/*
    * 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.html;
  
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.nio.charset.Charset;
  import java.util.Map;
  import java.util.Objects;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.htmlunit.FailingHttpStatusCodeException;
  import org.htmlunit.FrameContentHandler;
  import org.htmlunit.Page;
  import org.htmlunit.SgmlPage;
  import org.htmlunit.WebClient;
  import org.htmlunit.WebRequest;
  import org.htmlunit.WebWindow;
  import org.htmlunit.javascript.AbstractJavaScriptEngine;
  import org.htmlunit.javascript.PostponedAction;
  import org.htmlunit.protocol.javascript.JavaScriptURLConnection;
  import org.htmlunit.util.UrlUtils;
  import org.w3c.dom.Attr;
  
  /**
   * Base class for frame and iframe.
   *
   * @author Mike Bowler
   * @author David K. Taylor
   * @author Christian Sell
   * @author Marc Guillemot
   * @author David D. Kilzer
   * @author Stefan Anzinger
   * @author Ahmed Ashour
   * @author Dmitri Zoubkov
   * @author Daniel Gredler
   * @author Ronald Brill
   * @author Frank Danek
   * @author Lai Quang Duong
   */
  public abstract class BaseFrameElement extends HtmlElement {
  
      private static final Log LOG = LogFactory.getLog(BaseFrameElement.class);
      private FrameWindow enclosedWindow_;
      private boolean contentLoaded_;
      private boolean loadSrcWhenAddedToPage_;
  
      /**
       * Creates an instance of BaseFrame.
       *
       * @param qualifiedName the qualified name of the element type to instantiate
       * @param page the HtmlPage that contains this element
       * @param attributes the initial attributes
       */
      protected BaseFrameElement(final String qualifiedName, final SgmlPage page,
              final Map<String, DomAttr> attributes) {
          super(qualifiedName, page, attributes);
  
          init();
  
          if (null != page && page.isHtmlPage() && ((HtmlPage) page).isParsingHtmlSnippet()) {
              // if created by the HTMLParser the src attribute is not set via setAttribute() or some other method but is
              // part of the given attributes already.
              final String src = getSrcAttribute();
  
              // src-less IFrame or src='about:blank'
              // these are loaded sync
              if (ATTRIBUTE_NOT_DEFINED != src && !UrlUtils.ABOUT_BLANK.equals(src.trim())) {
                  loadSrcWhenAddedToPage_ = true;
              }
          }
      }
  
      private void init() {
          FrameWindow enclosedWindow = null;
          try {
              final HtmlPage htmlPage = getHtmlPageOrNull();
              if (null != htmlPage) { // if loaded as part of XHR.responseXML, don't load content
                  enclosedWindow = new FrameWindow(this);
                  // put about:blank in the window to allow JS to run on this frame before the
                  // real content is loaded
                  final WebClient webClient = htmlPage.getWebClient();
                  final HtmlPage temporaryPage = webClient.getPage(enclosedWindow, WebRequest.newAboutBlankRequest());
                  temporaryPage.setReadyState(READY_STATE_LOADING);
              }
         }
         catch (final FailingHttpStatusCodeException | IOException ignored) {
             // should never occur
         }
         enclosedWindow_ = enclosedWindow;
     }
 
     /**
      * <span style="color:red">INTERNAL API - SUBJECT TO CHANGE AT ANY TIME - USE AT YOUR OWN RISK.</span><br>
      *
      * Called after the node for the {@code frame} or {@code iframe} has been added to the containing page.
      * The node needs to be added first to allow JavaScript in the frame to see the frame in the parent.
      * @throws FailingHttpStatusCodeException if the server returns a failing status code AND the property
      *      {@link org.htmlunit.WebClientOptions#setThrowExceptionOnFailingStatusCode(boolean)} is
      *      set to true
      */
 
     public void loadInnerPage() throws FailingHttpStatusCodeException {
         String source = getSrcAttribute();
         if (source.isEmpty()) {
             source = UrlUtils.ABOUT_BLANK;
         }
 
         loadInnerPageIfPossible(source);
 
         final Page enclosedPage = getEnclosedPage();
         if (enclosedPage != null && enclosedPage.isHtmlPage()) {
             final HtmlPage htmlPage = (HtmlPage) enclosedPage;
 
