#!/usr/bin/env bash
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/.." && pwd)"
ENV_FILE="$ROOT/.env"
RUN_DIR="$ROOT/run"
PID_FILE="$RUN_DIR/codex-app-server.pid"
LOG_FILE="$RUN_DIR/codex-app-server.log"
STDIN_FIFO="$RUN_DIR/codex-app-server.stdin"

read_env_value() {
  local key="$1"
  if [[ -f "$ENV_FILE" ]]; then
    awk -F= -v key="$key" '$1 == key { sub(/^[^=]*=/, ""); print; exit }' "$ENV_FILE"
  fi
}

HOST_CODEX_SOCKET="${HOST_CODEX_SOCKET:-$(read_env_value HOST_CODEX_SOCKET)}"
HOST_CODEX_SOCKET="${HOST_CODEX_SOCKET:-$RUN_DIR/codex.sock}"

mkdir -p "$RUN_DIR"
chmod 700 "$RUN_DIR"

if [[ -f "$PID_FILE" ]]; then
  old_pid="$(tr -cd '0-9' < "$PID_FILE" || true)"
  if [[ -n "$old_pid" ]] && kill -0 "$old_pid" 2>/dev/null; then
    if [[ -S "$HOST_CODEX_SOCKET" ]]; then
      echo "codex app-server already running: pid=$old_pid socket=$HOST_CODEX_SOCKET"
      exit 0
    fi
    echo "pid $old_pid is running but socket is missing; refusing to start a second app-server" >&2
    exit 1
  fi
  rm -f "$PID_FILE"
fi

if [[ -e "$HOST_CODEX_SOCKET" ]]; then
  if [[ -S "$HOST_CODEX_SOCKET" ]]; then
    rm -f "$HOST_CODEX_SOCKET"
  else
    echo "socket path exists and is not a Unix socket: $HOST_CODEX_SOCKET" >&2
    exit 1
  fi
fi

rm -f "$STDIN_FIFO"
mkfifo "$STDIN_FIFO"
chmod 600 "$STDIN_FIFO"

: > "$LOG_FILE"
# Codex app-server currently exits if detached with stdin closed. A detached
# wrapper keeps a private FIFO writer open and then runs Codex on the host.
setsid -f bash -c '
  echo "$$" > "$3"
  tail -f /dev/null > "$1" &
  writer=$!
  trap "kill $writer 2>/dev/null || true" EXIT
  codex app-server --listen "$2" < "$1"
' codex-app-server "$STDIN_FIFO" "unix://$HOST_CODEX_SOCKET" "$PID_FILE" >> "$LOG_FILE" 2>&1

for _ in $(seq 1 50); do
  if [[ -f "$PID_FILE" ]]; then
    break
  fi
  sleep 0.1
done

pid="$(tr -cd '0-9' < "$PID_FILE" 2>/dev/null || true)"
if [[ -z "$pid" ]]; then
  echo "codex app-server did not write a pid file; log follows:" >&2
  sed -n '1,120p' "$LOG_FILE" >&2 || true
  exit 1
fi

for _ in $(seq 1 100); do
  if [[ -S "$HOST_CODEX_SOCKET" ]]; then
    sleep 0.5
    if kill -0 "$pid" 2>/dev/null; then
      echo "codex app-server started: pid=$pid socket=$HOST_CODEX_SOCKET log=$LOG_FILE"
      exit 0
    fi
  fi
  if ! kill -0 "$pid" 2>/dev/null; then
    echo "codex app-server exited before staying ready; log follows:" >&2
    sed -n '1,120p' "$LOG_FILE" >&2 || true
    rm -f "$PID_FILE"
    exit 1
  fi
  sleep 0.1
done

echo "codex app-server did not create socket within 10 seconds; log follows:" >&2
sed -n '1,120p' "$LOG_FILE" >&2 || true
exit 1