_name="generate",
                )

                status_btn.click(
                    fn=get_server_status,
                    inputs=[],
                    outputs=[status],
                    api_name="server_status",
                )

            # ============================================================
            # Tab 2: Train LoRA
            # ============================================================
            with gr.Tab("Train LoRA"):
                gr.Markdown(
                    "### LoRA Training\n"
                    "Fine-tune ACE-Step on your audio. "
                    "CPU training is slow -- ace-server stops during training."
                )

                with gr.Row(elem_classes="compact-row"):
                    with gr.Column(scale=2):
                        train_audio = gr.File(
                            label="Training Audio Files",
                            file_count="multiple",
                            file_types=["audio"],
                        )
                    with gr.Column(scale=1):
                        lora_name = gr.Textbox(label="LoRA Name", value="my-lora")
                        train_epochs = gr.Slider(
                            label="Epochs", minimum=1, maximum=1000,
                            value=3, step=1,
                        )
                        train_lr = gr.Number(label="Learning Rate", value=3e-4)
                        train_rank = gr.Slider(
                            label="Rank (r)", minimum=1, maximum=128,
                            value=32, step=1,
                        )

                with gr.Row(elem_classes="compact-row"):
                    train_btn = gr.Button("Train", variant="primary", scale=2)
                    cancel_btn = gr.Button("Cancel Training", variant="stop", visible=False, scale=1)
                    log_btn = gr.Button("Check Log", scale=1)

                train_log = gr.Textbox(
                    label="Training Log",
                    interactive=False,
                    lines=12,
                    elem_classes="status-box",
                )

                # Training generator -- yields (log, train_btn, cancel_btn)
                train_event = train_btn.click(
                    train_lora_ui,
                    inputs=[train_audio, lora_name, train_epochs, train_lr, train_rank],
                    outputs=[train_log, train_btn, cancel_btn],
                    api_name="train_lora",
                    concurrency_limit=1,
                )

                # After training completes, restore buttons and refresh LoRA dropdown
                def _post_training():
                    return (
                        gr.update(visible=True),
                        gr.update(visible=False),
                        gr.update(choices=_list_lora_choices()),
                    )

                train_event.then(
                    _post_training,
                    outputs=[train_btn, cancel_btn, lora_select],
                )

                # Cancel: set the flag, update status
                cancel_btn.click(
                    _on_cancel,
                    outputs=[train_log],
                )

                # Check log: show last training output
                log_btn.click(
                    _check_log,
                    outputs=[train_log],
                    api_name="check_log",
                )

        demo.launch(
            server_name="0.0.0.0",
            server_port=7860,
            mcp_server=True,
        )


# ---------------------------------------------------------------------------
# Entry point
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    # If any CLI arguments besides the script name, run CLI mode
    # (Gradio sets no extra args; start.sh calls `python3 /app/app.py`)
    if len(sys.argv) > 1:
        cli_main()
    else:
        gradio_main()