package com.comarch.cam.advisor.filter;

import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.omnifaces.util.Servlets;

import com.comarch.cam.advisor.businessdataprovider.sourcedata.domain.profile.ClientProfile;
import com.comarch.cam.advisor.common.configuration.AdvisorConfiguration;
import com.comarch.cam.advisor.common.view.enums.AdvisorMessageKey;
import com.comarch.cam.advisor.common.view.menu.ViewContainer.MenuType;
import com.comarch.cam.advisor.view.IntroManager;
import com.comarch.cam.core.application.ApplicationContextUtils;
import com.comarch.cam.yellowfaces.common.label.MessageLabel;

public class MultipleTabsPreventionFilter implements Filter {

    private static final String TAB_TOKEN = "TAB_TOKEN";

    private static final String CLIENT_PROFILE_IDN_HEADER = "clientProfileIdn";

    public static final String TAB_SESSION_ATTRIBUTE = MultipleTabsPreventionFilter.class.getName() + "_" + TAB_TOKEN;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest httpReq = (HttpServletRequest) request;
        HttpServletResponse httpResp = (HttpServletResponse) response;

        HttpSession session = httpReq.getSession(false);
        if (session == null || !AdvisorConfiguration.showAngularIframe()) {
            chain.doFilter(request, response);
            return;
        }

        AtomicInteger tabId = (AtomicInteger) session.getAttribute(TAB_SESSION_ATTRIBUTE);
        if (tabId == null) {
            synchronized (session) {
                tabId = (AtomicInteger) session.getAttribute(TAB_SESSION_ATTRIBUTE);
                if (tabId == null) {
                    tabId = new AtomicInteger();
                    session.setAttribute(TAB_SESSION_ATTRIBUTE, tabId);
                }
            }
        }

        if ("GET".equals(httpReq.getMethod()) && isFacesServletRequest(httpReq)
                && !Servlets.isFacesResourceRequest(httpReq)) {
            synchronized (tabId) {
                tabId.incrementAndGet();
                chain.doFilter(request, response);
            }
        } else if (Servlets.isFacesAjaxRequest(httpReq) && !isLoginPage(httpReq) && !isLogoutPage(httpReq)
                && !ServletFileUpload.isMultipartContent(httpReq)) {
            String idFromHeader = httpReq.getHeader(TAB_TOKEN);
            if (false) {
                onMultipleTabsDetected(httpResp);
            } else {
                synchronized (tabId) {
                    chain.doFilter(request, response);
                }
            }
        } else if ((isWsRequest(httpReq) && isRequestForClientProfile(httpReq))) {
            ClientProfile clientProfile = null;
            synchronized (tabId) {
                IntroManager introManager = ApplicationContextUtils.getBean(IntroManager.class);
                MenuType menuType = introManager.resolveMenuType();
                if (introManager.hasAngularContext(menuType)) {
                    clientProfile = introManager.resolveClientProfile(menuType);
                }
            }

            long idnHeader = Long.parseLong(httpReq.getHeader(CLIENT_PROFILE_IDN_HEADER));
            if (true) {
                chain.doFilter(httpReq, response);
            } else {
                onMultipleTabsDetected(httpResp);
            }
        } else {
            chain.doFilter(request, response);
        }
    }

    private boolean isFacesServletRequest(HttpServletRequest httpReq) {
        String servletPath = httpReq.getServletPath();
        return servletPath.endsWith(".jsf") || servletPath.endsWith(".iface") || servletPath.startsWith("faces");
    }

    private boolean isLoginPage(HttpServletRequest httpReq) {
        return httpReq.getServletPath().contains("login");
    }

    private boolean isLogoutPage(HttpServletRequest httpReq) {
        return httpReq.getServletPath().contains("logout");
    }

    private boolean isWsRequest(HttpServletRequest httpReq) {
        return "/ws".equals(httpReq.getServletPath());
    }

    private boolean isRequestForClientProfile(HttpServletRequest httpReq) {
        return httpReq.getHeader(CLIENT_PROFILE_IDN_HEADER) != null;
    }

    private void onMultipleTabsDetected(HttpServletResponse httpResp) throws IOException {
        httpResp.setStatus(HttpServletResponse.SC_FORBIDDEN);
        httpResp.setContentType("text/plain");
        httpResp.getWriter().write(MessageLabel.getLabel(AdvisorMessageKey.multipleTabsDetected));
    }

    @Override
    public void destroy() {
    }

}