#!/bin/bash
checkGMAD() {
  header=$(head -c4 $1 | xxd -ps)
  echo "'$header'"
  if [[ "$header" = "474d4144" ]]; then
    return 0
  else
    return 1
  fi
}

checkLZMA() {
  header=$(cat $1 | lzma -d - | head -c4 | xxd -ps)
  if [[ "$header" = "474d4144" ]]; then
    return 0
  else
    return 1
  fi
}

testNfix() {
  file=$1
  if checkGMAD "$file"; then
    echo "file is native GMAD"
  else
    if checkLZMA "$file"; then
      echo "file is lzma'd GMAD"
      cat "$file" | lzma -d > "$file.unc"
      if checkGMAD "$file.unc"; then
        mv "$file" "$file.lzma" && mv "$file.unc" "$file" && echo "file has been converted to GMAD" && exit 0
      else
        echo "file couldn't be converted"
      fi
      rm "$file.unc"
    else
      echo "file is somewhat else"
    fi
  fi
}