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.
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  package org.apache.beam.sdk.extensions.sql.expansion;
  
  import com.google.auto.service.AutoService;
  import java.util.Map;
  import org.apache.beam.sdk.expansion.ExternalTransformRegistrar;
  import org.apache.beam.sdk.extensions.sql.SqlTransform;
  import org.apache.beam.sdk.extensions.sql.impl.CalciteQueryPlanner;
  import org.apache.beam.sdk.extensions.sql.impl.QueryPlanner;
  import org.apache.beam.sdk.transforms.ExternalTransformBuilder;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PInput;
  import org.apache.beam.sdk.values.Row;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableMap;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  @AutoService(ExternalTransformRegistrar.class)
  public class ExternalSqlTransformRegistrar implements ExternalTransformRegistrar {
    private static final String URN = "beam:external:java:sql:v1";
    private static final ImmutableMap<String, Class<? extends QueryPlanner>> DIALECTS =
        ImmutableMap.<String, Class<? extends QueryPlanner>>builder()
            .put("calcite", CalciteQueryPlanner.class)
            .build();
  
    @Override
    public Map<String, Class<? extends ExternalTransformBuilder<?, ?, ?>>> knownBuilders() {
      return org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableMap.of(
          URN, Builder.class);
    }
  
    public static class Configuration {
      String query = "";
      @Nullable String dialect;
      @Nullable String ddl;
  
      public void setQuery(String query) {
        this.query = query;
      }
  
      public void setDialect(@Nullable String dialect) {
        this.dialect = dialect;
      }
  
      public void setDdl(@Nullable String ddl) {
        this.ddl = ddl;
      }
    }
  
    private static class Builder
        implements ExternalTransformBuilder<Configuration, PInput, PCollection<Row>> {
      @Override
      public PTransform<PInput, PCollection<Row>> buildExternal(Configuration configuration) {
        SqlTransform transform = SqlTransform.query(configuration.query);
        if (configuration.dialect != null) {
          Class<? extends QueryPlanner> queryPlanner =
              DIALECTS.get(configuration.dialect.toLowerCase());
          if (queryPlanner == null) {
            throw new IllegalArgumentException(
                String.format(
                    "Received unknown SQL Dialect '%s'. Known dialects: %s",
                    configuration.dialect, DIALECTS.keySet()));
          }
          transform = transform.withQueryPlannerClass(queryPlanner);
        }
        // Add any DDL string
        if (configuration.ddl != null) {
          transform = transform.withDdlString(configuration.ddl);
        }
        return transform;
      }
    }
  }
  