/*
    * Copyright (c) 2002-2025 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.html;
  
  import static org.htmlunit.BrowserVersionFeatures.ANCHOR_SEND_PING_REQUEST;
  
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.Locale;
  import java.util.Map;
  
  import org.apache.commons.lang3.ArrayUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.htmlunit.BrowserVersion;
  import org.htmlunit.HttpHeader;
  import org.htmlunit.HttpMethod;
  import org.htmlunit.Page;
  import org.htmlunit.SgmlPage;
  import org.htmlunit.WebClient;
  import org.htmlunit.WebRequest;
  import org.htmlunit.WebWindow;
  import org.htmlunit.javascript.host.event.Event;
  import org.htmlunit.javascript.host.html.HTMLElement;
  import org.htmlunit.protocol.javascript.JavaScriptURLConnection;
  import org.htmlunit.util.StringUtils;
  import org.htmlunit.util.UrlUtils;
  
  /**
   * Wrapper for the HTML element "a".
   *
   * @author Mike Bowler
   * @author David K. Taylor
   * @author Christian Sell
   * @author Ahmed Ashour
   * @author Dmitri Zoubkov
   * @author Ronald Brill
   * @author Frank Danek
   * @author Lai Quang Duong
   */
  public class HtmlAnchor extends HtmlElement {
  
      private static final Log LOG = LogFactory.getLog(HtmlAnchor.class);
  
      /** The HTML tag represented by this element. */
      public static final String TAG_NAME = "a";
  
      /**
       * Creates a new instance.
       *
       * @param qualifiedName the qualified name of the element type to instantiate
       * @param page the page that contains this element
       * @param attributes the initial attributes
       */
      HtmlAnchor(final String qualifiedName, final SgmlPage page,
              final Map<String, DomAttr> attributes) {
          super(qualifiedName, page, attributes);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      @SuppressWarnings("unchecked")
      public <P extends Page> P click(final Event event,
              final boolean shiftKey, final boolean ctrlKey, final boolean altKey,
              final boolean ignoreVisibility) throws IOException {
          WebWindow oldWebWindow = null;
          if (ctrlKey) {
              oldWebWindow = ((HTMLElement) event.getSrcElement()).getDomNodeOrDie()
                      .getPage().getWebClient().getCurrentWindow();
          }
  
          P page = super.click(event, shiftKey, ctrlKey, altKey, ignoreVisibility);
  
          if (ctrlKey) {
              page.getEnclosingWindow().getWebClient().setCurrentWindow(oldWebWindow);
              page = (P) oldWebWindow.getEnclosedPage();
          }
  
          return page;
      }
  
      /**
       * Same as {@link #doClickStateUpdate(boolean, boolean)}, except that it accepts an {@code href} suffix,
       * needed when a click is performed on an image map to pass information on the click position.
      *
      * @param shiftKey {@code true} if SHIFT is pressed
      * @param ctrlKey {@code true} if CTRL is pressed
      * @param hrefSuffix the suffix to add to the anchor's {@code href} attribute
      *        (for instance coordinates from an image map)
      * @throws IOException if an IO error occurs
      */
     protected void doClickStateUpdate(final boolean shiftKey, final boolean ctrlKey, final String hrefSuffix)
             throws IOException {
         final String href = (getHrefAttribute() + hrefSuffix).trim();
         if (LOG.isDebugEnabled()) {
             final String w = getPage().getEnclosingWindow().getName();
             LOG.debug("do click action in window '" + w + "', using href '" + href + "'");
         }
         if (ATTRIBUTE_NOT_DEFINED == getHrefAttribute()) {
             return;
         }
         final String downloadAttribute = getDownloadAttribute();
         HtmlPage page = (HtmlPage) getPage();
         if (StringUtils.startsWithIgnoreCase(href, JavaScriptURLConnection.JAVASCRIPT_PREFIX)) {
             final StringBuilder builder = new StringBuilder(href.length());
             builder.append(JavaScriptURLConnection.JAVASCRIPT_PREFIX);
             for (int i = JavaScriptURLConnection.JAVASCRIPT_PREFIX.length(); i < href.length(); i++) {
                 final char ch = href.charAt(i);
                 if (ch == '%' && i + 2 < href.length()) {
                     final char ch1 = Character.toUpperCase(href.charAt(i + 1));
                     final char ch2 = Character.toUpperCase(href.charAt(i + 2));
                     if ((Character.isDigit(ch1) || ch1 >= 'A' && ch1 <= 'F')
                             && (Character.isDigit(ch2) || ch2 >= 'A' && ch2 <= 'F')) {
                         builder.append((char) Integer.parseInt(href.substring(i + 1, i + 3), 16));
                         i += 2;
                         continue;
                     }
                 }
                 builder.append(ch);
             }
 
