content: /*
   * 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.beam.learning.katas.coretransforms.sideinput;
  
  // beam-playground:
  //   name: SideInput
  //   description: Task from katas to enrich each Person with the country based on the city he/she lives in.
  //   multifile: true
  //   context_line: 48
  //   categories:
  //     - Side Input
  //   complexity: BASIC
  //   tags:
  //     - transforms
  //     - strings
  
  import java.util.Map;
  import org.apache.beam.learning.katas.util.Log;
  import org.apache.beam.sdk.Pipeline;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.sdk.transforms.Create;
  import org.apache.beam.sdk.transforms.DoFn;
  import org.apache.beam.sdk.transforms.ParDo;
  import org.apache.beam.sdk.transforms.View;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionView;
  
  public class Task {
  
    public static void main(String[] args) {
      PipelineOptions options = PipelineOptionsFactory.fromArgs(args).create();
      Pipeline pipeline = Pipeline.create(options);
  
      PCollection<KV<String, String>> citiesToCountries =
          pipeline.apply("Cities and Countries",
              Create.of(
                  KV.of("Beijing", "China"),
                  KV.of("London", "United Kingdom"),
                  KV.of("San Francisco", "United States"),
                  KV.of("Singapore", "Singapore"),
                  KV.of("Sydney", "Australia")
              ));
  
      PCollectionView<Map<String, String>> citiesToCountriesView =
          createView(citiesToCountries);
  
      PCollection<Person> persons =
          pipeline.apply("Persons",
              Create.of(
                  new Person("Henry", "Singapore"),
                  new Person("Jane", "San Francisco"),
                  new Person("Lee", "Beijing"),
                  new Person("John", "Sydney"),
                  new Person("Alfred", "London")
              ));
  
      PCollection<Person> output = applyTransform(persons, citiesToCountriesView);
  
      output.apply(Log.ofElements());
  
      pipeline.run();
    }
  
    static PCollectionView<Map<String, String>> createView(
        PCollection<KV<String, String>> citiesToCountries) {
  
      return citiesToCountries.apply(View.asMap());
    }
  
    static PCollection<Person> applyTransform(
        PCollection<Person> persons, PCollectionView<Map<String, String>> citiesToCountriesView) {
  
      return persons.apply(ParDo.of(new DoFn<Person, Person>() {
  
        @ProcessElement
        public void processElement(@Element Person person, OutputReceiver<Person> out,
            ProcessContext context) {
          Map<String, String> citiesToCountries = context.sideInput(citiesToCountriesView);
          String city = person.getCity();
          String country = citiesToCountries.get(city);
  
          out.output(new Person(person.getName(), city, country));
        }
  
      }).withSideInputs(citiesToCountriesView));
    }
  
  }