#!/bin/bash

if [[ -z $1 ]]; then
  dns=$(gum choose --height 5 --header "Select DNS provider" Cloudflare DHCP Custom)
else
  dns=$1
fi

case "$dns" in
Cloudflare)
  sudo tee /etc/systemd/resolved.conf >/dev/null <<'EOF'
[Resolve]
DNS=1.1.1.1#cloudflare-dns.com 1.0.0.1#cloudflare-dns.com
FallbackDNS=8.8.8.8#dns.google 8.8.4.4#dns.google
DNSOverTLS=opportunistic
EOF
  sudo systemctl restart systemd-resolved
  ;;

DHCP)
  sudo tee /etc/systemd/resolved.conf >/dev/null <<'EOF'
[Resolve]
DNS=
FallbackDNS=
DNSOverTLS=no
EOF
  sudo systemctl restart systemd-resolved
  ;;

Custom)
  echo "Enter your DNS servers (space-separated, e.g. '192.168.1.1 1.1.1.1'):"
  read -r dns_servers

  if [[ -z "$dns_servers" ]]; then
    echo "Error: No DNS servers provided."
    exit 1
  fi

  sudo tee /etc/systemd/resolved.conf >/dev/null <<EOF
[Resolve]
DNS=$dns_servers
FallbackDNS=1.1.1.1 8.8.8.8
EOF
  sudo systemctl restart systemd-resolved

  ;;
esac