             final String target;
             if (shiftKey || ctrlKey || ATTRIBUTE_NOT_DEFINED != downloadAttribute) {
                 target = WebClient.TARGET_BLANK;
             }
             else {
                 target = page.getResolvedTarget(getTargetAttribute());
             }
             final WebWindow win = page.getWebClient().openTargetWindow(page.getEnclosingWindow(),
                     target, WebClient.TARGET_SELF);
             Page enclosedPage = win.getEnclosedPage();
             if (enclosedPage == null) {
                 win.getWebClient().getPage(win, WebRequest.newAboutBlankRequest());
                 enclosedPage = win.getEnclosedPage();
             }
             if (enclosedPage != null && enclosedPage.isHtmlPage()) {
                 page = (HtmlPage) enclosedPage;
                 page.executeJavaScript(builder.toString(), "javascript url", getStartLineNumber());
             }
             return;
         }
 
         final URL url = getTargetUrl(href, page);
 
         final WebClient webClient = page.getWebClient();
         final BrowserVersion browser = webClient.getBrowserVersion();
         if (ATTRIBUTE_NOT_DEFINED != getPingAttribute() && browser.hasFeature(ANCHOR_SEND_PING_REQUEST)) {
             final URL pingUrl = getTargetUrl(getPingAttribute(), page);
             final WebRequest pingRequest = new WebRequest(pingUrl, HttpMethod.POST);
             pingRequest.setAdditionalHeader(HttpHeader.PING_FROM, page.getUrl().toExternalForm());
             pingRequest.setAdditionalHeader(HttpHeader.PING_TO, url.toExternalForm());
             pingRequest.setRequestBody("PING");
             webClient.loadWebResponse(pingRequest);
         }
 
         final WebRequest webRequest = new WebRequest(url, browser.getHtmlAcceptHeader(),
                                                             browser.getAcceptEncodingHeader());
         // use the page encoding even if this is a GET requests
         webRequest.setCharset(page.getCharset());
 
         if (!relContainsNoreferrer()) {
             webRequest.setRefererHeader(page.getUrl());
         }
 
         if (LOG.isDebugEnabled()) {
             LOG.debug(
                     "Getting page for " + url.toExternalForm()
                     + ", derived from href '" + href
                     + "', using the originating URL "
                     + page.getUrl());
         }
 
         final String target;
         if (shiftKey || ctrlKey
                 || (webClient.getAttachmentHandler() == null
                         && ATTRIBUTE_NOT_DEFINED != downloadAttribute)) {
             target = WebClient.TARGET_BLANK;
         }
         else {
             target = page.getResolvedTarget(getTargetAttribute());
         }
         page.getWebClient().download(page.getEnclosingWindow(), target, webRequest,
                 true, (ATTRIBUTE_NOT_DEFINED == downloadAttribute) ? null : downloadAttribute, "Link click");
     }
 
     private boolean relContainsNoreferrer() {
         String rel = getRelAttribute();
         if (rel != null) {
             rel = rel.toLowerCase(Locale.ROOT);
             return ArrayUtils.contains(StringUtils.splitAtBlank(rel), "noreferrer");
         }
         return false;
     }
 
     /**
      * <span style="color:red">INTERNAL API - SUBJECT TO CHANGE AT ANY TIME - USE AT YOUR OWN RISK.</span><br>
      *
      * @param href the href
      * @param page the HtmlPage
      * @return the calculated target url.
      * @throws MalformedURLException if an IO error occurs
      */
     public static URL getTargetUrl(final String href, final HtmlPage page) throws MalformedURLException {
         URL url = page.getFullyQualifiedUrl(href);
         // fix for empty url
         if (StringUtils.isEmptyOrNull(href)) {
             url = UrlUtils.getUrlWithNewRef(url, null);
         }
         return url;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected boolean doClickStateUpdate(final boolean shiftKey, final boolean ctrlKey) throws IOException {
         doClickStateUpdate(shiftKey, ctrlKey, "");
         return false;
     }
 
     /**
      * Returns the value of the attribute {@code charset}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code charset} or an empty string if that attribute isn't defined
      */
     public final String getCharsetAttribute() {
         return getAttributeDirect("charset");
     }
 
