package com.jsql.util;
   
   import com.jsql.model.InjectionModel;
   import org.apache.commons.lang3.StringUtils;
   import org.apache.logging.log4j.LogManager;
   import org.apache.logging.log4j.Logger;
   import org.jsoup.Jsoup;
   
   import java.net.http.HttpRequest.Builder;
  import java.util.AbstractMap.SimpleEntry;
  import java.util.*;
  import java.util.stream.Stream;
  
  public class CsrfUtil {
      
      /**
       * Log4j logger sent to view.
       */
      private static final Logger LOGGER = LogManager.getRootLogger();
  
      private SimpleEntry<String, String> tokenCsrf = null;
      
      private static final String SET_COOKIE_RESPONSE = "set-cookie";
      private static final String INPUT_ATTR_VALUE = "value";
      private static final String MSG_ENABLE_CSRF = "Try with option CSRF processing enabled in preferences";
  
      private final InjectionModel injectionModel;
      
      public CsrfUtil(InjectionModel injectionModel) {
          this.injectionModel = injectionModel;
      }
  
      public void parseForCsrfToken(String pageSource, Map<String, String> headers) {
          this.parseCsrfFromCookie(headers);
          this.parseCsrfFromHtml(pageSource);
      }
  
      private void parseCsrfFromHtml(String pageSource) {
          // Change immutable list to mutable for adding user tag
          List<String> tags = new ArrayList<>(
              Arrays.asList(
                  "[name=_csrf]",
                  "[name=_token]",
                  "[name=csrf-token]",
                  "[name=_csrf_header]",
                  "[name=csrf_token]",
                  "[name=csrfToken]",
                  "[name=user_token]",
                  "[name=csrfmiddlewaretoken]",
                  "[name=form_build_id]"
              )
          );
          
          if (this.injectionModel.getMediatorUtils().getPreferencesUtil().isCsrfUserTag()) {
              tags.add(
                  String.format(
                      "[name='%s']",
                      this.injectionModel.getMediatorUtils().getPreferencesUtil().csrfUserTag()
                  )
              );
          }
          
          Optional<SimpleEntry<String, String>> optionalTokenCsrf = Jsoup.parse(pageSource)
              .select("input")
              .select(String.join(",", tags))
              .stream()
              .findFirst()
              .map(input ->
                  new SimpleEntry<>(
                      input.attr("name"),
                      input.attr(CsrfUtil.INPUT_ATTR_VALUE)
                  )
              );
          
          if (optionalTokenCsrf.isPresent()) {
              SimpleEntry<String, String> tokenCsrfFound = optionalTokenCsrf.get();
              LOGGER.log(
                  LogLevelUtil.CONSOLE_INFORM,
                  "Found Csrf token from HTML body: {}={}",
                  tokenCsrfFound::getKey,
                  tokenCsrfFound::getValue
              );
              if (
                  !this.injectionModel.getMediatorUtils().getPreferencesUtil().isNotProcessingCookies()
                  && this.injectionModel.getMediatorUtils().getPreferencesUtil().isProcessingCsrf()
              ) {
                  this.tokenCsrf = tokenCsrfFound;
                  LOGGER.log(
                      LogLevelUtil.CONSOLE_SUCCESS,
                      "Csrf token added to query and header: {}",
                      tokenCsrfFound::getValue
                  );
              } else {
                  LOGGER.log(LogLevelUtil.CONSOLE_INFORM, CsrfUtil.MSG_ENABLE_CSRF);
              }
          }
      }
  
      private void parseCsrfFromCookie(Map<String, String> mapResponse) {
         Optional<SimpleEntry<String, String>> optionalCookieCsrf = Optional.empty();
         
