Implement backup and restore functionality; add IBackupService and BackupService; refactor services to use DbContextFactory

.vscode/tasks.json

@@ -22,6 +22,37 @@
                 }
             }
         },
+        {
+            "label": "publish",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "publish",
+                "${workspaceFolder}/src/Duempelkas.Desktop/Duempelkas.Desktop.csproj",
+                "-c",
+                "Release",
+                "-r",
+                "win-x64",
+                "--self-contained",
+                "true",
+                "/p:PublishSingleFile=true",
+                "/p:EnableCompressionInSingleFile=true",
+                "/p:IncludeNativeLibrariesForSelfExtract=true",
+                "/p:IncludeAllContentForSelfExtract=true",
+                "/p:DebugType=None",
+                "/p:DebugSymbols=false",
+                "-o",
+                "${workspaceFolder}/Publish"
+            ],
+            "problemMatcher": "$msCompile",
+            "options": {
+                "statusbar": {
+                    "label": "$(package) Publish",
+                    "color": "#22c55e",
+                    "detail": "Publish desktop app into Publish folder"
+                }
+            }
+        },
         {
             "label": "watch",
             "command": "dotnet",
@@ -34,6 +65,10 @@
             ],
             "problemMatcher": "$msCompile",
             "isBackground": true,
+            "presentation": {
+                "reveal": "never",
+                "panel": "dedicated"
+            },
             "options": {
                 "statusbar": {
                     "label": "$(eye) Watch",

src/Duempelkas.App/Components/Layout/MainLayout.razor

@@ -1,4 +1,5 @@
 @inherits LayoutComponentBase
+@using System.Reflection
 
 <div class="d-flex flex-column vh-100">
     <nav class="app-navbar d-flex justify-content-between align-items-center">
@@ -43,10 +44,17 @@
     {
         get
         {
-            var now = DateTime.Now;
+            var entryAssembly = Assembly.GetEntryAssembly();
-            var yearShort = now.Year % 100;
+            var infoVersion = entryAssembly?
-            var dayOfYear = now.DayOfYear;
+                .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
-            return $"{yearShort}.{dayOfYear}";
+                .InformationalVersion;
+
+            if (!string.IsNullOrWhiteSpace(infoVersion))
+            {
+                return infoVersion.Split('+')[0];
+            }
+
+            return entryAssembly?.GetName().Version?.ToString(2) ?? "1.0";
         }
     }
 }

src/Duempelkas.App/Pages/Accounts/AccountDetail.razor

@@ -28,6 +28,7 @@
             <button class="btn btn-secondary btn-nav" @onclick="NavigateBack">
                 <i class="bi bi-arrow-left"></i> Zurück
             </button>
+            |
             <button class="btn btn-success btn-nav" @onclick="() => showAddEntry = true">
                 <i class="bi bi-plus-lg"></i> Buchung
             </button>
@@ -37,6 +38,7 @@
             <button class="btn btn-dark btn-nav" @onclick="HandleExport">
                 <i class="bi bi-file-earmark-pdf"></i> PDF
             </button>
+            |
             <button class="btn btn-nav @(showCurrentYearOnly ? "btn-primary" : "btn-outline-secondary")" @onclick="ToggleYearFilter">
                 <i class="bi bi-funnel"></i> @(showCurrentYearOnly ? $"Nur {DateTime.Now.Year}" : "Alle Buchungen")
             </button>

src/Duempelkas.App/Pages/Dashboard.razor

@@ -1,6 +1,9 @@
 @page "/"
 @inject IAccountService AccountService
+@inject IBackupService BackupService
 @inject ISettingsService SettingsService
+@inject IJSRuntime JsRuntime
+@inject NavigationManager NavigationManager
 
 <div class="container-fluid">
 
@@ -19,8 +22,22 @@
         <button class="btn-nav btn-primary" @onclick="() => showAddAccount = true">
             <i class="bi bi-plus-lg"></i> Neues Konto
         </button>
+        |
+        <button class="btn-nav btn-success" @onclick="HandleBackupAsync">
+            <i class="bi bi-save"></i> Backup
+        </button>
+        <button class="btn-nav btn-warning" @onclick="HandleRestoreAsync">
+            <i class="bi bi-arrow-counterclockwise"></i> Restore
+        </button>
     </div>
 
