/*
    * Copyright (c) 2002-2026 Gargoyle Software Inc.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * https://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.htmlunit.util;
  
  import static java.nio.charset.StandardCharsets.ISO_8859_1;
  
  import java.io.BufferedWriter;
  import java.io.EOFException;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.URL;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.nio.file.StandardOpenOption;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.regex.Pattern;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.htmlunit.FormEncodingType;
  import org.htmlunit.HttpMethod;
  import org.htmlunit.WebConnection;
  import org.htmlunit.WebRequest;
  import org.htmlunit.WebResponse;
  import org.htmlunit.WebResponseData;
  import org.htmlunit.javascript.JavaScriptEngine;
  
  /**
   * Wrapper around a "real" {@link WebConnection} that uses the wrapped connection
   * to perform the actual work and saves all received responses
   * in the temp directory with an overview page.<br>
   * <br>
   * This may be useful during development to understand what is being browsed.<br>
   * <br>
   * Example:
   * <pre>
   * final WebClient client = new WebClient();
   * final WebConnection connection = new DebuggingWebConnection(client.getWebConnection(), "myTest");
   * client.setWebConnection(connection);
   * </pre>
   * In this example an overview page will be generated under the name {@code myTest/index.html} in the temp directory
   * and all received responses will be saved into the {@code myTest} folder.<br>
   * <br>
   * <em>This class is only intended as a debugging aid during development.</em>
   *
   * @author Marc Guillemot
   * @author Ahmed Ashour
   * @author Ronald Brill
   */
  public class DebuggingWebConnection extends WebConnectionWrapper {
      private static final Log LOG = LogFactory.getLog(DebuggingWebConnection.class);
  
      private static final Pattern ESCAPE_QUOTE_PATTERN = Pattern.compile("'");
  
      private int counter_;
      private final WebConnection wrappedWebConnection_;
      private final File javaScriptFile_;
      private final File reportFolder_;
      private boolean uncompressJavaScript_ = true;
  
      /**
       * Wraps a web connection to have a report generated of the received responses.
       *
       * @param webConnection the web connection that does the real work
       * @param dirName the name of the directory to create in the temp folder to save received responses;
       *        if this folder already exists, it will be deleted first
       * @throws IOException if there is a problem writing the files
       */
      public DebuggingWebConnection(final WebConnection webConnection,
              final String dirName) throws IOException {
  
          super(webConnection);
  
          wrappedWebConnection_ = webConnection;
          final File tmpDir = new File(System.getProperty("java.io.tmpdir"));
          reportFolder_ = new File(tmpDir, dirName);
          if (reportFolder_.exists()) {
              FileUtils.forceDelete(reportFolder_);
          }
          FileUtils.forceMkdir(reportFolder_);
          javaScriptFile_ = new File(reportFolder_, "hu.js");
         createOverview();
     }
 
     /**
      * Calls the wrapped web connection and saves the received response.
      * {@inheritDoc}
      */
     @Override
     public WebResponse getResponse(final WebRequest request) throws IOException {
         WebResponse response = wrappedWebConnection_.getResponse(request);
         if (isUncompressJavaScript() && isJavaScript(response.getContentType())) {
             response = uncompressJavaScript(response);
         }
         saveResponse(response, request);
         return response;
     }
 
     /**
      * Tries to uncompress the JavaScript code in the provided response.
      *
      * @param response the response to uncompress
      * @return a new response with uncompressed JavaScript code, or the original response if uncompression fails
      */
     protected WebResponse uncompressJavaScript(final WebResponse response) {
         final WebRequest request = response.getWebRequest();
         final String scriptName = request.getUrl().toString();
         final String scriptSource = response.getContentAsString();
 
