using FluentValidation;
using FluentValidation.Results;
using Moq;
using Prefab.Shared.Catalog;
using Prefab.Shared.Catalog.Products;
using Prefab.Web.Gateway.Shared;
using Shouldly;

namespace Prefab.Tests.Unit.Web.Gateway;

[Trait(TraitName.Category, TraitCategory.Unit)]
public sealed class NavMenuServiceShould
{
    [Fact]
    public async Task ReturnOnlyFeaturedChildrenWhenAvailable()
    {
        var moduleClient = new Mock<IModuleClient>();
        var productClient = new Mock<IProductClient>();
        moduleClient.SetupGet(c => c.Product).Returns(productClient.Object);

        var featuredChild = CreateNode(
            name: "Featured",
            slug: "featured",
            displayOrder: 2,
            isFeatured: true,
            isLeaf: true);

        var secondaryChild = CreateNode(
            name: "Secondary",
            slug: "secondary",
            displayOrder: 1,
            isFeatured: false,
            isLeaf: true);

        var root = CreateNode(
            name: "Root",
            slug: "root",
            displayOrder: 0,
            isFeatured: false,
            isLeaf: false,
            children: new[] { secondaryChild, featuredChild });

        productClient
            .Setup(p => p.GetCategoryTree(It.IsAny<int>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GetCategoryTree.Response(new[] { root }));

        var sut = new NavMenu.Service(moduleClient.Object);

        var result = await sut.Get(2, CancellationToken.None);

        result.IsSuccess.ShouldBeTrue();
        var model = result.Value.ShouldNotBeNull();
        model.Depth.ShouldBe(2);
        model.Columns.Count.ShouldBe(1);

        var column = model.Columns.Single();
        column.Root.Name.ShouldBe("Root");
        column.Root.Url.ShouldBe("/catalog/category?category-slug=root");
        column.Items.Count.ShouldBe(1);

        var item = column.Items.Single();
        item.Name.ShouldBe("Featured");
        item.Url.ShouldBe("/catalog/products?category-slug=featured");
        column.HasMore.ShouldBeFalse();
        column.SeeAllUrl.ShouldBe("/catalog/category?category-slug=root");
    }

    [Fact]
    public async Task FallBackToAllChildrenWhenNoFeatured()
    {
        var moduleClient = new Mock<IModuleClient>();
        var productClient = new Mock<IProductClient>();
        moduleClient.SetupGet(c => c.Product).Returns(productClient.Object);

        var firstChild = CreateNode(
            name: "Alpha",
            slug: "alpha",
            displayOrder: 3,
            isFeatured: false,
            isLeaf: true);
        var secondChild = CreateNode(
            name: "Beta",
            slug: "beta",
            displayOrder: 1,
            isFeatured: false,
            isLeaf: false);
        var thirdChild = CreateNode(
            name: "Gamma",
            slug: "gamma",
            displayOrder: 2,
            isFeatured: false,
            isLeaf: true);

        var root = CreateNode(
            name: "Root",
            slug: "root",
            displayOrder: 0,
            isFeatured: false,
            isLeaf: false,
            children: new[] { firstChild, secondChild, thirdChild });

        productClient
            .Setup(p => p.GetCategoryTree(It.IsAny<int>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GetCategoryTree.Response(new[] { root }));

        var sut = new NavMenu.Service(moduleClient.Object);

        var result = await sut.Get(1, CancellationToken.None);

        result.IsSuccess.ShouldBeTrue();
        var model = result.Value.ShouldNotBeNull();
        model.Depth.ShouldBe(1);
        var names = model.Columns.Single().Items.Select(i => i.Name).ToList();
        names.ShouldBe(["Beta", "Gamma", "Alpha"]);
    }

    [Fact]
    public async Task ClampDepthBeforeCallingCatalog()
    {
        var moduleClient = new Mock<IModuleClient>();
        var productClient = new Mock<IProductClient>();
        moduleClient.SetupGet(c => c.Product).Returns(productClient.Object);

        var root = CreateNode("Root", "root", 0, false, false);

        productClient
            .Setup(p => p.GetCategoryTree(2, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GetCategoryTree.Response(new[] { root }));

        var sut = new NavMenu.Service(moduleClient.Object);
        await sut.Get(10, CancellationToken.None);

        productClient.Verify(p => p.GetCategoryTree(2, It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task ReturnProblemWhenCatalogValidationFails()
    {
        var moduleClient = new Mock<IModuleClient>();
        var productClient = new Mock<IProductClient>();
        moduleClient.SetupGet(c => c.Product).Returns(productClient.Object);

        productClient
            .Setup(p => p.GetCategoryTree(It.IsAny<int>(), It.IsAny<CancellationToken>()))
            .ThrowsAsync(new ValidationException([new ValidationFailure("Depth", "invalid")]));

        var sut = new NavMenu.Service(moduleClient.Object);

        var result = await sut.Get(-1, CancellationToken.None);

        result.IsSuccess.ShouldBeFalse();
        result.Value.ShouldBeNull();
        var problem = result.Problem.ShouldNotBeNull();
        problem.StatusCode.ShouldBe(400);
        problem.Detail.ShouldBe("Request did not satisfy validation rules.");
        problem.Errors.ShouldNotBeNull();
        problem.Errors!.ShouldContainKey("Depth");
        problem.Errors["Depth"].ShouldContain("invalid");
    }

    private static GetCategoryModels.CategoryNodeDto CreateNode(
        string name,
        string slug,
        int displayOrder,
        bool isFeatured,
        bool isLeaf,
        IReadOnlyList<GetCategoryModels.CategoryNodeDto>? children = null)
    {
        return new GetCategoryModels.CategoryNodeDto(
            Guid.NewGuid(),
            name,
            slug,
            null,
            null,
            null,
            displayOrder,
            isFeatured,
            isLeaf,
            children ?? []);
    }
}