package servlets.module.challenge;

import dbProcs.FileInputProperties;
import dbProcs.Getter;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.nio.charset.StandardCharsets;
import java.util.Locale;
import java.util.ResourceBundle;
import org.apache.commons.io.FileUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;
import org.owasp.encoder.Encode;
import utils.ShepherdLogManager;
import utils.Validate;

/**
 * XXE Challenge 1 <br>
 * <br>
 * This file is part of the Security Shepherd Project.
 *
 * <p>The Security Shepherd project is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software Foundation, either
 * version 3 of the License, or (at your option) any later version.<br>
 *
 * <p>The Security Shepherd project is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU General Public License for more details.<br>
 *
 * <p>You should have received a copy of the GNU General Public License along with the Security
 * Shepherd project. If not, see <http://www.gnu.org/licenses/>.
 *
 * @author ismisepaul
 */
public class XxeChallenge1 extends HttpServlet {

  private static final long serialVersionUID = 1L;
  private static final Logger log = LogManager.getLogger(XxeChallenge1.class);
  private static final String LEVEL_NAME = "XXE Challenge 1";
  private static final String LEVEL_HASH =
      "ac8f3f6224b1ea3fb8a0f017aadd0d84013ea2c80e232c980e54dd753700123e";

  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

    String ApplicationRoot = getServletContext().getRealPath("");
    String moduleId = Getter.getModuleIdFromHash(ApplicationRoot, LEVEL_HASH);

    // Setting IpAddress To Log and taking header for original IP if forwarded from proxy
    ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For"));
    log.debug(LEVEL_NAME + " Servlet Accessed");
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    out.print(getServletInfo());

    // Translation Stuff
    Locale locale = new Locale(Validate.validateLanguage(request.getSession()));
    ResourceBundle errors = ResourceBundle.getBundle("i18n.servlets.errors", locale);
    ResourceBundle bundle =
        ResourceBundle.getBundle("i18n.servlets.challenges.injection.xxe1", locale);

    try {
      HttpSession ses = request.getSession(true);
      if (Validate.validateSession(ses)) {
        if (Getter.isModuleOpen(getServletContext().getRealPath(""), moduleId)) {
          ShepherdLogManager.setRequestIp(
              request.getRemoteAddr(),
              request.getHeader("X-Forwarded-For"),
              ses.getAttribute("userName").toString());
          log.debug(LEVEL_NAME + " accessed by: " + ses.getAttribute("userName").toString());
          Cookie tokenCookie = Validate.getToken(request.getCookies());
          Object tokenHeader = request.getHeader("csrfToken").toString();

          if (Validate.validateTokens(tokenCookie, tokenHeader)) {
            InputStream json = request.getInputStream();
            String emailAddr = readJson(json, errors);
            emailAddr = Encode.forHtml(emailAddr);
            log.debug("Email Addr: " + emailAddr);

            String htmlOutput = new String();

            if (emailAddr == null) {
              htmlOutput += "<p>" + bundle.getString("response.blank.email") + "</p>";
              out.write(htmlOutput + emailAddr);
            } else if (Validate.isValidEmailAddress(emailAddr)) {
              log.debug("User Submitted - " + emailAddr);

              htmlOutput +=
                  "<p>"
                      + bundle.getString("response.success.reset")
                      + ": "
                      + emailAddr
                      + " has been reset</p>";
              out.write(htmlOutput);
            } else {
              htmlOutput +=
                  "<p>" + bundle.getString("response.invalid.email") + ": " + emailAddr + "</p>";
              out.write(htmlOutput);
            }
          }
        } else {
          log.error(LEVEL_NAME + " accessed but level is closed");
          out.write(errors.getString("error.notOpen"));
        }
      } else {
        log.error(LEVEL_NAME + " accessed with no session");
        out.write(errors.getString("error.noSession"));
      }
    } catch (Exception e) {
      out.write(errors.getString("error.funky"));
      log.fatal(LEVEL_NAME + " - " + e.toString());
    }
    log.debug("End of " + LEVEL_NAME + " Servlet");
  }

  public static String readJson(InputStream jsonEmail, ResourceBundle errors) {
    String result;

    JSONObject jsonObject;
    try {
      jsonObject =
          new JSONObject(new JSONTokener(new InputStreamReader(jsonEmail, StandardCharsets.UTF_8)));
      result = jsonObject.get("email").toString();
      return result;
    } catch (JSONException e) {
      e.printStackTrace();
      return errors.getString("error.funky");
    }
  }

  /** Creates the file with the solution key needed to pass the level */
  public static boolean createXxeChallenge1SolutionFile() {

    File lessonFile;
    String filename;
    String solution;

    try {
      filename =
          FileInputProperties.readPropFileClassLoader(
              "fileSystemKeys.properties", "xxe.challenge.1.file");
      solution =
          FileInputProperties.readPropFileClassLoader(
              "fileSystemKeys.properties", "xxe.challenge.1.solution");

      lessonFile = new File(filename);

      if (lessonFile.exists()) {
        log.info("XXE Challenge 1 Solution File " + filename + " already exists");
        FileUtils.deleteQuietly(lessonFile);
        log.info("XXE Challenge 1 Solution File " + filename + " deleted");
      }
      FileUtils.write(lessonFile, solution, "UTF-8");
      log.info("XXE Challenge 1 Solution File " + filename + " created");
      return true;
    } catch (FileNotFoundException e) {
      log.error(e);
      throw new RuntimeException(e);

    } catch (IOException e) {
      log.error(e);
      throw new RuntimeException(e);
    }
  }
}