app.py

import gradio as gr

from logging_config import logger, log_buffer
from ffmpeg_setup import ensure_ffmpeg_in_path
from youtube_utils import fetch_youtube_transcript
from transcription import fallback_whisper_transcription


def get_transcript(youtube_url: str, skip_official_transcript: bool):
    """
        Fetch the official YouTube transcript,
        or fall back to Whisper transcription if required
        returns (partial_transcript, logs_so_far).
    """
    # Clear logs
    log_buffer.seek(0)
    log_buffer.truncate()

    logger.info(f"Received YouTube URL: {youtube_url}")
    logger.info(f"Skip official transcript check? {skip_official_transcript}")
    logger.info("")
    yield "", log_buffer.getvalue()

    # If user wants to skip the official transcript, go straight to fallback
    if skip_official_transcript:
        logger.info("User selected to skip official transcript.")
        yield "", log_buffer.getvalue()
        for partial_transcript, current_logs in fallback_whisper_transcription(youtube_url):
            yield partial_transcript, current_logs
        return

    # Otherwise, try official transcript first
    transcript = fetch_youtube_transcript(youtube_url)
    logger.info("")
    yield "", log_buffer.getvalue()

    # If official transcript wasn't found, do fallback
    if transcript.startswith("Error"):
        logger.info("Transcript not found. Falling back to local Whisper transcription...")
        logger.info("")
        yield "", log_buffer.getvalue()

        for partial_transcript, current_logs in fallback_whisper_transcription(youtube_url):
            yield partial_transcript, current_logs
        return

    # Otherwise, we succeeded with the official transcript
    logger.info("Official transcript found successfully.")
    logger.info("")
    yield transcript, log_buffer.getvalue()


def run_demo():
    ensure_ffmpeg_in_path()

    demo = gr.Interface(
        fn=get_transcript,
        inputs=[
            gr.Textbox(label="YouTube URL"),
            gr.Checkbox(label="Skip official transcript check?", value=False)
        ],
        outputs=[
            gr.Textbox(label="Transcript"),
            gr.Textbox(label="Logs (Streaming)"),
        ],
        title="YouTube Transcript Tool",
        description=(
            "Enter a YouTube link to retrieve its official transcript. "
            "If that fails (or if 'Skip' is selected), we'll download the best "
            "audio track with yt-dlp, convert it to WAV (via ffmpeg), and "
            "then run Whisper to transcribe. Logs are displayed as it runs."
            "Currently does NOT run on Hugging Face Spaces. Download and run locally."
        ),
    )

    demo.launch()


if __name__ == "__main__":
    run_demo()