package com.jsql.util;
   
   import com.jsql.model.InjectionModel;
   import com.jsql.view.subscriber.Seal;
   import com.jsql.model.exception.InjectionFailureException;
   import com.jsql.model.exception.JSqlException;
   import com.jsql.model.injection.method.AbstractMethodInjection;
   import org.apache.commons.lang3.StringUtils;
   import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import java.io.IOException;
  import java.net.Authenticator;
  import java.net.CookieManager;
  import java.net.PasswordAuthentication;
  import java.net.URI;
  import java.net.http.HttpClient;
  import java.net.http.HttpClient.Version;
  import java.net.http.HttpHeaders;
  import java.net.http.HttpRequest;
  import java.net.http.HttpRequest.BodyPublishers;
  import java.net.http.HttpRequest.Builder;
  import java.net.http.HttpResponse;
  import java.net.http.HttpResponse.BodyHandlers;
  import java.security.SecureRandom;
  import java.time.Duration;
  import java.util.*;
  import java.util.AbstractMap.SimpleEntry;
  import java.util.Map.Entry;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  /**
   * Utility class in charge of connection to web resources and management
   * of source page and request and response headers.
   */
  public class ConnectionUtil {
      
      private static final Logger LOGGER = LogManager.getRootLogger();
      
      private String urlByUser;  // URL entered by user
      private String urlBase;  // URL entered by user without the query string
      private AbstractMethodInjection methodInjection;  // Method of injection: by query string, request or header
      private String typeRequest = StringUtil.GET;  // Default HTTP method. It can be changed to a custom method
      private final Random randomForUserAgent = new SecureRandom();
      private final InjectionModel injectionModel;
      private final CookieManager cookieManager = new CookieManager();
      
      public ConnectionUtil(InjectionModel injectionModel) {
          this.injectionModel = injectionModel;
      }
      
      public HttpClient.Builder getHttpClient() {
          var httpClientBuilder = HttpClient.newBuilder()
              .connectTimeout(Duration.ofSeconds(this.getTimeout()))
              .sslContext(this.injectionModel.getMediatorUtils().certificateUtil().getSslContext())
              .followRedirects(
                  this.injectionModel.getMediatorUtils().preferencesUtil().isFollowingRedirection()
                  ? HttpClient.Redirect.ALWAYS
                  : HttpClient.Redirect.NEVER
              );
          if (this.injectionModel.getMediatorUtils().preferencesUtil().isHttp2Disabled()) {
              httpClientBuilder.version(Version.HTTP_1_1);
          }
          if (!this.injectionModel.getMediatorUtils().preferencesUtil().isNotProcessingCookies()) {
              httpClientBuilder.cookieHandler(this.cookieManager);
          }
          if (this.injectionModel.getMediatorUtils().authenticationUtil().isAuthentEnabled()) {
              httpClientBuilder.authenticator(new Authenticator() {
                  @Override
                  protected PasswordAuthentication getPasswordAuthentication() {
                      return new PasswordAuthentication(
                          ConnectionUtil.this.injectionModel.getMediatorUtils().authenticationUtil().getUsernameAuthentication(),
                          ConnectionUtil.this.injectionModel.getMediatorUtils().authenticationUtil().getPasswordAuthentication().toCharArray()
                      );
                  }
              });
          }
          return httpClientBuilder;
      }
  
      public static <T> Map<String, String> getHeadersMap(HttpResponse<T> httpResponse) {
          Map<String, String> sortedMap = ConnectionUtil.getHeadersMap(httpResponse.headers());
          String responseCodeHttp = String.valueOf(httpResponse.statusCode());
          sortedMap.put(":status", responseCodeHttp);
          return sortedMap;
      }
      
      public static Map<String, String> getHeadersMap(HttpHeaders httpHeaders) {
          Map<String, String> unsortedMap = httpHeaders.map()
              .entrySet()
              .stream()
              .sorted(Entry.comparingByKey())
              .map(entrySet -> new SimpleEntry<>(
                  entrySet.getKey(),
                  String.join(", ", entrySet.getValue())
              ))
              .collect(Collectors.toMap(
                  SimpleEntry::getKey,
                 SimpleEntry::getValue
             ));
         return new TreeMap<>(unsortedMap);
     }
 
