import sys
import webvtt

def vtt_to_srt(vtt_file, srt_file):
    webvtt_file = webvtt.read(vtt_file)
    with open(srt_file, 'w', encoding='utf-8') as srt:
        counter = 1
        for caption in webvtt_file:
            srt.write(f"{counter}\n")
            srt.write(f"{caption.start.replace('.', ',')} --> {caption.end.replace('.', ',')}\n")
            srt.write(f"{caption.text}\n\n")
            counter += 1

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python convert_vtt_to_srt.py <path_to_vtt_file>")
        sys.exit(1)
    
    vtt_file = sys.argv[1]
    srt_file = vtt_file.replace('.vtt', '.srt')

    vtt_to_srt(vtt_file, srt_file)
    print(f"Converted {vtt_file} to {srt_file}")