refactor: split registration page into focused parts

lib/pages/registration/registration_calculations.dart

@@ -0,0 +1,161 @@
+import 'package:flutter/material.dart';
+import 'package:pad_scanner/services/api_service.dart';
+
+class RegistrationOverviewStats {
+  final int totalCount;
+  final int shelvedCount;
+  final int transferredCount;
+
+  const RegistrationOverviewStats({
+    required this.totalCount,
+    required this.shelvedCount,
+    required this.transferredCount,
+  });
+}
+
+class RegistrationOverviewSections {
+  final List<PaichaOverviewItem> scanned;
+  final List<PaichaOverviewItem> unscanned;
+
+  const RegistrationOverviewSections({
+    required this.scanned,
+    required this.unscanned,
+  });
+
+  bool get hasDivider => scanned.isNotEmpty && unscanned.isNotEmpty;
+}
+
+RegistrationOverviewStats overviewStats(PaichaOverviewResult? overview) {
+  if (overview?.success != true) {
+    return const RegistrationOverviewStats(
+      totalCount: 0,
+      shelvedCount: 0,
+      transferredCount: 0,
+    );
+  }
+
+  var shelvedCount = 0;
+  var transferredCount = 0;
+  for (final item in overview!.items) {
+    switch (item.status) {
+      case 'on_shelf':
+        shelvedCount++;
+      case 'transferred':
+        transferredCount++;
+    }
+  }
+
+  return RegistrationOverviewStats(
+    totalCount: overview.totalCount,
+    shelvedCount: shelvedCount,
+    transferredCount: transferredCount,
+  );
+}
+
+RegistrationOverviewSections splitOverviewItems({
+  required PaichaOverviewResult overview,
+  required Iterable<String> zongpaiNos,
+}) {
+  final scannedSet = zongpaiNos.toSet();
+  final scanned = <PaichaOverviewItem>[];
+  final unscanned = <PaichaOverviewItem>[];
+  for (final item in overview.items) {
+    if (scannedSet.contains(item.zongpaiNo)) {
+      scanned.add(item);
+    } else {
+      unscanned.add(item);
+    }
+  }
+  return RegistrationOverviewSections(scanned: scanned, unscanned: unscanned);
+}
+
+List<PaichaOverviewItem> findOnShelfItemsInScanned({
+  required PaichaOverviewResult? overview,
+  required Iterable<String> zongpaiNos,
+}) {
+  return _findScannedItemsByStatus(
+    overview: overview,
+    zongpaiNos: zongpaiNos,
+    status: 'on_shelf',
+  );
+}
+
+List<PaichaOverviewItem> findTransferredItemsInScanned({
+  required PaichaOverviewResult? overview,
+  required Iterable<String> zongpaiNos,
+}) {
+  return _findScannedItemsByStatus(
+    overview: overview,
+    zongpaiNos: zongpaiNos,
+    status: 'transferred',
+  );
+}
+
+bool hasAnyLocatedInScanned({
+  required PaichaOverviewResult? overview,
+  required Iterable<String> zongpaiNos,
+}) {
+  if (overview?.success != true) return false;
+  final scannedSet = zongpaiNos.toSet();
+  return overview!.items.any(
+    (item) =>
+        scannedSet.contains(item.zongpaiNo) &&
+        (item.status == 'on_shelf' || item.status == 'transferred'),
+  );
+}
+
+Color registrationBarColor({
+  required String status,
+  required bool isScanned,
+  required bool isTransitTarget,
+}) {
+  if (isScanned) {
+    return status == 'on_shelf' && !isTransitTarget
+        ? Colors.red
+        : const Color(0xFF43A047);
+  }
+
+  switch (status) {
+    case 'on_shelf':
+      return const Color(0xFF2196F3);
+    case 'transferred':
+      return const Color(0xFFFF9800);
+    default:
+      return Colors.grey.shade400;
+  }
+}
+
+Color registrationRowBgColor({
+  required String status,
+  required bool isScanned,
+  required bool isTransitTarget,
+}) {
+  if (isScanned) {
+    return status == 'on_shelf' && !isTransitTarget
+        ? Colors.red.shade50
+        : const Color(0xFFF1F8E9);
+  }
+
+  switch (status) {
+    case 'on_shelf':
+      return const Color(0xFFE3F2FD);
+    case 'transferred':
+      return const Color(0xFFFFF3E0);
+    default:
+      return const Color(0xFFF5F5F5);
+  }
+}
+
+List<PaichaOverviewItem> _findScannedItemsByStatus({
+  required PaichaOverviewResult? overview,
+  required Iterable<String> zongpaiNos,
+  required String status,
+}) {
+  if (overview?.success != true) return [];
+  final scannedSet = zongpaiNos.toSet();
+  return overview!.items
+      .where(
+        (item) => scannedSet.contains(item.zongpaiNo) && item.status == status,
+      )
+      .toList();
+}