         // skip if it is already formatted? => TODO
 
         try {
             final String decompileScript = JavaScriptEngine.uncompressJavaScript(scriptSource, scriptName);
 
             final List<NameValuePair> responseHeaders = new ArrayList<>(response.getResponseHeaders());
             for (int i = responseHeaders.size() - 1; i >= 0; i--) {
                 if ("content-encoding".equalsIgnoreCase(responseHeaders.get(i).getName())) {
                     responseHeaders.remove(i);
                 }
             }
             final WebResponseData wrd = new WebResponseData(decompileScript.getBytes(), response.getStatusCode(),
                 response.getStatusMessage(), responseHeaders);
             return new WebResponse(wrd, response.getWebRequest().getUrl(),
                 response.getWebRequest().getHttpMethod(), response.getLoadTime());
         }
         catch (final Exception e) {
             LOG.warn("Failed to decompress JavaScript response. Delivering as it.", e);
         }
 
         return response;
     }
 
     /**
      * Adds a mark that will be visible in the HTML result page generated by this class.
      *
      * @param mark the text of the mark
      * @throws IOException if a problem occurs writing the file
      */
     public void addMark(String mark) throws IOException {
         if (mark != null) {
             mark = mark.replace("\"", "\\\"");
         }
         appendToJSFile("tab[tab.length] = \"" + mark + "\";\n");
         if (LOG.isInfoEnabled()) {
             LOG.info("--- " + mark + " ---");
         }
     }
 
     /**
      * Saves the response content in the temp directory and adds it to the summary page.
      *
      * @param response the response to save
      * @param request the request used to obtain the response
      * @throws IOException if a problem occurs writing the file
      */
     protected void saveResponse(final WebResponse response, final WebRequest request)
         throws IOException {
         counter_++;
         final String extension = chooseExtension(response.getContentType());
         final File file = createFile(request.getUrl(), extension);
         int length = 0;
         try (InputStream input = response.getContentAsStream()) {
             try (OutputStream fos = Files.newOutputStream(file.toPath())) {
                 length = IOUtils.copy(input, fos);
             }
             catch (final EOFException ignored) {
                 // ignore
             }
         }
 
         final URL url = response.getWebRequest().getUrl();
         if (LOG.isInfoEnabled()) {
             LOG.info("Created file " + file.getAbsolutePath() + " for response " + counter_ + ": " + url);
         }
 
         final StringBuilder bduiler = new StringBuilder();
         bduiler.append("tab[tab.length] = {code: ").append(response.getStatusCode())
                 .append(", fileName: '").append(file.getName()).append("', ")
                 .append("contentType: '").append(response.getContentType())
                 .append("', method: '").append(request.getHttpMethod().name()).append("', ");
         if (request.getHttpMethod() == HttpMethod.POST && request.getEncodingType() == FormEncodingType.URL_ENCODED) {
             bduiler.append("postParameters: ").append(nameValueListToJsMap(request.getRequestParameters()))
                 .append(", ");
         }
         bduiler.append("url: '").append(escapeJSString(url.toString()))
                 .append("', loadTime: ").append(response.getLoadTime())
                 .append(", responseSize: ").append(length)
                 .append(", responseHeaders: ").append(nameValueListToJsMap(response.getResponseHeaders()))
                 .append("};\n");
         appendToJSFile(bduiler.toString());
     }
 
     static String escapeJSString(final String string) {
         return ESCAPE_QUOTE_PATTERN.matcher(string).replaceAll("\\\\'");
     }
 
     static String chooseExtension(final String contentType) {
         if (isJavaScript(contentType)) {
             return ".js";
         }
         else if (MimeType.TEXT_HTML.equals(contentType)) {
             return ".html";
         }
         else if (MimeType.TEXT_CSS.equals(contentType)) {
             return ".css";
         }
         else if (MimeType.TEXT_XML.equals(contentType)) {
             return ".xml";
         }
         else if (MimeType.IMAGE_GIF.equals(contentType)) {
             return ".gif";
         }
         return ".txt";
     }
 
     /**
      * Returns whether the response contains JavaScript content.
      *
      * @param contentType the response's content type
      * @return {@code false} if the content type is not recognized as JavaScript
      */
     static boolean isJavaScript(final String contentType) {
         return contentType.contains("javascript") || contentType.contains("ecmascript")
             || (contentType.startsWith("text/") && contentType.endsWith("js"));
     }
 
