using Bunit;
using Microsoft.Extensions.DependencyInjection;
using ZB.MOM.WW.ScadaBridge.CentralUI.Components.Shared;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Templates;

namespace ZB.MOM.WW.ScadaBridge.CentralUI.Tests.Shared;

/// <summary>
/// bUnit tests for the Create Instance template picker: templates are the only
/// selectable nodes, Select stays disabled until one is picked, double-click
/// selects, Cancel resolves null, and an InitialTemplateId opens the tree on
/// that template.
/// </summary>
public class TemplatePickerDialogTests : BunitContext
{
    private readonly DialogService _service = new();

    /// <summary>Registers the dialog service and loose JS interop the picker dialog needs.</summary>
    public TemplatePickerDialogTests()
    {
        Services.AddSingleton<IDialogService>(_service);
        JSInterop.Mode = JSRuntimeMode.Loose;
    }

    private static (List<TemplateFolder>, List<Template>) Catalogue()
    {
        var a = new TemplateFolder("A") { Id = 1 };
        var b = new TemplateFolder("B") { Id = 2, ParentFolderId = 1 };
        var other = new TemplateFolder("Other") { Id = 3 };
        var t7 = new Template("Deep") { Id = 7, FolderId = 2 };
        var t8 = new Template("Elsewhere") { Id = 8, FolderId = 3 };
        return (new() { a, b, other }, new() { t7, t8 });
    }

    private async Task<(IRenderedComponent<DialogHost> cut, Task<TemplatePickerDialog.TemplatePickResult?> pending)> Open(int? initial = null)
    {
        var (f, t) = Catalogue();
        var cut = Render<DialogHost>();
        Task<TemplatePickerDialog.TemplatePickResult?> pending = null!;
        // Block body, not an expression body: an expression-bodied lambda returning the
        // pending Task binds to InvokeAsync(Func<Task>) and would await the dialog itself.
        await cut.InvokeAsync(() =>
        {
            pending = _service.ShowAsync<TemplatePickerDialog.TemplatePickResult>(
            "Choose template",
            ctx => b =>
            {
                b.OpenComponent<TemplatePickerDialog>(0);
                b.AddAttribute(1, nameof(TemplatePickerDialog.Context), ctx);
                b.AddAttribute(2, nameof(TemplatePickerDialog.Folders), f);
                b.AddAttribute(3, nameof(TemplatePickerDialog.Templates), t);
                b.AddAttribute(4, nameof(TemplatePickerDialog.InitialTemplateId), initial);
                b.CloseComponent();
            },
                size: "modal-lg");
        });
        cut.Render();
        return (cut, pending);
    }

    private static void ExpandFolder(IRenderedComponent<DialogHost> cut, string label) =>
        cut.FindAll("li[role='treeitem']")
           .First(li => li.QuerySelector(".tv-label")!.TextContent.Trim() == label)
           .QuerySelector(".tv-toggle")!.Click();

    private static AngleSharp.Dom.IElement Label(IRenderedComponent<DialogHost> cut, string text) =>
        cut.FindAll(".tv-label").First(l => l.TextContent.Trim() == text);

    /// <summary>Verifies that the Select button is disabled until a template is clicked.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Select_IsDisabled_UntilATemplateIsClicked()
    {
        var (cut, _) = await Open();
        Assert.True(cut.Find("button[data-test='picker-select']").HasAttribute("disabled"));
        Assert.Contains("Select a template", cut.Find("[data-test='picker-status']").TextContent);
    }

    /// <summary>Verifies that clicking a template and then Select resolves the dialog with that template's id.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task ClickingTemplate_ThenSelect_ResolvesItsId()
    {
        var (cut, pending) = await Open();
        ExpandFolder(cut, "A");
        ExpandFolder(cut, "B");
        Label(cut, "Deep").Click();

        Assert.False(cut.Find("button[data-test='picker-select']").HasAttribute("disabled"));
        Assert.Contains("A / B / Deep", cut.Find("[data-test='picker-status']").TextContent);

        cut.Find("button[data-test='picker-select']").Click();
        Assert.Equal(7, (await pending)!.TemplateId);
    }

    /// <summary>Verifies that double-clicking a template resolves the dialog with that template.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task DoubleClickingTemplate_Resolves()
    {
        var (cut, pending) = await Open();
        ExpandFolder(cut, "A");
        ExpandFolder(cut, "B");
        Label(cut, "Deep").DoubleClick();
        Assert.Equal(7, (await pending)!.TemplateId);
    }

    /// <summary>Verifies that clicking a folder selects nothing.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task ClickingFolder_SelectsNothing()
    {
        var (cut, _) = await Open();
        Label(cut, "A").Click();
        Assert.True(cut.Find("button[data-test='picker-select']").HasAttribute("disabled"));
    }

    /// <summary>Verifies that Cancel resolves the dialog with null.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Cancel_ResolvesNull()
    {
        var (cut, pending) = await Open();
        cut.Find("button[data-test='picker-cancel']").Click();
        Assert.Null(await pending);
    }

    /// <summary>Verifies that the initial template id is revealed in the tree and highlighted.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task InitialTemplateId_IsRevealedAndHighlighted()
    {
        var (cut, _) = await Open(initial: 7);
        Assert.Contains("Deep", cut.Markup);
        Assert.DoesNotContain("Elsewhere", cut.Markup);
        Assert.False(cut.Find("button[data-test='picker-select']").HasAttribute("disabled"));
        Assert.Contains("A / B / Deep", cut.Find("[data-test='picker-status']").TextContent);
        Assert.Contains("text-primary", Label(cut, "Deep").ClassName);
    }

    /// <summary>Verifies that typing in the search box filters the tree.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Search_FiltersTree()
    {
        var (cut, _) = await Open();
        cut.Find("input[data-test='picker-search']").Input("Else");
        Assert.Contains("Elsewhere", cut.Markup);
        Assert.DoesNotContain("Deep", cut.Markup);
    }
}