app.py

import spaces
import gradio as gr
import logging
from pathlib import Path
import base64

from model import (
    MODEL_ID as WHISPER_MODEL_ID,
    PHI_MODEL_ID,
    transcribe_audio_local,
    transcribe_audio_phi,
    preload_models,
)

# Set up logging
logging.basicConfig(
    level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
logger = logging.getLogger(__name__)

# Constants
EXAMPLES_DIR = Path("./examples")
MODEL_CHOICES = {
    PHI_MODEL_ID: "Phi-4 Model",
    WHISPER_MODEL_ID: "Whisper Model",
}
EXAMPLE_FILES = [
    [str(EXAMPLES_DIR / "audio1.mp3"), PHI_MODEL_ID],
    [str(EXAMPLES_DIR / "audio2.mp3"), PHI_MODEL_ID],
]


def read_file_as_base64(file_path: str) -> str:
    """
    Read a file and encode it as base64.

    Args:
        file_path: Path to the file to read

    Returns:
        Base64 encoded string of file contents
    """
    try:
        with open(file_path, "rb") as f:
            return base64.b64encode(f.read()).decode()
    except Exception as e:
        logger.error(f"Failed to read file {file_path}: {str(e)}")
        raise


def combined_transcription(audio: str, model_choice: str) -> str:
    """
    Transcribe audio using the selected model.

    Args:
        audio: Path to audio file
        model_choice: Full model ID to use for transcription

    Returns:
        Transcription text
    """
    if not audio:
        return "Please provide an audio file to transcribe."

    try:
        if model_choice == PHI_MODEL_ID:
            return transcribe_audio_phi(audio)
        elif model_choice == WHISPER_MODEL_ID:
            return transcribe_audio_local(audio)
        else:
            logger.error(f"Unknown model choice: {model_choice}")
            return f"Error: Unknown model {model_choice}"
    except Exception as e:
        logger.error(f"Transcription failed: {str(e)}")
        return f"Error during transcription: {str(e)}"


def create_demo() -> gr.Blocks:
    """Create and configure the Gradio demo interface"""
    with gr.Blocks(theme=gr.themes.Soft()) as demo:
        gr.Markdown("# TWASR: Chinese (Taiwan) Automatic Speech Recognition")
        gr.Markdown(
            "Upload an audio file or record your voice to transcribe it to text."
        )
        gr.Markdown(
            "⚠️ First load may take a while to initialize the model, following requests will be faster."
        )

        with gr.Row():
            audio_input = gr.Audio(
                label="Audio Input", type="filepath", show_download_button=True
            )
            with gr.Column():
                model_choice = gr.Dropdown(
                    label="Select Model",
                    choices=list(MODEL_CHOICES.keys()),
                    value=PHI_MODEL_ID,
                    info="Select the model for transcription",
                )
                text_output = gr.Textbox(label="Transcription Output", lines=5)

        with gr.Row():
            transcribe_button = gr.Button("🎯 Transcribe", variant="primary")
            clear_button = gr.Button("🧹 Clear")

        transcribe_button.click(
            fn=combined_transcription,
            inputs=[audio_input, model_choice],
            outputs=[text_output],
            show_progress=True,
        )

        clear_button.click(
            fn=lambda: (None, ""),
            inputs=[],
            outputs=[audio_input, text_output],
        )

        gr.Examples(
            examples=EXAMPLE_FILES,
            inputs=[audio_input, model_choice],
            outputs=[text_output],
            fn=combined_transcription,
            cache_examples=True,
            cache_mode="lazy",
            run_on_click=True,
        )

        gr.Markdown("### Model Information")
        with gr.Accordion("Model Details", open=False):
            for model_id, model_name in MODEL_CHOICES.items():
                gr.Markdown(
                    f"**{model_name}:** [{model_id}](https://huggingface.co/{model_id})"
                )

    return demo


if __name__ == "__main__":
    # Preload models before starting the app to reduce cold start time
    logger.info("Preloading models to reduce cold start time")
    preload_models()

    demo = create_demo()
    demo.launch(share=False)