content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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
   *
   * http://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 com.alibaba.jstorm.ui.tags;
  
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.JspWriter;
  import javax.servlet.jsp.tagext.SimpleTagSupport;
  import java.io.IOException;
  
  /**
   * @author Jark (wuchong.wc@alibaba-inc.com)
   */
  public class PaginationTag extends SimpleTagSupport {
  
      private int pageSize;
      private int curPage;
      private String urlBase;
  
      public void setPageSize(int pageSize) {
          this.pageSize = pageSize;
      }
  
      public void setCurPage(int curPage) {
          this.curPage = curPage;
      }
  
      public void setUrlBase(String urlBase) {
          this.urlBase = urlBase;
      }
  
      @Override
      public void doTag() throws JspException {
          if (pageSize <= 1)  return;
          JspWriter out = getJspContext().getOut();
          try {
              StringBuilder sb = new StringBuilder();
              sb.append("<nav class='netty-pagination'><ul class='pagination'>");
              if (curPage > 1) {
                  sb.append(String.format("<li><a href='%s' class='previous'>", getUrl(curPage - 1)));
                  sb.append("<span class='glyphicon glyphicon-chevron-left'></span></a>");
                  sb.append("</li>");
              }
              if (pageSize <= 10) {
                  for (int i = 1; i <= pageSize; i++) {
                      sb.append(createPage(i, i == curPage));
                  }
              } else {
                  if (curPage <= 5) {
                      for (int i = 1; i <= curPage; i++) {
                          sb.append(createPage(i, i == curPage));
                      }
                  } else {
                      sb.append(createPage(curPage - 4, "...", false));
                      for (int i = curPage - 3; i <= curPage; i++) {
                          sb.append(createPage(i, i == curPage));
                      }
                  }
  
                  if (pageSize - curPage <= 5) {
                      for (int i = curPage + 1; i <= pageSize; i++) {
                          sb.append(createPage(i, false));
                      }
                  }else{
                      for (int i = curPage + 1; i <= curPage + 3; i++) {
                          sb.append(createPage(i, false));
                      }
                      sb.append(createPage(curPage + 4, "...", false));
                  }
              }
  
              if (curPage < pageSize) {
                  sb.append(String.format("<li><a href='%s' class='next'>", getUrl(curPage + 1)));
                  sb.append("<span class='glyphicon glyphicon-chevron-right'></span></a>");
                  sb.append("</li>");
              }
  
  
              sb.append("</ul></nav>");
              out.write(sb.toString());
          } catch (IOException e) {
              throw new JspException("Error: " + e.getMessage());
          }
      }
  
      private String createPage(int page, String text, boolean isActive) {
          if (isActive) {
              return String.format("<li class='%s'><a href='%s'>%s</a></li>", "active", getUrl(page), text);
          }else{
              return String.format("<li><a href='%s'>%s</a></li>", getUrl(page), text);
          }
      }
  
      private String createPage(int page, boolean isActive) {
          return createPage(page, page + "", isActive);
      }
  
      private String getUrl(int page) {
          return urlBase + "&page=" + page;
      }
  }
  