app.py

import random
import argparse
import os
import glob
import rtmidi
import gradio as gr
import numpy as np
import MIDI
import base64
import io
import soundfile as sf  # Placeholder for audio rendering
from huggingface_hub import hf_hub_download
from midi_synthesizer import MidiSynthesizer

MAX_SEED = np.iinfo(np.int32).max
in_space = os.getenv("SYSTEM") == "spaces"

SONG_DATA = {
    "title": "Do You Believe in Love",
    "progression": ["G", "D", "Em", "C"],
    "lyrics": ["I was walking down a one-way street", "Just a-looking for someone to meet"]
}

class MIDIDeviceManager:
    def __init__(self):
        self.midiout = rtmidi.MidiOut()
        self.midiin = rtmidi.MidiIn()

    def get_output_devices(self):
        return self.midiout.get_ports() or ["No MIDI output devices"]

    def get_input_devices(self):
        return self.midiin.get_ports() or ["No MIDI input devices"]

    def get_device_info(self):
        out_devices = self.get_output_devices()
        in_devices = self.get_input_devices()
        out_info = "\n".join([f"Out Port {i}: {name}" for i, name in enumerate(out_devices)]) if out_devices else "No MIDI output devices detected"
        in_info = "\n".join([f"In Port {i}: {name}" for i, name in enumerate(in_devices)]) if in_devices else "No MIDI input devices detected"
        return f"Output Devices:\n{out_info}\n\nInput Devices:\n{in_info}"

    def close(self):
        if self.midiout.is_port_open():
            self.midiout.close_port()
        if self.midiin.is_port_open():
            self.midiin.close_port()
        del self.midiout
        del self.midiin

class MIDIManager:
    def __init__(self):
        self.soundfont_path = hf_hub_download(repo_id="skytnt/midi-model", filename="soundfont.sf2")
        self.synthesizer = MidiSynthesizer(self.soundfont_path)
        self.loaded_midi = {}  # midi_id: (file_path, midi_obj)
        self.modified_files = []  # Stores (midi_base64, audio_base64) tuples
        self.is_playing = False
        self.instruments = self.random_instrument_set()
        self.drum_beat = self.create_drum_beat()
        self.starter_midi = self.create_starter_midi()
        self.example_files = self.load_example_midis()
        self.loaded_midi["starter"] = ("Starter MIDI", self.starter_midi)
        self.preload_default_midi()

    def random_instrument_set(self):
        instrument_pool = [0, 24, 32, 48]  # Piano, Guitar, Bass, Strings
        return random.sample(instrument_pool, 4)

    def create_drum_beat(self):
        return [(36, 100, 0), (42, 80, 50), (38, 90, 100), (42, 80, 150)]  # Kick, hi-hat, snare, hi-hat

    def create_starter_midi(self):
        midi = MIDI.MIDIFile(5)  # 4 instruments + 1 drum track
        for i, inst in enumerate(self.instruments):
            midi.addTrack()
            midi.addProgramChange(i, 0, 0, inst)
            for t in range(0, 400, 100):
                note = random.randint(60, 84)  # C4 to C6
                midi.addNote(i, 0, note, t, 100, 100)
        midi.addTrack()
        for note, vel, time in self.drum_beat:
            midi.addNote(4, 9, note, time, 100, vel)
        return midi

    def preload_default_midi(self):
        default_path = "default.mid"
        if os.path.exists(default_path):
            midi_id = "default"
            midi = MIDI.load(default_path)
            self.loaded_midi[midi_id] = (default_path, midi)
            midi_data, audio_data = self.generate_variation(midi_id)
            self.play_with_loop(midi_data)

    def load_example_midis(self):
        examples = {}
        for file_path in glob.glob("*.mid") + glob.glob("*.midi"):
            if file_path == "default.mid":
                continue
            midi_id = f"example_{len(examples)}"
            midi = MIDI.load(file_path)
            new_midi = MIDI.MIDIFile(5)
            notes, _ = self.extract_notes_and_instruments(midi)
            for i, inst in enumerate(self.instruments):
                new_midi.addTrack()
                new_midi.addProgramChange(i, 0, 0, inst)
                for note, vel, time in notes:
                    new_midi.addNote(i, 0, note, time, 100, vel)
            new_midi.addTrack()
            for note, vel, time in self.drum_beat:
                new_midi.addNote(4, 9, note, time, 100, vel)
            examples[midi_id] = (file_path, new_midi)
        self.loaded_midi.update(examples)
        return examples

    def load_midi(self, file_path):
        midi = MIDI.load(file_path)
        midi_id = f"midi_{len(self.loaded_midi) - len(self.example_files) - 1}"
        self.loaded_midi[midi_id] = (file_path, midi)
        return midi_id

