feat: per-program statistics dashboard (Fasa 9)

- StatisticsController: attendance by session/source, cert status, response rate, question averages
- Statistics export as CSV
- Chart.js visualisations: bar (session), doughnut (source), progress bars (cert status, ratings)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Http/Controllers/Admin/StatisticsController.php

@@ -3,9 +3,129 @@
 namespace App\Http\Controllers\Admin;
 
 use App\Http\Controllers\Controller;
+use App\Models\Program;
+use App\Models\Attendance;
+use App\Models\Certificate;
+use App\Models\QuestionnaireAnswer;
+use App\Models\QuestionnaireQuestion;
+use App\Models\QuestionnaireResponse;
 use Illuminate\Http\Request;
+use Illuminate\Http\Response;
+use Illuminate\View\View;
 
 class StatisticsController extends Controller
 {
-    //
+    public function show(Program $program): View
+    {
+        $program->load(['attendances.participant', 'questionnaire.questionnaireSet.questions']);
+
+        // Attendance by session
+        $bySession = $program->attendances()
+            ->selectRaw('attendance_session, COUNT(*) as total')
+            ->groupBy('attendance_session')
+            ->pluck('total', 'attendance_session')
+            ->toArray();
+
+        // Attendance by source
+        $bySource = $program->attendances()
+            ->selectRaw('source, COUNT(*) as total')
+            ->groupBy('source')
+            ->pluck('total', 'source')
+            ->toArray();
+
+        // Certificate status breakdown
+        $certStats = $program->certificates()
+            ->selectRaw('status, COUNT(*) as total')
+            ->groupBy('status')
+            ->pluck('total', 'status')
+            ->toArray();
+
+        // Response rate
+        $pq = $program->questionnaire;
+        $responseRate = null;
+        $questionStats = [];
+
+        if ($pq && $pq->is_confirmed) {
+            $totalAttended = $program->attendances()->count();
+            $totalResponses = QuestionnaireResponse::where('program_id', $program->id)->count();
+            $responseRate = $totalAttended > 0 ? round($totalResponses / $totalAttended * 100) : 0;
+
+            // Rating question averages
+            $questions = $pq->questionnaireSet->questions ?? collect();
+            foreach ($questions as $q) {
+                if ($q->question_type === 'rating') {
+                    $answers = QuestionnaireAnswer::where('questionnaire_question_id', $q->id)
+                        ->pluck('answer_value');
+                    $values = $answers->map(fn($v) => is_array($v) ? (int)($v[0] ?? 0) : (int)$v);
+                    $questionStats[] = [
+                        'id'      => $q->id,
+                        'text'    => $q->question_text,
+                        'type'    => 'rating',
+                        'average' => $values->count() > 0 ? round($values->avg(), 2) : null,
+                        'count'   => $values->count(),
+                    ];
+                } elseif (in_array($q->question_type, ['single_choice', 'multiple_choice'])) {
+                    $answers = QuestionnaireAnswer::where('questionnaire_question_id', $q->id)
+                        ->pluck('answer_value');
+                    $counts = [];
+                    foreach ($answers as $val) {
+                        $items = is_array($val) ? $val : [$val];
+                        foreach ($items as $item) {
+                            $counts[$item] = ($counts[$item] ?? 0) + 1;
+                        }
+                    }
+                    $questionStats[] = [
+                        'id'      => $q->id,
+                        'text'    => $q->question_text,
+                        'type'    => $q->question_type,
+                        'options' => $q->options_json ?? [],
+                        'counts'  => $counts,
+                        'total'   => $answers->count(),
+                    ];
+                }
+            }
+        }
+
+        $summary = [
+            'total_attendances'    => $program->attendances()->count(),
+            'pre_registered'       => $program->attendances()->where('source', 'pre_registered_staff')->count(),
+            'walk_in'              => $program->attendances()->where('source', 'walk_in_external')->count(),
+            'total_certificates'   => $program->certificates()->count(),
+            'generated_certs'      => $program->certificates()->whereIn('status', ['generated', 'emailed', 'downloaded'])->count(),
+            'downloaded_certs'     => $program->certificates()->where('status', 'downloaded')->count(),
+            'total_responses'      => QuestionnaireResponse::where('program_id', $program->id)->count(),
+        ];
+
+        return view('admin.programs.statistics.show', compact(
+            'program', 'summary', 'bySession', 'bySource',
+            'certStats', 'responseRate', 'questionStats'
+        ));
+    }
+
+    public function export(Program $program): Response
+    {
+        $rows = $program->attendances()
+            ->with('participant')
+            ->get()
+            ->map(fn($a) => [
+                $a->participant->name,
+                $a->participant->agency ?: '',
+                $a->attendance_session,
+                $a->source,
+                $a->checked_in_at->format('d/m/Y H:i'),
+            ]);
+
+        $csv = "\xEF\xBB\xBF";
+        $csv .= implode(',', ['Nama', 'Agensi', 'Sesi', 'Sumber', 'Masa Check-In']) . "\n";
+        foreach ($rows as $row) {
+            $csv .= implode(',', array_map(fn($v) => '"' . str_replace('"', '""', $v) . '"', $row)) . "\n";
+        }
+
+        $filename = 'statistik-' . str($program->title)->slug() . '-' . now()->format('Ymd') . '.csv';
+
+        return response($csv, 200, [
+            'Content-Type'        => 'text/csv; charset=UTF-8',
+            'Content-Disposition' => 'attachment; filename="' . $filename . '"',
+        ]);
+    }
 }