using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Driver;
using System.Collections.Generic;
using System.Linq;
using Xunit;

namespace IndexTest
{
    [BsonIgnoreExtraElements]
    public class Foo
    {
        public Foo() { }

        public List<Bar> Bars { get; set; }
    }

    [BsonIgnoreExtraElements]
    public class Bar
    {
        public Bar() { }

        public string Baz { get; set; }
    }

    public class TestClass
    {
        [Fact]
        public void Test()
        {
            var client = new MongoClient("mongodb://localhost:27017");
            var database = client.GetDatabase("test");
            var collection = database.GetCollection<Foo>("foos");

            // Invalid
            // { "Baz" : 1 }
            collection.Indexes.CreateOne(Builders<Foo>.IndexKeys.Ascending(x => x.Bars.First().Baz));

            //Invalid
            // { "Bar.0.Baz" : 1 }
            collection.Indexes.CreateOne(Builders<Foo>.IndexKeys.Ascending(x => x.Bars[0].Baz));

            // Valid but relies on magic string
            // { "Bar.Baz" : 1 }
            collection.Indexes.CreateOne("{\"Bar.Baz\" : 1}");

            // Failure
            // System.InvalidOperationException : Unable to determine the serialization information for x => x.Bars.Select(y => y.Baz).
            collection.Indexes.CreateOne(Builders<Foo>.IndexKeys.Ascending(x => x.Bars.Select(y => y.Baz)));
        }
    }
}