#!/usr/bin/with-contenv bash

mkdir -p /config

# install headers and wireguard
apt-get update
if apt-cache show linux-headers-$(uname -r) 2&>1 >/dev/null; then
  apt-get install -y \
    linux-headers-$(uname -r) \
    wireguard
elif uname -v | grep -q 'Ubuntu'; then
  curl -s http://archive.ubuntu.com/ubuntu/dists/xenial/Release.gpg | apt-key add -
  echo -e \
    "deb http://archive.ubuntu.com/ubuntu/ xenial main restricted\ndeb-src http://archive.ubuntu.com/ubuntu/ xenial main restricted\n\ndeb http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted\ndeb-src http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted" \
    > /etc/apt/sources.list.d/xenial.list
  apt-get update
  if apt-cache show linux-headers-$(uname -r) 2&>1 >/dev/null; then
    apt-get install -y \
      linux-headers-$(uname -r) \
      wireguard
  else
    echo "No kernel headers found!! Will try the headers from the wireguard ppa, may or may not work"
    apt-get install -y \
      wireguard
  fi
elif uname -v | grep -q 'Debian'; then
  curl -s https://ftp-master.debian.org/keys/archive-key-10.asc | apt-key add -
  echo -e \
    "deb http://deb.debian.org/debian buster main contrib non-free\ndeb-src http://deb.debian.org/debian buster main contrib non-free" \
    > /etc/apt/sources.list.d/debian.list
  apt-get update
  if apt-cache show linux-headers-$(uname -r) 2&>1 >/dev/null; then
    apt-get install -y \
      linux-headers-$(uname -r) \
      wireguard
  else
    curl -s https://ftp-master.debian.org/keys/archive-key-9.asc | apt-key add -
    sed -i 's/buster/stretch/g' /etc/apt/sources.list.d/debian.list
    apt-get update
    if apt-cache show linux-headers-$(uname -r) 2&>1 >/dev/null; then
      apt-get install -y \
        linux-headers-$(uname -r) \
        wireguard
    else
      echo "No kernel headers found!! Will try the headers from the wireguard ppa, may or may not work"
      apt-get install -y \
        wireguard
    fi
  fi
else
  echo "No kernel headers found!! Will try the headers from the wireguard ppa, may or may not work"
  apt-get install -y \
    wireguard
fi

rm -rf /etc/wireguard
mkdir -p /etc/wireguard
ln -s /config/wg0.conf /etc/wireguard/wg0.conf

if [ ! -f /config/wg0.conf ] && [ -n "$PEERS" ] && [ -n "$SERVERURL" ]; then
  SERVERPORT=${SERVERPORT:-51820}
  PEERDNS=${PEERDNS:-8.8.8.8}
  mkdir -p /config/server
  if [ ! -f /config/server/privatekey-server ]; then
    umask 077
    wg genkey | tee /config/server/privatekey-server | wg pubkey > /config/server/publickey-server
  fi
  cat <<DUDE > /config/wg0.conf
[Interface]
Address = 10.13.13.1
ListenPort = 51820
PrivateKey = $(cat /config/server/privatekey-server)
PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE

DUDE
  if ! [[ $PEERS =~ ^[0-9]+$ ]]; then
    echo "PEERS is not set to an integer, setting it to 1"
    PEERS="1"
  fi
  for i in $(seq 1 $PEERS); do
    mkdir -p /config/peer${i}
    if [ ! -f /config/peer${i}/privatekey-peer${i} ]; then
      umask 077
      wg genkey | tee /config/peer${i}/privatekey-peer${i} | wg pubkey > /config/peer${i}/publickey-peer${i}
    fi
    cat <<DUDE > /config/peer${i}/peer${i}.conf
[Interface]
Address = 10.13.13.$(( $i + 1 ))
PrivateKey = $(cat /config/peer${i}/privatekey-peer${i})
ListenPort = 51820
DNS = ${PEERDNS}

[Peer]
PublicKey = $(cat /config/server/publickey-server)
Endpoint = ${SERVERURL}:${SERVERPORT}
AllowedIPs = 0.0.0.0/0, ::/0
DUDE
    cat <<DUDE >> /config/wg0.conf
[Peer]
PublicKey = $(cat /config/peer${i}/publickey-peer${i})
AllowedIPs = 10.13.13.$(( $i + 1 ))/32

DUDE
    echo "PEER ${i} QR code:"
    qrencode -t ansiutf8 < /config/peer${i}/peer${i}.conf
    qrencode -o /config/peer${i}/peer${i}.png < /config/peer${i}/peer${i}.conf
  done
fi

# permissions
chown -R abc:abc \
	/config