+    @if (!string.IsNullOrWhiteSpace(operationMessage))
+    {
+        <div class="alert @operationMessageClass mb-3" role="alert">
+            @operationMessage
+        </div>
+    }
+
     @if (accounts == null)
     {
         <div class="text-center py-5">
@@ -56,6 +73,8 @@
     private bool showAddAccount;
     private bool showEditClubName;
     private string clubName = string.Empty;
+    private string? operationMessage;
+    private string operationMessageClass = "alert-info";
     private string DisplayClubName => string.IsNullOrWhiteSpace(clubName) ? "Mein Verein" : clubName;
 
     protected override async Task OnInitializedAsync()
@@ -87,4 +106,39 @@
         showEditClubName = false;
         await LoadClubName();
     }
+
+    private async Task HandleBackupAsync()
+    {
+        var message = await BackupService.CreateBackupAsync();
+        if(message.Contains("fehlgeschlagen", StringComparison.OrdinalIgnoreCase)) {
+            SetOperationMessage(message, false);
+        }
+        
+    }
+
+    private async Task HandleRestoreAsync()
+    {
+        var confirmed = await JsRuntime.InvokeAsync<bool>("confirm",
+            "Restore überschreibt die aktuelle Datenbank. Möchten Sie fortfahren?");
+
+        if (!confirmed) return;
+
+        var message = await BackupService.RestoreBackupAsync();
+        var isSuccess = message.StartsWith("Wiederherstellung erfolgreich", StringComparison.OrdinalIgnoreCase);
+
+        if (isSuccess)
+        {
+            // Reload the Blazor app so all components/services re-query from restored DB.
+            NavigationManager.NavigateTo("/", forceLoad: true);
+        } else {
+            SetOperationMessage(message, isSuccess);
+        }
+
+    }
+
+    private void SetOperationMessage(string message, bool success)
+    {
+        operationMessage = message;
+        operationMessageClass = success ? "alert-success" : "alert-danger";
+    }
 }

src/Duempelkas.App/Services/IBackupService.cs

@@ -0,0 +1,7 @@
+namespace Duempelkas.App.Services;
+
+public interface IBackupService
+{
+    Task<string> CreateBackupAsync();
+    Task<string> RestoreBackupAsync();
+}

src/Duempelkas.Desktop/Duempelkas.Desktop.csproj

@@ -2,8 +2,21 @@
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
     <OutputType>Exe</OutputType>
+    <OutputType Condition="$([MSBuild]::IsOSPlatform('Windows'))">WinExe</OutputType>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <Version>$([System.DateTime]::Now.ToString('yy')).$([System.DateTime]::Now.DayOfYear)</Version>
+    <PublishedExeFileName>Duempelkas-v$(Version).exe</PublishedExeFileName>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)' == 'Release'">
+    <SelfContained>true</SelfContained>
+    <PublishSingleFile>true</PublishSingleFile>
+    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
+    <IncludeAllContentForSelfExtract>true</IncludeAllContentForSelfExtract>
+    <DebugType>None</DebugType>
+    <DebugSymbols>false</DebugSymbols>
   </PropertyGroup>
 
   <ItemGroup>
@@ -24,4 +37,11 @@
     <ProjectReference Include="..\Duempelkas.App\Duempelkas.App.csproj" />
     <ProjectReference Include="..\Duempelkas.Infrastructure\Duempelkas.Infrastructure.csproj" />
   </ItemGroup>
+
+  <Target Name="FinalizePublishOutput" AfterTargets="Publish">
+    <Move SourceFiles="$(PublishDir)$(AssemblyName).exe"
+          DestinationFiles="$(PublishDir)$(PublishedExeFileName)"
+          Condition="Exists('$(PublishDir)$(AssemblyName).exe') and '$(AssemblyName).exe' != '$(PublishedExeFileName)'" />
+    <Touch Files="$(PublishDir)duempelkas.db" AlwaysCreate="true" Condition="!Exists('$(PublishDir)duempelkas.db')" />
+  </Target>
 </Project>

src/Duempelkas.Desktop/Program.cs

@@ -13,7 +13,8 @@ class Program
     {
         var appBuilder = PhotinoBlazorAppBuilder.CreateDefault(args);
 
