app.py

import gradio as gr
from openai import OpenAI
import tempfile
import time
import typing as tp
from pathlib import Path
from pydub import AudioSegment

from dotenv import load_dotenv
load_dotenv()

client = OpenAI()

class FileCleaner:
    def __init__(self, file_lifetime: float = 3600):
        self.file_lifetime = file_lifetime
        self.files = []

    def add(self, path: tp.Union[str, Path]):
        self._cleanup()
        self.files.append((time.time(), Path(path)))

    def _cleanup(self):
        now = time.time()
        for time_added, path in list(self.files):
            if now - time_added > self.file_lifetime:
                if path.exists():
                    path.unlink()
                self.files.pop(0)
            else:
                break


file_cleaner = FileCleaner()
intro = AudioSegment.from_mp3("intro.mp3")

DEFAULT_SYSTEM_PROMPT = """
You are a podcast editor that specialized to create a script out of a webpage.

[TASKS]
- You will receive a link to a webpage about some content.
- You will create a script out of the content.
- The script should be 1 minute long if you read it out loud.
- Start with an intro to peak the interest of the listener.
- Then, summarize the content in a way that is easy to understand. Ask questions about the the content and answer them.
- Conclude with the most intriguing part of the content.
- Refrain from adding section headers in the script like [INTRUCTION], [CONTENT], [CONCLUSION].
- The script should be inspiring, written in colloquialism with english words and proverbs understood around the world.
- Write in a relax tone.
- Use filler words like 'um', 'ah', 'well' etc. to make it sound more natural.

[BREAKS]
- Use the <break time="1s"/> tag to add a pause in the speech. Use it after each paragraph and after a sentence when appropriate to get to a relax tone.
- Use <break time="3s"/> for longer pauses, to emphasize a point.
"""

def generate_episode(system_prompt, weblink):
    response = client.chat.completions.create(
        model="gpt-4o",
        messages=[
            {"role": "system", "content": system_prompt},
            {"role": "user", "content": weblink},
        ]
    )
    script = response.choices[0].message.content    
    response = client.audio.speech.create(
        model="tts-1",
        voice="fable",
        input=script,
    )
        
    with tempfile.NamedTemporaryFile(suffix=".mp3", delete=False) as podcast_file:
        podcast_file.write(response.content) 
        file_cleaner.add(podcast_file.name)

    podcast = AudioSegment.from_mp3(podcast_file.name)
    merged_audio = intro + podcast
    
    with tempfile.NamedTemporaryFile(suffix=".mp3", delete=False) as final_file:
        merged_audio.export(final_file.name, format="mp3")

    print("MP3 files merged successfully!")

    return final_file.name, script

demo = gr.Interface(
    fn=generate_episode,
    inputs=[
        gr.Textbox(label="System Prompt"),
        gr.Textbox(label="Weblink"),
    ],
    outputs=[gr.Audio(label="Podcast Audio"), gr.Textbox(label="Podcast Script")],
    examples=[
        [DEFAULT_SYSTEM_PROMPT, "https://en.wikipedia.org/wiki/Mount_Tambora"],
        [DEFAULT_SYSTEM_PROMPT, "https://en.wikipedia.org/wiki/Great_Wall_of_China"],
        [DEFAULT_SYSTEM_PROMPT, "https://en.wikipedia.org/wiki/Apollo_11"],
    ],
    title="Webpage To Podcast",
    description="""
    <div style="text-align: center;">
        Welcome to our Podcast Script Generator! This tool transforms web content into captivating podcast scripts in a relaxed and natural tone. Simply provide a weblink, and in just moments, you’ll receive an engaging, one-minute script and audio version. Perfect for creating short podcast episodes from online articles and summaries!
    </div>
    """
)

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