app.py

"""midmid3: Guitar Hero Chart Generator Demo"""

import json
import os
from pathlib import Path

import gradio as gr

# ZeroGPU: import spaces if available (no-op locally)
try:
    import spaces
    ON_ZEROGPU = True
except ImportError:
    ON_ZEROGPU = False

from pipeline import generate_chart
from visualizer import build_visualizer_html

EXAMPLES_DIR = Path(__file__).parent / "examples"


def _load_example():
    """Load pre-computed demo - no GPU needed."""
    chart_path = EXAMPLES_DIR / "hot_mess.json"
    zip_path = EXAMPLES_DIR / "Hot Mess - Friday Pilots Club.zip"
    audio_path = EXAMPLES_DIR / "hot_mess_input.ogg"

    with open(chart_path) as f:
        chart_json = json.load(f)

    viz_html = build_visualizer_html(chart_json)
    return (
        str(audio_path),              # audio_input
        "Hot Mess",                   # title
        "Friday Pilots Club",         # artist
        "",                           # album
        "2022",                       # year
        "rock",                       # genre
        viz_html,                     # viz_output
        str(zip_path),                # zip_output
    )


PLACEHOLDER_HTML = """
<div style="font-family: system-ui, sans-serif; background: #111; border-radius: 12px;
    padding: 60px 20px; text-align: center; color: #666; max-width: 900px; margin: 0 auto;">
  <div style="font-size: 48px; margin-bottom: 12px;">🎸</div>
  <div style="font-size: 16px;">Upload a song and hit Generate to see your chart here</div>
</div>
"""


def _generate_wrapper(audio_path, title, artist, album, year, genre, progress=gr.Progress()):
    """Gradio-facing wrapper with validation and progress."""
    if not audio_path:
        raise gr.Error("Please upload an audio file.")
    if not title or not title.strip():
        raise gr.Error("Song title is required.")
    if not artist or not artist.strip():
        raise gr.Error("Artist name is required.")

    zip_path, chart_json = generate_chart(
        audio_path=audio_path,
        title=title.strip(),
        artist=artist.strip(),
        album=album.strip() if album else "",
        year=year.strip() if year else "",
        genre=genre.strip() if genre else "rock",
        progress_cb=progress,
    )

    html = build_visualizer_html(chart_json)
    return html, zip_path


# Apply ZeroGPU decorator if running on HF Spaces
if ON_ZEROGPU:
    _generate_wrapper = spaces.GPU(duration=180)(_generate_wrapper)


# --- UI ---
with gr.Blocks(
    title="midmid3: Guitar Hero Chart Generator",
) as demo:
    gr.Markdown(
        "# midmid3: Guitar Hero Chart Generator\n"
        "Upload a song, get a playable chart with 4 difficulty levels. "
        "Preview it here, then download the mod folder ready for GHWT:DE."
    )

    with gr.Row():
        with gr.Column(scale=1, min_width=280):
            audio_input = gr.Audio(
                label="Upload audio",
                type="filepath",
                sources=["upload"],
            )
            title_input = gr.Textbox(label="Song title *", placeholder="e.g. Through the Fire and Flames")
            artist_input = gr.Textbox(label="Artist *", placeholder="e.g. DragonForce")

            with gr.Row():
                album_input = gr.Textbox(label="Album", placeholder="(optional)")
                year_input = gr.Textbox(label="Year", placeholder="2026")

            genre_input = gr.Textbox(label="Genre", placeholder="rock", value="rock")

            generate_btn = gr.Button("Generate Chart", variant="primary", elem_id="generate-btn")
            example_btn = gr.Button("Load Example", variant="secondary", size="sm")
            zip_output = gr.File(label="Download song package (.zip)")

        with gr.Column(scale=3):
            viz_output = gr.HTML(value=PLACEHOLDER_HTML, label="Chart Preview")

    generate_btn.click(
        fn=_generate_wrapper,
        inputs=[audio_input, title_input, artist_input, album_input, year_input, genre_input],
        outputs=[viz_output, zip_output],
    )

    example_btn.click(
        fn=_load_example,
        inputs=[],
        outputs=[audio_input, title_input, artist_input, album_input, year_input, genre_input, viz_output, zip_output],
    )

    gr.Markdown(
        "---\n"
        "*Powered by [midmid3](https://huggingface.co/markury/midmid3-19m-0326) — "
        "a 19M-parameter masked-prediction transformer by Markury.*"
    )
    gr.HTML(
        '<div style="display:flex; justify-content:center; gap:8px; padding:8px 0;">'
        '<a href="https://github.com/markuryy/midmid"><img src="https://img.shields.io/badge/GitHub-midmid-181717?logo=github&logoColor=white" alt="GitHub"></a>'
        '<a href="https://huggingface.co/markury/midmid3-19m-0326"><img src="https://img.shields.io/badge/%F0%9F%A4%97%20Model-midmid3--19m--0326-yellow" alt="Model"></a>'
        '<a href="https://huggingface.co/spaces/markury/midmid3"><img src="https://img.shields.io/badge/%F0%9F%A4%97%20Demo-midmid3-blue" alt="Demo"></a>'
        '</div>'
    )


if __name__ == "__main__":
    demo.launch(
        theme=gr.themes.Base(primary_hue="purple", neutral_hue="gray"),
        css="#generate-btn { min-height: 48px; font-size: 16px; }",
    )