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.arrow.driver.jdbc.utils;
  
  import com.google.protobuf.Any;
  import com.google.protobuf.ByteString;
  import com.google.protobuf.Message;
  import java.util.Collections;
  import java.util.List;
  import org.apache.arrow.flight.CallStatus;
  import org.apache.arrow.flight.FlightDescriptor;
  import org.apache.arrow.flight.FlightEndpoint;
  import org.apache.arrow.flight.FlightInfo;
  import org.apache.arrow.flight.Location;
  import org.apache.arrow.flight.Result;
  import org.apache.arrow.flight.Ticket;
  import org.apache.arrow.flight.sql.BasicFlightSqlProducer;
  import org.apache.arrow.flight.sql.impl.FlightSql;
  import org.apache.arrow.vector.VectorSchemaRoot;
  import org.apache.arrow.vector.types.pojo.Schema;
  
  public class FallbackFlightSqlProducer extends BasicFlightSqlProducer {
    private final VectorSchemaRoot data;
  
    public FallbackFlightSqlProducer(VectorSchemaRoot resultData) {
      this.data = resultData;
    }
  
    @Override
    protected <T extends Message> List<FlightEndpoint> determineEndpoints(
        T request, FlightDescriptor flightDescriptor, Schema schema) {
      return Collections.emptyList();
    }
  
    @Override
    public void createPreparedStatement(
        FlightSql.ActionCreatePreparedStatementRequest request,
        CallContext context,
        StreamListener<Result> listener) {
      final FlightSql.ActionCreatePreparedStatementResult.Builder resultBuilder =
          FlightSql.ActionCreatePreparedStatementResult.newBuilder()
              .setPreparedStatementHandle(request.getQueryBytes());
  
      final ByteString datasetSchemaBytes =
          ByteString.copyFrom(data.getSchema().serializeAsMessage());
  
      resultBuilder.setDatasetSchema(datasetSchemaBytes);
      listener.onNext(new Result(Any.pack(resultBuilder.build()).toByteArray()));
      listener.onCompleted();
    }
  
    @Override
    public FlightInfo getFlightInfoStatement(
        FlightSql.CommandStatementQuery command, CallContext context, FlightDescriptor descriptor) {
      return getFlightInfo(descriptor, command.getQuery());
    }
  
    @Override
    public FlightInfo getFlightInfoPreparedStatement(
        FlightSql.CommandPreparedStatementQuery command,
        CallContext context,
        FlightDescriptor descriptor) {
      return getFlightInfo(descriptor, command.getPreparedStatementHandle().toStringUtf8());
    }
  
    @Override
    public void getStreamStatement(
        FlightSql.TicketStatementQuery ticket, CallContext context, ServerStreamListener listener) {
      listener.start(data);
      listener.putNext();
      listener.completed();
    }
  
    @Override
    public void closePreparedStatement(
        FlightSql.ActionClosePreparedStatementRequest request,
        CallContext context,
        StreamListener<Result> listener) {
      listener.onCompleted();
    }
  
    private FlightInfo getFlightInfo(FlightDescriptor descriptor, String query) {
      final List<FlightEndpoint> endpoints;
      final Ticket ticket =
          new Ticket(Any.pack(FlightSql.TicketStatementQuery.getDefaultInstance()).toByteArray());
      if (query.equals("fallback")) {
        endpoints =
            Collections.singletonList(
                FlightEndpoint.builder(ticket, Location.reuseConnection()).build());
      } else if (query.equals("fallback with error")) {
        endpoints =
            Collections.singletonList(
                FlightEndpoint.builder(
                        ticket,
                        Location.forGrpcInsecure("localhost", 9999),
                        Location.reuseConnection())
                    .build());
      } else if (query.equals("fallback with unresolvable")) {
        endpoints =
            Collections.singletonList(
                FlightEndpoint.builder(
                        ticket,
                        // Inaccessible IP
                        // https://stackoverflow.com/questions/10456044/what-is-a-good-invalid-ip-address-to-use-for-unit-tests
                        Location.forGrpcInsecure("203.0.113.0", 9999),
                        Location.reuseConnection())
                    .build());
      } else {
        throw CallStatus.UNIMPLEMENTED.withDescription(query).toRuntimeException();
      }
      return FlightInfo.builder(data.getSchema(), descriptor, endpoints).build();
    }
  }
  