import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../api/account_api.dart';
import '../core/network/api_exception.dart';
import '../models/account.dart';

/// 账户信息（余额 / 总收入 / 总支出）
class AccountNotifier extends AsyncNotifier<AccountInfo> {
  @override
  Future<AccountInfo> build() => ref.watch(accountApiProvider).getAccount();

  /// 把账户余额改成 [targetBalance]。
  ///
  /// 后端只能写期初余额，所以这里先反算：
  /// `initialBalance = targetBalance - totalIncome + totalExpense`
  Future<void> setBalance(double targetBalance) async {
    final current = state.value;
    if (current == null) throw ApiException(-1, '账户信息尚未加载完成');

    final initial = initialBalanceFor(
      targetBalance: targetBalance,
      totalIncome: current.totalIncome,
      totalExpense: current.totalExpense,
    );
    final updated = await ref.read(accountApiProvider).updateBalance(initial);
    state = AsyncData(updated);
  }
}

final accountProvider =
    AsyncNotifierProvider<AccountNotifier, AccountInfo>(AccountNotifier.new);