-        var dbPath = Path.Combine(AppContext.BaseDirectory, "duempelkas.db");
+        var exeDirectory = Path.GetDirectoryName(Environment.ProcessPath ?? AppContext.BaseDirectory) ?? AppContext.BaseDirectory;
+        var dbPath = Path.Combine(exeDirectory, "duempelkas.db");
         appBuilder.Services.AddInfrastructure($"Data Source={dbPath}");
 
         appBuilder.RootComponents.Add<Duempelkas.App.Components.App>("app");

src/Duempelkas.Infrastructure/DependencyInjection.cs

@@ -12,12 +12,15 @@ public static class DependencyInjection
     {
         services.AddDbContext<FinanceDbContext>(options =>
             options.UseSqlite(connectionString));
+        services.AddDbContextFactory<FinanceDbContext>(options =>
+            options.UseSqlite(connectionString));
 
         services.AddScoped<IAccountService, AccountService>();
         services.AddScoped<IEntryService, EntryService>();
         services.AddScoped<IBalanceQueryService, BalanceQueryService>();
         services.AddScoped<IPdfStatementService, PdfStatementService>();
         services.AddScoped<IFileSaveService, FileSaveService>();
+        services.AddSingleton<IBackupService, BackupService>();
         services.AddSingleton<ISettingsService, SettingsService>();
 
         return services;

src/Duempelkas.Infrastructure/Services/AccountService.cs

@@ -9,13 +9,15 @@ namespace Duempelkas.Infrastructure.Services;
 
 public class AccountService : IAccountService
 {
-    private readonly FinanceDbContext _db;
+    private readonly IDbContextFactory<FinanceDbContext> _dbFactory;
 
-    public AccountService(FinanceDbContext db) => _db = db;
+    public AccountService(IDbContextFactory<FinanceDbContext> dbFactory) => _dbFactory = dbFactory;
 
     public async Task<List<AccountSummaryDto>> GetAllAccountsAsync()
     {
-        var accounts = await _db.Accounts
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var accounts = await db.Accounts
             .Include(a => a.Entries)
             .OrderBy(a => a.Name)
             .ToListAsync();
@@ -25,7 +27,9 @@ public class AccountService : IAccountService
 
     public async Task<AccountSummaryDto> GetAccountAsync(int accountId)
     {
-        var account = await _db.Accounts
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var account = await db.Accounts
             .Include(a => a.Entries)
             .FirstOrDefaultAsync(a => a.Id == accountId)
             ?? throw new InvalidOperationException($"Account {accountId} not found.");
@@ -35,51 +39,59 @@ public class AccountService : IAccountService
 
     public async Task<AccountSummaryDto> CreateAccountAsync(string name)
     {
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
         var account = new Account { Name = name };
-        _db.Accounts.Add(account);
+        db.Accounts.Add(account);
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
         return new AccountSummaryDto(account.Id, account.Name, 0m, 0m, account.CreatedUtc);
     }
 
     public async Task RenameAccountAsync(int accountId, string newName)
     {
-        var account = await _db.Accounts.FindAsync(accountId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var account = await db.Accounts.FindAsync(accountId)
             ?? throw new InvalidOperationException($"Account {accountId} not found.");
         account.Name = newName;
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
     public async Task UpdateCarryoverAsync(int accountId, decimal carryoverBalance)
     {
-        var account = await _db.Accounts.FindAsync(accountId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var account = await db.Accounts.FindAsync(accountId)
             ?? throw new InvalidOperationException($"Account {accountId} not found.");
         account.CarryoverBalance = carryoverBalance;
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
     public async Task DeleteAccountAsync(int accountId)
     {
-        var account = await _db.Accounts
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var account = await db.Accounts
             .Include(a => a.Entries)
             .FirstOrDefaultAsync(a => a.Id == accountId)
             ?? throw new InvalidOperationException($"Account {accountId} not found.");
 
         var entryIds = account.Entries.Select(e => e.Id).ToList();
-        var transferLinks = await _db.TransferLinks
+        var transferLinks = await db.TransferLinks
             .Where(tl => entryIds.Contains(tl.SourceEntryId) || entryIds.Contains(tl.TargetEntryId))
             .ToListAsync();
 
