/*
 * 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.phoenix.parse;

import java.sql.SQLException;
import org.apache.phoenix.compile.ColumnResolver;

/**
 * Node representing the selection of all columns (*) in the SELECT clause of SQL
 * @since 0.1
 */
public class WildcardParseNode extends TerminalParseNode {
  public static final String NAME = "*";
  public static final WildcardParseNode INSTANCE = new WildcardParseNode(false);
  public static final WildcardParseNode REWRITE_INSTANCE = new WildcardParseNode(true);

  private final boolean isRewrite;

  private WildcardParseNode(boolean isRewrite) {
    this.isRewrite = isRewrite;
  }

  @Override
  public <T> T accept(ParseNodeVisitor<T> visitor) throws SQLException {
    return visitor.visit(this);
  }

  public boolean isRewrite() {
    return isRewrite;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + (isRewrite ? 1231 : 1237);
    return result;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) return true;
    if (obj == null) return false;
    if (getClass() != obj.getClass()) return false;
    WildcardParseNode other = (WildcardParseNode) obj;
    if (isRewrite != other.isRewrite) return false;
    return true;
  }

  @Override
  public void toSQL(ColumnResolver resolver, StringBuilder buf) {
    buf.append(' ');
    buf.append(NAME);
    buf.append(' ');
  }

  @Override
  public boolean isWildcardNode() {
    return true;
  }

  @Override
  public WildcardParseNode getRewritten() {
    return REWRITE_INSTANCE;
  }
}
