app.py

from __future__ import annotations

import tempfile
from pathlib import Path
from typing import Tuple

import gradio as gr
import modal

TITLE = "EraEcho"
DESCRIPTION = "Transpose modern music into the style of any historical decade."

DECADES = [f"{year}s" for year in range(1920, 2030, 10)]


def transform(audio_path: str | None, decade: str) -> Tuple[str | None, str]:
    if not audio_path:
        return None, "Please upload an audio file first."

    try:
        fn = modal.Function.from_name("eraecho", "transform_with_era_ai")
        with open(audio_path, "rb") as file:
            audio_bytes = file.read()
        transformed_bytes, report = fn.remote(audio_bytes, Path(audio_path).name, decade)
        output = tempfile.NamedTemporaryFile(delete=False, suffix=f"_{decade}_eraecho.wav")
        output.write(transformed_bytes)
        output.close()
        return output.name, report
    except Exception as exc:
        return None, f"Error calling Modal backend: {exc}"


with gr.Blocks(theme=gr.themes.Soft(), title=TITLE) as demo:
    gr.Markdown(f"# {TITLE}\n{DESCRIPTION}")
    gr.Markdown(
        "Upload a song, choose a decade, and EraEcho returns a historically flavored audio pass plus a fidelity report. "
        "Processing is handled by Modal (Qwen3-14B + DSP)."
    )
    with gr.Row():
        with gr.Column():
            audio = gr.Audio(label="Upload music", type="filepath")
            decade = gr.Dropdown(DECADES, value="1950s", label="Target decade")
            button = gr.Button("Transpose through time", variant="primary")
        with gr.Column():
            output_audio = gr.Audio(label="EraEcho transformed audio", type="filepath")
            report = gr.Markdown(label="Historical fidelity report")

    button.click(transform, inputs=[audio, decade], outputs=[output_audio, report])


if __name__ == "__main__":
    demo.launch()