#!/usr/bin/env bash

set -o xtrace

resolved_conf_d=(
  'openvpn.conf'
  'csit-test.conf'
  'csit-prod.conf'
  'nchc.conf'
)

function stopvpn() {
  mapfile -t vpn_pid <<< "$(pgrep openfortivpn) $(pgrep openvpn) $(pgrep openconnect)" 

  for pid in "${vpn_pid[@]}"; do
    if [[ -n "$pid" ]]; then
      echo "Kill process $pid."
      sudo kill "$pid"
    fi
  done

  for conf in "${resolved_conf_d[@]}"; do
    if [[ -e "/etc/systemd/resolved.conf.d/$conf" ]]; then
      sudo rm "/etc/systemd/resolved.conf.d/$conf"
    fi
  done
  
  sudo systemctl reload systemd-resolved
}

function resolved() {
  # Workaround, since openvpn didn't accept dns option for no reason
  sudo mkdir -p /etc/systemd/resolved.conf.d/

  if [[ "$1" == 'openvpn' ]]; then
    cat > /tmp/vpn-resolved << 'EOF'
[Resolve]
DNS=172.20.10.253
Domains=konchin.com
EOF
  elif [[ "$1" == 'csit-test' ]]; then
    cat > /tmp/vpn-resolved << 'EOF'
[Resolve]
DNS=10.2.1.1 10.2.1.2
Domains=test.cc.cs.nctu.edu.tw
EOF
  elif [[ "$1" == 'csit-prod' ]]; then
    cat > /tmp/vpn-resolved << 'EOF'
[Resolve]
DNS=10.1.1.1 10.1.1.2
Domains=cc.cs.nctu.edu.tw
EOF
  elif [[ "$1" == "nchc" ]]; then
    cat > /tmp/vpn-resolved << 'EOF'
[Resolve]
DNS=1.1.1.1
EOF
  fi

  sudo mv /tmp/vpn-resolved "/etc/systemd/resolved.conf.d/$1.conf"
  sudo systemctl reload systemd-resolved
}

function fortivpn() {
  echo "Start openfortivpn with realm $1."
  sudo sh <<EOF
    openfortivpn \
      --config "$HOME/.secret/openfortivpn/$1.conf" \
      >/dev/null </dev/null 2>/dev/null & disown
EOF
}

function ovpn() {
  echo "Start openvpn."
  sudo sh <<EOF
    openvpn \
      --config "$HOME/.secret/openvpn/$1.ovpn" \
      >/dev/null </dev/null 2>/dev/null & disown
EOF
}

function opencon() {
  echo "Start openconnect vpn"
  sudo sh <<EOF
    cat "$HOME/.secret/openconnect/$1.pass" | \
      openconnect --config "$HOME/.secret/openconnect/$1.conf" \
        >/dev/null 2>/dev/null & disown
EOF
}

function main() {
  sudo echo -n
  case "$1" in
    s|stop)
      stopvpn
      return
      ;;
    p|prod)
      stopvpn
      fortivpn prod
      resolved csit-prod
      ;;
    t|test)
      stopvpn
      fortivpn test
      resolved csit-test
      ;;
    h|home)
      stopvpn
      ovpn desktop
      resolved openvpn
      ;;
    n|nchc)
      stopvpn
      fortivpn nchc && sleep 0.5
      opencon nchc
      resolved nchc
  esac
}

main "$@"