content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.ui.dialogs.history.diff;
  
  import com.alkacon.diff.Diff;
  
  import org.opencms.main.CmsLog;
  import org.opencms.ui.A_CmsUI;
  import org.opencms.ui.CmsVaadinUtils;
  import org.opencms.util.CmsHtml2TextConverter;
  import org.opencms.util.CmsStringUtil;
  import org.opencms.workplace.comparison.CmsDiffViewMode;
  import org.opencms.workplace.comparison.CmsHtmlDifferenceConfiguration;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.StringReader;
  
  import org.apache.commons.logging.Log;
  
  import com.vaadin.ui.themes.ValoTheme;
  import com.vaadin.v7.data.Property.ValueChangeEvent;
  import com.vaadin.v7.data.Property.ValueChangeListener;
  import com.vaadin.v7.shared.ui.label.ContentMode;
  import com.vaadin.v7.ui.Label;
  import com.vaadin.v7.ui.OptionGroup;
  import com.vaadin.v7.ui.VerticalLayout;
  
  /**
   * Widget used to display a colorized diff view for two texts.<p>
   */
  public class CmsTextDiffPanel extends VerticalLayout {
  
      /** Logger instance for this class. */
      private static final Log LOG = CmsLog.getLog(CmsTextDiffPanel.class);
  
      /** Serial version  id. */
      private static final long serialVersionUID = 1L;
  
      /** Label containing the actual diff. */
      private Label m_diffHtml;
  
      /** The current diff mode. */
      private String m_diffMode = "diff";
  
      /** Selects between different diff modes. */
      private OptionGroup m_diffModeSelect;
  
      /** First text used for comparison. */
      private String m_text1;
  
      /** Second text used for comparison. */
      private String m_text2;
  
      /** The current text mode. */
      private String m_textMode = "html";
  
      /** Selects between different text modes. */
      private OptionGroup m_textOrHtmlSelect;
  
      /**
       * Creates a new instance.<p>
       *
       * @param text1 the first text
       * @param text2 the second text
       *
       * @param selectTextOrHtml true if the option to select between comparison as text and comparison as HTML should be shown
       * @param selectDiffMode true if the option to select between showing only the changed lines or all the lines should be displayed
       */
      public CmsTextDiffPanel(String text1, String text2, boolean selectTextOrHtml, boolean selectDiffMode) {
          CmsVaadinUtils.readAndLocalizeDesign(this, CmsVaadinUtils.getWpMessagesForCurrentLocale(), null);
          m_text1 = text1;
          m_text2 = text2;
          m_textOrHtmlSelect.addStyleName(ValoTheme.OPTIONGROUP_HORIZONTAL);
          m_textOrHtmlSelect.setValue("html");
          m_textOrHtmlSelect.setVisible(selectTextOrHtml);
          m_diffModeSelect.setValue("diff");
          m_diffModeSelect.addStyleName(ValoTheme.OPTIONGROUP_HORIZONTAL);
          m_diffModeSelect.setVisible(selectDiffMode);
  
          m_textOrHtmlSelect.addValueChangeListener(new ValueChangeListener() {
  
              private static final long serialVersionUID = 1L;
  
              @SuppressWarnings("synthetic-access")
              public void valueChange(ValueChangeEvent event) {
  
                  m_textMode = event.getProperty().getValue().toString();
                  update();
              }
          });
  
          m_diffModeSelect.addValueChangeListener(new ValueChangeListener() {
  
              private static final long serialVersionUID = 1L;
  
              @SuppressWarnings("synthetic-access")
              public void valueChange(ValueChangeEvent event) {
  
                  m_diffMode = event.getProperty().getValue().toString();
                  update();
              }
          });
  
          update();
      }
  
      /**
       * Gets the diff HTML based on the selected display options.<p>
       *
       * @return the diff HTML to display
       *
       * @throws Exception if something goes wrong
       */
      public String getDiffHtml() throws Exception {
  
          CmsDiffViewMode mode = "all".equals(m_diffMode) ? CmsDiffViewMode.ALL : CmsDiffViewMode.DIFF_ONLY;
          String text1 = m_text1;
          String text2 = m_text2;
          if ("text".equals(m_textMode)) {
              text1 = CmsHtml2TextConverter.html2text(text1, "UTF-8");
              text2 = CmsHtml2TextConverter.html2text(text2, "UTF-8");
          }
          CmsHtmlDifferenceConfiguration conf = new CmsHtmlDifferenceConfiguration(
              mode == CmsDiffViewMode.ALL ? -1 : 2,
              A_CmsUI.get().getLocale());
          String diff = Diff.diffAsHtml(text1, text2, conf);
          String html = null;
          if (CmsStringUtil.isNotEmpty(diff)) {
              html = diff;
          } else {
              html = wrapLinesWithUnchangedStyle(
                  CmsStringUtil.substitute(CmsStringUtil.escapeHtml(m_text1), "<br/>", ""));
          }
          return html;
  
      }
  
      /**
       * Updates the displayed diff based on the selected display options.<p>
       */
      public void update() {
  
          try {
              String diffHtml = "<pre class='o-text-diff'>" + getDiffHtml() + "</pre>";
              m_diffHtml.setContentMode(ContentMode.HTML);
              m_diffHtml.setValue(diffHtml);
          } catch (Exception e) {
              LOG.error(e.getLocalizedMessage(), e);
          }
  
      }
  
      /**
      *
      * Returns a diff text wrapped with formatting style.<p>
      *
      * @param diff the text to wrap with CSS formatting
      * @return the text with formatting styles wrapped
      * @throws IOException if something goes wrong
      */
      protected String wrapLinesWithUnchangedStyle(String diff) throws IOException {
  
          String line;
          StringBuffer result = new StringBuffer();
          BufferedReader br = new BufferedReader(new StringReader(diff));
          while ((line = br.readLine()) != null) {
              if ("".equals(line.trim())) {
                  line = "&nbsp;";
              }
              result.append("<div class=\"df-unc\"><span class=\"df-unc\">").append(line).append("</span></div>\n");
          }
          return result.toString();
      }
  
  }
  