feat(accounts): preview and confirm cross-year balance corrections (U12)

src/Duempelkas.Infrastructure/Services/AccountService.cs

@@ -93,15 +93,19 @@ public class AccountService : IAccountService
         return new AccountSummaryDto(account.Id, account.Name, account.CarryoverBalance, totalBalance, account.CreatedUtc);
     }
 
-    public async Task<AccountSummaryDto> CreateAccountAsync(string name)
+    public Task<AccountSummaryDto> CreateAccountAsync(string name) => CreateAccountAsync(name, 0m);
+
+    public async Task<AccountSummaryDto> CreateAccountAsync(string name, decimal initialBalance)
     {
+        if (string.IsNullOrWhiteSpace(name)) throw new ArgumentException("Bitte einen Kontonamen eingeben.");
+        if (decimal.Round(initialBalance, 2) != initialBalance) throw new ArgumentException("Ungültiger Anfangsbestand.");
         using var lease = await DatabaseLease.AcquireAsync(_location);
         await using var db = await _dbFactory.CreateDbContextAsync();
 
-        var account = new Account { Name = name };
+        var account = new Account { Name = name.Trim(), CarryoverBalance = initialBalance };
         db.Accounts.Add(account);
         await db.SaveChangesAsync();
-        return new AccountSummaryDto(account.Id, account.Name, 0m, 0m, account.CreatedUtc);
+        return new AccountSummaryDto(account.Id, account.Name, initialBalance, initialBalance, account.CreatedUtc);
     }
 
     public async Task RenameAccountAsync(int accountId, string newName)
@@ -148,6 +152,22 @@ public class AccountService : IAccountService
         await db.SaveChangesAsync();
     }
 
+    public async Task CorrectCarryoverAsync(int accountId, decimal value, int? year, decimal expectedCarryover, decimal expectedInitial)
+    {
+        if (decimal.Round(value, 2) != value) throw new ArgumentException("Ungültiger Bestand.");
+        using var lease = await DatabaseLease.AcquireAsync(_location);
+        await using var db = await _dbFactory.CreateDbContextAsync();
+        await using var transaction = await db.Database.BeginTransactionAsync();
+        var account = await db.Accounts.FindAsync(accountId) ?? throw new InvalidOperationException("Konto nicht mehr vorhanden.");
+        var movement = year.HasValue ? await db.Entries.Where(e => e.AccountId == accountId && !e.IsDeleted && e.Date.Year < year.Value)
+            .SumAsync(e => e.Type == EntryType.Income ? e.Amount : -e.Amount) : 0m;
+        if (account.CarryoverBalance != expectedInitial || account.CarryoverBalance + movement != expectedCarryover)
+            throw new InvalidOperationException("Der Bestand wurde inzwischen geändert. Bitte abbrechen und die Korrektur mit aktuellen Werten erneut öffnen.");
+        account.CarryoverBalance = value - movement;
+        await db.SaveChangesAsync();
+        await transaction.CommitAsync();
+    }
+
     public async Task DeleteAccountAsync(int accountId)
     {
         using var lease = await DatabaseLease.AcquireAsync(_location);