#!/bin/sh
# ---------------------------------------------------------------------------
#  run-server.sh <name> <dir> <logfile>
#
#  Keeps FXServer alive and gives it a console you can talk to.
#
#   * FXServer reads its console from stdin and quits the moment stdin hits
#     EOF, so it gets a FIFO whose write end this script holds open. That FIFO
#     doubles as the command channel used by bin/rcon.
#   * A server that dies instantly is usually failing for a reason that will
#     not fix itself (bad licence key, database down). The restart delay backs
#     off to 5 minutes so a broken server does not hammer Cfx, and resets once
#     it has stayed up for a while.
# ---------------------------------------------------------------------------
NAME="$1"; DIR="$2"; LOG="$3"
FIFO="/run/$NAME.stdin"
MIN=5; MAX=300; HEALTHY=120

mkdir -p "$(dirname "$LOG")"
echo $$ > "/run/$NAME.sup.pid"
[ -p "$FIFO" ] || { rm -f "$FIFO"; mkfifo "$FIFO"; }
exec 9<> "$FIFO"

cleanup() { kill "$CHILD" 2>/dev/null; rm -f "/run/$NAME.sup.pid" "/run/$NAME.child.pid"; exit 0; }
trap cleanup TERM INT

delay=$MIN
while true; do
  if [ -f "$LOG" ] && [ "$(stat -c %s "$LOG")" -gt 209715200 ]; then mv "$LOG" "$LOG.1"; fi
  echo "=== $(date -Is) starting $NAME ===" >> "$LOG"
  started=$(date +%s)

  ( cd "$DIR/server-data" && exec "$DIR/server/run.sh" +exec server.cfg ) >> "$LOG" 2>&1 <&9 &
  CHILD=$!
  echo $CHILD > "/run/$NAME.child.pid"
  wait $CHILD
  RC=$?

  ran=$(( $(date +%s) - started ))
  if [ "$ran" -ge "$HEALTHY" ]; then delay=$MIN; else delay=$(( delay * 2 )); [ "$delay" -gt "$MAX" ] && delay=$MAX; fi
  echo "=== $(date -Is) $NAME exited (rc=$RC) after ${ran}s, restarting in ${delay}s ===" >> "$LOG"
  sleep "$delay"
done