         foreach (var link in transferLinks)
         {
             var otherEntryId = entryIds.Contains(link.SourceEntryId) ? link.TargetEntryId : link.SourceEntryId;
-            var otherEntry = await _db.Entries.FindAsync(otherEntryId);
+            var otherEntry = await db.Entries.FindAsync(otherEntryId);
             if (otherEntry != null)
-                _db.Entries.Remove(otherEntry);
+                db.Entries.Remove(otherEntry);
         }
-        _db.TransferLinks.RemoveRange(transferLinks);
+        db.TransferLinks.RemoveRange(transferLinks);
 
-        _db.Accounts.Remove(account);
+        db.Accounts.Remove(account);
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
     private static AccountSummaryDto MapToSummary(Account account)

src/Duempelkas.Infrastructure/Services/BackupService.cs

@@ -0,0 +1,146 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using Duempelkas.App.Services;
+using Microsoft.Data.Sqlite;
+
+namespace Duempelkas.Infrastructure.Services;
+
+public class BackupService : IBackupService
+{
+    private static readonly string DbPath = Path.Combine(
+        Path.GetDirectoryName(Environment.ProcessPath ?? AppContext.BaseDirectory) ?? AppContext.BaseDirectory,
+        "duempelkas.db");
+
+    public async Task<string> CreateBackupAsync()
+    {
+        if (!File.Exists(DbPath))
+        {
+            return "Keine Datenbankdatei gefunden.";
+        }
+
+        var suggestedFileName = $"duempelkas-backup-{DateTime.Now:yyMMdd-HHmm}.bak";
+        var backupPath = await ShowSaveDialogAsync(suggestedFileName);
+
+        if (string.IsNullOrWhiteSpace(backupPath))
+        {
+            return "Backup wurde abgebrochen.";
+        }
+
+        backupPath = Path.ChangeExtension(backupPath, ".bak");
+
+        try
+        {
+            File.Copy(DbPath, backupPath, overwrite: true);
+            return $"Backup gespeichert: {backupPath}";
+        }
+        catch (Exception ex)
+        {
+            return $"Backup fehlgeschlagen: {ex.Message}";
+        }
+    }
+
+    public async Task<string> RestoreBackupAsync()
+    {
+        var backupPath = await ShowOpenDialogAsync();
+        if (string.IsNullOrWhiteSpace(backupPath))
+        {
+            return "Wiederherstellung wurde abgebrochen.";
+        }
+
+        if (!File.Exists(backupPath))
+        {
+            return "Die gewählte Backup-Datei wurde nicht gefunden.";
+        }
+
+        try
+        {
+            // Ensure no pooled connection keeps stale handles to the previous DB file.
+            SqliteConnection.ClearAllPools();
+
+            var targetDirectory = Path.GetDirectoryName(DbPath);
+            if (!string.IsNullOrWhiteSpace(targetDirectory))
+            {
+                Directory.CreateDirectory(targetDirectory);
+            }
+
+            File.Copy(backupPath, DbPath, overwrite: true);
+            SqliteConnection.ClearAllPools();
+            return "Wiederherstellung erfolgreich. Die Datenbank wurde neu geladen.";
+        }
+        catch (Exception ex)
+        {
+            return $"Wiederherstellung fehlgeschlagen: {ex.Message}";
+        }
+    }
+
+    private static Task<string?> ShowSaveDialogAsync(string suggestedFileName)
+    {
+        return Task.Run(() =>
+        {
+            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                var documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
+                return Path.Combine(documentsPath, suggestedFileName);
+            }
+
+            var script = $@"
+Add-Type -AssemblyName System.Windows.Forms
+$dialog = New-Object System.Windows.Forms.SaveFileDialog
+$dialog.Filter = 'Backup-Dateien (*.bak)|*.bak'
+$dialog.DefaultExt = 'bak'
+$dialog.AddExtension = $true
+$dialog.OverwritePrompt = $true
+$dialog.FileName = '{suggestedFileName.Replace("'", "''")}'
+$dialog.Title = 'Backup speichern'
+if ($dialog.ShowDialog() -eq 'OK') {{ $dialog.FileName }} else {{ '' }}
+";
+
+            return RunPowerShellDialog(script);
+        });
+    }
+
+    private static Task<string?> ShowOpenDialogAsync()
+    {
+        return Task.Run(() =>
+        {
+            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                return null;
+            }
+
+            var script = @"
+Add-Type -AssemblyName System.Windows.Forms
+$dialog = New-Object System.Windows.Forms.OpenFileDialog
+$dialog.Filter = 'Backup-Dateien (*.bak)|*.bak'
+$dialog.Multiselect = $false
+$dialog.Title = 'Backup auswählen'
+if ($dialog.ShowDialog() -eq 'OK') { $dialog.FileName } else { '' }
+";
+
+            return RunPowerShellDialog(script);
+        });
+    }
+
+    private static string? RunPowerShellDialog(string script)
+    {
+        var psi = new ProcessStartInfo
+        {
+            FileName = "powershell",
+            Arguments = $"-NoProfile -Command \"{script.Replace("\"", "\\\"") }\"",
+            RedirectStandardOutput = true,
+            UseShellExecute = false,
+            CreateNoWindow = true
+        };
+
+        using var process = Process.Start(psi);
+        if (process == null)
+        {
+            return null;
+        }
+
+        var result = process.StandardOutput.ReadToEnd().Trim();
+        process.WaitForExit();
+
+        return string.IsNullOrWhiteSpace(result) ? null : result;
+    }
+}

