package com.cloud.application.filter;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

@Slf4j
@Component
@WebFilter(urlPatterns = "/*", filterName = "loginFilter")
public class LoginDataFilter implements Filter {

    @Autowired
    private RestTemplate restTemplate;

    @Value("${loginData.redUrl}")
    private String loginHost;

    @Value("${loginData.redPort}")
    private String loginPort;

    @Value("${fdfsImgUrl.server}")
    private String httpImageUrl;

    private static final Pattern QUERY_PARAM_PATTREN = Pattern.compile("([^&=]+)(=?)([^&]+)?");

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

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        String url = request.getRequestURI();

        if(url.startsWith("/loginData")){
            Map<String, String[]> parMap = request.getParameterMap();
            Enumeration<String> parNames = request.getParameterNames();
            Set<String> set = parMap.keySet();

            MultiValueMap<String, String> mulMap = new LinkedMultiValueMap<>();
            for(String key: parMap.keySet()){
                String[] names = parMap.get(key);
                for(int i=0;i<names.length;i++){
                    mulMap.add(key, names[i]);
                }
            }
            log.info("mulMap:"+mulMap);
            String method = request.getMethod();
            log.info("请求方式："+method);
            HttpHeaders headers = new HttpHeaders();
            String body = null;
            String auth = request.getHeader("Authorization");
            headers.add("Accept", MediaType.APPLICATION_JSON.toString());
            if(auth !=null){
                mulMap.add("access_token",auth.substring(7));
                headers.add("Authorization",auth);
            }
            url ="http://"+loginHost+":"+loginPort+"/data"+url.substring(10);
            log.info("查询url："+url);
            HttpEntity<MultiValueMap<String,String>> reqEntity = new HttpEntity<>(mulMap, headers);
            if("get".equalsIgnoreCase(method)){
                body = restTemplate.getForObject(expandURL(url, mulMap),String.class, mulMap);
            }else{
                headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
                body = restTemplate.postForEntity(url, reqEntity, String.class).getBody();
            }
            log.info(body+"返回内容");
            if(body !=null){
                response.setContentType("application/json;charset=utf-8");
                response.setStatus(200);
                PrintWriter pw = response.getWriter();
                pw.write(body.toString());
                pw.close();
            }

        }else if(url.startsWith("/httpImage")){
            log.info("图片跳转url:"+url);
            response.sendRedirect(httpImageUrl+url.substring(11));
            response.setHeader("Access-Control-Allow-Origin","*");
            return;
        }else{
            log.info("其他url跳转："+url);
            filterChain.doFilter(servletRequest, servletResponse);
        }

    }

    // 添加url
    private static String expandURL(String url,  MultiValueMap<String, String> map) {
        Matcher mc = QUERY_PARAM_PATTREN.matcher(url);
        StringBuilder sb =new StringBuilder(url);
        if (!mc.find()){
            sb.append("&");
        }else {
            sb.append("?");
        }
        Set<String> keys = map.keySet();
        for (String key : keys) {
            List<String> value = map.get(key);
            for (String val : value) {
                sb.append(key).append("=").append(val).append("&");  // .append("}")
            }
        }
        return sb.deleteCharAt(sb.length() - 1).toString();
    }

    @Override
    public void destroy() {

    }

}