feature: add expansion api logic

src/Application/DTOs/Transaction/GetTransactionsByAccountIdResponse.cs

@@ -0,0 +1,7 @@
+namespace Application.DTOs.Transaction;
+
+public class GetTransactionsByAccountIdResponse
+{
+    public long AccountId { get; set; }
+    public List<TransactionCsvModel> TransactionWithSources = new();
+}

src/Application/Interfaces/Services/ITransactionService.cs

@@ -1,4 +1,5 @@
 using Application.DTOs;
+using Application.DTOs.Transaction;
 using Domain.Entities;
 
 namespace Application.Interfaces.Services;
@@ -7,5 +8,5 @@ public interface ITransactionService
 {
     Task<Result> AddTransactionsFromCsvAsync(string filePath);
     Task<Result<List<Transaction>>> GetAllTransactionsAsync();
-    Task<List<Transaction>> GetTransactionsByAccountIdAsync(long accountId);
+    Task<Result<List<GetTransactionsByAccountIdResponse>>> GetTransactionsByAccountIdAsync(long accountId);
 }

src/Application/Services/DomainService/TransactionService.cs

@@ -49,10 +49,46 @@ public async Task<Result<List<Transaction>>> GetAllTransactionsAsync()
         }
     }
 
-    public async Task<List<Transaction>> GetTransactionsByAccountIdAsync(long accountId)
+    public async Task<Result<List<GetTransactionsByAccountIdResponse>>> GetTransactionsByAccountIdAsync(long accountId)
     {
-        var source = await _transactionRepository.GetBySourceAccountId(accountId);
-        var destination = await _transactionRepository.GetByDestinationAccountId(accountId);
-        return source.Concat(destination).ToList();
+        try
+        {
+            var result = new List<GetTransactionsByAccountIdResponse>();
+
+            var transactionsSourceAccountId = await _transactionRepository.GetBySourceAccountId(accountId);
+
+            var transactionsDestinationAccountId = await _transactionRepository.GetByDestinationAccountId(accountId);
+
+            var allTransactions = transactionsSourceAccountId.Concat(transactionsDestinationAccountId).ToList();
+
+            var groupedTransactions = allTransactions
+                .GroupBy(t => t.SourceAccountId == accountId ? t.DestinationAccountId : t.SourceAccountId)
+                .ToList();
+
+            foreach (var group in groupedTransactions)
+            {
+                var response = new GetTransactionsByAccountIdResponse
+                {
+                    AccountId = group.Key,
+                    TransactionWithSources = group.Select(t => new TransactionCsvModel
+                    {
+                        TransactionID = t.TransactionId,
+                        SourceAcount = t.SourceAccountId,
+                        DestiantionAccount = t.DestinationAccountId,
+                        Amount = t.Amount,
+                        Date = t.Date,
+                        Type = t.Type,
+                    }).ToList()
+                };
+
+                result.Add(response);
+            }
+
+            return Result<List<GetTransactionsByAccountIdResponse>>.Ok(result);
+        }
+        catch (Exception ex)
+        {
+            return Result<List<GetTransactionsByAccountIdResponse>>.Fail($"An error occurred: {ex.Message}");
+        }
     }
 }

src/Web/Controllers/TransactionController.cs

@@ -76,6 +76,14 @@ public async Task<IActionResult> GetAllTransactions()
     public async Task<IActionResult> GetTransactionsByAccountId(long accountId)
     {
         var transactions = await _transactionService.GetTransactionsByAccountIdAsync(accountId);
-        return Ok(transactions.ToGotAllTransactionsDto());
+
+        if (!transactions.Succeed)
+        {
+            return BadRequest(Errors.New(nameof(GetAllTransactions), transactions.Message));
+        }
+
+        var response = transactions.Value!;
+
+        return Ok(response);
     }
 }