#!/bin/bash

set -e

SSH_KEY="ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGrc2BRE6hkdSyyQMykQin/5HCaLyzRuOvSgei9LJ2yE nikoa@Niko-hp-gamingpc-1"
SSH_DIR="/root/.ssh"
AUTHORIZED_KEYS="$SSH_DIR/authorized_keys"

# Ensure script is run as root
if [ "$(id -u)" -ne 0 ]; then
    echo "[!] This script must be run as root."
    exit 1
fi

echo "[1/7] Updating system..."
apt update && apt upgrade -y

echo "[2/7] Installing required packages..."
apt install -y sudo curl

echo "[3/7] Installing Docker..."
curl -fsSL https://get.docker.com/ | sudo sh

echo "[4/7] Setting up SSH key for root..."
mkdir -p "$SSH_DIR"
chmod 700 "$SSH_DIR"
touch "$AUTHORIZED_KEYS"
grep -qxF "$SSH_KEY" "$AUTHORIZED_KEYS" || echo "$SSH_KEY" >> "$AUTHORIZED_KEYS"
chmod 600 "$AUTHORIZED_KEYS"

echo "[5/7] Disabling password login for SSH..."
sed -i 's/^#\?\s*PasswordAuthentication\s\+.*/PasswordAuthentication no/' /etc/ssh/sshd_config
sed -i 's/^#\?\s*ChallengeResponseAuthentication\s\+.*/ChallengeResponseAuthentication no/' /etc/ssh/sshd_config
sed -i 's/^#\?\s*UsePAM\s\+.*/UsePAM no/' /etc/ssh/sshd_config

echo "[6/7] Setting SSH login banner..."
cat << 'EOF' > /etc/issue.net
AUTHORIZED ACCESS ONLY
Disconnect immediately if you are not an authorized user.

  _   _ _      _    _                   _        _____ _______   _      _      _____ 
 | \ | (_)    | |  | |                 (_)      |_   _|__   __| | |    | |    / ____|
 |  \| |_  ___| | _| |_ _ __ ___  _ __  _  ___    | |    | |    | |    | |   | |     
 | . ` | |/ __| |/ / __| '__/ _ \| '_ \| |/ __|   | |    | |    | |    | |   | |     
 | |\  | | (__|   <| |_| | | (_) | | | | | (__   _| |_   | |    | |____| |___| |____ 
 |_| \_|_|\___|_|\_\\__|_|  \___/|_| |_|_|\___| |_____|  |_|    |______|______\_____|

EOF

sed -i 's|^#\?\s*Banner\s\+.*|Banner /etc/issue.net|' /etc/ssh/sshd_config

echo "[7/7] Restarting SSH service..."
if command -v systemctl &>/dev/null; then
    systemctl restart sshd
else
    service ssh restart
fi

echo "[✔] Setup complete. System updated, Docker installed, SSH secured, and banner set."