// Copyright 2020 Google Inc.
//
// 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.

// [START spanner_create_client_with_query_options]

using Google.Cloud.Spanner.Data;
using System.Collections.Generic;
using System.Threading.Tasks;

public class CreateConnectionWithQueryOptionsAsyncSample
{
    public class Album
    {
        public int AlbumId { get; set; }
        public int SingerId { get; set; }
        public string AlbumTitle { get; set; }
    }

    public async Task<List<Album>> CreateConnectionWithQueryOptionsAsync(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";

        using var connection = new SpannerConnection(connectionString)
        {
            // Set query options on the connection.
            QueryOptions = QueryOptions.Empty
                .WithOptimizerVersion("1")
                // The list of available statistics packages for the database can
                // be found by querying the "INFORMATION_SCHEMA.SPANNER_STATISTICS"
                // table.
                .WithOptimizerStatisticsPackage("latest")
        };

        var albums = new List<Album>();
        var cmd = connection.CreateSelectCommand("SELECT SingerId, AlbumId, AlbumTitle FROM Albums");
        using var reader = await cmd.ExecuteReaderAsync();
        while (await reader.ReadAsync())
        {
            albums.Add(new Album
            {
                SingerId = reader.GetFieldValue<int>("SingerId"),
                AlbumId = reader.GetFieldValue<int>("AlbumId"),
                AlbumTitle = reader.GetFieldValue<string>("AlbumTitle")
            });
        }
        return albums;
    }
}
// [END spanner_create_client_with_query_options]
