from pytube import YouTube

# Asks the User for a YouTube video URL.
def get_video_url():
    try:
        video_url = input('YouTube video URL: ')
        return video_url
    except Exception as e:
        print(f"An error has occurred: {e}")

# Callback function to show the progress bar.
def progress_bar(stream, _chunk, bytes_remaining):
    try:
        current = ((stream.filesize - bytes_remaining)/stream.filesize)
        percent = ('{0:.1f}').format(current * 100)
        progress = int(50 * current)
        status = '█' * progress + '-' * (50 - progress)
        print(f'\r|{status}| {percent}%', end='')
    except Exception as e:
        print(f"An error has occurred: {e}")

# Downloads the video.
def video_download(video_url):
    try:
        youtube = YouTube(video_url, on_progress_callback=progress_bar)
        video = youtube.streams.get_highest_resolution()
        print("Downloading...")
        video.download()
        print("\nDownload complete!")
    except Exception as e:
        print(f"An error has occurred: {e}")

# Program main function.
def main():
    try:
        video_url = get_video_url()
        video_download(video_url)
    except KeyboardInterrupt:
        print("\nSession ended by user.")
    except Exception as e:
        print(f"An error has occurred: {e}")

if __name__ == "__main__":
    main()