import os
import subprocess
import re

def download(video_url, output_file_name, dest_dir='./', audio_only=False, progress_callback=None):
    # Ensure the destination directory exists
    if not os.path.exists(dest_dir):
        os.makedirs(dest_dir)

    # Prepare the command to predict filename extension
    if audio_only:
        predict_command = ['yt-dlp', '--newline', '-x', '--audio-format', 'mp3', '--get-filename', '-o', f'{output_file_name}.%(ext)s', video_url]
    else:
        predict_command = ['yt-dlp', '--newline', '--get-filename', '-o', f'{output_file_name}.%(ext)s', video_url]
    
    try:
        # Using yt-dlp with --get-filename to predict the output filename
        result = subprocess.check_output(predict_command)
        file_extension = os.path.splitext(result.decode('utf-8').strip())[1]
    except Exception as e:
        print(f'Unexpected error when getting filename: {e}')
        return

    # Prepare the command to download the media
    if audio_only:
        download_command = [
            'yt-dlp',
            '-x', '--audio-format', 'mp3',
            '-o', f'{dest_dir}/{output_file_name}{file_extension}',
            video_url
        ]
    else:
        download_command = [
            'yt-dlp',
            '-o', f'{dest_dir}/{output_file_name}{file_extension}',
            video_url
        ]

    try:
        # Execute the download command and capture stdout in real-time
        process = subprocess.Popen(download_command, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, universal_newlines=True)
        while True:
            line = process.stdout.readline()
            if not line:
                break
            if '[download]' in line:
                # Parse the progress from the output
                match = re.search(r'\[download\]\s+(\d+\.\d+|\d+)%', line)
                if match:
                    percentage = int(float(match.group(1)))
                    if progress_callback:
                        progress_callback(percentage)  # Call the callback with the parsed progress value
        process.communicate()  # Wait for the process to finish if it hasn't yet
    except subprocess.CalledProcessError:
        print('Error occurred while downloading the video/audio.')
    except Exception as e:
        print(f'Unexpected error: {e}')

if __name__ == '__main__':
    def update_progress_bar(percentage):
        print(percentage)
    download('https://www.youtube.com/watch?v=ON7QQtF-RNA', 'Khonsu -  A Jhator Ascension', progress_callback=update_progress_bar)