#!/usr/bin/env bash
#

declare -r script_name="$(basename $BASH_SOURCE)"
declare -r sbt_jar=/soft/inst/sbt/xsbt-launch.jar
declare -r default_java_opts="-Dfile.encoding=UTF8"
declare -r default_sbt_opts="-XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=512m -Xmx2g -Xss2m"
declare -r latest_28="2.8.1"
declare -r latest_29="2.9.0-1"
declare -r latest_210="2.10.0-SNAPSHOT"

# get completion if present
[[ -f .sbt_completion.sh ]] && source .sbt_completion.sh

usage () {
  cat <<EOM
Usage: $script_name [options]

  -help      prints this message
  -boot      path to shared sbt boot directory (default: none)
  -debug     set sbt log level to debug
  -global    path to directory containing global settings and plugins (default: ~/.sbt)
  -ivy       path to local Ivy repository (default: ~/.ivy2)
  -nocolor   disable ANSI color codes

  -28        set scala version to $latest_28
  -29        set scala version to $latest_29
  -210       set scala version to $latest_210

  -Dkey=val  pass -Dkey=val directly to the jvm
  -J-X       pass option -X directly to the jvm

The contents of the following environment variables, if any, will be
passed to the jvm. Later variables take priority over earlier ones, and
command line options (-D/-J) take priority over all of them.

  JAVA_OPTS   # defaults: $default_java_opts
  SBT_OPTS    # defaults: $default_sbt_opts

If an environment variable is set, its defaults are not given.
EOM
}

# no args - alert them there's stuff in here
[[ $# -gt 0 ]] || {
  echo "Starting $script_name: invoke with -help for other options"
  # so it still starts if we injected any sbt commands
  set -- "shell"
}

# pull -J and -D options to give to java.
declare -a args
declare -a java_args
declare -a sbt_commands
addJava () {
  java_args=("${java_args[@]}" "$1")
}
addSbt () {
  sbt_commands=("${sbt_commands[@]}" "$1")
}

while [ $# -gt 0 ]; do
  case "$1" in
        -help) usage; exit 1 ;;
      -global) addJava "-Dsbt.global.base=$2"; shift 2 ;;
        -boot) addJava "-Dsbt.boot.directory=$2"; shift 2 ;;
         -ivy) addJava "-Dsbt.ivy.home=$2"; shift 2 ;;
    -nocolors) addJava "-Dsbt.log.noformat=true"; shift ;;
          -28) addJava "-Dsbt.scala.version=$latest_28"; shift ;;
          -29) addJava "-Dsbt.scala.version=$latest_29"; shift ;;
         -210) addJava "-Dsbt.scala.version=$latest_210"; shift ;;

          -D*) addJava "$1"; shift ;;
          -J*) addJava "${1:2}"; shift ;;
       -debug) addSbt "set logLevel := Level.Debug"; shift ;;

            *) args=("${args[@]}" "$1") ; shift ;;
  esac
done

# reset "$@" to the residual args
set -- "${args[@]}"

# run sbt
java \
  $JAVA_OPTS \
  ${SBT_OPTS:-$default_sbt_opts} \
  ${java_args[@]} \
  -jar "$sbt_jar" \
  "${sbt_commands[@]}" \
  "$@"