prefab-page-detail/Prefab.Tests/Unit/Web/Pricing/FromPriceCalculatorShould.cs

using Prefab.Catalog.Domain.Entities;
using Prefab.Catalog.Domain.Services;
using Prefab.Tests;
using Prefab.Web.Pricing;
using Shouldly;

namespace Prefab.Tests.Unit.Web.Pricing;

[Trait(TraitName.Category, TraitCategory.Unit)]
public sealed class FromPriceCalculatorShould
{
    private readonly FromPriceCalculator _calculator = new();
    private readonly IUniqueChecker _uniqueChecker = new AlwaysUniqueChecker();

    [Fact]
    public async Task UseModelPriceWhenAvailable()
    {
        var cancellationToken = TestContext.Current.CancellationToken;

        var product = await Product.CreateModel(
            name: "Model A",
            slug: "model-a",
            description: null,
            uniqueChecker: _uniqueChecker,
            cancellationToken: cancellationToken);

        product.SetBasePrice(199.99m);

        var variant = await Product.CreateVariant(
            product.Id,
            sku: "SKU-1",
            name: "Variant 1",
            price: 149.99m,
            uniqueChecker: _uniqueChecker,
            cancellationToken: cancellationToken);
        product.AttachVariant(variant);

        var result = _calculator.Compute(product);

        result.IsPriced.ShouldBeTrue();
        result.Amount.ShouldBe(199.99m);
        result.Currency.ShouldBe("USD");
    }

    [Fact]
    public async Task UseLowestVariantPriceWhenModelPriceMissing()
    {
        var cancellationToken = TestContext.Current.CancellationToken;

        var product = await Product.CreateModel(
            name: "Model B",
            slug: "model-b",
            description: null,
            uniqueChecker: _uniqueChecker,
            cancellationToken: cancellationToken);

        var highVariant = await Product.CreateVariant(
            product.Id,
            sku: "HIGH",
            name: "High Variant",
            price: 249.50m,
            uniqueChecker: _uniqueChecker,
            cancellationToken: cancellationToken);
        var lowVariant = await Product.CreateVariant(
            product.Id,
            sku: "LOW",
            name: "Low Variant",
            price: 125.25m,
            uniqueChecker: _uniqueChecker,
            cancellationToken: cancellationToken);

        product.AttachVariant(highVariant);
        product.AttachVariant(lowVariant);

        var result = _calculator.Compute(product);

        result.IsPriced.ShouldBeTrue();
        result.Amount.ShouldBe(125.25m);
        result.Currency.ShouldBe("USD");
    }

    [Fact]
    public async Task ReturnUnpricedWhenNoPricesAvailable()
    {
        var cancellationToken = TestContext.Current.CancellationToken;

        var product = await Product.CreateModel(
            name: "Model C",
            slug: "model-c",
            description: null,
            uniqueChecker: _uniqueChecker,
            cancellationToken: cancellationToken);

        var result = _calculator.Compute(product);

        result.IsPriced.ShouldBeFalse();
        result.Amount.ShouldBeNull();
        result.Currency.ShouldBeNull();
    }

    private sealed class AlwaysUniqueChecker : IUniqueChecker
    {
        public Task<bool> CategoryNameIsUnique(string name, CancellationToken cancellationToken = default) =>
            Task.FromResult(true);

        public Task<bool> ProductModelNameIsUnique(string name, CancellationToken cancellationToken = default) =>
            Task.FromResult(true);

        public Task<bool> ProductSlugIsUnique(string? slug, CancellationToken cancellationToken = default) =>
            Task.FromResult(true);

        public Task<bool> ProductSkuIsUnique(string sku, CancellationToken cancellationToken = default) =>
            Task.FromResult(true);

        public Task<bool> OptionCodeIsUniqueForProduct(Guid productId, string code, CancellationToken cancellationToken = default) =>
            Task.FromResult(true);
    }
}