import cn.erika.demo.common.model.vo.Message;
import com.alibaba.fastjson.JSON;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.subject.Subject;
import org.apache.shiro.web.servlet.AdviceFilter;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Ajax請求處理 用于前后臺分離的場景
 */
public class AjaxFilter extends AdviceFilter {
  @Override
  protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
    // 先判斷是不是ajax請求 ajax請求都會自帶一個請求頭X-Requested-With
    // 如果有值而且是XMLHttpRequest那就可以確定是個ajax請求 返回json數據就行
    HttpServletRequest req = (HttpServletRequest) request;

    if ("XMLHttpRequest".equals(req.getHeader("X-Requested-With"))) {
      // 獲取到當前的登錄對象 如果是沒有經過認證的用戶就獲取不到認證信息
      Subject subject = SecurityUtils.getSubject();

      if (subject.getPrincipal() == null) {
        HttpServletResponse resp = (HttpServletResponse) response;

        // 設置響應類型和編碼字符 不然中文亂碼
        resp.setContentType("application/json;charset=utf-8");
        resp.setCharacterEncoding("UTF-8");

        // Message是我寫的一個包裝類,用來向前臺返回數據
        resp.getWriter().write(JSON.toJSONString(Message.failed("請登錄后操作")));
        return false;
      } else {
        // 經過認證的話就放過去 讓下一個過濾器處理
        return true;
      }
    } else {
      // 不是ajax請求的話也放過去 讓下一個過濾器處理
      return true;
    }
  }
}

@Bean(name = "shiroFilter")
public ShiroFilterFactoryBean shiroFilterFactoryBean(SecurityManager securityManager) {
  ShiroFilterFactoryBean factoryBean = new ShiroFilterFactoryBean();
  factoryBean.setSecurityManager(securityManager);
  // 設置登錄界面URL
  factoryBean.setLoginUrl(loginUrl);
  // 設置未經認證頁面的URL
  factoryBean.setUnauthorizedUrl(unauthorizedUrl);

  // 這里是設置過濾器
  // 要注意 如果你沒寫的話默認是有一個FormAuthenticationFilter
  // 如果你手動設置了過濾器會覆蓋掉默認設置
  // 在這里加上就好了
  HashMap<String, Filter> filter = new HashMap<>();
  filter.put("authc", new AjaxFilter());
  filter.put("authc", new FormAuthenticationFilter());
  factoryBean.setFilters(filter);

  // 需要認證的加到authc里面
  // 不需要認證的加到anon里面
  HashMap<String, String> filterChain = new HashMap<>();
  filterChain.put("/favicon.ico", "anon");
  filterChain.put("/login", "anon");
  filterChain.put("/logout", "logout");
  filterChain.put("/**", "authc");
  factoryBean.setFilterChainDefinitionMap(filterChain);

  return factoryBean;
}