/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 * Copyright (c) 2013, MPL CodeInside http://codeinside.ru
 */

package ru.codeinside.adm;

import ru.codeinside.gws.api.ServerException;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.DependsOn;
import javax.ejb.Lock;
import javax.ejb.LockType;
import javax.ejb.Singleton;
import javax.ejb.Startup;
import javax.inject.Inject;

@Singleton
@Startup
@DependsOn("BaseBean")
@Lock(LockType.READ)
public class AdminServiceProvider {

  @Inject
  AdminService adminService;

  transient static AdminService instance;

  Object ticket;

  @PostConstruct
  public void initialize() {
    synchronized (AdminServiceImpl.class) {
      if (instance == null) {
        instance = adminService;
      }
    }
    ticket = adminService.afterCreate();
    adminService.init();
  }

  @PreDestroy
  public void shutdown() {
    adminService.preDestroy(ticket);
    synchronized (AdminServiceImpl.class) {
      if (instance == adminService) {
        instance = null;
      }
    }
  }

  public static AdminService tryGet() {
    return instance;
  }

  public static AdminService get() {
    AdminService result = instance;
    if (result == null) {
      throw new IllegalStateException("Сервис не зарегистрирован!");
    }
    return result;
  }

  public static AdminService forApi() {
    AdminService result = instance;
    if (result == null) {
      throw new ServerException("Сервис исполнения не доступен");
    }
    return result;
  }

  public static boolean getBoolProperty(String key) {
    return Boolean.parseBoolean(get().getSystemProperty(key));
  }
}