public void GetBalances_SplitsExpensesBetweenAll()
{
var userA = CreateSettlementUser();
var userB = CreateSettlementUser();
var userC = CreateSettlementUser();
var users = new[] { userA, userB, userC };
_settlementUsersRepository.GetSettlementUsers(_settlementId)
.Returns(users);
var expenses = new[]
{
new Expense {
WhoPaid = userA, Amount = 9
}
};
_expensesRepository.GetExpenses(_settlementId)
.Returns(expenses);
var provider = CreateBalancesProvider();
var balances = provider.GetBalances(_settlementId);
Assert.Collection(balances,
item => Assert.Equal(6M, item.Balance),
item => Assert.Equal(-3M, item.Balance),
item => Assert.Equal(-3M, item.Balance)
);
}
public IReadOnlyList <UserBalance> GetBalances(string settlementId)
{
var expenses = _expensesRepository.GetExpenses(settlementId).ToList();
var expensesSumByWhoPaid = expenses
.GroupBy(e => e.WhoPaid.Id)
.ToDictionary(g => g.Key, g => g.Sum(e => e.Amount));
var settlementUsers = _settlementUsersRepository.GetSettlementUsers(settlementId)
.ToList();
var usersCount = settlementUsers.Count();
var expensesSumByParticipant = settlementUsers
.ToDictionary(u => u.Id, u =>
Round(expenses
.Where(e => e.Participants.IsNullOrEmpty() || e.Participants.Any(p => p.Id == u.Id))
.Sum(e => e.Amount / (e.Participants.IsNullOrEmpty() ? usersCount : e.Participants.Count))));
var transactions = _transactionsRepository.GetTransactions(settlementId)
.ToList();
var outgoingTransactionsSumByUser = transactions
.GroupBy(t => t.From.Id)
.ToDictionary(g => g.Key, g => g.Sum(t => t.Amount));
var incomingTransactionsSumByUser = transactions
.GroupBy(t => t.To.Id)
.ToDictionary(g => g.Key, g => g.Sum(t => t.Amount));
return(settlementUsers
.Select(u => new UserBalance
{
User = u,
Balance = expensesSumByWhoPaid.GetValueOrDefault(u.Id, 0)
- expensesSumByParticipant.GetValueOrDefault(u.Id, 0)
+ outgoingTransactionsSumByUser.GetValueOrDefault(u.Id, 0)
- incomingTransactionsSumByUser.GetValueOrDefault(u.Id, 0)
})
.ToList());
}
public ActionResult GetAll(string settlementId)
{
return(Ok(_settlementUsersRepository.GetSettlementUsers(settlementId)));
}