#!/bin/sh
# Bounded wait for a TCP listener. Exits 0 as soon as it connects, 1 on timeout.
#
# Used as the FIFA17 host's ExecStartPre so the host cannot start "successfully"
# while Core is absent. A TCP connect is a MEANINGFUL readiness signal here, not
# a guess: openfut-core binds its listener only after it has opened the
# database, run migrations and loaded the content pack — the startup log order
# is `Running database migrations` -> `Loaded N cards` -> `Listening`, and the
# 2026-08-22 promotion demonstrated it directly when a bind collision aborted a
# Core that had already applied migration 0028. So "port open" implies
# "migrations done, content loaded".
#
# Deliberately no retry-forever: a host that blocks indefinitely looks healthy
# to a supervisor while serving nothing. It fails, and the restart policy
# decides what happens next.
#
# usage: openfut-wait-tcp.sh <host> <port> <timeout-seconds>
set -eu

HOST="${1:?host}"
PORT="${2:?port}"
TIMEOUT="${3:-30}"

i=0
while [ "$i" -lt "$TIMEOUT" ]; do
    # /dev/tcp is a bash-ism; use a portable connect instead.
    if command -v nc >/dev/null 2>&1; then
        nc -z "$HOST" "$PORT" 2>/dev/null && exit 0
    else
        python3 - "$HOST" "$PORT" <<'PY' && exit 0
import socket, sys
s = socket.socket()
s.settimeout(1)
sys.exit(0 if s.connect_ex((sys.argv[1], int(sys.argv[2]))) == 0 else 1)
PY
    fi
    i=$((i + 1))
    sleep 1
done

echo "openfut-wait-tcp: $HOST:$PORT did not accept connections within ${TIMEOUT}s" >&2
exit 1