             final AbstractJavaScriptEngine<?> jsEngine = htmlPage.getWebClient().getJavaScriptEngine();
             if (jsEngine != null && jsEngine.isScriptRunning()) {
                 final PostponedAction action = new PostponedAction(getPage(), "BaseFrame.loadInnerPage") {
                     @Override
                     public void execute() {
                         htmlPage.setReadyState(READY_STATE_COMPLETE);
                     }
                 };
                 jsEngine.addPostponedAction(action);
             }
             else {
                 htmlPage.setReadyState(READY_STATE_COMPLETE);
             }
         }
     }
 
     /**
      * Indicates if the content specified by the {@code src} attribute has been loaded or not.
      * The initial state of a frame contains an "about:blank" that is not loaded like
      * something specified in {@code src} attribute.
      * @return {@code false} if the frame is still in its initial state.
      */
     boolean isContentLoaded() {
         return contentLoaded_;
     }
 
     /**
      * Changes the state of the {@code contentLoaded_} attribute to true.
      * This is needed, if the content is set from javascript to avoid
      * later overwriting from method org.htmlunit.html.HtmlPage.loadFrames().
      */
     void setContentLoaded() {
         contentLoaded_ = true;
     }
 
     private void loadInnerPageIfPossible(final String src) throws FailingHttpStatusCodeException {
         setContentLoaded();
 
         String source = src;
         final SgmlPage page = getPage();
         final WebClient webClient = page.getWebClient();
         final FrameContentHandler handler = webClient.getFrameContentHandler();
         if (null != handler && !handler.loadFrameDocument(this)) {
             source = UrlUtils.ABOUT_BLANK;
         }
 
         if (!source.isEmpty()) {
             final URL url;
             try {
                 url = ((HtmlPage) page).getFullyQualifiedUrl(source);
             }
             catch (final MalformedURLException e) {
                 notifyIncorrectness("Invalid src attribute of " + getTagName() + ": url=[" + source + "]. Ignored.");
                 return;
             }
 
             final URL pageUrl = page.getUrl();
 
             // accessing to local resource is forbidden for security reason
             if (!"file".equals(pageUrl.getProtocol()) && "file".equals(url.getProtocol())) {
                 notifyIncorrectness("Not allowed to load local resource: " + source);
                 return;
             }
 
             final Charset pageCharset = page.getCharset();
             final WebRequest request = new WebRequest(url, pageCharset, pageUrl);
 
             if (isAlreadyLoadedByAncestor(url, request.getCharset())) {
                 notifyIncorrectness("Recursive src attribute of " + getTagName() + ": url=[" + source + "]. Ignored.");
                 return;
             }
 
             // Use parent document's charset as container charset if same origin
             // https://html.spec.whatwg.org/multipage/parsing.html#determining-the-character-encoding
             if (Objects.equals(pageUrl.getProtocol(), url.getProtocol())
                     && Objects.equals(pageUrl.getAuthority(), url.getAuthority())) {
                 request.setDefaultResponseContentCharset(pageCharset);
             }
 
             try {
                 webClient.getPage(enclosedWindow_, request);
             }
             catch (final IOException e) {
                 if (LOG.isErrorEnabled()) {
                     LOG.error("IOException when getting content for " + getTagName() + ": url=[" + url + "]", e);
                 }
             }
         }
     }
 
     /**
      * Test if the provided URL is the one of the parents which would cause an infinite loop.
      * @param url the URL to test
      * @param charset the request charset
      * @return {@code false} if no parent has already this URL
      */
     private boolean isAlreadyLoadedByAncestor(final URL url, final Charset charset) {
         WebWindow window = getPage().getEnclosingWindow();
         int nesting = 0;
         while (window instanceof FrameWindow) {
             nesting++;
             if (nesting > 9) {
                 return true;
             }
 
             final URL encUrl = UrlUtils.encodeUrl(url, charset);
             if (UrlUtils.sameFile(encUrl, window.getEnclosedPage().getUrl())) {
                 return true;
             }
 
             if (window == window.getParentWindow()) {
                 // TODO: should getParentWindow() return null on top windows?
                 window = null;
             }
             else {
                 window = window.getParentWindow();
             }
         }
         return false;
     }
 