     /**
      * Returns the value of the attribute {@code type}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code type} or an empty string if that attribute isn't defined
      */
     public final String getTypeAttribute() {
         return getAttributeDirect(TYPE_ATTRIBUTE);
     }
 
     /**
      * Returns the value of the attribute {@code name}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code name} or an empty string if that attribute isn't defined
      */
     public final String getNameAttribute() {
         return getAttributeDirect(NAME_ATTRIBUTE);
     }
 
     /**
      * Returns the value of the attribute {@code href}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code href} or an empty string if that attribute isn't defined
      */
     public final String getHrefAttribute() {
         return getAttributeDirect("href").trim();
     }
 
     /**
      * Returns the value of the attribute {@code hreflang}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code hreflang} or an empty string if that attribute isn't defined
      */
     public final String getHrefLangAttribute() {
         return getAttributeDirect("hreflang");
     }
 
     /**
      * Returns the value of the attribute {@code rel}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code rel} or an empty string if that attribute isn't defined
      */
     public final String getRelAttribute() {
         return getAttributeDirect("rel");
     }
 
     /**
      * Returns the value of the attribute {@code rev}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code rev} or an empty string if that attribute isn't defined
      */
     public final String getRevAttribute() {
         return getAttributeDirect("rev");
     }
 
     /**
      * Returns the value of the attribute {@code accesskey}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code accesskey} or an empty string if that attribute isn't defined
      */
     public final String getAccessKeyAttribute() {
         return getAttributeDirect("accesskey");
     }
 
     /**
      * Returns the value of the attribute {@code shape}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code shape} or an empty string if that attribute isn't defined
      */
     public final String getShapeAttribute() {
         return getAttributeDirect("shape");
     }
 
     /**
      * Returns the value of the attribute {@code coords}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code coords} or an empty string if that attribute isn't defined
      */
     public final String getCoordsAttribute() {
         return getAttributeDirect("coords");
     }
 
     /**
      * Returns the value of the attribute {@code tabindex}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code tabindex} or an empty string if that attribute isn't defined
      */
     public final String getTabIndexAttribute() {
         return getAttributeDirect("tabindex");
     }
 
     /**
      * Returns the value of the attribute {@code onfocus}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code onfocus} or an empty string if that attribute isn't defined
      */
     public final String getOnFocusAttribute() {
         return getAttributeDirect("onfocus");
     }
 
     /**
      * Returns the value of the attribute {@code onblur}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code onblur} or an empty string if that attribute isn't defined
      */
     public final String getOnBlurAttribute() {
         return getAttributeDirect("onblur");
     }
 
     /**
      * Returns the value of the attribute {@code target}. Refer to the
      * <a href="http://www.w3.org/TR/html401/">HTML 4.01</a>
      * documentation for details on the use of this attribute.
      *
      * @return the value of the attribute {@code target} or an empty string if that attribute isn't defined
      */
     public final String getTargetAttribute() {
         return getAttributeDirect("target");
     }
 
     /**
      * Open this link in a new window, much as web browsers do when you shift-click a link or use the context
      * menu to open in a new window.
      * <p>
      * It should be noted that even web browsers will sometimes not give the expected result when using this
      * method of following links. Links that have no real href and rely on JavaScript to do their work will
      * fail.
      *
      * @return the page opened by this link, nested in a new {@link org.htmlunit.TopLevelWindow}
      * @throws MalformedURLException if the href could not be converted to a valid URL
      */
     public final Page openLinkInNewWindow() throws MalformedURLException {
         final URL target = ((HtmlPage) getPage()).getFullyQualifiedUrl(getHrefAttribute());
         final String windowName = "HtmlAnchor.openLinkInNewWindow() target";
         final WebWindow newWindow = getPage().getWebClient().openWindow(target, windowName);
         return newWindow.getEnclosedPage();
     }
 
     @Override
     protected boolean isEmptyXmlTagExpanded() {
         return true;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public DisplayStyle getDefaultStyleDisplay() {
         return DisplayStyle.INLINE;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean handles(final Event event) {
         if (Event.TYPE_BLUR.equals(event.getType()) || Event.TYPE_FOCUS.equals(event.getType())) {
             return true;
         }
         return super.handles(event);
     }
 
     /**
      * Returns the value of the attribute {@code ping}.
      *
      * @return the value of the attribute {@code ping}
      */
     public final String getPingAttribute() {
         return getAttributeDirect("ping");
     }
 
     /**
      * Returns the value of the attribute {@code download}.
      *
      * @return the value of the attribute {@code download}
      */
     public final String getDownloadAttribute() {
         return getAttributeDirect("download");
     }
 }