// Version: 1.5 - Sale モデル定義（売上）
import '../services/database_helper.dart';

/// 売上項目クラス
class SaleItem {
  int productId;
  String productName;
  double unitPrice;
  int quantity;

  SaleItem({
    required this.productId,
    required this.productName,
    required this.unitPrice,
    this.quantity = 1,
  });

  /// 小計金額（税込）を取得
  double get subtotal => unitPrice * quantity;

  Map<String, dynamic> toMap() {
    return {
      'productId': productId,
      'productName': productName,
      'unitPrice': unitPrice,
      'quantity': quantity,
      'subtotal': subtotal,
    };
  }

  factory SaleItem.fromMap(Map<dynamic, dynamic> map) {
    return SaleItem(
      productId: map['productId'] as int,
      productName: map['productName'] as String,
      unitPrice: (map['unitPrice'] as num).toDouble(),
      quantity: map['quantity'] as int? ?? 1,
    );
  }

  static List<SaleItem> fromMaps(List<dynamic> maps) {
    return maps.map((e) => SaleItem.fromMap(e as Map)).toList();
  }
}

/// 売上モデル
class Sale {
  int? id;
  String customerCode; // データベースでは product_code として保存（顧客コード）
  DateTime saleDate;
  double totalAmount;
  int taxRate;
  List<SaleItem> items = [];
  DateTime createdAt;
  DateTime updatedAt;

  Sale({
    this.id,
    required this.customerCode,
    required this.saleDate,
    this.totalAmount = 0.0,
    this.taxRate = 8, // デフォルト：8%
    DateTime? createdAt,
    DateTime? updatedAt,
    List<SaleItem>? items,
  }) : createdAt = createdAt ?? DateTime.now(),
       updatedAt = updatedAt ?? DateTime.now(),
       items = items ?? [];

  /// マップから Sale オブジェクトへ変換
  factory Sale.fromMap(Map<String, dynamic> map) {
    return Sale(
      id: map['id'] as int?,
      customerCode: map['customer_code'] as String, // 'product_code' を 'customer_code' として扱う
      saleDate: DateTime.parse(map['sale_date']),
      totalAmount: (map['total_amount'] as num).toDouble(),
      taxRate: map['tax_rate'] as int? ?? 8,
      createdAt: DateTime.parse(map['created_at']),
      updatedAt: DateTime.parse(map['updated_at']),
    );
  }

  /// Map に変換
  Map<String, dynamic> toMap() {
    return {
      'id': id,
      'customer_code': customerCode,
      'sale_date': saleDate.toIso8601String(),
      'total_amount': totalAmount,
      'tax_rate': taxRate,
      'product_items': items.map((item) => item.toMap()).toList(),
      'created_at': createdAt.toIso8601String(),
      'updated_at': updatedAt.toIso8601String(),
    };
  }

  /// カピービルダ
  Sale copyWith({
    int? id,
    String? customerCode,
    DateTime? saleDate,
    double? totalAmount,
    int? taxRate,
    DateTime? createdAt,
    DateTime? updatedAt,
    List<SaleItem>? items,
  }) {
    return Sale(
      id: id ?? this.id,
      customerCode: customerCode ?? this.customerCode,
      saleDate: saleDate ?? this.saleDate,
      totalAmount: totalAmount ?? this.totalAmount,
      taxRate: taxRate ?? this.taxRate,
      createdAt: createdAt ?? this.createdAt,
      updatedAt: updatedAt ?? this.updatedAt,
      items: items ?? this.items,
    );
  }

  /// 合計金額を再計算（items から集計）
  void recalculate() {
    totalAmount = items.fold(0, (sum, item) => sum + item.subtotal);
  }
}