package us.codecraft.webmagic.configurable;
   
   import us.codecraft.webmagic.selector.JsonPathSelector;
   import us.codecraft.webmagic.selector.Selector;
   
   import static us.codecraft.webmagic.selector.Selectors.*;
   
   /**
    * @author code4crafter@gmail.com
   */
  public class ExtractRule {
  
      private String fieldName;
  
      private ExpressionType expressionType;
  
      private String expressionValue;
  
      private String[] expressionParams;
  
      private boolean multi = false;
  
      private volatile Selector selector;
  
      private boolean notNull = false;
  
      public String getFieldName() {
          return fieldName;
      }
  
      public void setFieldName(String fieldName) {
          this.fieldName = fieldName;
      }
  
      public ExpressionType getExpressionType() {
          return expressionType;
      }
  
      public void setExpressionType(ExpressionType expressionType) {
          this.expressionType = expressionType;
      }
  
      public String getExpressionValue() {
          return expressionValue;
      }
  
      public void setExpressionValue(String expressionValue) {
          this.expressionValue = expressionValue;
      }
  
      public String[] getExpressionParams() {
          return expressionParams;
      }
  
      public void setExpressionParams(String[] expressionParams) {
          this.expressionParams = expressionParams;
      }
  
      public boolean isMulti() {
          return multi;
      }
  
      public void setMulti(boolean multi) {
          this.multi = multi;
      }
  
      public Selector getSelector() {
          if (selector == null) {
              synchronized (this) {
                  if (selector == null) {
                      selector = compileSelector();
                  }
              }
          }
          return selector;
      }
  
      private Selector compileSelector() {
          switch (expressionType) {
              case Css:
                  if (expressionParams.length >= 1) {
                      return $(expressionValue, expressionParams[0]);
                  } else {
                      return $(expressionValue);
                  }
              case XPath:
                  return xpath(expressionValue);
              case Regex:
                  if (expressionParams.length >= 1) {
                      return regex(expressionValue, Integer.parseInt(expressionParams[0]));
                  } else {
                      return regex(expressionValue);
                  }
              case JsonPath:
                  return new JsonPathSelector(expressionValue);
              default:
                  return xpath(expressionValue);
          }
      }
 
     public void setSelector(Selector selector) {
         this.selector = selector;
     }
 
     public boolean isNotNull() {
         return notNull;
     }
 
     public void setNotNull(boolean notNull) {
         this.notNull = notNull;
     }
 }