app.py

import gradio as gr
from utils import generate_script, generate_audio, truncate_text, extract_text_from_url
from prompts import SYSTEM_PROMPT
import pypdf
import os
import tempfile

def generate_podcast(file, url, tone, length):
    try:
        if file and url:
            return None, "Please provide either a PDF file or a URL, not both."
        
        if file:
            if not file.name.lower().endswith('.pdf'):
                return None, "Please upload a PDF file."
            
            pdf_reader = pypdf.PdfReader(file.name)
            text = ""
            for page in pdf_reader.pages:
                text += page.extract_text()
        elif url:
            text = extract_text_from_url(url)
        else:
            return None, "Please provide either a PDF file or a URL."
        
        truncated_text = truncate_text(text)
        if len(truncated_text) < len(text):
            print("Warning: The input text was truncated to fit within 2048 tokens.")
        
        script = generate_script(SYSTEM_PROMPT, truncated_text, tone, length)
        
        audio_files = []
        transcript = ""
        for item in script.dialogue:
            audio_file = generate_audio(item.text, item.speaker)
            audio_files.append(audio_file)
            transcript += f"**{item.speaker}**: {item.text}\n\n"
        
        # Combine audio files
        with tempfile.NamedTemporaryFile(delete=False, suffix=".mp3") as combined_audio:
            for audio_file in audio_files:
                with open(audio_file, 'rb') as f:
                    combined_audio.write(f.read())
                os.remove(audio_file)  # Clean up individual audio files
        
        return combined_audio.name, transcript
    
    except Exception as e:
        return None, f"An error occurred: {str(e)}"

instructions = """
# Podcast Generator

Welcome to the Podcast Generator project! This tool allows you to create custom podcast episodes using AI-generated content.

## Features
* Generate podcast scripts from PDF content or web pages
* Convert text to speech for a natural listening experience
* Choose the tone of your podcast
* Export episodes as MP3 files

## How to Use
1. Upload a PDF file OR enter a URL (content will be truncated to 2048 tokens if longer)
2. Select the desired tone (humorous, casual, formal)
3. Choose the podcast length
4. Click "Generate" to create your podcast
5. Listen to the generated audio and review the transcript

Note: This tool uses the LLaMa 3.1 70B model for script generation and Voice RSS for text-to-speech conversion. The input is limited to 2048 tokens to ensure compatibility with the model. The podcast features John (Male, American accent) and Lily (Female, British accent) as hosts.
"""

iface = gr.Interface(
    fn=generate_podcast,
    inputs=[
        gr.File(label="Upload PDF file (optional)", file_types=[".pdf"]),
        gr.Textbox(label="OR Enter URL"),
        gr.Radio(["humorous", "casual", "formal"], label="Select podcast tone", value="casual"),
        gr.Radio(["Short (1-2 min)", "Medium (3-5 min)"], label="Podcast length", value="Medium (3-5 min)")
    ],
    outputs=[
        gr.Audio(label="Generated Podcast"),
        gr.Markdown(label="Transcript")
    ],
    title="Custom NotebookLM-type Podcast Generator (2048 token limit)",
    description=instructions,
    allow_flagging="never",
    theme=gr.themes.Soft()
)

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