src/Duempelkas.Infrastructure/Services/BalanceQueryService.cs

@@ -8,13 +8,15 @@ namespace Duempelkas.Infrastructure.Services;
 
 public class BalanceQueryService : IBalanceQueryService
 {
-    private readonly FinanceDbContext _db;
+    private readonly IDbContextFactory<FinanceDbContext> _dbFactory;
 
-    public BalanceQueryService(FinanceDbContext db) => _db = db;
+    public BalanceQueryService(IDbContextFactory<FinanceDbContext> dbFactory) => _dbFactory = dbFactory;
 
     public async Task<AccountBalanceDto> GetAccountBalanceAsync(int accountId)
     {
-        var account = await _db.Accounts
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var account = await db.Accounts
             .Include(a => a.Entries)
             .FirstOrDefaultAsync(a => a.Id == accountId)
             ?? throw new InvalidOperationException($"Konto {accountId} nicht gefunden.");

src/Duempelkas.Infrastructure/Services/EntryService.cs

@@ -9,13 +9,15 @@ namespace Duempelkas.Infrastructure.Services;
 
 public class EntryService : IEntryService
 {
-    private readonly FinanceDbContext _db;
+    private readonly IDbContextFactory<FinanceDbContext> _dbFactory;
 
-    public EntryService(FinanceDbContext db) => _db = db;
+    public EntryService(IDbContextFactory<FinanceDbContext> dbFactory) => _dbFactory = dbFactory;
 
     public async Task<List<EntryDto>> GetEntriesAsync(int accountId, bool currentYearOnly)
     {
-        var query = _db.Entries.Where(e => e.AccountId == accountId);
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var query = db.Entries.Where(e => e.AccountId == accountId);
 
         if (currentYearOnly)
             query = query.Where(e => e.Date.Year == DateTime.Now.Year);
@@ -27,7 +29,7 @@ public class EntryService : IEntryService
 
         var entryIds = entries.Select(e => e.Id).ToList();
 
-        var transferLinks = await _db.TransferLinks
+        var transferLinks = await db.TransferLinks
             .Include(tl => tl.SourceEntry).ThenInclude(e => e.Account)
             .Include(tl => tl.TargetEntry).ThenInclude(e => e.Account)
             .Where(tl => entryIds.Contains(tl.SourceEntryId) || entryIds.Contains(tl.TargetEntryId))
@@ -59,7 +61,9 @@ public class EntryService : IEntryService
 
     public async Task<EntryDto> CreateEntryAsync(int accountId, EntryType type, DateTime date, string title, decimal amount)
     {
-        var displayId = await GenerateDisplayIdAsync(accountId, date.Year);
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var displayId = await GenerateDisplayIdAsync(db, accountId, date.Year);
 