     /**
      * Returns the value of the attribute {@code longdesc}. 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 longdesc} or an empty string if that attribute isn't defined
      */
     public final String getLongDescAttribute() {
         return getAttributeDirect("longdesc");
     }
 
     /**
      * 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);
     }
 
     /**
      * Sets the value of the {@code name} attribute.
      *
      * @param name the new window name
      */
     public final void setNameAttribute(final String name) {
         setAttribute(NAME_ATTRIBUTE, name);
     }
 
     /**
      * Returns the value of the attribute {@code src}. 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 src} or an empty string if that attribute isn't defined
      */
     public final String getSrcAttribute() {
         return getSrcAttributeNormalized();
     }
 
     /**
      * Returns the value of the attribute {@code frameborder}. 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 frameborder} or an empty string if that attribute isn't defined
      */
     public final String getFrameBorderAttribute() {
         return getAttributeDirect("frameborder");
     }
 
     /**
      * Returns the value of the attribute {@code marginwidth}. 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 marginwidth} or an empty string if that attribute isn't defined
      */
     public final String getMarginWidthAttribute() {
         return getAttributeDirect("marginwidth");
     }
 
     /**
      * Returns the value of the attribute {@code marginheight}. 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 marginheight} or an empty string if that attribute isn't defined
      */
     public final String getMarginHeightAttribute() {
         return getAttributeDirect("marginheight");
     }
 
     /**
      * Returns the value of the attribute {@code noresize}. 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 noresize} or an empty string if that attribute isn't defined
      */
     public final String getNoResizeAttribute() {
         return getAttributeDirect("noresize");
     }
 
     /**
      * Returns the value of the attribute {@code scrolling}. 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 scrolling} or an empty string if that attribute isn't defined
      */
     public final String getScrollingAttribute() {
         return getAttributeDirect("scrolling");
     }
 
     /**
      * Returns the value of the attribute {@code onload}. This attribute is not
      * actually supported by the HTML specification however it is supported
      * by the popular browsers.
      *
      * @return the value of the attribute {@code onload} or an empty string if that attribute isn't defined
      */
     public final String getOnLoadAttribute() {
         return getAttributeDirect("onload");
     }
 
     /**
      * Returns the currently loaded page in the enclosed window.
      * This is a facility method for <code>getEnclosedWindow().getEnclosedPage()</code>.
      * @see WebWindow#getEnclosedPage()
      * @return the currently loaded page in the enclosed window, or {@code null} if no page has been loaded
      */
     public Page getEnclosedPage() {
         return getEnclosedWindow().getEnclosedPage();
     }
 
     /**
      * Gets the window enclosed in this frame.
      * @return the window enclosed in this frame
      */
     public FrameWindow getEnclosedWindow() {
         return enclosedWindow_;
     }
 
     /**
      * Sets the value of the {@code src} attribute. Also loads the frame with the specified URL, if possible.
      * @param attribute the new value of the {@code src} attribute
      */
     public final void setSrcAttribute(final String attribute) {
         setAttribute(SRC_ATTRIBUTE, attribute);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected void setAttributeNS(final String namespaceURI, final String qualifiedName, final String attributeValue,
             final boolean notifyAttributeChangeListeners, final boolean notifyMutationObserver) {
         final String qualifiedNameLC = org.htmlunit.util.StringUtils.toRootLowerCase(qualifiedName);
 
         if (null != attributeValue && SRC_ATTRIBUTE.equals(qualifiedNameLC)) {
             final String attributeValueTrimmed = attributeValue.trim();
 
             super.setAttributeNS(namespaceURI, qualifiedNameLC, attributeValueTrimmed, notifyAttributeChangeListeners,
                     notifyMutationObserver);
 
