#!/usr/bin/env bash
#
# Game-server role of the combined image. The panel runs the same image with
# its default command; this script is reached only when the panel creates a
# server container and overrides the entrypoint.
set -euo pipefail

INSTALL_DIR=/home/steam/pz
DATA_DIR=/home/steam/Zomboid
STEAMCMD=/opt/steamcmd/steamcmd.sh

# Defaults live here rather than as image-level ENV, because this image also
# runs the panel and those variables would be meaningless there. With `set -u`
# an unset variable is a fatal error, so every one the script reads needs a
# default even when the panel normally supplies it.
: "${PZ_SERVER_NAME:=servertest}"
: "${PZ_ADMIN_PASSWORD:=}"
: "${PZ_MEMORY:=4096m}"
: "${PZ_STEAM_BRANCH:=}"
: "${PZ_SKIP_UPDATE:=false}"
: "${PZ_UPDATE_RETRIES:=3}"
# steamcmd bootstraps into $HOME/Steam; the game-server uid owns /home/steam.
: "${HOME:=/home/steam}"
export HOME

log() { echo "[entrypoint] $*"; }

# --- 0. Fail fast on unwritable mounts --------------------------------------
# SteamCMD does not error on an unwritable force_install_dir; it quietly
# installs into ~/Steam instead. Catch that here rather than after a 7 GB
# download that lands nowhere useful.
for dir in "${INSTALL_DIR}" "${DATA_DIR}"; do
  if [ ! -w "${dir}" ]; then
    log "FATAL: ${dir} is not writable by uid $(id -u)."
    log "       Ensure the mounted directory is owned by uid 1000 on the host."
    exit 1
  fi
done

# Without a password the server prompts on stdin for one, and with no TTY that
# is an immediate NoSuchElementException after the whole 7 GB install.
if [ -z "${PZ_ADMIN_PASSWORD}" ]; then
  log "FATAL: PZ_ADMIN_PASSWORD is empty."
  log "       The server requires an admin password and cannot prompt for one"
  log "       in a container. Set PZ_ADMIN_PASSWORD and start again."
  exit 1
fi

# --- 1. Install / update the dedicated server -------------------------------
# App 380870 is the free dedicated server, anonymous login. Build 42 has been
# the default branch since 42.20 went stable, so PZ_STEAM_BRANCH is only needed
# to pin something else (e.g. "legacy41" for Build 41 mod compatibility).
installed() { [ -x "${INSTALL_DIR}/start-server.sh" ]; }

if [ "${PZ_SKIP_UPDATE}" != "true" ]; then
  BRANCH_ARGS=()
  if [ -n "${PZ_STEAM_BRANCH}" ]; then
    BRANCH_ARGS=(-beta "${PZ_STEAM_BRANCH}")
  fi

  # force_install_dir MUST precede login. With the order reversed, SteamCMD
  # ignores it and fails with "Missing configuration".
  #
  # That same error also shows up intermittently on a correct invocation — it
  # is a transient Steam backend condition that succeeds on retry. Without this
  # loop a blip leaves the container to be restarted forever by Docker.
  attempt=1
  updated=false
  while [ "${attempt}" -le "${PZ_UPDATE_RETRIES}" ]; do
    log "Updating dedicated server (app 380870), attempt ${attempt}/${PZ_UPDATE_RETRIES}..."

    if "${STEAMCMD}" \
        +force_install_dir "${INSTALL_DIR}" \
        +login anonymous \
        +app_update 380870 "${BRANCH_ARGS[@]}" validate \
        +quit; then
      updated=true
      break
    fi

    if [ "${attempt}" -lt "${PZ_UPDATE_RETRIES}" ]; then
      log "Attempt ${attempt} failed, retrying in $((attempt * 15))s..."
      sleep "$((attempt * 15))"
    fi
    attempt=$((attempt + 1))
  done

  if [ "${updated}" = true ]; then
    log "Update complete."
  elif installed; then
    # A Steam outage should not take down a server whose files are already
    # complete — boot the existing install rather than failing.
    log "WARNING: update failed, starting the existing install instead."
  else
    log "FATAL: no server install at ${INSTALL_DIR} and the update failed."
    exit 1
  fi
else
  log "PZ_SKIP_UPDATE=true, skipping SteamCMD."
  if ! installed; then
    log "FATAL: PZ_SKIP_UPDATE=true but ${INSTALL_DIR}/start-server.sh is missing."
    exit 1
  fi
fi

# --- 2. Apply the heap size --------------------------------------------------
# start-server.sh reads JVM args from ProjectZomboid64.json. Rewriting -Xmx
# there is the only override that survives across server versions.
PZ_JSON="${INSTALL_DIR}/ProjectZomboid64.json"
if [ -f "${PZ_JSON}" ]; then
  log "Setting max heap to ${PZ_MEMORY}"
  sed -i -E "s/\"-Xmx[0-9]+[mgMG]\"/\"-Xmx${PZ_MEMORY}\"/" "${PZ_JSON}"
fi

# --- 3. Hand off to the server ----------------------------------------------
# The panel writes ${DATA_DIR}/Server/<name>.ini before starting us, so the
# server picks up its config on first boot instead of generating a default.
mkdir -p "${DATA_DIR}/Server"

cd "${INSTALL_DIR}"

ARGS=(
  -cachedir="${DATA_DIR}"
  -servername "${PZ_SERVER_NAME}"
  -adminpassword "${PZ_ADMIN_PASSWORD}"
)

log "Starting server '${PZ_SERVER_NAME}'"
exec ./start-server.sh "${ARGS[@]}" "$@"