fitur petugas

lib/app/services/pembayaran_service.dart

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+import 'package:supabase_flutter/supabase_flutter.dart';
+import '../data/models/pembayaran_model.dart';
+
+class PembayaranService {
+  final SupabaseClient _supabase = Supabase.instance.client;
+
+  /// Ambil data pembayaran antara [start] (inklusif) dan [end] (eksklusif).
+  Future<List<PembayaranModel>> _fetchBetween(
+    DateTime start,
+    DateTime end,
+  ) async {
+    final data = await _supabase
+        .from('pembayaran')
+        .select('id, metode_pembayaran, total_pembayaran, waktu_pembayaran')
+        .gte('waktu_pembayaran', start.toIso8601String())
+        .lt('waktu_pembayaran', end.toIso8601String())
+        .order('waktu_pembayaran', ascending: true);
+
+    return (data as List<dynamic>)
+        .map((e) => PembayaranModel.fromJson(e as Map<String, dynamic>))
+        .toList();
+  }
+
+  /// Hitung statistik yang diminta.
+  Future<Map<String, dynamic>> fetchStats() async {
+    final now = DateTime.now();
+
+    // Rentang bulan ini: [awal bulan ini, awal bulan depan)
+    final thisMonthStart = DateTime(now.year, now.month, 1);
+    final nextMonthStart = DateTime(now.year, now.month + 1, 1);
+
+    // Bulan lalu: [awal bulan lalu, awal bulan ini)
+    final lastMonthStart = DateTime(now.year, now.month - 1, 1);
+    final thisMonthEnd = thisMonthStart;
+
+    // 6 bulan terakhir: [6 bulan lalu, sekarang]
+    final sixMonthsAgo = DateTime(now.year, now.month - 6, 1);
+
+    // 1) Data bulan ini & bulan lalu
+    final thisMonthData = await _fetchBetween(thisMonthStart, nextMonthStart);
+    final lastMonthData = await _fetchBetween(lastMonthStart, thisMonthEnd);
+
+    // 2) Data 6 bulan terakhir
+    final sixMonthsData = await _fetchBetween(sixMonthsAgo, nextMonthStart);
+
+    // 3) Hitung total pendapatan
+    double sum(List<PembayaranModel> list) =>
+        list.fold(0.0, (acc, e) => acc + e.totalPembayaran);
+
+    final totalThis = sum(thisMonthData);
+    final totalLast = sum(lastMonthData);
+    final totalSix = sum(sixMonthsData);
+
+    // 4) Persentase selisih (bulanan)
+    double percentDiff = 0.0;
+    if (totalLast != 0) {
+      percentDiff = ((totalThis - totalLast) / totalLast) * 100;
+    }
+
+    // 5) Total per metode (hanya dari bulan ini, misalnya)
+    double totTunai = 0.0, totTransfer = 0.0;
+    for (var p in thisMonthData) {
+      if (p.metodePembayaran.toLowerCase() == 'tunai') {
+        totTunai += p.totalPembayaran;
+      } else if (p.metodePembayaran.toLowerCase() == 'transfer') {
+        totTransfer += p.totalPembayaran;
+      }
+    }
+
+    // 6) Trend per month (6 months, oldest to newest)
+    List<double> trendPerMonth = [];
+    for (int i = 5; i >= 0; i--) {
+      final dt = DateTime(now.year, now.month - i, 1);
+      final dtNext = DateTime(now.year, now.month - i + 1, 1);
+      final monthData = await _fetchBetween(dt, dtNext);
+      trendPerMonth.add(sum(monthData));
+    }
+
+    return {
+      'totalThisMonth': totalThis,
+      'percentComparedLast': percentDiff,
+      'totalTunai': totTunai,
+      'totalTransfer': totTransfer,
+      'totalLastSixMonths': totalSix,
+      'trendPerMonth': trendPerMonth,
+    };
+  }
+}