only for expenses

Adds TransactionDataset.GetValue(bool, string accountId), which
negates the value when the given account is the transaction's origin
(paying out) so the account's own transaction list and charts show
a minus sign for outgoing money, regardless of account class. Removes
the old Activa-only sign flip baked into
ViewService.GetTransactionViewListAsync(accountId), which would have
double-negated Activa bookings against the new accountId-aware
GetValue. ChartService's booking-text totals now sum through the same
accountId-aware GetValue instead of filtering to inbound transactions
only, so a booking text nets its in/out transactions correctly.

Schaad.Accounting.Common/Datasets/TransactionDataset.cs

@@ -33,5 +33,15 @@ namespace Schaad.Accounting.Datasets
             else
                 return Value;
         }
+
+        public decimal GetValue(bool withFxRate, string accountId)
+        {
+            if (accountId == OriginAccountId)
+            {
+                return -1 * GetValue(withFxRate);
+            }
+
+            return GetValue(withFxRate);
+        }
     }
 }

Schaad.Accounting.Services/ChartService.cs

@@ -112,7 +112,7 @@ namespace Schaad.Accounting.Services
             {
                 var groupedByMonth = grp
                     .GroupBy(t => t.ValueDate.Month)
-                    .ToDictionary(g => g.Key, g => g.Sum(t => t.GetValue(account.IsFxAccount)));
+                    .ToDictionary(g => g.Key, g => g.Sum(t => t.GetValue(account.IsFxAccount, accountId)));
                 EnsureEntryForEveryMonth(groupedByMonth, maxMonth);
 
                 list.Add(new DataSerie(
@@ -131,8 +131,9 @@ namespace Schaad.Accounting.Services
             var transactions = await viewService.GetTransactionViewListAsync(accountId);
 
             return transactions
+                .Where(t => t.TargetAccountId == accountId)
                 .GroupBy(t => t.Text)
-                .Select(g => new CategoryTotal(g.Key, g.Sum(t => t.GetValue(account.IsFxAccount))))
+                .Select(g => new CategoryTotal(g.Key, g.Sum(t => t.GetValue(account.IsFxAccount, accountId))))
                 .Where(c => c.Value != 0)
                 .ToList();
         }

Schaad.Accounting.Services/ViewService.cs

@@ -132,8 +132,9 @@ namespace Schaad.Accounting.Services
         }
 
         /// <summary>
-        /// Get transaction list filtered to a single account, with values sign-flipped
-        /// when the requested account is the origin of an activa booking.
+        /// Get transaction list filtered to a single account. Sign is not baked in here -
+        /// callers use <see cref="TransactionDataset.GetValue(bool, string)"/> with this
+        /// account's id to get a value that's negative when the account is paying out.
         /// </summary>
         public async Task<List<TransactionDataset>> GetTransactionViewListAsync(string accountId)
         {
@@ -143,22 +144,10 @@ namespace Schaad.Accounting.Services
 
             return transactionList.Select(t =>
                     new TransactionDataset(
-                        WithDisplaySign(t),
+                        t,
                         accountsById[t.OriginAccountId],
                         accountsById[t.TargetAccountId]))
                 .ToList();
-
-            Transaction WithDisplaySign(Transaction t)
-            {
-                var originAccount = accountsById[t.OriginAccountId];
-                if (originAccount.Class == ClassIds.Activa && accountId == t.OriginAccountId)
-                {
-                    var copy = t.Clone();
-                    copy.Value *= -1;
-                    return copy;
-                }
-                return t;
-            }
         }
 
         /// <summary>

Schaad.Accounting.Tests/ChartServiceTestShould.cs

@@ -186,11 +186,27 @@ public class ChartServiceTestShould
 
         series.Count.ShouldBe(2);
         var migros = series.Single(s => s.Name == "Migros");
-        migros.Y[0].ShouldBe(50m);
+        migros.Y[0].ShouldBe(-50m);
         migros.Y[1].ShouldBe(0m);
         var coop = series.Single(s => s.Name == "Coop");
         coop.Y[0].ShouldBe(0m);
-        coop.Y[1].ShouldBe(20m);
+        coop.Y[1].ShouldBe(-20m);
+    }
+
+    [Fact]
+    public async Task ShowPositiveValueWhenAccountIsTargetOfBookingTextTransaction()
+    {
+        var checking = MakeAccount("chk", 1010);
+        var salary = MakeAccount("sal", 3000);
+        viewService.GetAccountViewAsync("chk").Returns(AsDataset(checking));
+        viewService.GetTransactionViewListAsync("chk").Returns(new List<TransactionDataset>
+        {
+            MakeTransaction(salary, checking, value: 5000m, valueDate: new DateTime(2026, 1, 5), text: "Lohn")
+        });
+
+        var series = await BuildService().GetBookingTextExpensesPerMonthAsync("chk");
+
+        series.Single().Y.Single().ShouldBe(5000m);
     }
 
     [Fact]
@@ -206,7 +222,7 @@ public class ChartServiceTestShould
 
         var series = await BuildService().GetBookingTextExpensesPerMonthAsync("chk");
 
-        series.Single().Y.Single().ShouldBe(200m);
+        series.Single().Y.Single().ShouldBe(-200m);
     }
 