     /**
      * Check that the connection to the website is working correctly.
      * It uses authentication defined by user, with fixed timeout, and warn
      * user in case of authentication detected.
      */
     public HttpResponse<String> checkConnectionResponse() throws IOException, InterruptedException, JSqlException {
         var queryString = this.injectionModel.getMediatorUtils().parameterUtil().getQueryStringFromEntries();
         var testUrl = this.getUrlBase().replaceAll("\\?$", StringUtils.EMPTY);
 
         if (StringUtils.isNotEmpty(queryString)) {
             testUrl += "?"+ queryString;
         }
 
         String contentTypeRequest = "text/plain";
 
         var body = this.injectionModel.getMediatorUtils().parameterUtil().getRawRequest();
 
         if (this.injectionModel.getMediatorUtils().parameterUtil().isMultipartRequest()) {
             body = body.replaceAll("(?s)\\\\n", "\r\n");
         } else if (this.injectionModel.getMediatorUtils().parameterUtil().isRequestSoap()) {
             contentTypeRequest = "text/xml";
         } else if (!this.injectionModel.getMediatorUtils().parameterUtil().getListRequest().isEmpty()) {
             contentTypeRequest = "application/x-www-form-urlencoded";
         }
 
         // Test the HTTP connection
         Builder httpRequest = HttpRequest.newBuilder();
         try {
             httpRequest.uri(
                 URI.create(
                     testUrl  // Get encoded params without fragment
                     .replace(InjectionModel.STAR, StringUtils.EMPTY)  // Ignore injection point during the test
                 )
             );
         } catch (IllegalArgumentException e) {
             throw new JSqlException(e);
         }
         httpRequest.setHeader(HeaderUtil.CONTENT_TYPE_REQUEST, contentTypeRequest)
             .timeout(Duration.ofSeconds(this.getTimeout()));
         
         this.injectionModel.getMediatorUtils().csrfUtil().addHeaderToken(httpRequest);
         this.injectionModel.getMediatorUtils().digestUtil().addHeaderToken(httpRequest);
 
         httpRequest.method(this.typeRequest, BodyPublishers.ofString(body));
 
         // Add headers if exists (Authorization:Basic, etc.)
         for (SimpleEntry<String, String> header: this.injectionModel.getMediatorUtils().parameterUtil().getListHeader()) {
             HeaderUtil.sanitizeHeaders(httpRequest, header);
         }
 
         return this.injectionModel.getMediatorUtils().headerUtil().checkResponseHeader(httpRequest, body);
     }
 
     public void testConnection() throws IOException, InterruptedException, JSqlException {
         // Check connection is working: define Cookie management, check HTTP status, parse <form> parameters, process CSRF
         LOGGER.log(LogLevelUtil.CONSOLE_DEFAULT, () -> I18nUtil.valueByKey("LOG_CONNECTION_TEST"));
         this.getCookieManager().getCookieStore().removeAll();
         HttpResponse<String> httpResponse = this.checkConnectionResponse();
 
         if (
             (httpResponse.statusCode() == 401 || httpResponse.statusCode() == 403)
             && !this.injectionModel.getMediatorUtils().preferencesUtil().isNotProcessingCookies()
             && (
                 this.injectionModel.getMediatorUtils().csrfUtil().isCsrf()
                 || this.injectionModel.getMediatorUtils().digestUtil().isDigest()
             )
         ) {
             if (this.injectionModel.getMediatorUtils().preferencesUtil().isProcessingCsrf()) {
                 LOGGER.log(LogLevelUtil.CONSOLE_INFORM, () -> "Testing CSRF handshake from previous connection...");
             } else if (StringUtils.isNotEmpty(this.injectionModel.getMediatorUtils().digestUtil().getTokenDigest())) {
                 LOGGER.log(LogLevelUtil.CONSOLE_INFORM, () -> "Testing Digest handshake from previous connection...");
             }
             httpResponse = this.checkConnectionResponse();
         }
 
         if (httpResponse.statusCode() >= 400 && !this.injectionModel.getMediatorUtils().preferencesUtil().isNotTestingConnection()) {
             throw new InjectionFailureException(String.format("Connection failed: problem when calling %s", httpResponse.uri().toURL()));
         }
     }
 