         if (mapResponse.containsKey(CsrfUtil.SET_COOKIE_RESPONSE)) {
             // Spring: Cookie XSRF-TOKEN => Header X-XSRF-TOKEN, GET/POST parameter _csrf
             // Laravel, Zend, Symfony
             String[] cookieValues = StringUtils.split(mapResponse.get(CsrfUtil.SET_COOKIE_RESPONSE), ";");
             optionalCookieCsrf = Stream.of(cookieValues)
                 .filter(cookie -> cookie.trim().toLowerCase().startsWith("xsrf-token"))
                 .map(cookie -> {
                     String[] cookieEntry = StringUtils.split(cookie, "=");
                     return new SimpleEntry<>(
                         cookieEntry[0].trim(),
                         cookieEntry[1].trim()
                     );
                 })
                 .findFirst();
         }
         
         if (optionalCookieCsrf.isPresent()) {
             SimpleEntry<String, String> cookieCsrf = optionalCookieCsrf.get();
             LOGGER.log(
                 LogLevelUtil.CONSOLE_ERROR,
                 "Found CSRF token from Cookie: {}={}",
                 cookieCsrf::getKey,
                 cookieCsrf::getValue
             );
             SimpleEntry<String, String> headerCsrf = new SimpleEntry<>(
                 cookieCsrf.getKey(),
                 cookieCsrf.getValue()
             );
             if (
                 !this.injectionModel.getMediatorUtils().getPreferencesUtil().isNotProcessingCookies()
                 && this.injectionModel.getMediatorUtils().getPreferencesUtil().isProcessingCsrf()
             ) {
                 this.tokenCsrf = headerCsrf;
             } else {
                 LOGGER.log(LogLevelUtil.CONSOLE_INFORM, CsrfUtil.MSG_ENABLE_CSRF);
             }
         }
     }
 
     public void addHeaderToken(Builder httpRequest) {
         if (this.tokenCsrf == null) {
              return;
         }
 
         httpRequest.setHeader("X-XSRF-TOKEN", this.tokenCsrf.getValue());
         httpRequest.setHeader("X-CSRF-TOKEN", this.tokenCsrf.getValue());
         
         if (this.injectionModel.getMediatorUtils().getPreferencesUtil().isCsrfUserTag()) {
             httpRequest.setHeader(
                 this.injectionModel.getMediatorUtils().getPreferencesUtil().csrfUserTagOutput(),
                 this.tokenCsrf.getValue()
             );
         }
     }
 
     public void addRequestToken(StringBuilder httpRequest) {
         if (this.tokenCsrf == null) {
             return;
         }
         httpRequest.append(
             String.format(
                 "%s=%s&",
                 this.tokenCsrf.getKey(),
                 this.tokenCsrf.getValue()
             )
         );
         httpRequest.append(
             String.format(
                 "_csrf=%s&",
                 this.tokenCsrf.getValue()
             )
         );
         if (this.injectionModel.getMediatorUtils().getPreferencesUtil().isCsrfUserTag()) {
             httpRequest.append(
                 String.format(
                     "%s=%s&",
                     this.injectionModel.getMediatorUtils().getPreferencesUtil().csrfUserTagOutput(),
                     this.tokenCsrf.getValue()
                 )
             );
         }
     }
     
     public String addQueryStringToken(String urlInjection) {
         String urlInjectionFixed = urlInjection;
         if (this.tokenCsrf == null) {
             return urlInjectionFixed;
         }
         urlInjectionFixed += String.format(
             "&%s=%s",
             this.tokenCsrf.getKey(),
             this.tokenCsrf.getValue()
         );
         urlInjectionFixed += String.format(
             "&_csrf=%s",
             this.tokenCsrf.getValue()
         );
         if (this.injectionModel.getMediatorUtils().getPreferencesUtil().isCsrfUserTag()) {
             urlInjectionFixed += String.format(
                 "&%s=%s",
                 this.injectionModel.getMediatorUtils().getPreferencesUtil().csrfUserTagOutput(),
                 this.tokenCsrf.getValue()
             );
         }
         return urlInjectionFixed;
     }
     
     
     // Getter / Setter
 
     public boolean isCsrf() {
         return this.tokenCsrf != null;
     }
 
     public SimpleEntry<String, String> getTokenCsrf() {
         return this.tokenCsrf;
     }
 
     public void setTokenCsrf(SimpleEntry<String, String> tokenCsrf) {
         this.tokenCsrf = tokenCsrf;
     }
 }