     [Fact]
@@ -225,8 +241,25 @@ public class ChartServiceTestShould
         var totals = await BuildService().GetBookingTextTotalsAsync("chk");
 
         totals.Count.ShouldBe(2);
-        totals.ShouldContain(t => t.Name == "Migros" && t.Value == 80m);
-        totals.ShouldContain(t => t.Name == "Coop" && t.Value == 20m);
+        totals.ShouldContain(t => t.Name == "Migros" && t.Value == -80m);
+        totals.ShouldContain(t => t.Name == "Coop" && t.Value == -20m);
+    }
+
+    [Fact]
+    public async Task NetOutgoingAndIncomingBookingsWithTheSameTextWhenBuildingTotalsForAccount()
+    {
+        var checking = MakeAccount("chk", 1010);
+        var groceries = MakeAccount("groc", 4200);
+        viewService.GetAccountViewAsync("chk").Returns(AsDataset(checking));
+        viewService.GetTransactionViewListAsync("chk").Returns(new List<TransactionDataset>
+        {
+            MakeTransaction(checking, groceries, value: 50m, valueDate: new DateTime(2026, 1, 5), text: "Migros"),
+            MakeTransaction(groceries, checking, value: 20m, valueDate: new DateTime(2026, 1, 6), text: "Migros")
+        });
+
+        var totals = await BuildService().GetBookingTextTotalsAsync("chk");
+
+        totals.Single().Value.ShouldBe(-30m);
     }
 
     [Fact]

Schaad.Accounting.Tests/TransactionDatasetTestShould.cs

@@ -0,0 +1,54 @@
+using Schaad.Accounting.Datasets;
+using Schaad.Accounting.Models;
+using Shouldly;
+
+namespace Schaad.Accounting.Tests;
+
+public class TransactionDatasetTestShould
+{
+    private static Account MakeAccount(string id) => new() { Id = id, Name = id, Currency = "CHF" };
+
+    private static TransactionDataset MakeTransaction(Account origin, Account target, decimal value, decimal? fxRate = null) =>
+        new(
+            new Transaction
+            {
+                Id = Guid.NewGuid().ToString(),
+                OriginAccountId = origin.Id,
+                TargetAccountId = target.Id,
+                Value = value,
+                FxRate = fxRate,
+                ValueDate = DateTime.Now,
+                BookingDate = DateTime.Now
+            },
+            origin, target);
+
+    [Fact]
+    public void ReturnNegativeValueWhenAccountIsOrigin()
+    {
+        var checking = MakeAccount("chk");
+        var groceries = MakeAccount("groc");
+        var transaction = MakeTransaction(checking, groceries, value: 50m);
+
+        transaction.GetValue(withFxRate: false, accountId: "chk").ShouldBe(-50m);
+    }
+
+    [Fact]
+    public void ReturnPositiveValueWhenAccountIsTarget()
+    {
+        var checking = MakeAccount("chk");
+        var groceries = MakeAccount("groc");
+        var transaction = MakeTransaction(groceries, checking, value: 50m);
+
+        transaction.GetValue(withFxRate: false, accountId: "chk").ShouldBe(50m);
+    }
+
+    [Fact]
+    public void ApplyFxConversionBeforeApplyingSignWhenAccountIsOrigin()
+    {
+        var checking = MakeAccount("chk");
+        var groceries = MakeAccount("groc");
+        var transaction = MakeTransaction(checking, groceries, value: 100m, fxRate: 0.5m);
+
+        transaction.GetValue(withFxRate: true, accountId: "chk").ShouldBe(-200m);
+    }
+}

Schaad.Accounting.UI/Components/Pages/Transactions.razor

@@ -44,6 +44,8 @@
                 </FluentGridItem>
             </FluentGrid>
             
+            @if (selectedAccount.Class == ClassIds.Expenses)
+            {
                 <FluentGrid Justify="JustifyContent.FlexStart">
                     <FluentGridItem xs="6">
                         <BookingTextOverTime @key="selectedAccount.Id" AccountId="@selectedAccount.Id"/>
@@ -52,6 +54,7 @@
                         <BookingTextBreakdown @key="selectedAccount.Id" AccountId="@selectedAccount.Id"/>
                     </FluentGridItem>
                 </FluentGrid>
+            }
 
             <FluentPaginator State="@pagination" SummaryTemplate="@template"/>
             <FluentDataGrid Items="@transactionList" Pagination="@pagination" RowSize="DataGridRowSize.Medium">
@@ -62,7 +65,7 @@
                     @GetAccountName(context)
                 </TemplateColumn>
                 <TemplateColumn Title="Betrag" Align="Align.End">
-                    @context.GetValue(selectedAccount.IsFxAccount).ToString("N2") @selectedAccount.Currency
+                    @context.GetValue(selectedAccount.IsFxAccount, selectedAccountId).ToString("N2") @selectedAccount.Currency
                 </TemplateColumn>
                 <TemplateColumn Align="Align.Center" Width="50px">
                     <FluentButton IconEnd="@(new Icons.Regular.Size16.Delete())" Appearance="Appearance.Neutral" title="Löschen" aria-label="Löschen" OnClick="@(() => DeleteAsync(context.Id))"/>