     /**
      * Call a URL and return the source page.
      * @param url to call
      * @return the source page of the URL
      */
     public String getSourceLineFeed(String url) {
         return this.getSource(url, true, false);
     }
 
     public String getSource(String url) {
         return this.getSource(url, false, false);
     }
 
     public String getSource(String url, boolean isConnectIssueIgnored) {  // reverse init result can be ignored
         return this.getSource(url, false, isConnectIssueIgnored);
     }
 
     public String getSource(String url, boolean lineFeed, boolean isConnectIssueIgnored) {
         String pageSource = StringUtils.EMPTY;
         Map<String, String> requestHeaders = Map.of();
         Map<String, String> responseHeaders = Map.of();
 
         try (var httpClient = this.getHttpClient().build()) {
             var httpRequest = HttpRequest.newBuilder()
                 .uri(URI.create(url))
                 .timeout(Duration.ofSeconds(this.getTimeout()))
                 .build();
 
             if (lineFeed) {
                 HttpResponse<Stream<String>> response = httpClient.send(httpRequest, BodyHandlers.ofLines());
                 pageSource = response.body().collect(Collectors.joining("\n"));
                 responseHeaders = ConnectionUtil.getHeadersMap(response.headers());
             } else {
                 HttpResponse<String> response = httpClient.send(httpRequest, BodyHandlers.ofString());
                 pageSource = response.body();
                 responseHeaders = ConnectionUtil.getHeadersMap(response.headers());
             }
             requestHeaders = ConnectionUtil.getHeadersMap(httpRequest.headers());
 
         } catch (IOException e) {
             if (!isConnectIssueIgnored) {  // ignoring reverse connection timeout
                 LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
             }
         } catch (InterruptedException e) {
             LOGGER.log(LogLevelUtil.IGNORE, e, e);
             Thread.currentThread().interrupt();
         } finally {
             // Inform the view about the log infos
             this.injectionModel.sendToViews(new Seal.MessageHeader(
                 url,
                 null,
                 requestHeaders,
                 responseHeaders,
                 pageSource,
                 null,
                 null,
                 null,
                 null
             ));
         }
         
         return pageSource.trim();
     }
 
     public void setCustomUserAgent(Builder httpRequest) {
         if (this.injectionModel.getMediatorUtils().preferencesUtil().isUserAgentRandom()) {
             String agents = this.injectionModel.getMediatorUtils().userAgentUtil().getCustomUserAgent();
             List<String> listAgents = Stream.of(agents.split("[\\r\\n]+"))
                 .filter(q -> !q.matches("^#.*"))
                 .toList();
             String randomElement = listAgents.get(this.randomForUserAgent.nextInt(listAgents.size()));
             httpRequest.setHeader("User-Agent", randomElement);
         }
     }
     
     
     // Builder
 
     public ConnectionUtil withMethodInjection(AbstractMethodInjection methodInjection) {
         this.methodInjection = methodInjection;
         return this;
     }
     
     public ConnectionUtil withTypeRequest(String typeRequest) {
         this.typeRequest = typeRequest;
         return this;
     }
     
     
     // Getters and setters
     
     public String getUrlByUser() {
         return this.urlByUser;
     }
 
     public void setUrlByUser(String urlByUser) {
         this.urlByUser = urlByUser;
     }
     
     public String getUrlBase() {
         return this.urlBase;
     }
 
     public void setUrlBase(String urlBase) {
         this.urlBase = urlBase;
     }
     
     public AbstractMethodInjection getMethodInjection() {
         return this.methodInjection;
     }
 
     public void setMethodInjection(AbstractMethodInjection methodInjection) {
         this.methodInjection = methodInjection;
     }
     
     public String getTypeRequest() {
         return this.typeRequest;
     }
 
     public void setTypeRequest(String typeRequest) {
         this.typeRequest = typeRequest;
     }
 
     /**
      * Default timeout used by the jcifs fix. It's the default value used usually by the JVM.
      */
     public Integer getTimeout() {
         return this.injectionModel.getMediatorUtils().preferencesUtil().countConnectionTimeout();
     }
 
     public CookieManager getCookieManager() {
         return this.cookieManager;
     }
 }