/*
 * Copyright © 2014 - 2021 Leipzig University (Database Research Group)
 *
 * Licensed 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.gradoop.flink.algorithms.btgs.functions;

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.typeutils.ResultTypeQueryable;
import org.apache.flink.api.java.typeutils.TypeExtractor;
import org.gradoop.common.model.api.entities.GraphHead;
import org.gradoop.common.model.api.entities.GraphHeadFactory;
import org.gradoop.flink.algorithms.btgs.BusinessTransactionGraphs;
import org.gradoop.common.model.impl.id.GradoopId;

/**
 * Creates an graph head representing a business transaction graphs.
 * @param <G> graph head type
 */
public class NewBtgGraphHead<G extends GraphHead>
  implements MapFunction<GradoopId, G>, ResultTypeQueryable<G> {

  /**
   * graph head factory
   */
  private final GraphHeadFactory<G> graphHeadFactory;

  /**
   * Constructor
   * @param graphHeadFactory graph head factory
   */
  public NewBtgGraphHead(GraphHeadFactory<G> graphHeadFactory) {
    this.graphHeadFactory = graphHeadFactory;
  }

  @Override
  public G map(GradoopId graphId) throws Exception {
    G graphHead = graphHeadFactory
      .createGraphHead(BusinessTransactionGraphs.BTG_LABEL);

    graphHead.setId(graphId);

    return graphHead;
  }

  @Override
  public TypeInformation<G> getProducedType() {
    return TypeExtractor.createTypeInfo(graphHeadFactory.getType());
  }
}