         var entry = new Entry
         {
@@ -70,8 +74,8 @@ public class EntryService : IEntryService
             Title = title,
             Amount = amount
         };
-        _db.Entries.Add(entry);
+        db.Entries.Add(entry);
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
 
         return new EntryDto(entry.Id, entry.AccountId, entry.DisplayId, entry.Type, entry.Date, entry.Title, entry.Amount, false, false, null, null, null);
     }
@@ -81,9 +85,10 @@ public class EntryService : IEntryService
         if (sourceAccountId == targetAccountId)
             throw new InvalidOperationException("Umbuchung innerhalb desselben Kontos ist nicht möglich.");
 
-        await using var transaction = await _db.Database.BeginTransactionAsync();
+        await using var db = await _dbFactory.CreateDbContextAsync();
+        await using var transaction = await db.Database.BeginTransactionAsync();
 
-        var sourceDisplayId = await GenerateDisplayIdAsync(sourceAccountId, date.Year);
+        var sourceDisplayId = await GenerateDisplayIdAsync(db, sourceAccountId, date.Year);
 
         var sourceEntry = new Entry
         {
@@ -95,10 +100,10 @@ public class EntryService : IEntryService
             Amount = amount
         };
 
-        _db.Entries.Add(sourceEntry);
+        db.Entries.Add(sourceEntry);
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
 
-        var targetDisplayId = await GenerateDisplayIdAsync(targetAccountId, date.Year);
+        var targetDisplayId = await GenerateDisplayIdAsync(db, targetAccountId, date.Year);
 
         var targetEntry = new Entry
         {
@@ -110,8 +115,8 @@ public class EntryService : IEntryService
             Amount = amount
         };
 
-        _db.Entries.Add(targetEntry);
+        db.Entries.Add(targetEntry);
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
 
         var link = new TransferLink
         {
@@ -119,62 +124,68 @@ public class EntryService : IEntryService
             TargetEntryId = targetEntry.Id,
             Note = $"Umbuchung: {title}"
         };
-        _db.TransferLinks.Add(link);
+        db.TransferLinks.Add(link);
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
 
         sourceEntry.TransferLinkId = link.Id;
         targetEntry.TransferLinkId = link.Id;
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
 
         await transaction.CommitAsync();
     }
 
     public async Task DeleteEntryAsync(int entryId)
     {
-        var entry = await _db.Entries.FindAsync(entryId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var entry = await db.Entries.FindAsync(entryId)
             ?? throw new InvalidOperationException($"Eintrag {entryId} nicht gefunden.");
 
         entry.IsDeleted = true;
 
-        var link = await _db.TransferLinks
+        var link = await db.TransferLinks
             .FirstOrDefaultAsync(tl => tl.SourceEntryId == entryId || tl.TargetEntryId == entryId);
 
         if (link != null)
         {
             var otherEntryId = link.SourceEntryId == entryId ? link.TargetEntryId : link.SourceEntryId;
-            var otherEntry = await _db.Entries.FindAsync(otherEntryId);
+            var otherEntry = await db.Entries.FindAsync(otherEntryId);
             if (otherEntry != null) otherEntry.IsDeleted = true;
         }
 
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
     public async Task RestoreEntryAsync(int entryId)
     {
-        var entry = await _db.Entries.FindAsync(entryId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var entry = await db.Entries.FindAsync(entryId)
             ?? throw new InvalidOperationException($"Eintrag {entryId} nicht gefunden.");
 
         entry.IsDeleted = false;
 
-        var link = await _db.TransferLinks
+        var link = await db.TransferLinks
             .FirstOrDefaultAsync(tl => tl.SourceEntryId == entryId || tl.TargetEntryId == entryId);
 
         if (link != null)
         {
             var otherEntryId = link.SourceEntryId == entryId ? link.TargetEntryId : link.SourceEntryId;
-            var otherEntry = await _db.Entries.FindAsync(otherEntryId);
+            var otherEntry = await db.Entries.FindAsync(otherEntryId);
             if (otherEntry != null) otherEntry.IsDeleted = false;
         }
 
