/*
    * Copyright 2021 LINE Corporation
    *
    * LINE Corporation 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:
    *
    *   https://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 com.linecorp.centraldogma.client.armeria;
  
  import static java.util.Objects.requireNonNull;
  
  import com.linecorp.armeria.client.Endpoint;
  import com.linecorp.armeria.client.endpoint.EndpointSelectionStrategy;
  import com.linecorp.armeria.client.endpoint.EndpointSelector;
  import com.linecorp.centraldogma.client.Watcher;
  
  /**
   * Builds a {@link CentralDogmaEndpointGroup} that retrieves the list of {@link Endpoint}s from an entry
   * in Central Dogma.
   *
   * @param <T> the type of the file in Central Dogma
   */
  public final class CentralDogmaEndpointGroupBuilder<T> {
  
      private final Watcher<T> watcher;
      private final EndpointListDecoder<T> endpointListDecoder;
      private EndpointSelectionStrategy selectionStrategy = EndpointSelectionStrategy.weightedRoundRobin();
  
      CentralDogmaEndpointGroupBuilder(Watcher<T> watcher, EndpointListDecoder<T> endpointListDecoder) {
          this.watcher = requireNonNull(watcher, "watcher");
          this.endpointListDecoder = requireNonNull(endpointListDecoder, "endpointListDecoder");
      }
  
      /**
       * Sets the {@link EndpointSelectionStrategy} that creates an {@link EndpointSelector}.
       */
      public CentralDogmaEndpointGroupBuilder selectionStrategy(EndpointSelectionStrategy selectionStrategy) {
          this.selectionStrategy = requireNonNull(selectionStrategy, "selectionStrategy");
          return this;
      }
  
      /**
       * Returns a newly-created {@link CentralDogmaEndpointGroup} that retrieves the list {@link Endpoint}s
       * from an entry in Central Dogma.
       */
      public CentralDogmaEndpointGroup<T> build() {
          return new CentralDogmaEndpointGroup<>(selectionStrategy, watcher, endpointListDecoder);
      }
  }