#!/usr/bin/env bash

add(){

  token=${1:-""}

  eval "${token}_flag=1" ; shift

  if [[ -n "$format" ]] ; then

    format="${format}-\$${token}"

  else

    format="\$${token}"

  fi

  return 0
}

rvm_gemset_separator="${rvm_gemset_separator:-"@"}"

ruby=$(command -v ruby)

if [[ -n "$ruby" && -n "$(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)      add "unicode"      ;;

      s|system)       add "system"       ;;

      -d|--no-default) no_default=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 [[ -n "$no_default" ]]; then

    # Do not display anything if no default flag was provided
    #   and we are using the default ruby

    # Only people who explicitely ask for this will have the
    #   slight performance penalty associated.

    if [[ "$(rvm tools identifier)" = "$(rvm alias show default)"  ]] ; then

      exit 0

    fi

  fi

  strings=(${ruby_string//-/ })

  if [[ ${interpreter_flag:-0} -gt 0 || -n "$unicode_flag" ]] ; then

    interpreter=${strings[0]}

  fi

  if [[ ${version_flag:-0} -gt 0 || -n "$unicode_flag" ]] ; then

    version=${strings[1]}

  fi

  if [[ ${#strings[@]} -gt 2 ]] ; then

    if [[ ${patchlevel_flag:-0} -gt 0 ]] ; then

      patchlevel=${strings[2]}

    fi

  fi

  if [[ ${architecture_flag:-0} -gt 0 ]] ; then

    architecture="$(echo "$(ruby -v)" | sed 's/^.*\[//' | sed 's/\].*$//')"

  fi

  if [[ ${gemset_flag:-0} -gt 0 ]] ; then

    case "${GEM_HOME:-""}" in

      *${rvm_gemset_separator:-"@"}*)

        gemset="${rvm_gemset_separator:-"@"}${GEM_HOME/*${rvm_gemset_separator:-"@"}/}"

        ;;

    esac

  fi

  if [[ ${unicode_flag:-0} -gt 0 ]] ; 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 echo "$ruby_string" | \grep -q '-head' ; then

      unicode="${unicode}〠"

    fi

  fi

  eval "prompt=\"$format\""

  echo "$prompt" \
    | sed -e 's#^[[:space:]]*-*##g' \
          -e 's#--*#-#g' \
          -e 's#-*[[:space:]]*$##' \
          -e 's#-'${rvm_gemset_separator:-"@"}'#'${rvm_gemset_separator:-"@"}'#'


else

  while [[ $# -gt 0 ]] ; do

    token="$1" ; shift

    case "$token" in

      s|system) echo "system" ;;

    esac

  done

fi

exit 0