package us.codecraft.webmagic.selector;
   
   
   import java.util.ArrayList;
   import java.util.List;
   import org.apache.commons.collections4.CollectionUtils;
   import org.jsoup.nodes.Element;
   import org.jsoup.nodes.Node;
   import org.jsoup.nodes.TextNode;
  import org.jsoup.select.Elements;
  
  /**
   * CSS selector. Based on Jsoup.
   *
   * @author code4crafter@gmail.com <br>
   * @since 0.1.0
   */
  public class CssSelector extends BaseElementSelector {
  
      private String selectorText;
  
      private String attrName;
  
      public CssSelector(String selectorText) {
          this.selectorText = selectorText;
      }
  
      public CssSelector(String selectorText, String attrName) {
          this.selectorText = selectorText;
          this.attrName = attrName;
      }
  
      private String getValue(Element element) {
          if (attrName == null) {
              return element.outerHtml();
          } else if ("innerHtml".equalsIgnoreCase(attrName)) {
              return element.html();
          } else if ("text".equalsIgnoreCase(attrName)) {
              return getText(element);
          } else if ("allText".equalsIgnoreCase(attrName)) {
              return element.text();
          } else {
              return element.attr(attrName);
          }
      }
  
      protected String getText(Element element) {
          StringBuilder accum = new StringBuilder();
          for (Node node : element.childNodes()) {
              if (node instanceof TextNode) {
                  TextNode textNode = (TextNode) node;
                  accum.append(textNode.text());
              }
          }
          return accum.toString();
      }
  
      @Override
      public String select(Element element) {
          List<Element> elements = selectElements(element);
          if (CollectionUtils.isEmpty(elements)) {
              return null;
          }
          return getValue(elements.get(0));
      }
  
      @Override
      public List<String> selectList(Element doc) {
          List<String> strings = new ArrayList<String>();
          List<Element> elements = selectElements(doc);
          if (CollectionUtils.isNotEmpty(elements)) {
              for (Element element : elements) {
                  String value = getValue(element);
                  if (value != null) {
                      strings.add(value);
                  }
              }
          }
          return strings;
      }
  
      @Override
      public Element selectElement(Element element) {
          Elements elements = element.select(selectorText);
          if (CollectionUtils.isNotEmpty(elements)) {
              return elements.get(0);
          }
          return null;
      }
  
      @Override
      public List<Element> selectElements(Element element) {
          return element.select(selectorText);
      }
  
      @Override
      public boolean hasAttribute() {
          return attrName != null;
      }
 }