import 'package:pad_scanner/pages/boxing/boxing_models.dart';
import 'package:pad_scanner/services/api_service.dart';

class BoxMutationResult {
  final List<BoxDetailData> boxes;
  final int maxBoxNo;

  const BoxMutationResult({required this.boxes, required this.maxBoxNo});
}

int maxBoxNoFor(List<BoxDetailData> boxes) {
  return boxes.fold<int>(0, (max, box) => box.boxNo > max ? box.boxNo : max);
}

BoxMutationResult addExistingBoxItem({
  required List<BoxDetailData> existingBoxes,
  required int boxNo,
  required int quantity,
  required int? boxItemId,
  required String zongpaiNo,
  required String? workOrderNo,
  required int? totalQuantity,
}) {
  final item = BoxItemData(
    boxItemId: boxItemId,
    zongpaiNo: zongpaiNo,
    workOrderNo: workOrderNo,
    quantity: quantity,
    totalQuantity: totalQuantity,
  );
  final index = existingBoxes.indexWhere((box) => box.boxNo == boxNo);
  if (index < 0) {
    final boxes = [
      ...existingBoxes,
      BoxDetailData(boxNo: boxNo, items: [item]),
    ]..sort((a, b) => a.boxNo.compareTo(b.boxNo));
    return BoxMutationResult(boxes: boxes, maxBoxNo: maxBoxNoFor(boxes));
  }

  final boxes = List<BoxDetailData>.from(existingBoxes);
  final box = boxes[index];
  boxes[index] = BoxDetailData(boxNo: box.boxNo, items: [...box.items, item]);
  return BoxMutationResult(boxes: boxes, maxBoxNo: maxBoxNoFor(boxes));
}

BoxMutationResult replaceExistingBoxItem({
  required List<BoxDetailData> existingBoxes,
  required CurrentZongpaiBoxData editing,
  required int boxNo,
  required int quantity,
  required String zongpaiNo,
  required String? workOrderNo,
  required int? totalQuantity,
}) {
  final updatedItem = BoxItemData(
    boxItemId: editing.boxItemId,
    zongpaiNo: zongpaiNo,
    workOrderNo: workOrderNo,
    quantity: quantity,
    totalQuantity: totalQuantity,
  );
  return _replaceItemById(
    existingBoxes: existingBoxes,
    boxItemId: editing.boxItemId,
    targetBoxNo: boxNo,
    updatedItem: updatedItem,
  );
}

BoxMutationResult replaceExistingPackedItem({
  required List<BoxDetailData> existingBoxes,
  required ManyToOnePackedItem item,
  required int boxNo,
  required int quantity,
}) {
  final updatedItem = BoxItemData(
    boxItemId: item.boxItemId,
    zongpaiNo: item.zongpaiNo,
    workOrderNo: item.workOrderNo,
    quantity: quantity,
    totalQuantity: item.totalQuantity,
  );
  return _replaceItemById(
    existingBoxes: existingBoxes,
    boxItemId: item.boxItemId,
    targetBoxNo: boxNo,
    updatedItem: updatedItem,
  );
}

BoxMutationResult removeExistingBoxItem({
  required List<BoxDetailData> existingBoxes,
  required int boxItemId,
}) {
  final boxes = <BoxDetailData>[];
  for (final box in existingBoxes) {
    final items = box.items
        .where((item) => item.boxItemId != boxItemId)
        .toList();
    if (items.isNotEmpty) {
      boxes.add(BoxDetailData(boxNo: box.boxNo, items: items));
    }
  }
  return BoxMutationResult(boxes: boxes, maxBoxNo: maxBoxNoFor(boxes));
}

BoxMutationResult _replaceItemById({
  required List<BoxDetailData> existingBoxes,
  required int boxItemId,
  required int targetBoxNo,
  required BoxItemData updatedItem,
}) {
  final boxes = <BoxDetailData>[];
  for (final box in existingBoxes) {
    final items = box.items.where((item) {
      return item.boxItemId != boxItemId;
    }).toList();
    if (items.isNotEmpty) {
      boxes.add(BoxDetailData(boxNo: box.boxNo, items: items));
    }
  }

  final targetIndex = boxes.indexWhere((box) => box.boxNo == targetBoxNo);
  if (targetIndex >= 0) {
    final target = boxes[targetIndex];
    boxes[targetIndex] = BoxDetailData(
      boxNo: target.boxNo,
      items: [...target.items, updatedItem],
    );
  } else {
    boxes.add(BoxDetailData(boxNo: targetBoxNo, items: [updatedItem]));
  }
  boxes.sort((a, b) => a.boxNo.compareTo(b.boxNo));
  return BoxMutationResult(boxes: boxes, maxBoxNo: maxBoxNoFor(boxes));
}