using After;
using static BeforeAfter.Tests.TestData.ClientBuilder;
using static BeforeAfter.Tests.TestData.OrderBuilder;

namespace BeforeAfter.Tests;

/// <summary>
/// EXERCISE 2 — the domain gained OrderLines; persistence still stores one
/// flat row per order. (This is the solution participants arrive at from the
/// stub in EXERCISE2.md.)
/// </summary>
public class OrderLinesEvolutionTests
{
    [Fact] // EXERCISE STEP 3a
    public void A_reloaded_order_can_be_discounted()
    {
        var db = new DbContext();
        var order = ValidOrder().WithDescription("big order").WithTotal(150_00).Build();
        var client = ValidClient().WithName("Acme").WithOrder(order).Build();
        db.Save(client);
        db.Save(order);

        var loaded = db.LoadOrder(order.Id)!;

        // The discount works off the computed total of the RELOADED order:
        var discounted = DiscountCalculator.CalculateDiscount(
            loaded, discountBarrierCents: 100_00, discountPercentage: 10);

        Assert.Equal(135_00, discounted.DiscountedTotalInCents);
        Assert.Equal(10, discounted.DiscountPercentage);
    }

    [Fact] // EXERCISE STEP 3b — the accepted loss
    public void A_multi_line_order_flattens_to_a_single_line_when_stored()
    {
        var db = new DbContext();
        var order = ValidOrder().WithDescription("mixed order").Build();
        order.Lines.Add(new OrderLine("first item", 100_00));
        order.Lines.Add(new OrderLine("second item", 50_00));

        db.Save(order);

        var loaded = db.LoadOrder(order.Id)!;

        // Storage flattened the order: one line, the flat total, and the
        // order-level description. Documented, not hidden.
        var line = Assert.Single(loaded.Lines);
        Assert.Equal(150_00, line.AmountInCents);
        Assert.Equal("mixed order", line.Description);
    }
}