#!/usr/bin/env bash

set -eu

if [[ $# == 0 ]]; then
  FILES=(-)
else
  FILES=("${@}")
fi

CUR_DIR=$(dirname ${BASH_SOURCE[0]})

for FILE in "${FILES[@]}"; do
  if [ "${FILE}" == "-" ]; then
    FILE=/dev/stdin
  fi
  while IFS='' read -r LINE || [ -n "${LINE}" ]; do

    #My template substitution
    while [[ "$LINE" =~ (\[\{)([A-Za-z0-9_]*)(\}\]) ]]; do
      LINE=${LINE/"${BASH_REMATCH[0]}"/${!BASH_REMATCH[2]-}}
    done
    
    #My SOURCE substitution
    if echo $LINE | grep -q ^SOURCE; then
      SOURCE=$(echo "${LINE}" | sed -E 's|^SOURCE[ ]+(.*)|\1|')
      if [ "${SOURCE:0:1}" != "/" ] && [ -f "${CUR_DIR}/${SOURCE}" ]; then
        SOURCE="${CUR_DIR}/${SOURCE}"
      fi
      if [ ! -f "${SOURCE}" ]; then
        echo "Could not find a readable ${SOURCE}" >& 2
        exit 1
      fi
      "${BASH_SOURCE[0]}" "${SOURCE}" | grep -vi '^FROM' | grep -vi '^MAINTAINER'
    else
      echo "${LINE}"
    fi
  done < ${FILE}
done