AccountingNext/Schaad.Accounting.Tests/ViewServiceTestShould.cs

using NSubstitute;
using Schaad.Accounting.Datasets;
using Schaad.Accounting.Interfaces;
using Schaad.Accounting.Models;
using Schaad.Accounting.Services;
using Schaad.Finance.Api;
using Shouldly;

namespace Schaad.Accounting.Tests;

public class ViewServiceTestShould
{
    private readonly IAccountRepository accountRepo = Substitute.For<IAccountRepository>();
    private readonly ITransactionRepository transactionRepo = Substitute.For<ITransactionRepository>();
    private readonly IBankTransactionRepository bankTransactionRepo = Substitute.For<IBankTransactionRepository>();
    private readonly IBookingRuleRepository bookingRuleRepo = Substitute.For<IBookingRuleRepository>();
    private readonly ISubclassRepository subclassRepo = Substitute.For<ISubclassRepository>();
    private readonly IFxService fxService = Substitute.For<IFxService>();
    private readonly ISettingsService settingsService = Substitute.For<ISettingsService>();

    public ViewServiceTestShould()
    {
        // Cover every subclass number a test might reference (Account.SubClass = Number / 100).
        subclassRepo.GetSubClassList().Returns(
            Enumerable.Range(10, 50).Select(n => new SubClass { Number = n, Name = "sub-" + n }).ToList());
        subclassRepo.GetClass(Arg.Any<int>()).Returns("");
        settingsService.GetSettings().Returns(new SettingsDataset { DataPath = "", FixerIoApiKey = "" });

        // Passthrough FX by default (CHF-only). Individual tests can override.
        fxService.ConvertCurrency(Arg.Any<decimal>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>())
            .Returns(ci => ci.ArgAt<decimal>(0));
    }

    private ViewService BuildService() =>
        new(accountRepo, bankTransactionRepo, transactionRepo, subclassRepo, bookingRuleRepo, fxService, settingsService);

    // --- Balance math ---------------------------------------------------------

    [Fact]
    public void SumActivaAndPassivaTotalsSeparatelyWhenGettingBalanceView()
    {
        var cash = Account("cash", 1000, "CHF", startBalance: 100m);
        var receivables = Account("recv", 1100, "CHF", startBalance: 50m);
        var payables = Account("pay", 2000, "CHF", startBalance: -200m);

        accountRepo.GetAccountList().Returns(new List<Account> { cash, receivables, payables });
        transactionRepo.GetTransactionList().Returns(new List<Transaction>());

        var view = BuildService().GetBalanceView();

        view.ActivaAccountList.Count.ShouldBe(2);
        view.PassivaAccountList.Count.ShouldBe(1);
        view.TotalActivaCHF.ShouldBe(150m);
        view.TotalPassivaCHF.ShouldBe(200m);
    }

    [Fact]
    public void ApplyTransactionsToStartBalanceWhenComputingAccountBalance()
    {
        var cash = Account("cash", 1000, "CHF", startBalance: 1000m);
        var groceries = Account("groc", 4000, "CHF");
        accountRepo.GetAccountList().Returns(new List<Account> { cash, groceries });

        // Debit cash 50, credit groceries 50 (spending)
        transactionRepo.GetTransactionList().Returns(new List<Transaction>
        {
            new() { Id = "t1", OriginAccountId = "cash", TargetAccountId = "groc", Value = 50m, ValueDate = new DateTime(2026, 1, 1) },
            new() { Id = "t2", OriginAccountId = "cash", TargetAccountId = "groc", Value = 30m, ValueDate = new DateTime(2026, 1, 2) },
        });

        var accounts = BuildService().GetAccountViewList();

        accounts.Single(a => a.Id == "cash").Balance.ShouldBe(920m); // 1000 - 80
        accounts.Single(a => a.Id == "groc").Balance.ShouldBe(80m);
    }

    [Fact]
    public void ConvertBalanceToChfWhenAccountUsesForeignCurrency()
    {
        var usd = Account("usd", 1050, "USD", startBalance: 100m);
        accountRepo.GetAccountList().Returns(new List<Account> { usd });
        transactionRepo.GetTransactionList().Returns(new List<Transaction>());

        // 1 USD = 0.90 CHF
        fxService.ConvertCurrency(Arg.Any<decimal>(), "USD", "CHF", Arg.Any<string>())
            .Returns(ci => ci.ArgAt<decimal>(0) * 0.9m);

        var account = BuildService().GetAccountViewList().Single();

        account.Balance.ShouldBe(100m);         // account currency
        account.BalanceCHF.ShouldBe(90m);       // FX-converted
        account.StartBalanceCHF.ShouldBe(90m);
    }