    def extract_notes_and_instruments(self, midi):
        notes = []
        instruments = set()
        for track in midi.tracks:
            for event in track.events:
                if event.type == 'note_on' and event.velocity > 0:
                    notes.append((event.note, event.velocity, event.time))
                if hasattr(event, 'program'):
                    instruments.add(event.program)
        return notes, list(instruments)

    def generate_variation(self, midi_id, length_factor=2, variation=0.3):
        if midi_id not in self.loaded_midi:
            return None, None
        _, midi = self.loaded_midi[midi_id]
        notes, instruments = self.extract_notes_and_instruments(midi)
        new_notes = []
        for _ in range(int(length_factor)):
            for note, vel, time in notes:
                if random.random() < variation:
                    new_note = min(127, max(0, note + random.randint(-2, 2)))
                    new_vel = min(127, max(0, vel + random.randint(-10, 10)))
                    new_notes.append((new_note, new_vel, time))
                else:
                    new_notes.append((note, vel, time))

        new_midi = MIDI.MIDIFile(len(instruments) or 1)
        for i, inst in enumerate(instruments or [0]):
            new_midi.addTrack()
            new_midi.addProgramChange(i, 0, 0, inst)
            for note, vel, time in new_notes:
                new_midi.addNote(i, 0, note, time, 100, vel)
        
        midi_output = io.BytesIO()
        new_midi.writeFile(midi_output)
        midi_data = base64.b64encode(midi_output.getvalue()).decode('utf-8')
        
        temp_midi = 'temp.mid'
        with open(temp_midi, 'wb') as f:
            f.write(midi_output.getvalue())
        audio_output = io.BytesIO()
        # Placeholder for audio rendering; needs fluidsynth or similar
        self.synthesizer.play_midi(new_midi)
        audio_data = None  # See Notes below
        if os.path.exists(temp_midi):
            os.remove(temp_midi)
        
        self.modified_files.append((midi_data, audio_data))
        return midi_data, audio_data

    def apply_synth_effect(self, midi_data, effect, intensity):
        midi = MIDI.load(io.BytesIO(base64.b64decode(midi_data)))
        if effect == "tempo":
            factor = 1 + (intensity - 0.5) * 0.4
            for track in midi.tracks:
                for event in track.events:
                    event.time = int(event.time * factor)
        
        midi_output = io.BytesIO()
        midi.writeFile(midi_output)
        midi_data = base64.b64encode(midi_output.getvalue()).decode('utf-8')
        
        temp_midi = 'temp.mid'
        with open(temp_midi, 'wb') as f:
            f.write(midi_output.getvalue())
        audio_output = io.BytesIO()
        self.synthesizer.play_midi(midi)
        audio_data = None  # Placeholder
        if os.path.exists(temp_midi):
            os.remove(temp_midi)
        
        self.modified_files.append((midi_data, audio_data))
        return midi_data, audio_data

    def play_with_loop(self, midi_data):
        self.is_playing = True
        midi_file = MIDI.load(io.BytesIO(base64.b64decode(midi_data)))
        while self.is_playing:
            self.synthesizer.play_midi(midi_file)
        return "Stopped"

    def stop_playback(self):
        self.is_playing = False
        return "Stopping..."

def create_download_list():
    html = "<h3>Downloads</h3><ul>"
    for i, (midi_data, audio_data) in enumerate(midi_processor.modified_files):
        html += f'<li><a href="data:audio/midi;base64,{midi_data}" download="midi_{i}.mid">MIDI {i}</a>'
        if audio_data:
            html += f' | <a href="data:audio/wav;base64,{audio_data}" download="audio_{i}.wav">Audio {i}</a>'
        html += '</li>'
    html += "</ul>"
    return html

def get_midi_choices():
    return [(os.path.basename(path), midi_id) for midi_id, (path, _) in midi_processor.loaded_midi.items()]

if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--port", type=int, default=7860)
    parser.add_argument("--share", action="store_true")
    parser.add_argument("--batch", type=int, default=1)
    opt = parser.parse_args()

    midi_manager = MIDIDeviceManager()
    midi_processor = MIDIManager()

    with gr.Blocks(theme=gr.themes.Soft()) as app:
        gr.Markdown("<h1>🎵 MIDI Composer 🎵</h1>")
        
        with gr.Tabs():
            # Tab 1: MIDI Prompt (Main Tab)
            with gr.Tab("MIDI Prompt"):
                midi_files = gr.File(label="Upload MIDI Files", file_count="multiple")
                loaded_display = gr.HTML(value="No files loaded")
                output = gr.Audio(label="Generated Preview", type="bytes", autoplay=True)
                
                def load_and_generate(files):
                    html = "<h3>Loaded Files</h3>"
                    midi_data = None
                    for file in files or []:
                        midi_id = midi_processor.load_midi(file.name)
                        html += f"<div>{file.name} <button onclick=\"remove_midi('{midi_id}')\">X</button></div>"
                        midi_data, _ = midi_processor.generate_variation(midi_id)
                    return html, (io.BytesIO(base64.b64decode(midi_data)) if midi_data else None), get_midi_choices(), create_download_list()
                
                midi_files.change(load_and_generate, inputs=[midi_files], 
                                outputs=[loaded_display, output, gr.State(get_midi_choices()), "downloads"])