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
     public async Task UpdateEntryAsync(int entryId, DateTime date, string title, decimal amount)
     {
-        var entry = await _db.Entries.FindAsync(entryId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var entry = await db.Entries.FindAsync(entryId)
             ?? throw new InvalidOperationException($"Eintrag {entryId} nicht gefunden.");
 
-        var link = await _db.TransferLinks
+        var link = await db.TransferLinks
             .FirstOrDefaultAsync(tl => tl.SourceEntryId == entryId || tl.TargetEntryId == entryId);
 
         entry.Date = date;
@@ -184,7 +195,7 @@ public class EntryService : IEntryService
         if (link != null)
         {
             var otherEntryId = link.SourceEntryId == entryId ? link.TargetEntryId : link.SourceEntryId;
-            var otherEntry = await _db.Entries.FindAsync(otherEntryId);
+            var otherEntry = await db.Entries.FindAsync(otherEntryId);
             if (otherEntry != null)
             {
                 otherEntry.Date = date;
@@ -193,20 +204,22 @@ public class EntryService : IEntryService
             }
         }
 
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
     public async Task UpdateTransferAsync(int entryId, int newLinkedAccountId, DateTime date, string title, decimal amount)
     {
-        var entry = await _db.Entries.FindAsync(entryId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var entry = await db.Entries.FindAsync(entryId)
             ?? throw new InvalidOperationException($"Eintrag {entryId} nicht gefunden.");
 
-        var link = await _db.TransferLinks
+        var link = await db.TransferLinks
             .FirstOrDefaultAsync(tl => tl.SourceEntryId == entryId || tl.TargetEntryId == entryId)
             ?? throw new InvalidOperationException($"Kein Transfer-Link für Eintrag {entryId} gefunden.");
 
         var otherEntryId = link.SourceEntryId == entryId ? link.TargetEntryId : link.SourceEntryId;
-        var otherEntry = await _db.Entries.FindAsync(otherEntryId)
+        var otherEntry = await db.Entries.FindAsync(otherEntryId)
             ?? throw new InvalidOperationException($"Gegeneintrag {otherEntryId} nicht gefunden.");
 
         // Update date, title, amount on both sides
@@ -221,16 +234,16 @@ public class EntryService : IEntryService
         if (otherEntry.AccountId != newLinkedAccountId)
         {
             otherEntry.AccountId = newLinkedAccountId;
-            otherEntry.DisplayId = await GenerateDisplayIdAsync(newLinkedAccountId, date.Year);
+            otherEntry.DisplayId = await GenerateDisplayIdAsync(db, newLinkedAccountId, date.Year);
         }
 
-        await _db.SaveChangesAsync();
+        await db.SaveChangesAsync();
     }
 
-    private async Task<string> GenerateDisplayIdAsync(int accountId, int year)
+    private static async Task<string> GenerateDisplayIdAsync(FinanceDbContext db, int accountId, int year)
     {
         var prefix = $"{year}-";
-        var maxDisplayId = await _db.Entries
+        var maxDisplayId = await db.Entries
             .Where(e => e.DisplayId.StartsWith(prefix))
             .Select(e => e.DisplayId)
             .MaxAsync(id => (string?)id);

src/Duempelkas.Infrastructure/Services/PdfStatementService.cs

@@ -12,15 +12,15 @@ namespace Duempelkas.Infrastructure.Services;
 
 public class PdfStatementService : IPdfStatementService
 {
-    private readonly FinanceDbContext _db;
+    private readonly IDbContextFactory<FinanceDbContext> _dbFactory;
     private readonly IEntryService _entryService;
     private readonly IBalanceQueryService _balanceQueryService;
     private readonly ISettingsService _settingsService;
     private static readonly CultureInfo DeLocale = new("de-DE");
 
