// 功能描述：充值创建前持久化及到账恢复，不将支付拉起视作到账；版本：1.0.0。
import '../repositories/client_repository.dart';
import '../../domain/models/recharge.dart';
import 'recharge_draft_store.dart';
import 'api_client.dart';

/// 单个页面使用一个实例；所有网络写入前确认存储所属账号。
class RechargeFlow {
  RechargeFlow(this.repository, this.store);
  final ClientRepository repository;
  final RechargeDraftStore store;
  bool _busy = false;

  Future<Map<String, Object?>> create(PendingRecharge draft) async {
    if (_busy) throw StateError('充值正在处理中');
    _busy = true;
    try {
      final owner = await repository.rechargeDraftOwner();
      final previous = await store.read(owner);
      if (previous != null &&
          (previous.request != draft.request ||
              previous.amount != draft.amount ||
              previous.channel != draft.channel ||
              previous.payType != draft.payType)) {
        throw StateError('请先查询待确认充值');
      }
      if (previous != null) {
        // 重试先读取入账事实，避免到账后再次拉起原支付参数。
        try {
          final result = await repository.rechargeResult(previous.request);
          if (result.amount != previous.amount || result.channel != previous.channel) {
            throw StateError('充值结果与原请求不一致');
          }
          if (await repository.rechargeDraftOwner() != owner) throw StateError('充值账户已切换');
          if (result.credited) return {'recharge_status': 23};
        } on ApiException catch (error) {
          // 明确不存在才允许使用相同请求重发，网络异常不能推断订单不存在。
          if (error.code != 1112) rethrow;
        }
      }
      await store.write(owner, draft);
      if (await repository.rechargeDraftOwner() != owner) throw StateError('充值账户已切换');
      return await repository.createRecharge(
        request: draft.request,
        amount: draft.amount,
        channel: draft.channel,
        payType: draft.payType,
      );
    } finally {
      _busy = false;
    }
  }

  /// 未到账、查询失败或业务关联异常均保留原请求，方便再次核对。
  Future<RechargeRecord?> recover() async {
    if (_busy) throw StateError('充值正在处理中');
    _busy = true;
    try {
      final owner = await repository.rechargeDraftOwner();
      final draft = await store.read(owner);
      if (draft == null) return null;
      if (await repository.rechargeDraftOwner() != owner) throw StateError('充值账户已切换');
      final result = await repository.rechargeResult(draft.request);
      if (result.amount != draft.amount || result.channel != draft.channel) {
        throw StateError('充值结果与原请求不一致');
      }
      if (await repository.rechargeDraftOwner() != owner) throw StateError('充值账户已切换');
      if (result.credited) await store.delete(owner);
      return result;
    } finally {
      _busy = false;
    }
  }
}