food-market/tests/food-market.IntegrationTests/PromotionFlowTests.cs

using System.Net.Http.Json;
using System.Text.Json;
using FluentAssertions;
using foodmarket.IntegrationTests.Support;
using Xunit;

namespace foodmarket.IntegrationTests;

/// <summary>Промокод: создание + применение к чеку (Percent от Subtotal,
/// scope=All) + проверка что Total уменьшился ровно на промо-скидку.
/// Проверка валидации: невалидный код → 400 с понятным сообщением.</summary>
[Collection(ApiCollection.Name)]
public class PromotionFlowTests
{
    private readonly ApiFactory _factory;
    public PromotionFlowTests(ApiFactory factory) => _factory = factory;

    [Fact]
    public async Task Promocode_percent_discounts_total()
    {
        var actor = new ApiActor(_factory.CreateClient());
        var email = $"pro-{Guid.NewGuid():N}@example.kz";
        (await actor.SignupAsync(email, "Passw0rd!", "Pro Org")).EnsureSuccessStatusCode();
        actor.UseToken(await actor.TokenAsync(email, "Passw0rd!"));

        // Промокод SALE20 = 20%
        var promoResp = await actor.Http.PostAsJsonAsync("/api/promotions", new
        {
            name = "Скидка 20%",
            description = (string?)null,
            code = "SALE20",
            type = 1 /* Percent */,
            value = 20m,
            scope = 1 /* All */,
            minSaleAmount = 0m,
            startsAt = DateTime.UtcNow.AddDays(-1),
            endsAt = (DateTime?)null,
            isActive = true,
            productGroupIds = Array.Empty<Guid>(),
            productIds = Array.Empty<Guid>(),
        });
        promoResp.EnsureSuccessStatusCode();

        var (productId, storeId, retailPointId, currencyId) = await SeedAsync(actor);

        // Чек на 500, промокод SALE20 → total = 400
        var saleResp = await actor.Http.PostAsJsonAsync("/api/sales/retail", new
        {
            date = DateTime.UtcNow,
            storeId, retailPointId, currencyId,
            payment = 0, isReturn = false,
            lines = new[] { new { productId, quantity = 5m, unitPrice = 100m, discount = 0m, vatPercent = 12m } },
            subtotal = 500m, discountTotal = 0m, total = 500m,
            paidCash = 500m, paidCard = 0m,
            promotionCode = "SALE20",
        });
        saleResp.EnsureSuccessStatusCode();
        var sale = await saleResp.Content.ReadFromJsonAsync<JsonElement>();
        sale.GetProperty("promotionDiscount").GetDecimal().Should().Be(100m); // 20% от 500
        sale.GetProperty("total").GetDecimal().Should().Be(400m);
        sale.GetProperty("promotionCode").GetString().Should().Be("SALE20");
    }

    [Fact]
    public async Task Invalid_promocode_returns_400_with_message()
    {
        var actor = new ApiActor(_factory.CreateClient());
        var email = $"proi-{Guid.NewGuid():N}@example.kz";
        (await actor.SignupAsync(email, "Passw0rd!", "ProI Org")).EnsureSuccessStatusCode();
        actor.UseToken(await actor.TokenAsync(email, "Passw0rd!"));
        var (productId, storeId, retailPointId, currencyId) = await SeedAsync(actor);

        var saleResp = await actor.Http.PostAsJsonAsync("/api/sales/retail", new
        {
            date = DateTime.UtcNow,
            storeId, retailPointId, currencyId,
            payment = 0, isReturn = false,
            lines = new[] { new { productId, quantity = 1m, unitPrice = 100m, discount = 0m, vatPercent = 12m } },
            subtotal = 100m, discountTotal = 0m, total = 100m,
            paidCash = 100m, paidCard = 0m,
            promotionCode = "NOPE-NOEXIST",
        });
        saleResp.StatusCode.Should().Be(System.Net.HttpStatusCode.BadRequest);
        var body = await saleResp.Content.ReadFromJsonAsync<JsonElement>();
        body.GetProperty("error").GetString().Should().MatchRegex("(NOPE|не активен|не найден)");
        body.GetProperty("field").GetString().Should().Be("promotionCode");
    }

    private async Task<(string ProductId, string StoreId, string RetailPointId, string CurrencyId)>
        SeedAsync(ApiActor actor)
    {
        var units = (await actor.GetJsonAsync("/api/catalog/units-of-measure?pageSize=200"))
            .GetProperty("items").EnumerateArray().First(x => x.GetProperty("code").GetString() == "796");
        var groups = (await actor.GetJsonAsync("/api/catalog/product-groups"))
            .GetProperty("items").EnumerateArray().First();
        var pts = (await actor.GetJsonAsync("/api/catalog/price-types"))
            .GetProperty("items").EnumerateArray().First(x => x.GetProperty("isRetail").GetBoolean());
        var curs = (await actor.GetJsonAsync("/api/catalog/currencies"))
            .GetProperty("items").EnumerateArray().First(x => x.GetProperty("code").GetString() == "KZT");
        var stores = (await actor.GetJsonAsync("/api/catalog/stores"))
            .GetProperty("items").EnumerateArray().First(x => x.GetProperty("isMain").GetBoolean());
        var retailPoints = (await actor.GetJsonAsync("/api/catalog/retail-points"))
            .GetProperty("items").EnumerateArray().First();

        var prodResp = await actor.Http.PostAsJsonAsync("/api/catalog/products", new
        {
            name = "Promo test", article = $"PRM-{Guid.NewGuid():N}",
            unitOfMeasureId = units.GetProperty("id").GetString(),
            vat = 12, vatEnabled = true,
            productGroupId = groups.GetProperty("id").GetString(),
            packaging = 1,
            prices = new[] { new { priceTypeId = pts.GetProperty("id").GetString(), amount = 100m, currencyId = curs.GetProperty("id").GetString() } },
            barcodes = new[] { new { code = "7000000000017", type = 1, isPrimary = true } },
        });
        prodResp.EnsureSuccessStatusCode();
        var prod = await prodResp.Content.ReadFromJsonAsync<JsonElement>();
        var productId = prod.GetProperty("id").GetString()!;

        var supplier = await (await actor.Http.PostAsJsonAsync("/api/catalog/counterparties",
            new { name = "Sup", type = 2 })).Content.ReadFromJsonAsync<JsonElement>();
        var supply = await (await actor.Http.PostAsJsonAsync("/api/purchases/supplies", new
        {
            date = DateTime.UtcNow,
            supplierId = supplier.GetProperty("id").GetString(),
            storeId = stores.GetProperty("id").GetString(),
            currencyId = curs.GetProperty("id").GetString(),
            lines = new[] { new { productId, quantity = 50m, unitPrice = 50m } },
        })).Content.ReadFromJsonAsync<JsonElement>();
        (await actor.Http.PostAsync($"/api/purchases/supplies/{supply.GetProperty("id").GetString()}/post", null))
            .EnsureSuccessStatusCode();

        return (productId,
            stores.GetProperty("id").GetString()!,
            retailPoints.GetProperty("id").GetString()!,
            curs.GetProperty("id").GetString()!);
    }
}