/*
 * 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.iotdb.db.queryengine.plan.relational.sql.ast;

import com.google.common.collect.ImmutableList;
import org.apache.tsfile.utils.RamUsageEstimator;

import java.util.List;
import java.util.Objects;

import static com.google.common.base.MoreObjects.toStringHelper;
import static java.util.Objects.requireNonNull;

public class AliasedRelation extends Relation {
  private static final long INSTANCE_SIZE =
      RamUsageEstimator.shallowSizeOfInstance(AliasedRelation.class);

  private final Relation relation;
  private final Identifier alias;
  private final List<Identifier> columnNames;

  public AliasedRelation(Relation relation, Identifier alias, List<Identifier> columnNames) {
    super(null);
    this.relation = requireNonNull(relation, "relation is null");
    this.alias = requireNonNull(alias, "alias is null");
    this.columnNames = columnNames;
  }

  public AliasedRelation(
      NodeLocation location, Relation relation, Identifier alias, List<Identifier> columnNames) {
    super(requireNonNull(location, "location is null"));
    this.relation = requireNonNull(relation, "relation is null");
    this.alias = requireNonNull(alias, "alias is null");
    this.columnNames = columnNames;
  }

  public Relation getRelation() {
    return relation;
  }

  public Identifier getAlias() {
    return alias;
  }

  public List<Identifier> getColumnNames() {
    return columnNames;
  }

  @Override
  public <R, C> R accept(AstVisitor<R, C> visitor, C context) {
    return visitor.visitAliasedRelation(this, context);
  }

  @Override
  public List<Node> getChildren() {
    return ImmutableList.of(relation);
  }

  @Override
  public String toString() {
    return toStringHelper(this)
        .add("relation", relation)
        .add("alias", alias)
        .add("columnNames", columnNames)
        .omitNullValues()
        .toString();
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    AliasedRelation that = (AliasedRelation) o;
    return Objects.equals(relation, that.relation)
        && Objects.equals(alias, that.alias)
        && Objects.equals(columnNames, that.columnNames);
  }

  @Override
  public int hashCode() {
    return Objects.hash(relation, alias, columnNames);
  }

  @Override
  public boolean shallowEquals(Node other) {
    if (!sameClass(this, other)) {
      return false;
    }

    AliasedRelation otherRelation = (AliasedRelation) other;
    return alias.equals(otherRelation.alias)
        && Objects.equals(columnNames, otherRelation.columnNames);
  }

  @Override
  public long ramBytesUsed() {
    long size = INSTANCE_SIZE;
    size += AstMemoryEstimationHelper.getEstimatedSizeOfNodeLocation(getLocationInternal());
    size += AstMemoryEstimationHelper.getEstimatedSizeOfAccountableObject(relation);
    size += AstMemoryEstimationHelper.getEstimatedSizeOfAccountableObject(alias);
    size += AstMemoryEstimationHelper.getEstimatedSizeOfNodeList(columnNames);
    return size;
  }
}
