#!/bin/sh
set -e

readonly programName="${0##*/}"

programMessage() {
  local message="${1}"

  echo "${programName}: ${message}"
}

syntaxError() {
  local message="${1}"

  programMessage "${message}"
  exit 2
}

semanticError() {
  local message="${1}"

  programMessage "${message}"
  exit 3
}

makeIcon() {
  local name="${1}"
  local size="${2}"

  convert "${imageFile}" -resize "${size}" "res/drawable-${name}/${imageName}.png"
}

[ "${#}" -ge 1 ] || syntaxError "missing image file"
imageFile="${1}"
shift 1

[ "${#}" -eq 0 ] || syntaxError "too many parameters"

[ -f "${imageFile}" ] || semanticError "image file not found: ${imageFile}"
[ -r "${imageFile}" ] || semanticError "image file not readable: ${imageFile}"

imageName="${imageFile%.*}"

makeIcon ldpi 36x36
makeIcon mdpi 48x48
makeIcon hdpi 72x72
makeIcon xhdpi 96x96

exit 0