#!/bin/bash

# move into script directory
base_dir=$(dirname "${BASH_SOURCE[0]}")
cd "$base_dir"



#----- DECLARE FUNCTIONS -----#

function is-service-installed
{
	if [ ! -f '.installed' ]
	then
		return 1
	fi
	return 0
}


function ensure-service-installed
{
	if ! is-service-installed
	then
		>&2 echo "service is not installed"
		exit 1
	fi
}


function ensure-root
{
	# ensure root
	if [[ $EUID -ne 0 ]]
	then
		>&2 echo "You must be effective root to use this command"
		exit 1
	fi
}


function install-service
{
	ensure-root

	# ensure /etc/init.d exists
	if [ ! -d '/etc/init.d' ]
	then
		>&2 echo "/etc/init.d does not exist! quitting..."
		return 2
	fi

	# install service
	cp -f 'browser-cmd.service' '/etc/init.d/browser-cmd'
	touch '.installed'
	chmod 600 '.installed'

	# ensure service is recognized
	if type systemctl &> /dev/null
	then
		systemctl daemon-reload
		return $?
	elif type update-rc.d &> /dev/null
	then
		update-rc.d browser-cmd defaults
		return $?
	elif type chkconfig &> /dev/null
	then
		chkconfig --add browser-cmd
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to manage the service manually"
		return 0
	fi
}


function uninstall-service
{
	ensure-root

	# ensure /etc/init.d exists
	if [ ! -d '/etc/init.d' ]
	then
		>&2 echo "/etc/init.d does not exist! quitting..."
		return 2
	fi

	# stop and disable service
	stop-service
	disable-service

	# remove any extra links
	if type update-rc.d &> /dev/null
	then
		update-rc.d browser-cmd remove
	elif type chkconfig &> /dev/null
	then
		chkconfig --del browser-cmd
	fi

	# uninstall service
	rm -f '/etc/init.d/browser-cmd'
	rm -f '.installed'

	# cleanup
	if type systemctl &> /dev/null
	then
		systemctl daemon-reload
		systemctl reset-failed
	fi
	return 0
}


function enable-service
{
	ensure-root
	ensure-service-installed

	# enable service
	if type systemctl &> /dev/null
	then
		systemctl enable browser-cmd
		return $?
	elif type update-rc.d &> /dev/null
	then
		update-rc.d browser-cmd enable
		return $?
	elif type chkconfig &> /dev/null
	then
		chkconfig browser-cmd on
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to manage the service manually"
		return 2
	fi
}


function disable-service
{
	ensure-root
	ensure-service-installed

	# disable service
	if type systemctl &> /dev/null
	then
		systemctl disable browser-cmd
		return $?
	elif type update-rc.d &> /dev/null
	then
		update-rc.d browser-cmd disable
		return $?
	elif type chkconfig &> /dev/null
	then
		chkconfig browser-cmd off
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to manage the service manually"
		return 2;
	fi
}


function start-service
{
	ensure-root
	ensure-service-installed

	# start service
	if type service &> /dev/null
	then
		service browser-cmd start
		return $?
	elif type systemctl &> /dev/null
	then
		systemctl start browser-cmd
		return $?
	elif type update-rc.d
	then
		update-rc.d browser-cmd start
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to manage the service manually"
		return 2
	fi
}


function stop-service
{
	ensure-root
	ensure-service-installed

	# stop service
	if type service &> /dev/null
	then
		service browser-cmd stop
		return $?
	elif type systemctl &> /dev/null
	then
		systemctl stop browser-cmd
		return $?
	elif type update-rc.d &> /dev/null
	then
		update-rc.d browser-cmd stop
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to manage the service manually"
		return 2
	fi
}


function restart-service
{
	ensure-root
	ensure-service-installed

	# restart service
	if type service
	then
		service browser-cmd restart
		return $?
	elif type systemctl
	then
		systemctl restart browser-cmd
		return $?
	elif type update-rc.d
	then
		update-rc.d browser-cmd stop
		update-rc.d browser-cmd start
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to manage the service manually"
		return 2
	fi
}


function service-status
{
	if ! is-service-installed
	then
		echo "service is not installed"
		return 0
	fi

	if type service &> /dev/null
	then
		service browser-cmd status
		return $?
	elif type systemctl &> /dev/null
	then
		systemctl status browser-cmd
		return $?
	else
		>&2 echo "unrecognized init system; you'll have to check the service's status manually"
		return 2
	fi
}



#----- HANDLE COMMANDS -----#


if [ "$1" == 'install' ]
then
	install-service "$@"
	exit $?
elif [ "$1" == 'uninstall' ]
then
	uninstall-service "$@"
	exit $?
elif [ "$1" == 'enable' ]
then
	enable-service "$@"
	exit $?
elif [ "$1" == 'disable' ]
then
	disable-service "$@"
	exit $?
elif [ "$1" == 'start' ]
then
	start-service "$@"
	exit $?
elif [ "$1" == 'stop' ]
then
	stop-service "$@"
	exit $?
elif [ "$1" == 'restart' ]
then
	restart-service "$@"
	exit $?
elif [ "$1" == 'status' ]
then
	service-status "$@"
	exit $?
else
	>&2 echo "invalid command $1"
	exit 1
fi