import gradio as gr
from youtube_transcript_api import YouTubeTranscriptApi, TranscriptsDisabled, NoTranscriptFound
from pytube import YouTube
import tempfile
import whisper
import os

def extract_video_id(url):
    if "watch?v=" in url:
        return url.split("watch?v=")[-1].split("&")[0]
    elif "youtu.be/" in url:
        return url.split("youtu.be/")[-1].split("?")[0]
    return None

def fetch_transcript(video_id):
    try:
        transcript_list = YouTubeTranscriptApi.get_transcript(video_id)
        full_text = ""
        for entry in transcript_list:
            full_text += f"[{entry['start']:.2f}s - {entry['start'] + entry['duration']:.2f}s]: {entry['text']}\n"
        return full_text, "YouTube Captions"
    except (TranscriptsDisabled, NoTranscriptFound):
        return None, "Transcript Not Found"

def download_audio(video_url):
    yt = YouTube(video_url)
    stream = yt.streams.filter(only_audio=True).first()
    temp_audio = tempfile.NamedTemporaryFile(delete=False, suffix=".mp4")
    stream.download(filename=temp_audio.name)
    return temp_audio.name

def transcribe_with_whisper(audio_path):
    model = whisper.load_model("base")  # "tiny", "base", "small", "medium", "large"
    result = model.transcribe(audio_path)
    return result['text']

def get_video_text(youtube_url):
    video_id = extract_video_id(youtube_url)
    if not video_id:
        return "Invalid YouTube URL. Please paste the full video link.", None

    transcript, source = fetch_transcript(video_id)
    if transcript:
        return f"✅ Transcript Source: {source}\n\n{transcript}", source

    # If no transcript found, use Whisper AI
    audio_file = download_audio(youtube_url)
    transcript = transcribe_with_whisper(audio_file)
    os.remove(audio_file)
    return f"🧠 Transcript Source: OpenAI Whisper\n\n{transcript}", "Whisper AI"

# Gradio Interface
iface = gr.Interface(
    fn=get_video_text,
    inputs=gr.Textbox(label="Paste YouTube Video URL here", placeholder="https://www.youtube.com/watch?v=dQw4w9WgXcQ"),
    outputs=gr.Textbox(label="📜 Transcript (Full with Timestamps)", lines=20),
    title="🎥 YouTube Video Transcript Extractor",
    description="Fetch full video content as text using YouTube captions or OpenAI Whisper AI fallback. Works on most public videos with or without captions.",
)

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