messengerapi.Broker/code/MessengerBroker.Configuration/Parsers/ApiEnvironmentPersistenceConfigurationParser.cs

using MessengerApi.Configuration.Model.Persistence;
using MessengerApi.Configuration.Model.Persistence.Base;
using MessengerApi.Configuration.Parsers;
using MessengerApi.Configuration.Sources.Environment;
using MessengerBroker.Configuration.Sources.Environment;

namespace MessengerBroker.Configuration.Parsers
{
    public class ApiEnvironmentPersistenceConfigurationParser
    {
        public static PersistenceConfiguration Parse(IEnvironmentConfigurationSource config)
        {
            var type = PersistenceTypeParser.Parse(config.GetValue<string>(Constants.EnvironmentVariables.API_PERSISTENCE_TYPE));

            if (type == MessengerApi.Configuration.Enums.PersistenceTypes.Sql)
            {
                return new SqlPersistenceConfiguration(config.GetValue<string>(Constants.EnvironmentVariables.API_SQL_CONNECTIONSTRING));
            }
            else if (type == MessengerApi.Configuration.Enums.PersistenceTypes.PostgreSql)
            {
                return new NpgPersistenceConfiguration(config.GetValue<string>(Constants.EnvironmentVariables.API_NPG_CONNECTIONSTRING));
            }

            throw new InvalidOperationException("Unrecognized persistence type.");
        }
    }
}