#!/usr/bin/env bash

add(){
  token="$1"
  eval "${token}_flag=1" ; shift
  if [[ ! -z "$format" ]] ; then
    format="${format}-\$${token}"
  else
    format="\$${token}"
  fi
}

rvm_gemset_separator=${rvm_gemset_separator:-"+"}
ruby=$(command -v ruby)
if [[ ! -z "$ruby" ]] && [[ ! -z "$(echo "$ruby" | awk '/rvm/{print}')" ]] ; then
  unset format
  while [[ $# -gt 0 ]] ; do
    token="$1" ; shift
    case "$token" in
      i|interpreter)  add "interpreter"  ;;
      v|version)      add "version"      ;;
      p|patchlevel)   add "patchlevel"   ;;
      r|revision)     add "revision"     ;;
      a|architecture) add "architecture" ;;
      g|gemset)       add "gemset"       ;;
      u|unicode)      unicode_flag=1     ;;
      *) echo "Unrecognized command line option '$token' for $0" ; exit 1 ;;
    esac
  done

  if [[ -z "$format" ]] ; then
    add "interpreter"
    add "version"
    add "patchlevel"
    add "gemset"
  fi

  ruby_string=$(dirname "$ruby" | xargs dirname | xargs basename)

  if [[ ! -z "$interpreter_flag" ]] ; then
    interpreter="$(echo $ruby_string | awk -F'-' '{print $1}')"
  fi

  if [[ ! -z "$version_flag" ]] ; then
    version="$(echo $ruby_string | awk -F'-' '{print $2}')"
  fi

  if [[ ! -z "$patchlevel_flag" ]] ; then
    patchlevel=$(echo $ruby_string | awk -F'-' '{print $3}')
  fi

  if [[ ! -z "$architecture_flag" ]] ; then
    architecture="$(echo "$(ruby -v)" | sed 's/^.*\[//' | sed 's/\].*$//')"
  fi

  if [[ ! -z "$gemset_flag" ]] ; then
    gemset="$(echo $GEM_HOME | awk -F${rvm_gemset_separator} '{print $2}')"
    if [[ ! -z "$gemset" ]] ; then gemset="${rvm_gemset_separator}$gemset" ; fi
  fi

  if [[ ! -z "$unicode_flag" ]] ; then
    case "$interpreter" in
      jruby)    unicode="☯" ;;
      rbx)      unicode="☃" ;;
      ree)      unicode="✈" ;;
      macruby)  unicode="⌘" ;;
      maglev)   unicode="㎖" ;;
      ironruby) unicode="♭" ;;
      mput)     unicode="⎈" ;;
      system)   unicode="➆" ;;
      ruby)
        case "$version" in
          1.8.6)  unicode="❻"  ;;
          1.8.7)  unicode="❼"  ;;
          1.9.1)  unicode="❶"  ;;
          1.9.2)  unicode="❷"  ;;
          *)      unicode="♢"  ;;
        esac ;;
      *) unicode="♢" ;;
    esac

    if [[ ! -z "$(echo $ruby_string | awk '/-head/')" ]] ; then
      unicode="${unicode}〠"
    fi
    # TODO: Architecture
    # TODO: gemset
    echo $unicode
  else
    command="prompt=\"$format\""
    eval "$command"
    echo "$prompt" | sed 's#-\s*$##' | sed 's#-'${rvm_gemset_separator}'#'${rvm_gemset_separator}'#'
  fi
else
  echo "system"
fi

exit 0