using System;

using System.Collections.Generic;

using System.Linq;

using System.Reflection;

using System.Threading.Tasks;

using JetBrains.Annotations;

using Npgsql.PostgresTypes;

using Npgsql.Util;

using NpgsqlTypes;

namespace Npgsql

{

class PostgresMinimalDatabaseInfoFactory : INpgsqlDatabaseInfoFactory

{

public Task<NpgsqlDatabaseInfo> Load(NpgsqlConnection conn, NpgsqlTimeout timeout, bool async)

=> Task.FromResult(

new NpgsqlConnectionStringBuilder(conn.ConnectionString).ServerCompatibilityMode == ServerCompatibilityMode.NoTypeLoading

? (NpgsqlDatabaseInfo)new PostgresMinimalDatabaseInfo(conn)

: null

);

}

class PostgresMinimalDatabaseInfo : PostgresDatabaseInfo

{

static readonly Version DefaultVersion = new Version(10, 0);

static readonly PostgresBaseType[] Types = typeof(NpgsqlDbType).GetFields()

.Select(f => f.GetCustomAttribute<BuiltInPostgresType>())

.Where(a => a != null)

.Select(a => new PostgresBaseType("pg_catalog", a.Name, a.OID))

.ToArray();

protected override IEnumerable<PostgresType> GetTypes() => Types;

internal PostgresMinimalDatabaseInfo([NotNull] NpgsqlConnection conn)

{

var csb = new NpgsqlConnectionStringBuilder(conn.ConnectionString);

Host = csb.Host;

Port = csb.Port;

Name = csb.Database;

Version = conn.PostgresParameters.TryGetValue("server_version", out string versionString)

? ParseServerVersion(versionString)

: DefaultVersion;

HasIntegerDateTimes = !conn.PostgresParameters.TryGetValue("integer_datetimes", out var intDateTimes) ||

intDateTimes == "on";

}

}

}