from youtube_transcript_api import YouTubeTranscriptApi
from youtube_transcript_api.formatters import TextFormatter
from transformers import pipeline
import re
import gradio as gr

pipe = pipeline("summarization", model="Falconsai/text_summarization", device=-1)

def chunk_length(text, max_length = 1024):
    words = text.split()
    for i in range(0, len(words), max_length):
        yield " ".join(words[i:i + max_length])

def extract_youtube_id(url):
    """
    Extracts the YouTube video ID from a given URL.

    Args:
        url (str): The YouTube video URL.

    Returns:
        str: The extracted video ID, or None if no match is found.
    """
    # Regular expression to match YouTube video IDs
    pattern = r"(?:https?:\/\/)?(?:www\.)?(?:youtube\.com\/(?:[^\/\n\s]+\/\S+\/|(?:v|e(?:mbed)?)\/|\S*?[?&]v=)|youtu\.be\/)([a-zA-Z0-9_-]{11})"
    match = re.search(pattern, url)

    if match:
        return match.group(1)
    return None

def summary(text_transcript):
    try:
        chunks = chunk_text(text_transcript)
        summarized_chunks = [pipe(chunk)[0]['summary_text'] for chunk in chunks]
        return " ".join(summarized_chunks)
    except Exception as e:
        return f"Error during summarization: {e}"

def get_youtube_transcript(link):
    video_id= extract_youtube_id(link)
    if not video_id:
        return "Video ID could not be extracted"

    try:
        transcript= YouTubeTranscriptApi.get_transcript(video_id) # fetches the trancript

        formatter= TextFormatter()
        text_transcript = formatter.format_transcript(transcript) # This will format the transcript
        
        summarized_text = summary(text_transcript)
        
        return summarized_text
    except Exception as e:
        return f"An error has occured: {e}"



demo = gr.Interface(fn=get_youtube_transcript,
                   inputs=[gr.Textbox(label="Input youtube url to generate the summary of video", lines=6)],
                   outputs=[gr.Textbox(label="Summary of youtube video")],
                   title='Generate Video Summary',
                   description='This is a project to generate the summary of a video')
demo.launch(share='True')