K18 fertig.

Erstellte Datei: src/Koogle.Web/Controllers/CashBookController.cs

  Endpoints:
  - GET /api/cashbook/export/excel?year=2026&month=1 → Excel-Download
  - GET /api/cashbook/export/pdf?year=2026&month=1 → PDF-Download

  Policy: ClubTreasurer

  Reports.razor.cs aktualisiert → Export-Buttons öffnen jetzt die Controller-Endpoints.

docs/IMPLEMENTATION_PLAN.md

@@ -1716,7 +1716,7 @@ public enum CashBookEntryType { Income = 0, Expense = 1 }
 | ✓ | K15 | Web | Reports UI | 2 |
 | ✓ | K16 | Application | Excel Export (ClosedXML) | 3 |
 | ✓ | K17 | Application | PDF Export (QuestPDF) | 1 |
-| ☐ | K18 | Web | Export Controller | 1 |
+| ✓ | K18 | Web | Export Controller | 1 |
 | ☐ | K19 | Web | Membership Fees Feature | 2 |
 | ☐ | K20 | Web | Club Settings Extension | 3 |
 | ☐ | K21 | Web | Navigation Integration | 1 |

src/Koogle.Web/Components/Pages/CashBook/Reports.razor.cs

@@ -2,6 +2,7 @@ using Koogle.Application.DTOs;
 using Koogle.Domain.Enums;
 using Koogle.Web.Store.CashBookState;
 using Microsoft.AspNetCore.Components;
+using Microsoft.JSInterop;
 using MudBlazor;
 
 namespace Koogle.Web.Components.Pages.CashBook;
@@ -11,6 +12,8 @@ namespace Koogle.Web.Components.Pages.CashBook;
 /// </summary>
 public partial class Reports
 {
+    [Inject] private IJSRuntime JS { get; set; } = default!;
+
     private int _selectedMonth = DateTime.Today.Month;
     private int _selectedYear = DateTime.Today.Year;
 
@@ -80,15 +83,15 @@ public partial class Reports
         return type == CashBookEntryType.Income ? Color.Success : Color.Error;
     }
 
-    private void ExportExcel()
+    private async Task ExportExcel()
     {
-        // Will be implemented in K16
-        Snackbar.Add("Excel-Export wird in einer späteren Version verfügbar sein", Severity.Info);
+        var url = $"/api/cashbook/export/excel?year={_selectedYear}&month={_selectedMonth}";
+        await JS.InvokeVoidAsync("open", url, "_blank");
     }
 
-    private void ExportPdf()
+    private async Task ExportPdf()
     {
-        // Will be implemented in K17
-        Snackbar.Add("PDF-Export wird in einer späteren Version verfügbar sein", Severity.Info);
+        var url = $"/api/cashbook/export/pdf?year={_selectedYear}&month={_selectedMonth}";
+        await JS.InvokeVoidAsync("open", url, "_blank");
     }
 }

src/Koogle.Web/Controllers/CashBookController.cs

@@ -0,0 +1,79 @@
+using Koogle.Application.Interfaces;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Koogle.Web.Controllers;
+
+/// <summary>
+/// Controller for cash book export operations.
+/// </summary>
+[Route("api/cashbook")]
+[Authorize(Policy = "ClubTreasurer")]
+public class CashBookController : Controller
+{
+    private readonly ICashBookService _cashBookService;
+    private readonly ICashBookExportService _exportService;
+    private readonly ICurrentClubContext _clubContext;
+
+    public CashBookController(
+        ICashBookService cashBookService,
+        ICashBookExportService exportService,
+        ICurrentClubContext clubContext)
+    {
+        _cashBookService = cashBookService;
+        _exportService = exportService;
+        _clubContext = clubContext;
+    }
+
+    /// <summary>
+    /// Exports cash book report to Excel format.
+    /// </summary>
+    [HttpGet("export/excel")]
+    public async Task<IActionResult> ExportExcel([FromQuery] int year, [FromQuery] int? month)
+    {
+        var (from, to) = GetDateRange(year, month);
+        var report = await _cashBookService.GetReportAsync(from, to);
+
+        var bytes = await _exportService.ExportToExcelAsync(report, _clubContext.ClubName);
+        var fileName = GetFileName("xlsx", year, month);
+
+        return File(bytes, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", fileName);
+    }
+
+    /// <summary>
+    /// Exports cash book report to PDF format.
+    /// </summary>
+    [HttpGet("export/pdf")]
+    public async Task<IActionResult> ExportPdf([FromQuery] int year, [FromQuery] int? month)
+    {
+        var (from, to) = GetDateRange(year, month);
+        var report = await _cashBookService.GetReportAsync(from, to);
+
+        var bytes = await _exportService.ExportToPdfAsync(report, _clubContext.ClubName);
+        var fileName = GetFileName("pdf", year, month);
+
+        return File(bytes, "application/pdf", fileName);
+    }
+
+    private static (DateTime from, DateTime to) GetDateRange(int year, int? month)
+    {
+        if (month.HasValue)
+        {
+            var from = new DateTime(year, month.Value, 1);
+            var to = from.AddMonths(1).AddDays(-1);
+            return (from, to);
+        }
+        else
+        {
+            var from = new DateTime(year, 1, 1);
+            var to = new DateTime(year, 12, 31);
+            return (from, to);
+        }
+    }
+
+    private static string GetFileName(string extension, int year, int? month)
+    {
+        var period = month.HasValue ? $"{year}-{month:D2}" : $"{year}";
+        return $"Kassenbericht_{period}.{extension}";
+    }
+}