#!/usr/bin/bash

print_ylw(){
  echo -e "\033[33m$1\033[0m"
}

function is_x64 {
  print_ylw "[ determine architecture ]"
  arch=$(lscpu | grep -i architecture | cut -d ":" -f2)
  if [ $arch != "x86_64" ]; then
    false
  else
    true
  fi
}

function choose_packages {
  if is_x64 ; then
    print_ylw "[ with docker ]"
    packages="curl git nmap tcpdump net-tools wireguard tmux mc docker docker-compose"
  else
    print "[ without docker ]"
    packages="curl git nmap tcpdump net-tools wireguard tmux"
  fi
}

function disable_ipv6 {
print_ylw "[ ipv6 turn off ]"
cat << EOF >> /etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv4.ip_forward=1
EOF
sysctl -p
}

function sshd_cfg_bup {
print_ylw "[ sshd_config backup ]"
cat /etc/ssh/sshd_config > /etc/ssh/sshd_config_BUP &&
}

function sshd_config {
print_ylw "[ configuring sshd ]"

cat << EOF > /etc/ssh/sshd_config
Include /etc/ssh/sshd_config.d/*.conf
Port 22
ListenAddress 0.0.0.0
PermitRootLogin yes
PubkeyAuthentication yes
PasswordAuthentication no
PermitEmptyPasswords no
KbdInteractiveAuthentication no
UsePAM yes
X11Forwarding yes
PrintMotd no
AcceptEnv LANG LC_*
Subsystem	sftp	/usr/lib/openssh/sftp-server
EOF
}

function add_authorized_keys {
  print_ylw "[ appending ssh-keys ]"
  echo "ssh-rsa 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" >> ~/.ssh/authorized_keys
  echo "ssh-rsa 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 u0_a294@poco"
}

function restart_sshd {
  print_ylw "[ restart sshd ]"
  systemctl restart sshd
}

function install_packages {
  print_ylw "[ packages installation: $packages ]"
  apt install $packages
}


disable_ipv6
sshd_cfg_bup
sshd_config
add_authorized_keys
restart_sshd
choose_packages
install_packages

print_ylw "[ DONE ]"