#!/usr/bin/env bash
# PiVPN: Uninstall Script

### FIXME: global: config storage, refactor all scripts to adhere to the storage
### FIXME: use variables where appropriate, reduce magic numbers by 99.9%, at least.

# Find the rows and columns. Will default to 80x24 if it can not be detected.
screen_size=$(stty size 2>/dev/null || echo 24 80)
rows=$(echo "$screen_size" | awk '{print $1}')
columns=$(echo "$screen_size" | awk '{print $2}')

# Divide by two so the dialogs take up half of the screen, which looks nice.
r=$(( rows / 2 ))
c=$(( columns / 2 ))
# Unless the screen is tiny
r=$(( r < 20 ? 20 : r ))
c=$(( c < 70 ? 70 : c ))

                       chooseVPNCmd=(whiptail --backtitle "Setup PiVPN" --title "Installation mode" --separate-output --radiolist "WireGuard is a new kind of VPN that provides near-instantaneous connection speed, high performance, and modern cryptography.\\n\\nIt's the recommended choice especially if you use mobile devices where WireGuard is easier on battery than OpenVPN.\\n\\nOpenVPN is still available if you need the traditional, flexible, trusted VPN protocol or if you need features like TCP and custom search domain.\\n\\nChoose a VPN to uninstall (press space to select):" "${r}" "${c}" 2)
                        VPNChooseOptions=(WireGuard "" on
                                                                OpenVPN "" off)

                        if VPN=$("${chooseVPNCmd[@]}" "${VPNChooseOptions[@]}" 2>&1 >/dev/tty) ; then
                                echo "::: Using VPN: $VPN"
                                VPN="${VPN,,}"
                        else
                                echo "::: Cancel selected, exiting...."
                                exit 1
                        fi

PKG_MANAGER="apt-get"
UPDATE_PKG_CACHE="${PKG_MANAGER} update"
dnsmasqConfig="/etc/dnsmasq.d/02-pivpn.conf"
setupVars="/etc/pivpn/${VPN}/setupVars.conf"

if [ ! -f "${setupVars}" ]; then
	echo "::: Missing setup vars file!"
	exit 1
fi

# shellcheck disable=SC1090
source "${setupVars}"

### FIXME: introduce global lib
spinner(){
	local pid=$1
	local delay=0.50
	local spinstr='/-\|'
	while ps a | awk '{print $1}' | grep -q "$pid"; do
		local temp=${spinstr#?}
		printf " [%c]  " "$spinstr"
		local spinstr=$temp${spinstr%"$temp"}
		sleep $delay
		printf "\\b\\b\\b\\b\\b\\b"
	done
	printf "    \\b\\b\\b\\b"
}

removeAll(){
	# Stopping and disabling services
	echo "::: Stopping and disabling services..."

	if [ "$VPN" = "wireguard" ]; then
		systemctl stop wg-quick@wg0
		systemctl disable wg-quick@wg0 &> /dev/null
	elif [ "$VPN" = "openvpn" ]; then
		systemctl stop openvpn
		systemctl disable openvpn &> /dev/null
	fi

	# Removing firewall rules.
	echo "::: Removing firewall rules..."

	if [ "$USING_UFW" -eq 1 ]; then

    ### FIXME: SC2154
		ufw delete allow "${pivpnPORT}"/"${pivpnPROTO}" > /dev/null
    ### FIXME: SC2154
		ufw route delete allow in on "${pivpnDEV}" from "${pivpnNET}/${subnetClass}" out on "${IPv4dev}" to any > /dev/null
		sed -z "s/*nat\\n:POSTROUTING ACCEPT \\[0:0\\]\\n-I POSTROUTING -s ${pivpnNET}\\/${subnetClass} -o ${IPv4dev} -j MASQUERADE -m comment --comment ${VPN}-nat-rule\\nCOMMIT\\n\\n//" -i /etc/ufw/before.rules
		iptables -t nat -D POSTROUTING -s "${pivpnNET}/${subnetClass}" -o "${IPv4dev}" -j MASQUERADE -m comment --comment "${VPN}-nat-rule"
		ufw reload &> /dev/null

	elif [ "$USING_UFW" -eq 0 ]; then

		if [ "$INPUT_CHAIN_EDITED" -eq 1 ]; then
			iptables -D INPUT -i "${IPv4dev}" -p "${pivpnPROTO}" --dport "${pivpnPORT}" -j ACCEPT -m comment --comment "${VPN}-input-rule"
		fi

		if [ "$FORWARD_CHAIN_EDITED" -eq 1 ]; then
			iptables -D FORWARD -d "${pivpnNET}/${subnetClass}" -i "${IPv4dev}" -o "${pivpnDEV}" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -m comment --comment "${VPN}-forward-rule"
			iptables -D FORWARD -s "${pivpnNET}/${subnetClass}" -i "${pivpnDEV}" -o "${IPv4dev}" -j ACCEPT -m comment --comment "${VPN}-forward-rule"
		fi

		iptables -t nat -D POSTROUTING -s "${pivpnNET}/${subnetClass}" -o "${IPv4dev}" -j MASQUERADE -m comment --comment "${VPN}-nat-rule"
		iptables-save > /etc/iptables/rules.v4

	fi

	# Disable IPv4 forwarding
	sed -i '/net.ipv4.ip_forward=1/c\#net.ipv4.ip_forward=1' /etc/sysctl.conf
	sysctl -p

	# Purge dependencies
	echo "::: Purge dependencies..."

	for i in "${INSTALLED_PACKAGES[@]}"; do
		while true; do
			read -rp "::: Do you wish to remove $i from your system? [Y/n]: " yn
			case $yn in
				[Yy]* ) if [ "${i}" = "wireguard" ]; then

