feat: Phase 2 - admin layout, dashboard, page CRUD, subscribers, user management

app/Services/DashboardStatisticsService.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services;
+
+use App\Models\PreregistrationPage;
+use App\Models\Subscriber;
+use App\Models\User;
+use Illuminate\Support\Carbon;
+
+final class DashboardStatisticsService
+{
+    /**
+     * @return array{total_pages: int, total_subscribers: int, active_pages: int}
+     */
+    public function forUser(User $user): array
+    {
+        $pagesQuery = PreregistrationPage::query();
+        if (! $user->isSuperadmin()) {
+            $pagesQuery->where('user_id', $user->id);
+        }
+
+        $now = Carbon::now();
+        $totalPages = (clone $pagesQuery)->count();
+        $pageIds = (clone $pagesQuery)->pluck('id');
+        $totalSubscribers = $pageIds->isEmpty()
+            ? 0
+            : Subscriber::whereIn('preregistration_page_id', $pageIds)->count();
+        $activePages = (clone $pagesQuery)
+            ->where('start_date', '<=', $now)
+            ->where('end_date', '>=', $now)
+            ->count();
+
+        return [
+            'total_pages' => $totalPages,
+            'total_subscribers' => $totalSubscribers,
+            'active_pages' => $activePages,
+        ];
+    }
+}