#!/usr/bin/env bash
# Build, install and register the ghost_relay server as a systemd service.
#
# Run on the VPS from the repo root (or after copying tools/ and
# src/native/skate3_native_ghost_* to the server). The relay is
# dependency-free: it needs only a C++23 compiler (g++/clang), no CMake or
# rexglue.
#
# Usage:
#   ./tools/ghost_relay_deploy.sh
#   GHOST_RELAY_PORT=40002 ./tools/ghost_relay_deploy.sh
#   GHOST_RELAY_VERBOSE=1 ./tools/ghost_relay_deploy.sh
#
# Afterwards: systemctl status ghost-relay, journalctl -u ghost-relay -f.
# Open the UDP port (the script tries `ufw allow <port>/udp`).

set -euo pipefail

PORT="${GHOST_RELAY_PORT:-40001}"
VERBOSE_FLAG=""
if [[ "${GHOST_RELAY_VERBOSE:-0}" == "1" ]]; then
  VERBOSE_FLAG="--verbose"
fi
SERVICE_NAME="ghost-relay"
BIN_PATH="/usr/local/bin/ghost_relay"
SERVICE_PATH="/etc/systemd/system/${SERVICE_NAME}.service"

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"

echo "==> Building ghost_relay"
g++ -std=c++23 -O2 -DSKATE3_RELAY_STANDALONE \
    -I"${REPO_ROOT}/src/native" \
    "${REPO_ROOT}/tools/ghost_relay_main.cpp" \
    "${REPO_ROOT}/src/native/skate3_native_ghost_relay.cpp" \
    -o /tmp/ghost_relay
/tmp/ghost_relay --help >/dev/null 2>&1 || {
  echo "ERROR: build produced a binary that does not run (missing C++23?)" >&2
  exit 1
}

echo "==> Installing to ${BIN_PATH}"
sudo install -m 0755 /tmp/ghost_relay "${BIN_PATH}"
rm -f /tmp/ghost_relay

echo "==> Writing ${SERVICE_PATH}"
sudo tee "${SERVICE_PATH}" >/dev/null <<EOF
[Unit]
Description=Skate 3 recomp ghost multiplayer relay
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
ExecStart=${BIN_PATH} --port ${PORT} --max-clients 64 ${VERBOSE_FLAG}
Restart=on-failure
RestartSec=2
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=full

[Install]
WantedBy=multi-user.target
EOF

echo "==> Enabling + starting ${SERVICE_NAME}"
sudo systemctl daemon-reload
sudo systemctl enable "${SERVICE_NAME}" >/dev/null
sudo systemctl restart "${SERVICE_NAME}"

echo "==> Opening UDP ${PORT}"
sudo ufw allow "${PORT}/udp" >/dev/null 2>&1 || \
  echo "    (ufw not available or not permitted; open UDP ${PORT} yourself)"

echo "==> Status"
sleep 1
sudo systemctl status "${SERVICE_NAME}" --no-pager || true

IP="$(hostname -I 2>/dev/null | awk '{print $1}')"
if [[ -z "${IP}" ]]; then IP="<this-server-ip>"; fi
echo
echo "Done. Clients connect to ${IP}:${PORT}"
echo "Logs: journalctl -u ${SERVICE_NAME} -f"
echo "Set the compiled-in default in src/native/skate3_native_ghost_proto.h"
echo "  (kGhostDefaultServer / kGhostDefaultServerPort), or tell players to"
echo "  set skate3_ghost_server=${IP}:${PORT} in the M menu."