#!/usr/bin/env zsh

: ${PGHOST:=localhost}
: ${PGUSER:=postgres}

# TODO: add default postgresql port
: ${pgport}
: ${dbname}

: ${command}
: ${cmdparameters}

: ${simulation}

function usage() {
	cat <<END
usage: $0 [OPTIONS] command [parameters]
OPTIONS:
--pghost=<...>		postgresql hostname
--pgport=<...>		postgresql port
--pgdatadir=<...>	postgresql data dir
--pguser=<...>		postgresql username
--dbuser=<...>		database username
--dbpassfile=<...>	database password file
--dbname=<...>		database name
--simulation		print commands

command:
	create_user
	create_db
	create_user_and_db
	delete_user_and_db
END
}

function print_create_user() {
	cat <<END
# user creation
psql -p ${pgport} -c "CREATE USER ${dbuser};"
psql -p ${pgport} -c "ALTER USER ${dbuser} WITH ENCRYPTED PASSWORD '${dbpass}';"
END
}

function create_user() {
	su postgres -c "
		psql -p ${pgport} -c \"CREATE USER ${dbuser};\"
		psql -p ${pgport} -c \"ALTER USER ${dbuser} WITH ENCRYPTED PASSWORD '${dbpass}';\"
		"
}

function print_delete_user() {
	cat <<END
# user deletion
psql -p ${pgport} -c "DROP USER ${dbuser};"
END
}

function delete_user() {
	su postgres -c "
		psql -p ${pgport} -c \"DROP USER ${dbuser};\"
		"
}

function print_create_db() {
	cat <<END
# database creation
psql -p ${pgport} -c "CREATE DATABASE ${dbname} OWNER ${dbuser};"
END
}

function create_db() {
	su postgres -c "psql -p ${pgport} -c \"CREATE DATABASE ${dbname} OWNER ${dbuser};\""
}

function print_delete_db() {
	cat <<END
# database deletion
psql -p ${pgport} -c "DROP DATABASE ${dbname};"
END
}

function delete_db() {
	su postgres -c "psql -p ${pgport} -c \"DROP DATABASE ${dbname};\""
}

for i
do
	case $i in
		(--pghost*)		export PGHOST=$(echo ${i} | sed "s/--pghost=//") ;;
		(--pgport*)		export pgport=$(echo ${i} | sed "s/--pgport=//") ;;
		(--pgdatadir*)	export PGDATA=$(echo ${i} | sed "s/--pgdatadir=//") ;;
		(--pguser*)		export PGUSER=$(echo ${i} | sed "s/--pguser=//") ;;
		(--dbuser*)		export dbuser=$(echo ${i} | sed "s/--dbuser=//") ;;
		(--dbpassfile*)	dbpassfile=$(echo ${i} | sed "s/--dbpassfile=//") ;;
		(--dbname*)		export dbname=$(echo ${i} | sed "s/--dbname=//") ;;

		(--simulation*)	simulation="yes" ;;
		(-*) echo "option ${i} not recognized" ; usage $0 ; exit 0 ;;
		(*) [ -z $command ] && command=${i} || cmdparameters=(${cmdparameters} ${i})
	esac
done

if [ -z ${dbpassfile} ]
then
	echo "There is no password file for the database"
	exit 1
fi

export dbpass="$(<$dbpassfile)"

lacking_information=

[ -z ${PGHOST} ] 		&& lacking_information="yes" && echo "There is no pghost parameter"
[ -z ${pgport} ] 		&& lacking_information="yes" && echo "There is no pgport parameter"
[ -z ${PGDATA} ] 		&& lacking_information="yes" && echo "There is no datadir parameter"
[ -z ${PGUSER} ] 		&& lacking_information="yes" && echo "There is no pguser parameter"
[ -z ${dbuser} ] 		&& lacking_information="yes" && echo "There is no dbuser parameter"
[ -z ${dbpassfile} ] 	&& lacking_information="yes" && echo "There is no passfile parameter"
[ -z ${dbname} ] 		&& lacking_information="yes" && echo "There is no dbname parameter"

if [ ! -z ${lacking_information} ]
then
	echo "Some information is missing"
	exit 1
fi

if [ -z $simulation ]
then
	case ${command} in
		(create_db)   create_db ;;
		(create_user) create_user ;;
		(create_user_and_db) create_user ; create_db ;;
		(delete_user_and_db) delete_user ; delete_db ;;
		(*) usage $0 ; exit 1 ;;
	esac
else
	case ${command} in
		(create_db)   print_create_db ;;
		(create_user) print_create_user ;;
		(create_user_and_db) print_create_user ; print_create_db ;;
		(delete_user_and_db) print_delete_user ; print_delete_db ;;
		(*) usage $0 ; exit 1 ;;
	esac
fi