using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MongoDB.Driver;

namespace MongoAllBug
{
	class Program
	{
		static void Main(string[] args)
		{
			var client = new MongoClient();
			var collection = client.GetDatabase("Test").GetCollection<Product>("Products");
			var queryable = collection.AsQueryable();
			var requiredMeta = new List<MetaField>
			{
				new MetaField {Key = "Key1", Value = "Val1"},
				new MetaField {Key = "Key2", Value = "Val2"}
			};

			var results = queryable
				.Where(x => x.Occurrences.Any(o => requiredMeta.All(i => o.Meta.Contains(i))))
				.ToList();

			/* Resulting aggregation pipeline (note missing Occurrences part):
				[
					 {
						  "$match" : {
								"Meta" : {
									 "$all" : [ 
										  {
												"Key" : "Key1",
												"Value" : "Val1"
										  }, 
										  {
												"Key" : "Key2",
												"Value" : "Val2"
										  }
									 ]
								}
						  }
					 }
				]
			 */
		}
	}

	public class Product
	{
		public string Name { get; set; }

		public List<Occurrence> Occurrences { get; set; }
	}

	public class Occurrence
	{
		public List<MetaField> Meta { get; set; }

		public Occurrence()
		{
			Meta = new List<MetaField>();
		}
	}

	public class MetaField
	{
		public string Key { get; set; }

		public string Value { get; set; }
	}
}