Multi map reduce index

gistfile1.cs

using System;
using System.Linq;
using Raven.Client;
using Raven.Client.Document;
using Raven.Client.Indexes;
namespace RavenTest
{
    public class ExtractionUser
    {
        public string Id { get; set; }
        public string[] AssignedFields { get; set; }
    }

    public class WorkItem
    {
        public string Id { get; set; }
        public string DocumentId { get; set; }
        public string FieldId { get; set; }
        public string Status { get; set; }
    }

    public class UserWorkItem : AbstractMultiMapIndexCreationTask<UserWorkItem.Result>
    {
        public class Result
        {
            public string FieldId { get; set; }
            public string UserId { get; set; }
            public string DocumentId { get; set; }
            public int Count { get; set; }
            public int Validated { get; set; }
        }

        public UserWorkItem()
        {
            AddMap<ExtractionUser>(users => users.SelectMany(u => u.AssignedFields, (user, fied) => new
            {
                FieldId = fied,
                UserId = user.Id,
                DocumentId = (string)null,
                Count = 0,
                Validated = 0
            }));

            AddMap<WorkItem>(items => items.Select(item => new
            {
                FieldId = item.FieldId,
                UserId = (string)null,
                DocumentId = item.DocumentId,
                Count = 1,
                Validated = item.Status == "Validated" ? 1 : 0
            }));

            Reduce = results => results.GroupBy(r => r.FieldId)
                // gather all the users and all the documents with a common field
                .Select(g => new
                {
                    FieldId = g.Key,
                    Users = g.Where(u => u.UserId != null)
                        .Select(d => d.UserId)
                        .DefaultIfEmpty(),
                    Documents = g.Where(d => d.DocumentId != null)
                        .Select(d => new
                        {
                            DocumentId = d.DocumentId,
                            Count = d.Count,
                            Validated = d.Validated
                        }).DefaultIfEmpty(new
                        {
                            DocumentId = (string)null,
                            Count = 0,
                            Validated = 0
                        })
                })
                // make all combinations of field , user , document by .SelectMany first on Users then on Documents
                .SelectMany(d => d.Users, (d, user) => new
                {
                    FieldId = d.FieldId,
                    UserId = user,
                    Documents = d.Documents,
                })
                .SelectMany(d => d.Documents, (d, document) => new
                {
                    // if we have a value for UserId and for DocumentId then compose a FieldId from these values else use the initial FieldId
                    FieldId = (d.UserId != null && document.DocumentId != null) ?
                        d.UserId + " " + document.DocumentId : d.FieldId,
                    UserId = d.UserId,
                    DocumentId = document.DocumentId,
                    Count = document.Count,
                    Validated = document.Validated
                })
                // aggregate the final result
                .GroupBy(d => new { d.FieldId, d.UserId, d.DocumentId })
                .Select(g => new
                {
                    FieldId = g.Key.FieldId,
                    UserId = g.Key.UserId,
                    DocumentId = g.Key.DocumentId,
                    Count = g.Sum(d => d.Count),
                    Validated = g.Sum(d => d.Validated)
                });
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            //using (EmbeddableDocumentStore store = new EmbeddableDocumentStore { RunInMemory = true })
            using (DocumentStore store = new DocumentStore { ConnectionStringName = "RavenDb" })
            {
                store.Initialize();
                IndexCreation.CreateIndexes(typeof(UserWorkItem).Assembly, store);
                //using (var session = store.OpenSession())
                //{
                //    CreateDocs(session);
                //    session.SaveChanges();
                //}

                //using (var session = store.OpenSession())
                //{
                //    var result = session.Query<WorkItem, UserWorkItem>()
                //        .Customize(q => q.WaitForNonStaleResults())
                //        .As<UserWorkItem.Result>()
                //        .ToArray();
                //}
            }

            Console.WriteLine("Done");
            Console.ReadKey();
        }

        private static void CreateDocs(IDocumentSession session)
        {
            //ExtractionUser u1 = new ExtractionUser { Id = "ExtractionUsers/1", AssignedFields = new string[] { "field1", "field2" } };
            //ExtractionUser u2 = new ExtractionUser { Id = "ExtractionUsers/2", AssignedFields = new string[] { "field1", "field3" } };
            //ExtractionUser u3 = new ExtractionUser { Id = "ExtractionUsers/3", AssignedFields = new string[] { "field1", "field4" } };

            //WorkItem wi1 = new WorkItem { DocumentId = "documents/1", FieldId = "field1", Status = "Ready" };
            //WorkItem wi2 = new WorkItem { DocumentId = "documents/1", FieldId = "field2", Status = "Ready" };
            //WorkItem wi3 = new WorkItem { DocumentId = "documents/1", FieldId = "field3", Status = "Ready" };
            //WorkItem wi4 = new WorkItem { DocumentId = "documents/1", FieldId = "field4", Status = "Ready" };
            //WorkItem wi5 = new WorkItem { DocumentId = "documents/2", FieldId = "field1", Status = "Ready" };
            //WorkItem wi6 = new WorkItem { DocumentId = "documents/2", FieldId = "field2", Status = "Ready" };
            //WorkItem wi7 = new WorkItem { DocumentId = "documents/2", FieldId = "field3", Status = "Ready" };
            //WorkItem wi8 = new WorkItem { DocumentId = "documents/2", FieldId = "field4", Status = "Ready" };

            //WorkItem wi9 = new WorkItem { DocumentId = "documents/3", FieldId = "field4", Status = "Ready" };
            //session.Store(wi9);
            //session.Store(u1);
            //session.Store(u2);
            //session.Store(u3);

            //session.Store(wi1);
            //session.Store(wi2);
            //session.Store(wi3);
            //session.Store(wi4);
            //session.Store(wi5);
            //session.Store(wi6);
            //session.Store(wi7);
            //session.Store(wi8);
        }
    }
}