    // --- Bank-transaction auto-matching --------------------------------------

    [Fact]
    public void MatchBankTransactionByBookingRuleWhenLookupTextIsContained()
    {
        var checking = Account("chk", 1010, "CHF", bankAccountNumber: "CH01");
        var utilities = Account("util", 4200, "CHF");
        accountRepo.GetAccountList().Returns(new List<Account> { checking, utilities });
        bookingRuleRepo.GetBookingRuleList().Returns(new List<BookingRule>
        {
            new() { Id = "r1", LookupText = "electric", AccountId = "util", BookingText = "Strom" }
        });
        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
        {
            new() { Id = "b1", Text = "Monthly Electric Bill", Value = -85m, BankAccountNumber = "CH01",
                    ValueDate = new DateTime(2026, 3, 5), BookingDate = new DateTime(2026, 3, 5) }
        });
        transactionRepo.GetTransactionList().Returns(new List<Transaction>());

        var matched = BuildService().MatchOpenBankTransactions().Single();

        matched.Text.ShouldBe("Strom");
        // negative value => bank account is origin; rule fills the target
        matched.OriginAccountId.ShouldBe("chk");
        matched.TargetAccountId.ShouldBe("util");
    }

    [Fact]
    public void PreferBookingRuleWithMatchingValueWhenMultipleRulesMatchText()
    {
        var checking = Account("chk", 1010, "CHF", bankAccountNumber: "CH01");
        var rent = Account("rent", 4100, "CHF");
        var groceries = Account("groc", 4200, "CHF");
        accountRepo.GetAccountList().Returns(new List<Account> { checking, rent, groceries });
        bookingRuleRepo.GetBookingRuleList().Returns(new List<BookingRule>
        {
            new() { Id = "r1", LookupText = "coop", LookupValue = 0m, AccountId = "groc", BookingText = "Groceries" },
            new() { Id = "r2", LookupText = "coop", LookupValue = 1200m, AccountId = "rent", BookingText = "Rent via Coop" }
        });
        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
        {
            new() { Id = "b1", Text = "COOP payment", Value = -1200m, BankAccountNumber = "CH01",
                    ValueDate = new DateTime(2026, 3, 1), BookingDate = new DateTime(2026, 3, 1) }
        });
        transactionRepo.GetTransactionList().Returns(new List<Transaction>());

        var matched = BuildService().MatchOpenBankTransactions().Single();

        matched.Text.ShouldBe("Rent via Coop");
        matched.TargetAccountId.ShouldBe("rent");
    }

    [Fact]
    public void FallBackToSameAccountsLastMonthWhenNoBookingRuleMatches()
    {
        var checking = Account("chk", 1010, "CHF", bankAccountNumber: "CH01");
        var salary = Account("sal", 3000, "CHF");
        accountRepo.GetAccountList().Returns(new List<Account> { checking, salary });
        bookingRuleRepo.GetBookingRuleList().Returns(new List<BookingRule>());
        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
        {
            new() { Id = "b2", Text = "Salary Feb", Value = 5000m, BankAccountNumber = "CH01",
                    ValueDate = new DateTime(2026, 2, 25), BookingDate = new DateTime(2026, 2, 25) }
        });
        // A prior-month booking with same accounts + value should be picked up
        transactionRepo.GetTransactionList().Returns(new List<Transaction>
        {
            new()
            {
                Id = "t1",
                OriginAccountId = "sal",
                TargetAccountId = "chk",
                Value = 5000m,
                Text = "Monatslohn",
                ValueDate = new DateTime(2026, 1, 25),
                BookingDate = new DateTime(2026, 1, 25)
            }
        });

        var matched = BuildService().MatchOpenBankTransactions().Single();

        matched.Text.ShouldBe("Monatslohn");
    }

    [Fact]
    public void ExcludeIgnoredAndAlreadyBookedWhenGettingOpenBankTransactions()
    {
        bankTransactionRepo.GetBankTransactionList().Returns(new List<BankTransaction>
        {
            new() { Id = "open", Text = "still open", Ignore = false },
            new() { Id = "ignored", Text = "ignore me", Ignore = true },
            new() { Id = "booked", Text = "already booked", Ignore = false }
        });
        transactionRepo.GetTransactionList().Returns(new List<Transaction>
        {
            new() { Id = "t1", BankTransactionId = "booked", OriginAccountId = "a", TargetAccountId = "b", Value = 10 }
        });

        var open = BuildService().GetOpenBankTransactionList();

        open.Count.ShouldBe(1);
        open[0].Id.ShouldBe("open");
    }

    // --- Helpers -------------------------------------------------------------

    private static Account Account(string id, int number, string currency, decimal startBalance = 0m, string? bankAccountNumber = null)
        => new()
        {
            Id = id,
            Number = number,
            Name = id,
            Currency = currency,
            StartBalance = startBalance,
            BankAccountNumber = bankAccountNumber
        };
}