app.py

import streamlit as st
import os
import subprocess
import whisper

URL = 'URL'
TEXT = 'TEXT'
TITLE = 'TITLE'

PROCESSING = 'PROCESSING'
AUDIO_EXISTS = "AUDIO_EXISTS"
TRANSCRIPT_EXISTS = "TRANSCRIPT_EXISTS"
STATES = [ TEXT, TITLE]
BOOL_STATES = [ AUDIO_EXISTS, TRANSCRIPT_EXISTS, PROCESSING]
AUDIO_FILE = "audio.mp3"
TRANSCRIPT = "transcript.txt"

model = ''

st.title('Youtube Assistant')

def init_state():
    # print("Page refreshed")
    for state in STATES:
        if state not in st.session_state:
            st.session_state[state] = ''

    for state in BOOL_STATES:
        if state not in st.session_state:
            st.session_state[state] = False


def clear_old_files():
    print("Clearing old files")
    for file in os.listdir():
        if file.endswith(".mp3") or file == TRANSCRIPT:
            os.remove(file)
            print(f"Removed old files::{file}")
    #Refresh audio state
    check_audio()

@st.cache_data
def load_whisper():
    check_audio()
    model = whisper.load_model("small")
    print('Loaded Whisper Medium model')
    return model
    
def transcribe():
    if st.session_state[AUDIO_EXISTS]:
        model = load_whisper()
        result = model.transcribe("audio.mp3")
        text = result["text"]

        st.session_state[TEXT] = text
        print(f"Start - { text[:100]}")
        print(f"End - { text[-100:]}")
        write_file(text, "transcript.txt")
        check_audio()
        write_file(str(result["segments"]), "segments.txt")
        return text

def check_audio():
    st.session_state[AUDIO_EXISTS] = os.path.exists(AUDIO_FILE)
    st.session_state[TRANSCRIPT_EXISTS] = os.path.exists(TRANSCRIPT)

def load_audio():
    if AUDIO_EXISTS in st.session_state and st.session_state[AUDIO_EXISTS]:
        audio_file = open(AUDIO_FILE, 'rb')
        audio_bytes = audio_file.read()
        st.audio(audio_bytes, format="audio/mp3")

def display():
    check_audio()
    container = st.container()
    text_container = st.container()

    with container:
        with st.form(key='input_form', clear_on_submit=False):
            user_input = st.text_input("Youtube URL:", placeholder="https://www.youtube.com", key=URL)
            input_submit_button = st.form_submit_button(label='Send')
        
    if input_submit_button and user_input:
        st.session_state[PROCESSING] = True
        clear_old_files()
        with st.spinner('Downloading Audio...'):
            download()
            load_audio()
        with st.spinner('Transcribing Audio...'):
            transcribe()
        st.session_state[PROCESSING] = False
    
    with text_container:
       st.text_area(label=f"Youtube Transcript: {st.session_state[TITLE]}",
                    height=200,
                    value=st.session_state[TEXT],
                    )
    
        #Download Button section
    col1, col2 = st.columns(2)
    with col1:
        if AUDIO_EXISTS in st.session_state and st.session_state[AUDIO_EXISTS]:
            with open("audio.mp3", "rb") as f:
                data = f.read()
                st.download_button('Download MP3', data,"audio.mp3", key="mp3")
    with col2:
        if st.session_state[TRANSCRIPT_EXISTS]:
            if st.session_state[TEXT] == '':
                with open(TRANSCRIPT, "rb") as f:
                    data = f.read()
                    # convert bytes to utf-8 string
                    data = data.decode("utf-8")
                    st.session_state[TEXT] =  data
                    
            st.download_button("Download Transcript",st.session_state[TEXT],"transcript.txt", key="transcript")


def download():
  #Get youtube title
  text = subprocess.run(["yt-dlp", "--get-title", st.session_state[URL]], capture_output=True)
  st.session_state[TITLE] = text.stdout.decode("utf-8").strip()
  # Download and convert audio
  command = [f"yt-dlp --no-config -v --extract-audio --audio-format mp3 {st.session_state[URL]} -o audio.mp3"]
  print(command)
  subprocess.run(command, shell=True)
  check_audio()

def write_file(text, filename):
    with open(filename, "w") as f:
        f.write(text)

def main():
    init_state()
    display()


if __name__ == "__main__":
    main()