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/*
 * 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.solr.cluster.placement.impl;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import org.apache.solr.cluster.Node;
import org.apache.solr.cluster.Replica;
import org.apache.solr.cluster.SolrCollection;
import org.apache.solr.cluster.placement.ReplicaPlacement;
import org.apache.solr.common.cloud.ReplicaPosition;

class ReplicaPlacementImpl implements ReplicaPlacement {
  private final SolrCollection solrCollection;
  private final String shardName;
  private final Node node;
  private final Replica.ReplicaType replicaType;

  ReplicaPlacementImpl(
      SolrCollection solrCollection, String shardName, Node node, Replica.ReplicaType replicaType) {
    this.solrCollection = solrCollection;
    this.shardName = shardName;
    this.node = node;
    this.replicaType = replicaType;
  }

  @Override
  public SolrCollection getCollection() {
    return solrCollection;
  }

  @Override
  public String getShardName() {
    return shardName;
  }

  @Override
  public Node getNode() {
    return node;
  }

  @Override
  public Replica.ReplicaType getReplicaType() {
    return replicaType;
  }

  @Override
  public String toString() {
    return solrCollection.getName() + "/" + shardName + "/" + replicaType + "->" + node.getName();
  }

  /**
   * Translates a set of {@link ReplicaPlacement} returned by a plugin into a list of {@link
   * ReplicaPosition} expected by {@link
   * org.apache.solr.cloud.api.collections.Assign.AssignStrategy}
   */
  static List toReplicaPositions(
      String collection, Set replicaPlacementSet) {
    // The replica index in ReplicaPosition is not as strict a concept as it might seem. It is used
    // in rules based placement (for sorting replicas) but its presence in ReplicaPosition is not
    // justified (and when the code is executing here, it means rules based placement is not used).
    // Looking at ReplicaAssigner.tryAllPermutations, it is well possible to create replicas with
    // same index living on a given node for the same shard. This likely never happens because of
    // the way replicas are placed on nodes (never two on the same node for same shard). Adopting
    // the same shortcut/bad design here, but index should be removed at some point from
    // ReplicaPosition.
    List replicaPositions = new ArrayList<>(replicaPlacementSet.size());
    // This really an arbitrary value when adding replicas and a possible source of core name
    // collisions
    int index = 0;
    for (ReplicaPlacement placement : replicaPlacementSet) {
      replicaPositions.add(
          new ReplicaPosition(
              collection,
              placement.getShardName(),
              index++,
              SimpleClusterAbstractionsImpl.ReplicaImpl.toCloudReplicaType(
                  placement.getReplicaType()),
              placement.getNode().getName()));
    }

    return replicaPositions;
  }
}