app.py

import gradio as gr
import yt_dlp
from collections import defaultdict
import tempfile
import google.generativeai as genai
import os

prompt_filepath = "./system_instructions.txt"
def read_system_instruction_from_file(filepath):
  try:
    with open(filepath, 'r') as f:
      system_instruction = f.read().strip()
      return system_instruction
  except FileNotFoundError:
    return "Error: System instruction file not found."
  except Exception as e:
    return f"Error reading system instruction file: {str(e)}"

      
def download_and_convert_subtitles(url):
  """Downloads VTT subtitles from a YouTube URL, extracts text, and returns it.

  Args:
      url: The URL of the YouTube video.

  Returns:
      A string containing the extracted subtitles text or an error message.
  """

  # Download subtitles using yt-dlp with temporary directory
  with tempfile.TemporaryDirectory() as download_dir:
    ydl_opts = {
        'skip_download': True,
        'writeautomaticsub': True,
        'subtitlesformat': 'vtt',
        'outtmpl': f'{download_dir}/%(id)s.%(ext)s',
    }

    try:
      # Use context manager properly (Option 1)
      with yt_dlp.YoutubeDL(ydl_opts) as ydl:
        ydl.download([url])  # Download only subtitles

      # Extract video ID and handle language code extension
      info = ydl.extract_info(url, download=False)
      video_id = info['id']

      # Extract text from downloaded VTT file (in temp directory)
      vtt_file_path = f"{download_dir}/{video_id}.{info.get('language', '')}.vtt"
      return extract_text_from_vtt(vtt_file_path)

    except Exception as e:
      return f"Error downloading and converting subtitles: {str(e)}"


def extract_text_from_vtt(vtt_file_path):
  """Extracts text content from a VTT file.

  Args:
      vtt_file_path: The path to the VTT file (in temporary directory).

  Returns:
      A string containing all text lines from the VTT file.
  """

  text_lines = []
  with open(vtt_file_path, 'r', encoding='utf-8') as f:
    for line in f:
      if not line.strip() or '-->' in line:
        continue
      text = line.strip().split("<", 1)[0]  # Extract text content
      text_lines.append(text)
  
  user_prompt = "\n".join(text_lines)
  genai.configure(api_key=os.getenv("GEMINI_API_KEY"))
  generation_config = {
  "temperature": 1,
  "top_p": 0.95,
  "top_k": 0,
  "max_output_tokens": 8192,
}
  safety_settings = [
  {
    "category": "HARM_CATEGORY_HARASSMENT",
    "threshold": "BLOCK_MEDIUM_AND_ABOVE"
  },
  {
    "category": "HARM_CATEGORY_HATE_SPEECH",
    "threshold": "BLOCK_MEDIUM_AND_ABOVE"
  },
  {
    "category": "HARM_CATEGORY_SEXUALLY_EXPLICIT",
    "threshold": "BLOCK_MEDIUM_AND_ABOVE"
  },
  {
    "category": "HARM_CATEGORY_DANGEROUS_CONTENT",
    "threshold": "BLOCK_MEDIUM_AND_ABOVE"
  },
]
  a = read_system_instruction_from_file(prompt_filepath)
    
  model = genai.GenerativeModel(model_name="gemini-1.5-pro-latest",
                              generation_config=generation_config,
                              system_instruction=a,
                              safety_settings=safety_settings)
  convo = model.start_chat(history=[
])
  convo.send_message(user_prompt)
  ai_model_output = convo.last.text

  return ai_model_output


# Gradio interface definition
interface = gr.Interface(
  fn=download_and_convert_subtitles,
  inputs="text",
  outputs="text",
  title="Podcast Summary Generator",
  description="Enter a YouTube video URL of a podcast to get a short summary."
  
)

# Launch the Gradio interface
interface.launch()