/*
    * 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 org.apache.commons.jxpath.ri.compiler;
  
  import org.apache.commons.jxpath.ri.Compiler;
  
  /**
   * @author Dmitri Plotnikov
   * @version $Revision: 1523200 $ $Date: 2013-09-14 11:48:25 +0200 (Sa, 14 Sep 2013) $
   */
  public class Step {
      private int axis;
      private NodeTest nodeTest;
      private Expression[] predicates;
  
      /**
       * Create a new Step.
       * @param axis axis code
       * @param nodeTest step test
       * @param predicates predicate expressions
       */
      protected Step(int axis, NodeTest nodeTest, Expression[] predicates) {
          this.axis = axis;
          this.nodeTest = nodeTest;
          this.predicates = predicates;
      }
  
      /**
       * Get the axis code.
       * @return int
       */
      public int getAxis() {
          return axis;
      }
  
      /**
       * Get the step test.
       * @return NodeTest
       */
      public NodeTest getNodeTest() {
          return nodeTest;
      }
  
      /**
       * Get the predicates.
       * @return Expression[]
       */
      public Expression[] getPredicates() {
          return predicates;
      }
  
      /**
       * Learn whether this step contains any predicate that is context dependent.
       * @return boolean
       */
      public boolean isContextDependent() {
          if (predicates != null) {
              for (int i = 0; i < predicates.length; i++) {
                  if (predicates[i].isContextDependent()) {
                      return true;
                  }
              }
          }
          return false;
      }
  
      public String toString() {
          StringBuffer buffer = new StringBuffer();
          int axis = getAxis();
          if (axis == Compiler.AXIS_CHILD) {
              buffer.append(nodeTest);
          }
          else if (axis == Compiler.AXIS_ATTRIBUTE) {
              buffer.append('@');
              buffer.append(nodeTest);
          }
          else if (axis == Compiler.AXIS_SELF
                  && nodeTest instanceof NodeTypeTest
                  && ((NodeTypeTest) nodeTest).getNodeType()
                      == Compiler.NODE_TYPE_NODE) {
              buffer.append(".");
          }
          else if (axis == Compiler.AXIS_PARENT
                  && nodeTest instanceof NodeTypeTest
                  && ((NodeTypeTest) nodeTest).getNodeType()
                     == Compiler.NODE_TYPE_NODE) {
             buffer.append("..");
         }
         else if (axis == Compiler.AXIS_DESCENDANT_OR_SELF
                 && nodeTest instanceof NodeTypeTest
                 && ((NodeTypeTest) nodeTest).getNodeType()
                     == Compiler.NODE_TYPE_NODE
                 && (predicates == null || predicates.length == 0)) {
             buffer.append("");
         }
         else {
             buffer.append(axisToString(axis));
             buffer.append("::");
             buffer.append(nodeTest);
         }
         Expression[] predicates = getPredicates();
         if (predicates != null) {
             for (int i = 0; i < predicates.length; i++) {
                 buffer.append('[');
                 buffer.append(predicates[i]);
                 buffer.append(']');
             }
         }
         return buffer.toString();
     }
 
     /**
      * Decode an axis code to its name.
      * @param axis int code
      * @return String name.
      * @see Compiler
      * @see "http://www.w3.org/TR/xpath#axes"
      */
     public static String axisToString(int axis) {
         switch (axis) {
             case Compiler.AXIS_SELF :
                 return "self";
             case Compiler.AXIS_CHILD :
                 return "child";
             case Compiler.AXIS_PARENT :
                 return "parent";
             case Compiler.AXIS_ANCESTOR :
                 return "ancestor";
             case Compiler.AXIS_ATTRIBUTE :
                 return "attribute";
             case Compiler.AXIS_NAMESPACE :
                 return "namespace";
             case Compiler.AXIS_PRECEDING :
                 return "preceding";
             case Compiler.AXIS_FOLLOWING :
                 return "following";
             case Compiler.AXIS_DESCENDANT :
                 return "descendant";
             case Compiler.AXIS_ANCESTOR_OR_SELF :
                 return "ancestor-or-self";
             case Compiler.AXIS_FOLLOWING_SIBLING :
                 return "following-sibling";
             case Compiler.AXIS_PRECEDING_SIBLING :
                 return "preceding-sibling";
             case Compiler.AXIS_DESCENDANT_OR_SELF :
                 return "descendant-or-self";
             default:
                 return "UNKNOWN";
         }
     }
 }