             // do not use equals() here
             // see HTMLIFrameElement2Test.documentCreateElement_onLoad_srcAboutBlank()
             if (UrlUtils.ABOUT_BLANK != attributeValueTrimmed) {
                 if (isAttachedToPage()) {
                     loadSrc();
                 }
                 else {
                     loadSrcWhenAddedToPage_ = true;
                 }
             }
 
             return;
         }
 
         super.setAttributeNS(namespaceURI, qualifiedNameLC, attributeValue, notifyAttributeChangeListeners,
                 notifyMutationObserver);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Attr setAttributeNode(final Attr attribute) {
         final String qualifiedName = attribute.getName();
         String attributeValue = null;
         if (SRC_ATTRIBUTE.equals(qualifiedName)) {
             attributeValue = attribute.getValue().trim();
         }
 
         final Attr result = super.setAttributeNode(attribute);
 
         if (SRC_ATTRIBUTE.equals(qualifiedName) && !UrlUtils.ABOUT_BLANK.equals(attributeValue)) {
             if (isAttachedToPage()) {
                 loadSrc();
             }
             else {
                 loadSrcWhenAddedToPage_ = true;
             }
         }
 
         return result;
     }
 
     private void loadSrc() {
         loadSrcWhenAddedToPage_ = false;
         final String src = getSrcAttribute();
 
         // recreate a window if the old one was closed
         if (enclosedWindow_.isClosed()) {
             init();
         }
 
         final AbstractJavaScriptEngine<?> jsEngine = getPage().getWebClient().getJavaScriptEngine();
         // When src is set from a script, loading is postponed until script finishes
         // in fact this implementation is probably wrong: JavaScript URL should be
         // first evaluated and only loading, when any, should be postponed.
         if (jsEngine == null || !jsEngine.isScriptRunning()
                 || src.startsWith(JavaScriptURLConnection.JAVASCRIPT_PREFIX)) {
             loadInnerPageIfPossible(src);
         }
         else {
             final Page pageInFrame = getEnclosedPage();
             final PostponedAction action = new PostponedAction(getPage(), "BaseFrame.loadSrc") {
                 @Override
                 public void execute() throws Exception {
                     if (!src.isEmpty() && getSrcAttribute().equals(src)) {
                         loadInnerPage();
                     }
                 }
 
                 @Override
                 public boolean isStillAlive() {
                     // skip if page in frame has already been changed
                     return super.isStillAlive() && pageInFrame == getEnclosedPage();
                 }
             };
             jsEngine.addPostponedAction(action);
         }
     }
 
     /**
      * Creates a new {@link WebWindow} for the new clone.
      * {@inheritDoc}
      */
     @Override
     public DomNode cloneNode(final boolean deep) {
         final BaseFrameElement clone = (BaseFrameElement) super.cloneNode(deep);
         clone.init();
         return clone;
     }
 
     @Override
     protected void onAddedToPage() {
         super.onAddedToPage();
 
         if (loadSrcWhenAddedToPage_) {
             loadSrc();
         }
     }
 
     @Override
     public void remove() {
         super.remove();
         loadSrcWhenAddedToPage_ = true;
         getEnclosedWindow().close();
     }
 
     @Override
     public final void removeAttribute(final String attributeName) {
         super.removeAttribute(attributeName);
 
         // TODO find a better implementation without all the code duplication
         if (isAttachedToPage()) {
             loadSrcWhenAddedToPage_ = false;
             final String src = getSrcAttribute();
 
             final AbstractJavaScriptEngine<?> jsEngine = getPage().getWebClient().getJavaScriptEngine();
             // When src is set from a script, loading is postponed until script finishes
             // in fact this implementation is probably wrong: JavaScript URL should be
             // first evaluated and only loading, when any, should be postponed.
             if (jsEngine == null || !jsEngine.isScriptRunning()) {
                 loadInnerPageIfPossible(src);
             }
             else {
                 final Page pageInFrame = getEnclosedPage();
                 final PostponedAction action = new PostponedAction(getPage(), "BaseFrame.removeAttribute") {
                     @Override
                     public void execute() throws Exception {
                         loadInnerPage();
                     }
 
                     @Override
                     public boolean isStillAlive() {
                         // skip if page in frame has already been changed
                         return super.isStillAlive() && pageInFrame == getEnclosedPage();
                     }
                 };
                 jsEngine.addPostponedAction(action);
             }
         }
         else {
             loadSrcWhenAddedToPage_ = true;
         }
     }
 }