     /**
      * Returns whether JavaScript responses should be uncompressed before saving.
      *
      * @return {@code true} if JavaScript responses should be uncompressed; default is {@code true}
      */
     public boolean isUncompressJavaScript() {
         return uncompressJavaScript_;
     }
 
     /**
      * Sets whether responses recognized as JavaScript should be uncompressed.
      * Uncompressing is useful for debugging when the original script is minified to a single line,
      * as it produces more readable output and more useful error messages.
      *
      * @param decompress {@code true} if JavaScript responses should be uncompressed
      */
     public void setUncompressJavaScript(final boolean decompress) {
         uncompressJavaScript_ = decompress;
     }
 
     private void appendToJSFile(final String str) throws IOException {
         try (BufferedWriter jsFileWriter = Files.newBufferedWriter(javaScriptFile_.toPath(),
                                                     StandardCharsets.UTF_8, StandardOpenOption.APPEND)) {
             jsFileWriter.write(str);
         }
     }
 
     /**
      * Computes the best file name to save the response for the given URL.
      *
      * @param url the requested URL
      * @param extension the preferred file extension
      * @return the file to create
      * @throws IOException if a problem occurs creating the file
      */
     private File createFile(final URL url, final String extension) throws IOException {
         String name = url.getPath().replaceFirst("/$", "").replaceAll(".*/", "");
         name = org.htmlunit.util.StringUtils.substringBefore(name, "?"); // remove query
         name = org.htmlunit.util.StringUtils.substringBefore(name, ";"); // remove additional info
         name = StringUtils.substring(name, 0, 30); // avoid exceptions due to too long file names
         name = org.htmlunit.util.StringUtils.sanitizeForFileName(name);
         if (!name.endsWith(extension)) {
             name += extension;
         }
         int counter = 0;
         while (true) {
             final String fileName;
             if (counter != 0) {
                 fileName = StringUtils.substringBeforeLast(name, ".")
                     + "_" + counter + "." + StringUtils.substringAfterLast(name, ".");
             }
             else {
                 fileName = name;
             }
             final File f = new File(reportFolder_, fileName);
             if (f.createNewFile()) {
                 return f;
             }
             counter++;
         }
     }
 
     /**
      * Produces a JavaScript map literal string from a list of {@link NameValuePair}s,
      * e.g. {@code {'key1': 'value1', 'key 2': 'value2'}}.
      *
      * @param headers a list of {@link NameValuePair}s
      * @return the JavaScript map literal string
      */
     static String nameValueListToJsMap(final List<NameValuePair> headers) {
         if (headers == null || headers.isEmpty()) {
             return "{}";
         }
         final StringBuilder bduiler = new StringBuilder("{");
         for (final NameValuePair header : headers) {
             bduiler.append('\'').append(header.getName()).append("': '")
                     .append(escapeJSString(header.getValue())).append("', ");
         }
         bduiler.delete(bduiler.length() - 2, bduiler.length());
         bduiler.append('}');
         return bduiler.toString();
     }
 
     /**
      * Creates the summary file and the JavaScript file that will be updated for each received response.
      *
      * @throws IOException if a problem occurs writing the files
      */
     private void createOverview() throws IOException {
         FileUtils.writeStringToFile(javaScriptFile_, "var tab = [];\n", ISO_8859_1);
 
         final URL indexResource = DebuggingWebConnection.class.getResource("DebuggingWebConnection.index.html");
         if (indexResource == null) {
             throw new RuntimeException("Missing dependency DebuggingWebConnection.index.html");
         }
         final File summary = new File(reportFolder_, "index.html");
         FileUtils.copyURLToFile(indexResource, summary);
 
         if (LOG.isInfoEnabled()) {
             LOG.info("Summary will be in " + summary.getAbsolutePath());
         }
     }
 
     File getReportFolder() {
         return reportFolder_;
     }
 }