/*
 * 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.sdk.extensions.sql.meta.provider.bigquery;

import java.io.Serializable;
import org.apache.beam.sdk.annotations.Experimental;
import org.apache.beam.sdk.extensions.sql.impl.schema.BaseBeamTable;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryIO;
import org.apache.beam.sdk.io.gcp.bigquery.BigQueryUtils;
import org.apache.beam.sdk.schemas.Schema;
import org.apache.beam.sdk.values.PBegin;
import org.apache.beam.sdk.values.PCollection;
import org.apache.beam.sdk.values.POutput;
import org.apache.beam.sdk.values.Row;

/**
 * {@code BeamBigQueryTable} represent a BigQuery table as a target. This provider does not
 * currently support being a source.
 */
@Experimental
public class BeamBigQueryTable extends BaseBeamTable implements Serializable {
  private String tableSpec;

  public BeamBigQueryTable(Schema beamSchema, String tableSpec) {
    super(beamSchema);
    this.tableSpec = tableSpec;
  }

  @Override
  public PCollection<Row> buildIOReader(PBegin begin) {
    // TODO: make this more generic.
    return begin
        .apply(BigQueryIO.read(BigQueryUtils.toBeamRow(schema)).from(tableSpec))
        .setRowSchema(getSchema());
  }

  @Override
  public POutput buildIOWriter(PCollection<Row> input) {
    return input.apply(
        BigQueryIO.<Row>write()
            .withSchema(BigQueryUtils.toTableSchema(getSchema()))
            .withFormatFunction(BigQueryUtils.toTableRow())
            .to(tableSpec));
  }

  String getTableSpec() {
    return tableSpec;
  }
}