-    public PdfStatementService(FinanceDbContext db, IEntryService entryService, IBalanceQueryService balanceQueryService, ISettingsService settingsService)
+    public PdfStatementService(IDbContextFactory<FinanceDbContext> dbFactory, IEntryService entryService, IBalanceQueryService balanceQueryService, ISettingsService settingsService)
     {
-        _db = db;
+        _dbFactory = dbFactory;
         _entryService = entryService;
         _balanceQueryService = balanceQueryService;
         _settingsService = settingsService;
@@ -28,7 +28,9 @@ public class PdfStatementService : IPdfStatementService
 
     public async Task<byte[]> GenerateStatementAsync(int accountId, bool currentYearOnly)
     {
-        var account = await _db.Accounts.FindAsync(accountId)
+        await using var db = await _dbFactory.CreateDbContextAsync();
+
+        var account = await db.Accounts.FindAsync(accountId)
             ?? throw new InvalidOperationException($"Konto {accountId} nicht gefunden.");
 
         var entries = await _entryService.GetEntriesAsync(accountId, currentYearOnly);

tests/Duempelkas.Tests/TransferServiceTests.cs

@@ -17,15 +17,17 @@ public class TransferServiceTests : IDisposable
     public TransferServiceTests()
     {
         var options = new DbContextOptionsBuilder<FinanceDbContext>()
-            .UseSqlite("Data Source=:memory:")
+            .UseSqlite("Data Source=duempelkas-transfer-tests;Mode=Memory;Cache=Shared")
             .Options;
 
         _db = new FinanceDbContext(options);
         _db.Database.OpenConnection();
         _db.Database.EnsureCreated();
 
-        _entryService = new EntryService(_db);
+        var dbFactory = new TestDbContextFactory(options);
-        _balanceQueryService = new BalanceQueryService(_db);
+
+        _entryService = new EntryService(dbFactory);
+        _balanceQueryService = new BalanceQueryService(dbFactory);
     }
 
     [Fact]
@@ -77,6 +79,7 @@ public class TransferServiceTests : IDisposable
 
         await _entryService.DeleteEntryAsync(sourceEntry.Id);
 
+        _db.ChangeTracker.Clear();
         var entries = await _db.Entries.ToListAsync();
         entries.Should().HaveCount(2);
         entries.Should().AllSatisfy(e => e.IsDeleted.Should().BeTrue());
@@ -107,4 +110,19 @@ public class TransferServiceTests : IDisposable
         _db.Database.CloseConnection();
         _db.Dispose();
     }
+
+    private sealed class TestDbContextFactory : IDbContextFactory<FinanceDbContext>
+    {
+        private readonly DbContextOptions<FinanceDbContext> _options;
+
+        public TestDbContextFactory(DbContextOptions<FinanceDbContext> options)
+        {
+            _options = options;
+        }
+
+        public FinanceDbContext CreateDbContext() => new(_options);
+
+        public Task<FinanceDbContext> CreateDbContextAsync(CancellationToken cancellationToken = default)
+            => Task.FromResult(new FinanceDbContext(_options));
+    }
 }

tests/Duempelkas.Tests/YearlyStatementCalculationTests.cs

@@ -17,15 +17,17 @@ public class BalanceCalculationTests : IDisposable
     public BalanceCalculationTests()
     {
         var options = new DbContextOptionsBuilder<FinanceDbContext>()
-            .UseSqlite("Data Source=:memory:")
+            .UseSqlite("Data Source=duempelkas-balance-tests;Mode=Memory;Cache=Shared")
             .Options;
 
         _db = new FinanceDbContext(options);
         _db.Database.OpenConnection();
         _db.Database.EnsureCreated();
 
-        _balanceQueryService = new BalanceQueryService(_db);
+        var dbFactory = new TestDbContextFactory(options);
-        _entryService = new EntryService(_db);
+
+        _balanceQueryService = new BalanceQueryService(dbFactory);
+        _entryService = new EntryService(dbFactory);
     }
 
     [Fact]
@@ -106,4 +108,19 @@ public class BalanceCalculationTests : IDisposable
         _db.Database.CloseConnection();
         _db.Dispose();
     }
+
+    private sealed class TestDbContextFactory : IDbContextFactory<FinanceDbContext>
+    {
+        private readonly DbContextOptions<FinanceDbContext> _options;
+
+        public TestDbContextFactory(DbContextOptions<FinanceDbContext> options)
+        {
+            _options = options;
+        }
+
+        public FinanceDbContext CreateDbContext() => new(_options);
+
+        public Task<FinanceDbContext> CreateDbContextAsync(CancellationToken cancellationToken = default)
+            => Task.FromResult(new FinanceDbContext(_options));
+    }
 }