#!/bin/bash

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

sleep 2

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

if [[ "n" !=  "$ansFirewallSetup" ]]; then
	echo "\n Do you want to block non-LAN ssh connections? [Y/n/ip range]: "
	read -n 1 sshBlockRange


	if [[ "$sshBlockRange" == "y"
		||"$sshBlockRange" == "Y"
		||"$sshBlockRange" == "" ]]; then
	
		### Have to found how to locate LAN
		$sshBlockRange = "y"

	elif [[ "$sshBlockRange" == "n"
		||  "$sshBlockRange" == "N"]]; then
		
		$sshBlockRange = ""

	elif [[ -n "$sshBlockRange" ]]; then

		echo "Hope you know what you are doing, I am not checking these :]"

		echo "You have 5 seconds to stope this by pressing Ctrl+C" 

		sleep 5

		echo "OK, lets go now"

		echo "Dont worry you will have time to chack if it is looking righ later."

		sleep 2
	fi
fi


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

sudo apt update
sudo apt upgrade -y

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

# User and groupe managment
echo "\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
echo "+ 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

echo "\n+ Unpacking mods \n \n"

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

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

# SystemD service
echo "+ 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

	echo "+ 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 

	echo "\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