#!/bin/bash

use_dnbd3() {
	mountpoint -q /mnt/store && [ -x "/opt/dnbd3/dnbd3-server" ]
}

is_dnbd3() {
	systemctl -q is-active dnbd3-server.service || return 1
	systemctl -q is-active dnbd3-ssl-in.service || return 1
	systemctl -q is-active dnbd3-ssl-out.service || return 1
	return 0
}

enable_dnbd3() {
	echo "Enabling dnbd3 proxy"
	systemctl disable --now bwlp-master-socat@5006.service
	systemctl enable --now dnbd3-server.service
	systemctl enable --now dnbd3-ssl-in.service
	systemctl enable --now dnbd3-ssl-out.service
}

disable_dnbd3() {
	echo "Disabling dnbd3 proxy"
	systemctl disable --now dnbd3-server.service
	systemctl disable --now dnbd3-ssl-in.service
	systemctl disable --now dnbd3-ssl-out.service
}

is_passthrough() {
	systemctl -q is-active apache2.service || return 1
	systemctl -q is-active bwlp-master-socat@9090.service || return 1
	systemctl -q is-active bwlp-master-socat@9091.service || return 1
	local lnk=$( readlink -f /etc/apache2/sites-enabled/110-bwlp.conf )
	[ "$lnk" = "/etc/apache2/sites-available/110-bwlp-passthrough.conf" ] || return 1
	return 0
}

is_active() {
	systemctl -q is-active apache2.service || return 1
	systemctl -q is-active bwlp-master.service || return 1
	local lnk=$( readlink -f /etc/apache2/sites-enabled/110-bwlp.conf )
	[ "$lnk" = "/etc/apache2/sites-available/110-bwlp-active.conf" ] || return 1
	return 0
}

passthrough() {
	is_passthrough && return 0
	echo "Enabling passthrough"
	systemctl disable --now bwlp-master.service
	ln -nfs ../sites-available/110-bwlp-passthrough.conf /etc/apache2/sites-enabled/110-bwlp.conf
	systemctl restart apache2.service
	systemctl enable --now bwlp-master-socat@9090.service
	systemctl enable --now bwlp-master-socat@9091.service
	systemctl enable --now bwlp-master-socat@9050.service
	systemctl enable --now bwlp-master-socat@9051.service
	if ! use_dnbd3; then
		systemctl enable --now bwlp-master-socat@5006.service
	fi
}

activate() {
	is_active && return 0
	echo "Enabling active mode"
	systemctl disable --now bwlp-master-socat@9090.service
	systemctl disable --now bwlp-master-socat@9091.service
	systemctl disable --now bwlp-master-socat@9050.service
	systemctl disable --now bwlp-master-socat@9051.service
	systemctl disable --now bwlp-master-socat@5006.service
	ln -nfs ../sites-available/110-bwlp-active.conf /etc/apache2/sites-enabled/110-bwlp.conf
	systemctl restart apache2.service
	systemctl enable --now bwlp-master.service
}

# Check connectivity

if curl -L -m 10 -o /dev/null -sS \
		--retry-max-time 40 --retry 4 --retry-all-errors \
		https://%DOMAIN%/webif/; then
	# OK
	passthrough
else
	# Take over
	activate
fi

if use_dnbd3; then
	is_dnbd3 || enable_dnbd3
else
	is_dnbd3 && disable_dnbd3
fi

exit 0