/*
 * 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.execution.operator.schema.source;

import org.apache.iotdb.commons.schema.table.TsTable;
import org.apache.iotdb.commons.schema.table.column.TsTableColumnSchema;
import org.apache.iotdb.db.queryengine.transformation.dag.column.ColumnTransformer;
import org.apache.iotdb.db.queryengine.transformation.dag.column.leaf.LeafColumnTransformer;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.IDeviceSchemaInfo;

import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

import static java.util.Objects.requireNonNull;

public class DevicePredicateFilter extends DevicePredicateHandler
    implements Iterator<IDeviceSchemaInfo> {
  private int curIndex = 0;

  public DevicePredicateFilter(
      final List<LeafColumnTransformer> filterLeafColumnTransformerList,
      final ColumnTransformer filterOutputTransformer,
      final List<TsTableColumnSchema> columnSchemaList,
      final String database,
      final TsTable table) {
    super(
        filterLeafColumnTransformerList,
        filterOutputTransformer,
        columnSchemaList,
        database,
        table);
    requireNonNull(filterOutputTransformer);
  }

  @Override
  public boolean hasNext() {
    final boolean result = curIndex < indexes.size();
    if (!result && hasComputedResult()) {
      curIndex = 0;
      clear();
    }
    return result;
  }

  @Override
  public IDeviceSchemaInfo next() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }
    return deviceSchemaBatch.get(indexes.get(curIndex++));
  }
}
