#!/bin/bash

# - this script creates a .env file in the same directory of the model.env
# - the model.env file is given in argument, otherwise it default to current path

# change to where the script is relatively to where the execution is made
#cd $(dirname $0)

CURRENT_PATH=$(dirname $0)
if [ $# -eq 0 ]; then
	FILE_PATH="${CURRENT_PATH}/model.env"
	ENV_PATH=${CURRENT_PATH}
else
	FILE_PATH="$1"
	ENV_PATH=$(dirname $FILE_PATH)
fi
if [ ! -f "$FILE_PATH" ]; then
	echo ""
	echo "  no file 'model.env' found"
	echo ""
	echo "  you need to create one in the same directory of this script,"
	echo "  or to give the path to a valide one in argument"
	echo ""
	echo "  like './create_env path/to/model.env'"
	echo "  "
	echo "  note that the .env file will be created where the model.env is"
	echo ""
	exit 1
fi

TMP_FILE="tmpfile_3289442091310922474928"
TMP_BEFORE="env_before.tmp"
TMP_AFTER="env_after.tmp"

# add lines at beginning and end of a temp env file
echo "set | sort > ${TMP_BEFORE}" > ${TMP_FILE}
cat ${FILE_PATH} >> ${TMP_FILE}
echo "set | sort > ${TMP_AFTER}" >> ${TMP_FILE}

source ${TMP_FILE}

# diff between the two set files == the newly created env var
NEW_ENV=$(comm -13 ${TMP_BEFORE} ${TMP_AFTER} | grep -v "^_=")
echo "${NEW_ENV}" > ${CURRENT_PATH}/.env

rm -f ${TMP_BEFORE} ${TMP_AFTER} ${TMP_FILE}