/*
 * Copyright 2020 Google LLC
 *
 * Licensed 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 com.google.cloud.solutions.datalineage.service;

import static com.google.common.collect.ImmutableSet.toImmutableSet;

import com.google.cloud.solutions.datalineage.converter.BigQuerySchemaConverter;
import com.google.common.collect.ImmutableSet;
import com.google.zetasql.SimpleTable;

/**
 * Loads requested Table Schema using provided {@link BigQueryTableLoadService} followed by schema
 * translation using {@link BigQuerySchemaConverter}.
 */
public final class BigQueryZetaSqlSchemaLoader implements ZetaSqlSchemaLoader {

  private final BigQueryTableLoadService bqTableLoader;

  public BigQueryZetaSqlSchemaLoader(BigQueryTableLoadService bqTableLoader) {
    this.bqTableLoader = bqTableLoader;
  }

  @Override
  public ImmutableSet<SimpleTable> loadSchemas(String... tableNames) {
    return bqTableLoader.loadTables(tableNames).stream()
        .map(BigQuerySchemaConverter::convert)
        .collect(toImmutableSet());
  }

  @Override
  public ImmutableSet<SimpleTable> loadSchemas(ImmutableSet<String> tableNames) {
    return loadSchemas(tableNames.asList().toArray(new String[0]));
  }
}
