#!/bin/sh

fname="$(basename "$0")"
usage()
{
  echo "$fname <operation>
Operations:
  gen [bin_file...]      Generate a desktop file
  add <desktop_file...>  Add desktop file to applications"
}

gen_file()
{
  unset name
  if [ -n "$1" ]
  then
    file="$1"
    name="$(echo "$1" | sed 's|.[^.]*$||g')"
    [ -z "$name" ] && name="$1"
  else
    name="$(basename "$(pwd)")"
    file=""
  fi

  desktop_file=$(echo "$name.desktop" | tr '[:upper:]' '[:lower:]')
  [ -f "$desktop_file" ] && { mv "$desktop_file" "$desktop_file.bak" || return $?; }

  cat > "$desktop_file" << EOF
[Desktop Entry]
Name=$name
Comment=$name
Type=Application
Exec=$(pwd)/$file
Icon=$(pwd)/icon.png
Categories=Game
Keywords=keyword;keyword
EOF
}

add_file()
{
  if [ -f "$1" ]
  then
    ln -sf "$(pwd)/$1" "$HOME/.local/share/applications"
  else
    echo "'$1' is not a file" > /dev/stderr
    return 1
  fi
}

[ $# -le 0 ] && { usage && exit 1; }

case $1 in
  gen)
    if [ $# -gt 1 ]
    then
      shift $((OPTIND))
      for N
      do
        gen_file "$N" || exit $?
      done
    else
      gen_file || exit $?
    fi
  ;;
  add)
    if [ $# -gt 1 ]
    then
      shift $((OPTIND))
      for N
      do
        add_file "$N" || exit $?
      done
    else
      echo "$fname add <desktop_file...>" > /dev/stderr
      exit 1
    fi
  ;;
  *) usage && exit 1;;
esac