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.examples.multilanguage.schematransforms;
  
  import static org.apache.beam.examples.multilanguage.schematransforms.WriteWordsProvider.Configuration;
  
  import com.google.auto.service.AutoService;
  import com.google.auto.value.AutoValue;
  import org.apache.beam.sdk.io.TextIO;
  import org.apache.beam.sdk.schemas.AutoValueSchema;
  import org.apache.beam.sdk.schemas.annotations.DefaultSchema;
  import org.apache.beam.sdk.schemas.annotations.SchemaFieldDescription;
  import org.apache.beam.sdk.schemas.transforms.SchemaTransform;
  import org.apache.beam.sdk.schemas.transforms.SchemaTransformProvider;
  import org.apache.beam.sdk.schemas.transforms.TypedSchemaTransformProvider;
  import org.apache.beam.sdk.transforms.MapElements;
  import org.apache.beam.sdk.util.Preconditions;
  import org.apache.beam.sdk.values.PCollectionRowTuple;
  import org.apache.beam.sdk.values.TypeDescriptors;
  
  @AutoService(SchemaTransformProvider.class)
  public class WriteWordsProvider extends TypedSchemaTransformProvider<Configuration> {
    @Override
    public String identifier() {
      return "beam:schematransform:org.apache.beam:write_words:v1";
    }
  
    @Override
    protected SchemaTransform from(Configuration configuration) {
      return new WriteWordsTransform(configuration);
    }
  
    static class WriteWordsTransform extends SchemaTransform {
      private final String filePathPrefix;
  
      WriteWordsTransform(Configuration configuration) {
        this.filePathPrefix = configuration.getFilePathPrefix();
      }
  
      @Override
      public PCollectionRowTuple expand(PCollectionRowTuple input) {
        input
            .get("input")
            .apply(
                MapElements.into(TypeDescriptors.strings())
                    .via(row -> Preconditions.checkStateNotNull(row.getString("line"))))
            .apply(TextIO.write().to(filePathPrefix));
  
        return PCollectionRowTuple.empty(input.getPipeline());
      }
    }
  
    @DefaultSchema(AutoValueSchema.class)
    @AutoValue
    public abstract static class Configuration {
      public static Builder builder() {
        return new AutoValue_WriteWordsProvider_Configuration.Builder();
      }
  
      @SchemaFieldDescription("Writes to output files with this prefix.")
      public abstract String getFilePathPrefix();
  
      @AutoValue.Builder
      public abstract static class Builder {
        public abstract Builder setFilePathPrefix(String filePathPrefix);
  
        public abstract Configuration build();
      }
    }
  }
  