app.py

import gradio as gr
import requests
import os
from dotenv import load_dotenv
from datetime import datetime
from pathlib import Path
from basic_pitch.inference import predict_and_save
from basic_pitch import ICASSP_2022_MODEL_PATH
from music21 import converter
import base64

# === 1. Environment Configuration ===
load_dotenv()
MUSICGEN_API_URL = os.getenv("MUSICGEN_API_URL")
VEROVIO_API_URL = os.getenv("VEROVIO_API_URL")

Path("output").mkdir(exist_ok=True)

# === 2. Utility Functions ===
def wav_to_musicxml(wav_path: str, timestamp: str = None) -> str:
    """
    Convert a WAV audio file to a MusicXML score using pitch detection.
    Args:
        wav_path (str): Path to the input WAV audio file.
        timestamp (str, optional): Custom timestamp for output naming. Defaults to current time.
    Returns:
        str: File path to the generated MusicXML file.
    Raises:
        FileNotFoundError: If the MIDI file could not be generated.
    """
    timestamp = timestamp or datetime.now().strftime("%Y%m%d_%H%M%S")
    output_dir = Path("output")
    for f in output_dir.glob("*_basic_pitch.mid"):
        f.unlink()

    predict_and_save(
        audio_path_list=[wav_path],
        output_directory=str(output_dir),
        save_midi=True,
        sonify_midi=False,
        save_model_outputs=False,
        save_notes=False,
        model_or_model_path=ICASSP_2022_MODEL_PATH
    )

    midi_files = list(output_dir.glob("*.mid"))
    if not midi_files:
        raise FileNotFoundError("❌ Failed to generate MIDI file")

    midi_path = midi_files[0]
    score = converter.parse(midi_path)
    musicxml_path = output_dir / f"generated_{timestamp}.musicxml"
    score.write("musicxml", fp=musicxml_path)
    return str(musicxml_path)


def render_musicxml_via_verovio_api(musicxml_path: str) -> str:
    """
    Render a MusicXML file to an SVG score preview using the Verovio API.
    Args:
        musicxml_path (str): Path to the MusicXML file.
    Returns:
        str: HTML string containing base64-encoded SVG score image, or error message on failure.
    """
    if not VEROVIO_API_URL:
        return "❌ VEROVIO_API_URL is not configured"

    try:
        with open(musicxml_path, "rb") as f:
            files = {'file': f}
            response = requests.post(VEROVIO_API_URL, files=files)
    except Exception as e:
        return f"❌ Verovio API call failed: {e}"

    if response.status_code != 200:
        return f"❌ Verovio API error {response.status_code}: {response.text}"

    try:
        svg = response.json()["svg"]
        svg_b64 = base64.b64encode(svg.encode("utf-8")).decode("utf-8")
        html = f'''
        <div style="background-color: white; padding: 10px; border-radius: 8px;">
            <img src="data:image/svg+xml;base64,{svg_b64}" style="width:100%; max-height:600px;" />
        </div>
        '''
        return html
    except Exception as e:
        return f"⚠️ Failed to parse SVG: {e}"


def generate_music_from_hum(melody_file, prompt):
    """
    Generate music from a humming audio file and a style prompt using an external MusicGen API.
    Args:
        melody_file (str): Path to the recorded humming audio (.wav).
        prompt (str): Text prompt describing desired music style.
    Returns:
        str: Path to the generated WAV music file, or error message on failure.
    """
    if not MUSICGEN_API_URL:
        return "❌ MUSICGEN_API_URL is not configured."

    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    wav_out_path = f"output/generated_{timestamp}.wav"

    try:
        with open(melody_file, "rb") as f:
            files = {"melody": ("hum.wav", f, "audio/wav")}
            data = {"text": prompt}
            response = requests.post(MUSICGEN_API_URL, files=files, data=data)

        if response.status_code != 200:
            return f"❌ API error {response.status_code}: {response.text}"

        with open(wav_out_path, "wb") as out:
            out.write(response.content)

        return wav_out_path
    except Exception as e:
        return f"❌ Music generation failed: {e}"


def generate_score_from_audio(wav_file):
    """
    Generate a MusicXML score from an input audio (.wav) file.
    Args:
        wav_file (str): Path to the WAV music file.
    Returns:
        str: File path to the generated MusicXML file, or error message on failure.
    """
    try:
        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
        return wav_to_musicxml(wav_file, timestamp)
    except Exception as e:
        return f"❌ Score generation failed: {e}"

# === 3. UI Construction ===

interface1 = gr.Interface(
    fn=wav_to_musicxml,
    inputs=[gr.Audio(type="filepath", label="WAV File")],
    outputs=gr.Textbox(label="Generated MusicXML File Path")
)
interface2 = gr.Interface(
    fn=render_musicxml_via_verovio_api,
    inputs=gr.Textbox(label="MusicXML File Path"),
    outputs=gr.HTML(label="Rendered SVG Score")
)
interface3 = gr.Interface(
    fn=generate_music_from_hum,
    inputs=[
        gr.Audio(type="filepath", label="Humming Audio (.wav)"),
        gr.Textbox(label="Prompt: describe music style")
    ],
    outputs=gr.Audio(type="filepath", label="Generated Music (.wav)")
)
interface4 = gr.Interface(
    fn=generate_score_from_audio,
    inputs=[gr.Audio(type="filepath", label="Generated Music (.wav)")],
    outputs=gr.Textbox(label="Generated MusicXML File Path")
)

with gr.Blocks(title="🎵 Vibe Jamming - Modular Tools") as demo:
    gr.Markdown("## 🎼 Vibe Jamming - Modular AI Music Tools")
    with gr.Tabs():
        with gr.TabItem("1️⃣ WAV ➜ MusicXML"):
            interface1.render()
        with gr.TabItem("2️⃣ MusicXML ➜ Score Preview"):
            interface2.render()
        with gr.TabItem("3️⃣ Humming + Prompt ➜ Music"):
            interface3.render()
        with gr.TabItem("4️⃣ Generated Music ➜ Score"):
            interface4.render()

# === 4. Launch MCP Tool App ===
if __name__ == "__main__":
    demo.launch(mcp_server=True)