package com.ots.framework.shiro.web.filter.kickout;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.ots.common.constant.ShiroConstants;
import com.ots.common.utils.ServletUtils;
import com.ots.common.utils.security.ShiroUtils;
import com.ots.framework.web.domain.AjaxResult;
import com.ots.project.system.user.domain.User;
import org.apache.shiro.cache.Cache;
import org.apache.shiro.cache.CacheManager;
import org.apache.shiro.session.Session;
import org.apache.shiro.session.mgt.DefaultSessionKey;
import org.apache.shiro.session.mgt.SessionManager;
import org.apache.shiro.subject.Subject;
import org.apache.shiro.web.filter.AccessControlFilter;
import org.apache.shiro.web.util.WebUtils;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayDeque;
import java.util.Deque;

public class KickoutSessionFilter extends AccessControlFilter {
    private final static ObjectMapper objectMapper = new ObjectMapper();
    
    private int maxSession = -1;
    
    private Boolean kickoutAfter = false;
    
    private String kickoutUrl;
    private SessionManager sessionManager;
    private Cache<String, Deque<Serializable>> cache;
    @Override
    protected boolean isAccessAllowed(ServletRequest servletRequest, ServletResponse servletResponse, Object o)
            throws Exception {
        return false;
    }
    @Override
    protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
        Subject subject = getSubject(request, response);
        if (!subject.isAuthenticated() && !subject.isRemembered() || maxSession == -1) {
            
            return true;
        }
        try {
            Session session = subject.getSession();
            
            User user = ShiroUtils.getSysUser();
            String loginName = user.getLoginName();
            Serializable sessionId = session.getId();
            
            Deque<Serializable> deque = cache.get(loginName);
            if (deque == null) {
                
                deque = new ArrayDeque<Serializable>();
            }
            
            if (!deque.contains(sessionId) && session.getAttribute("kickout") == null) {
                
                deque.push(sessionId);
                
                cache.put(loginName, deque);
            }
            
            while (deque.size() > maxSession) {
                Serializable kickoutSessionId = null;
                
                if (kickoutAfter) {
                    
                    kickoutSessionId = deque.removeFirst();
                } else {
                    
                    kickoutSessionId = deque.removeLast();
                }
                
                cache.put(loginName, deque);
                try {
                    
                    Session kickoutSession = sessionManager.getSession(new DefaultSessionKey(kickoutSessionId));
                    if (null != kickoutSession) {
                        
                        kickoutSession.setAttribute("kickout", true);
                    }
                } catch (Exception e) {
                    
                }
            }
            
            if ((Boolean) session.getAttribute("kickout") != null && (Boolean) session.getAttribute("kickout") == true) {
                
                subject.logout();
                saveRequest(request);
                return isAjaxResponse(request, response);
            }
            return true;
        } catch (Exception e) {
            return isAjaxResponse(request, response);
        }
    }
    private boolean isAjaxResponse(ServletRequest request, ServletResponse response) throws IOException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
        if (ServletUtils.isAjaxRequest(req)) {
            AjaxResult ajaxResult = AjaxResult.error("您已在别处登录，请您修改密码或重新登录");
            ServletUtils.renderString(res, objectMapper.writeValueAsString(ajaxResult));
        } else {
            WebUtils.issueRedirect(request, response, kickoutUrl);
        }
        return false;
    }
    public void setMaxSession(int maxSession) {
        this.maxSession = maxSession;
    }
    public void setKickoutAfter(boolean kickoutAfter) {
        this.kickoutAfter = kickoutAfter;
    }
    public void setKickoutUrl(String kickoutUrl) {
        this.kickoutUrl = kickoutUrl;
    }
    public void setSessionManager(SessionManager sessionManager) {
        this.sessionManager = sessionManager;
    }
    
    public void setCacheManager(CacheManager cacheManager) {
        
        this.cache = cacheManager.getCache(ShiroConstants.SYS_USERCACHE);
    }
}