#!/bin/bash

declare -A USE_MAP
declare -a ENABLES

# export_name dependency dependecy dependency...
USE_MAP['HBASE']='USE_HBASE HCATALOG HUE'
USE_MAP['PIG']='USE_PIG'
USE_MAP['HUE']='USE_HUE'
USE_MAP['HCATALOG']='USE_HCATALOG'
USE_MAP['PRESTO']='USE_PRESTO HCATALOG'
ENABLES=()

function use() {
  local dep=(${USE_MAP["$1"]})
  ENABLES+=(${dep[0]})
  dep=("${dep[@]:1}")
  if [ ! -z "$dep" ]; then
    for item in ${dep[@]}; do
      use $item
    done
  fi
}

function export_enabled() {
  sorted_use=($(echo "${ENABLES[@]}" | tr ' ' '\n' | sort -u | tr '\n' ' '))
  for item in ${sorted_use[@]}; do
    echo "export $item";
  done
}

use HBASE
export_enabled

------

$ bash resolve.sh
export USE_HBASE
export USE_HCATALOG
export USE_HUE