// 功能描述：钱包账单的严格金额与收支语义模型；版本：1.0.0。
import 'client_models.dart';

/// 账单是已记账事实，不把未完成订单或提现申请伪装成成功流水。
class WalletBill {
  const WalletBill({
    required this.identity,
    required this.number,
    required this.direction,
    required this.tradeType,
    required this.amount,
    required this.fee,
    required this.balanceAfter,
    required this.createdAt,
    required this.channel,
  });
  final String identity, number, direction, tradeType, channel;
  final int amount, fee, balanceAfter;
  final DateTime createdAt;
  bool get income => direction == 'income';
  String get signedAmount => '${income ? '+' : '-'}${moneyText(amount)}';
  String get title => switch (tradeType) {
    'recharge' => '余额充值',
    'refund' => '退款入账',
    'ec_order' => '商城订单',
    'gas_order' => '气瓶订单',
    'withdrawal_reserve' => '提现资金冻结',
    'withdrawal_release' => '提现资金退回',
    'withdrawal_complete' => '提现完成',
    _ => '其他账单',
  };
  factory WalletBill.fromJson(Map<String, Object?> json) {
    int amount(String key, {bool positive = false}) {
      final value = json[key];
      if (value is! int || value < (positive ? 1 : 0)) {
        throw const FormatException('账单金额格式异常');
      }
      return value;
    }

    final direction = json['direction'];
    final date = DateTime.tryParse(json['created_at'] as String? ?? '');
    if (!['income', 'expense'].contains(direction) ||
        date == null ||
        (json['identity'] as String? ?? '').isEmpty) {
      throw const FormatException('账单信息不完整');
    }
    return WalletBill(
      identity: json['identity'] as String,
      number: json['record_no'] as String? ?? '',
      direction: direction as String,
      tradeType: json['trade_type'] as String? ?? '',
      amount: amount('amount', positive: true),
      fee: amount('fee'),
      balanceAfter: amount('balance_after'),
      createdAt: date.toLocal(),
      channel: json['pay_channel'] as String? ?? '',
    );
  }
}

/// 分页游标由服务端提供，不依据客户端条数猜测是否还有数据。
class WalletBillPage {
  const WalletBillPage(this.items, this.nextCursor);
  final List<WalletBill> items;
  final String nextCursor;
}