using MongoDB.Bson;
using MongoDB.Driver;

namespace PrivaPub.Infrastructure.Data
{
	// Whether the mongod is a replica set member (production's is a one-member set, rs0): only then can a read session
	// hold one point in time across collections (a snapshot), which a backup needs to be consistent.
	public static class MongoTopology
	{
		public static async Task<bool> IsReplicaSet(IMongoDatabase database, CancellationToken token)
		{
			try
			{
				var hello = await database.Client.GetDatabase("admin").RunCommandAsync<BsonDocument>(new BsonDocument("hello", 1), cancellationToken: token);
				return hello.Contains("setName");
			}
			catch (MongoCommandException)
			{
				return false;
			}
		}
	}
}