package com.newyetai.common.util;

import java.io.Serializable;
import java.util.Optional;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

/**
 * spring上下文工具类
 * 
 * @author sr on 2020-05-20
 */
@Component
public class SpringContextHolder implements ApplicationContextAware {

  private static ApplicationContext applicationContext;

  @Override
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    SpringContextHolder.applicationContext = applicationContext;
  }

  public static ApplicationContext getApplicationContext() {
    return applicationContext;
  }

  /**
   * 获取bean
   * 
   * @param <T>
   * @param beanId
   * @return
   * @author sr on 2020-05-20
   */
  @SuppressWarnings("unchecked")
  public static <T> T getBean(String beanId) {
    return (T) applicationContext.getBean(beanId);
  }

  public static <T> T getBean(Class<T> clazz) {
    return applicationContext.getBean(clazz);
  }

  public static Optional<ServletRequestAttributes> getRequestAttributes() {
    return Optional
        .ofNullable((ServletRequestAttributes) RequestContextHolder.getRequestAttributes());
  }

  /**
   * 获取当前线程的request
   */
  public static HttpServletRequest getRequest() {
    return getRequestAttributes().map(ServletRequestAttributes :: getRequest).orElse(null);
  }
  
  /**
   * 获取当前线程的response
   */
  public static HttpServletResponse getResponse() {
    return getRequestAttributes().map(ServletRequestAttributes :: getResponse).orElse(null);
  }

  /**
   * 获取HttpSession
   */
  public static HttpSession getHttpSession() {
    return getRequest().getSession();
  }

  /**
   * 把值放入session
   */
  public static void setSessionAttribute(String key, Serializable entity) {
    getHttpSession().setAttribute(key, entity);
  }

  public static Object getSessionAttribute(String key) {
    return getHttpSession().getAttribute(key);
  }

  /**
   * 把值放入当前request
   */
  public static void setRequestAttribute(String key, Object entity) {
    getRequest().setAttribute(key, entity);
  }

  public static Object getRequestAttribute(String key) {
    return getRequest().getAttribute(key);
  }

}