/*
 * 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;
import org.apache.phoenix.util.SchemaUtil;

/**
 * Node representing a subselect in the FROM clause of SQL
 * @since 0.1
 */
public class DerivedTableNode extends TableNode {

  private final SelectStatement select;

  DerivedTableNode(String alias, SelectStatement select) {
    super(SchemaUtil.normalizeIdentifier(alias));
    this.select = select;
  }

  public SelectStatement getSelect() {
    return select;
  }

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

  @Override
  public void toSQL(ColumnResolver resolver, StringBuilder buf) {
    buf.append('(');
    select.toSQL(resolver, buf);
    buf.append(')');
    buf.append(" " + (this.getAlias() == null ? "" : this.getAlias()));
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((select == null) ? 0 : select.hashCode());
    return result;
  }

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