#!/bin/bash

printf "Better to run as root, because of permisions handeling."

sleep 2

printf "Do you want to set up firewall rules by iptables? [Y/n]: "
read ansFirewallSetup


if [[ "$ansFirewallSetup" =~ ("N"|"n") ]]; then

	printf "+ Thanks, working on next bit\n"

else
	
	printf "Do you want to block non-LAN ssh connections? [Y/n/ip range]: "
	read sshBlockRange


	if [[ $sshBlockRange =~ ("n"|"N") ]]; then
	
		#$sshBlockRange = ""
		printf 'N\n'

	elif [[ $sshBlockRange =~ ("y"|"Y") || -z $sshBlockRange ]]; then
	
		### Have to found how to locate LAN
		#$sshBlockRange = "y"
		printf 'Y\n'

	else
			printf "\nHope you know what you are doing, I am not checking these :]"
			printf "\nyou typed $sshBlockRange"
			sleep 2
			printf "\nDont worry you will have time to chack if it is looking righ later.\n"

	fi
fi


# Just to be shure
printf "\n+ Starting to upgrade base system\n\n"

sudo apt update
sudo apt upgrade -y

# Installing depandencies
printf "\n+ Installing depandencies \n\n" 
sudo apt install openjdk-17-jre-headless screen p7zip-full iptables -y

# User and groupe managment
printf "\n+ Creating user minecraft and basic file structure"
groupadd minecraft

useradd --system --shell /usr/sbin/nologin --home /opt/minecraft -g minecraft minecraft

# File strukture and basic install
mkdir /opt/minecraft 

mv Forge-1.20.1.jar /opt/minecraft/

cd /opt/minecraft/

# Installing server
printf "+ Installing Forge 1.20.1 \n \n"

java -Xms512M -Xmx2048M -jar Forge-1.20.1.jar --installServer

cd -

mv eula.txt /opt/minecraft/
mv server-icon.png /opt/minecraft/
mv server.properties /opt/minecraft/

mv run.sh /opt/minecraft

mkdir /opt/minecraft/mods

printf "\n+ Unpacking mods \n \n"

7z x Mods.zip -o/opt/minecraft/mods/

# Permision handeling 
printf "\n+ Permision handeling"
chown -R minecraft:minecraft /opt/minecraft

# SystemD service
printf "+ Preparign systemD service"
cp mc-forge.service /etc/systemd/system/

systemctl daemon-reload

systemctl start mc-forge.service

systemctl enable mc-forge


# integration of Maxopoly's instructions on firewall

if [[ "n" !=  "$ansFirewallSetup" ]]; then

	printf "+ Executing firewall setup"

	iptables -P INPUT ACCEPT #Clears existing rules

	iptables -A INPUT -i lo -j ACCEPT #Allow loopback

	iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT #Allow continuing connections

	iptables -A INPUT -p tcp --dport 22 --source 172.18.42.0/24 -j ACCEPT #Allow ssh from set network

	iptables -A INPUT -p tcp --dport 25565 -j ACCEPT #Allow MC port


	iptables -L ### Good place to paste a manual check to not lock yourself out 

	printf "\n Does it looks right? [Y/n]: "
	read ansFirewallOK


	if [[ "n" !=  "$ansFirewallOK" ]]; then

		iptables -P INPUT DROP #Disallow everythink else

		iptables -P FORWARD DROP #Block all forwarding

		iptables -P OUTPUT ACCEPT #Allow all outgouing
	fi

	apt install iptables-persistent -y

fi