#!/bin/bash

for srt in *.srt; do
  [[ -f "$srt" ]] || { echo "no .srt files found"; exit 1; }

  episode=$(echo "$srt" | grep -o "S[0-9]\{2\}E[0-9]\{2\}")
  if [[ -z "$episode" ]]; then
    echo "no episode number found in '$srt'"
    exit
  fi

  video_file=$(find . -maxdepth 1 -type f -name "*${episode}*.mkv")
  if [[ $video_file == '' ]] then
    epnumber=$(echo "$episode" | head -c6 | tail -c2)
    echo "no matching video file found for '$episode', trying ep number $epnumber..."
    video_file=$(find . -maxdepth 1 -type f -name "* ${epnumber} *.mkv")
  fi

  if [[ -n "$video_file" ]]; then
    echo "found video file: $video_file"
    video_basename=$(basename "$video_file" .mkv)
    new_name="${video_basename}.srt"

    if [[ "$srt" != "$new_name" ]]; then
      mv -v "$srt" "$new_name"
    fi
  else
    echo "no matching video file found for '$srt'"
  fi
done