							# On Debian and Raspbian, remove the bullseye repo. On Ubuntu, remove the PPA.
							if [ "$PLAT" = "Debian" ] || [ "$PLAT" = "Raspbian" ]; then
								rm -f /etc/apt/sources.list.d/pivpn-bullseye.list
								rm -f /etc/apt/preferences.d/pivpn-limit-bullseye
							elif [ "$PLAT" = "Ubuntu" ]; then
								add-apt-repository ppa:wireguard/wireguard -r -y
							fi
							echo "::: Updating package cache..."
							${UPDATE_PKG_CACHE} &> /dev/null & spinner $!

						elif [ "${i}" = "unattended-upgrades" ]; then

							rm -rf /var/log/unattended-upgrades
							rm -rf /etc/apt/apt.conf.d/*periodic
							rm -rf /etc/apt/apt.conf.d/*unattended-upgrades

						elif [ "${i}" = "openvpn" ]; then

							if [ "$PLAT" = "Debian" ] || [ "$PLAT" = "Ubuntu" ]; then
								rm -f /etc/apt/sources.list.d/pivpn-openvpn-repo.list
								echo "::: Updating package cache..."
								${UPDATE_PKG_CACHE} &> /dev/null & spinner $!
							fi
							deluser openvpn
							rm -f /etc/rsyslog.d/30-openvpn.conf
							rm -f /etc/logrotate.d/openvpn

						fi
						printf ":::\\tRemoving %s..." "$i"; $PKG_MANAGER -y remove --purge "$i" &> /dev/null & spinner $!; printf "done!\\n";
						break
						;;
				[Nn]* ) printf ":::\\tSkipping %s\\n" "$i";
						break
						;;
				* ) printf "::: You must answer yes or no!\\n";;
			esac
		done
	done

	# Take care of any additional package cleaning
	printf "::: Auto removing remaining dependencies..."
	$PKG_MANAGER -y autoremove &> /dev/null & spinner $!; printf "done!\\n";
	printf "::: Auto cleaning remaining dependencies..."
	$PKG_MANAGER -y autoclean &> /dev/null & spinner $!; printf "done!\\n";

	echo ":::"
	# Removing pivpn files
	echo "::: Removing pivpn system files..."

	if [ -f "$dnsmasqConfig" ]; then
		rm -f "$dnsmasqConfig"
		pihole restartdns
	fi

	rm -rf /opt/pivpn/${VPN}
        # if dual installation, other installation will cause next line to fail
        rmdir /opt/pivpn
	rm -rf /etc/.pivpn/${VPN}
        rmdir /etc/.pivpn
	rm -rf /etc/pivpn/${VPN}
        rmdir  /etc/pivpn
	rm -f /var/log/*pivpn*
	rm -f /usr/local/bin/pivpn/${VPN}
        # TODO fix bash_completion removal
	rm -f /etc/bash_completion.d/pivpn

	echo ":::"
	echo "::: Removing VPN configuration files..."

	if [ "$VPN" = "wireguard" ]; then
		rm -f /etc/wireguard/wg0.conf
		rm -rf /etc/wireguard/configs
		rm -rf /etc/wireguard/keys
    ### FIXME SC2154
		rm -rf "$install_home/configs"
	elif [ "$VPN" = "openvpn" ]; then
		rm -rf /var/log/*openvpn*
		rm -f /etc/openvpn/server.conf
		rm -f /etc/openvpn/crl.pem
		rm -rf /etc/openvpn/easy-rsa
		rm -rf /etc/openvpn/ccd
		rm -rf "$install_home/ovpns"
	fi

	echo ":::"
	printf "::: Finished removing PiVPN from your system.\\n"
	printf "::: Reinstall by simpling running\\n:::\\n:::\\tcurl -L https://install.pivpn.io | bash\\n:::\\n::: at any time!\\n:::\\n"
}

askreboot(){
	printf "It is \\e[1mstrongly\\e[0m recommended to reboot after un-installation.\\n"
	read -p "Would you like to reboot now? [y/n]: " -n 1 -r
	echo
	if [[ ${REPLY} =~ ^[Yy]$ ]]; then
		printf "\\nRebooting system...\\n"
		sleep 3
		shutdown -r now
	fi
}

######### SCRIPT ###########
echo "::: Preparing to remove packages, be sure that each may be safely removed depending on your operating system."
echo "::: (SAFE TO REMOVE ALL ON RASPBIAN)"
while true; do
	read -rp "::: Do you wish to completely remove PiVPN configuration and installed packages from your system? (You will be prompted for each package) [y/n]: " yn
	case $yn in
		[Yy]* ) removeAll; askreboot; break;;

		[Nn]* ) printf "::: Not removing anything, exiting...\\n"; break;;
	esac
done