            # Tab 2: Examples
            with gr.Tab("Examples"):
                example_select = gr.Dropdown(label="Select Example", choices=get_midi_choices(), value=None)
                example_output = gr.Audio(label="Example Preview", type="bytes", autoplay=True)
                
                def load_example(midi_id):
                    if not midi_id:
                        return None
                    midi_data, audio_data = midi_processor.generate_variation(midi_id)
                    midi_processor.play_with_loop(midi_data)
                    return io.BytesIO(base64.b64decode(midi_data)), create_download_list()
                
                example_select.change(load_example, inputs=[example_select], 
                                    outputs=[example_output, "downloads"])
                gr.State(get_midi_choices()).change(lambda choices: gr.update(choices=choices), 
                                                  inputs=[gr.State()], outputs=[example_select])

            # Tab 3: Generate & Perform
            with gr.Tab("Generate & Perform"):
                midi_select = gr.Dropdown(label="Select MIDI", choices=get_midi_choices(), value="starter")
                length_factor = gr.Slider(1, 5, value=2, step=1, label="Length Factor")
                variation = gr.Slider(0, 1, value=0.3, label="Variation")
                generate_btn = gr.Button("Generate")
                effect = gr.Radio(["tempo"], label="Synth Effect", value="tempo")
                intensity = gr.Slider(0, 1, value=0.5, label="Effect Intensity")
                apply_btn = gr.Button("Apply Effect")
                stop_btn = gr.Button("Stop Playback")
                output = gr.Audio(label="Preview", type="bytes", autoplay=True)
                status = gr.Textbox(label="Status", value="Ready")
                midi_device = gr.Dropdown(label="MIDI Output Device", choices=midi_manager.get_output_devices(), type="index")
                tempo = gr.Slider(label="Tempo (BPM)", minimum=40, maximum=200, value=120, step=1)
                device_info = gr.Textbox(label="Connected MIDI Devices", value=midi_manager.get_device_info(), readonly=True)
                refresh_btn = gr.Button("🔄 Refresh MIDI Devices")

                def update_dropdown(choices):
                    return gr.update(choices=choices)
                
                gr.State(get_midi_choices()).change(update_dropdown, inputs=[gr.State()], outputs=[midi_select])
                
                def generate(midi_id, length, var):
                    if not midi_id:
                        return None, "Select a MIDI file", create_download_list()
                    midi_data, audio_data = midi_processor.generate_variation(midi_id, length, var)
                    midi_processor.play_with_loop(midi_data)
                    return io.BytesIO(base64.b64decode(midi_data)), "Playing", create_download_list()
                
                def apply_effect(midi_data, fx, inten):
                    if not midi_data:
                        return None, "Generate a MIDI first", create_download_list()
                    new_midi_data, audio_data = midi_processor.apply_synth_effect(midi_data.decode('utf-8'), fx, inten)
                    midi_processor.play_with_loop(new_midi_data)
                    return io.BytesIO(base64.b64decode(new_midi_data)), "Playing", create_download_list()
                
                def refresh_devices():
                    return midi_manager.get_output_devices(), midi_manager.get_device_info()
                
                generate_btn.click(generate, inputs=[midi_select, length_factor, variation], 
                                outputs=[output, status, "downloads"])
                apply_btn.click(apply_effect, inputs=[output, effect, intensity], 
                                outputs=[output, status, "downloads"])
                stop_btn.click(midi_processor.stop_playback, inputs=None, outputs=[status])
                refresh_btn.click(refresh_devices, inputs=None, outputs=[midi_device, device_info])

            # Tab 4: Downloads
            with gr.Tab("Downloads", elem_id="downloads"):
                downloads = gr.HTML(value=create_download_list())

        gr.Markdown("""
        <div style='text-align: center; margin-top: 20px;'>
            <img src='https://huggingface.co/front/assets/huggingface_logo-noborder.svg' alt='Hugging Face Logo' style='width: 50px;'><br>
            <strong>Hugging Face</strong><br>
            <a href='https://huggingface.co/models'>Models</a> | 
            <a href='https://huggingface.co/datasets'>Datasets</a> | 
            <a href='https://huggingface.co/spaces'>Spaces</a> | 
            <a href='https://huggingface.co/posts'>Posts</a> | 
            <a href='https://huggingface.co/docs'>Docs</a> | 
            <a href='https://huggingface.co/enterprise'>Enterprise</a> | 
            <a href='https://huggingface.co/pricing'>Pricing</a>
        </div>
        """)

    app.queue().launch(server_port=opt.port, share=opt.share, inbrowser=True)
    midi_manager.close()