pagination for backtest and optimization

src/Managing.Infrastructure.Database/BacktestRepository.cs

@@ -1,9 +1,11 @@
-using Managing.Application.Abstractions.Repositories;
+using System.Diagnostics;
+using Managing.Application.Abstractions.Repositories;
 using Managing.Domain.Backtests;
 using Managing.Domain.Users;
 using Managing.Infrastructure.Databases.MongoDb;
 using Managing.Infrastructure.Databases.MongoDb.Abstractions;
 using Managing.Infrastructure.Databases.MongoDb.Collections;
+using MongoDB.Driver;
 
 namespace Managing.Infrastructure.Databases;
 
@@ -41,6 +43,48 @@ public class BacktestRepository : IBacktestRepository
         return backtests.Select(b => MongoMappers.Map(b));
     }
 
+    public (IEnumerable<Backtest> Backtests, int TotalCount) GetBacktestsByRequestIdPaginated(string requestId, int page, int pageSize)
+    {
+        var stopwatch = Stopwatch.StartNew();
+        var collection = _backtestRepository.GetCollection(); // You may need to expose this in your repo
+
+        var filter = Builders<BacktestDto>.Filter.Eq(b => b.RequestId, requestId);
+
+        var afterQueryMs = stopwatch.ElapsedMilliseconds;
+        var totalCount = collection.CountDocuments(filter);
+        var afterCountMs = stopwatch.ElapsedMilliseconds;
+
+        var projection = Builders<BacktestDto>.Projection
+            .Include(b => b.Identifier)
+            .Include(b => b.FinalPnl)
+            .Include(b => b.WinRate)
+            .Include(b => b.GrowthPercentage)
+            .Include(b => b.HodlPercentage)
+            .Include(b => b.User)
+            .Include(b => b.Statistics)
+            .Include(b => b.StartDate)
+            .Include(b => b.EndDate)
+            .Include(b => b.Score)
+            .Include(b => b.RequestId)
+            .Include(b => b.Metadata)
+            .Include(b => b.Config);
+
+        var afterProjectionMs = stopwatch.ElapsedMilliseconds;
+        var backtests = collection
+            .Find(filter)
+            .Project<BacktestDto>(projection)
+            .Skip((page - 1) * pageSize)
+            .Limit(pageSize)
+            .ToList();
+        var afterToListMs = stopwatch.ElapsedMilliseconds;
+
+        Console.WriteLine($"[BacktestRepo] Query: {afterQueryMs}ms, Count: {afterCountMs - afterQueryMs}ms, Projection: {afterProjectionMs - afterCountMs}ms, ToList: {afterToListMs - afterProjectionMs}ms, Total: {afterToListMs}ms");
+
+        var mappedBacktests = backtests.Select(b => MongoMappers.Map(b));
+        
+        return (mappedBacktests, (int)totalCount);
+    }
+
     public Backtest GetBacktestByIdForUser(User user, string id)
     {
         var backtest = _backtestRepository.FindById(id);

src/Managing.Infrastructure.Database/MongoDb/Abstractions/IMongoRepository.cs

@@ -1,6 +1,6 @@
-using Managing.Infrastructure.Databases.MongoDb.Configurations;
+using System.Linq.Expressions;
+using Managing.Infrastructure.Databases.MongoDb.Configurations;
 using MongoDB.Driver;
-using System.Linq.Expressions;
 
 namespace Managing.Infrastructure.Databases.MongoDb.Abstractions
 {
@@ -53,5 +53,6 @@ namespace Managing.Infrastructure.Databases.MongoDb.Abstractions
         void Update(TDocument entity);
         void CreateIndex(string column);
         void DropCollection();
+        IMongoCollection<TDocument> GetCollection();
     }
 }

src/Managing.Infrastructure.Database/MongoDb/MongoRepository.cs

@@ -1,9 +1,9 @@
-using Managing.Infrastructure.Databases.MongoDb.Abstractions;
+using System.Linq.Expressions;
+using Managing.Infrastructure.Databases.MongoDb.Abstractions;
 using Managing.Infrastructure.Databases.MongoDb.Attributes;
 using Managing.Infrastructure.Databases.MongoDb.Configurations;
 using MongoDB.Bson;
 using MongoDB.Driver;
-using System.Linq.Expressions;
 
 namespace Managing.Infrastructure.Databases.MongoDb
 {
@@ -174,5 +174,10 @@ namespace Managing.Infrastructure.Databases.MongoDb
             var model = new CreateIndexModel<TDocument>(keys, indexOptions);
             _collection.Indexes.CreateOne(model);
         }
+
+        public IMongoCollection<TDocument> GetCollection()
+        {
+            return _collection;
+        }
     }
 }