using System.Security.Claims;
using Bunit;
using Microsoft.AspNetCore.Components.Authorization;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using NSubstitute;
using ScadaLink.Commons.Entities.Instances;
using ScadaLink.Commons.Entities.Sites;
using ScadaLink.Commons.Entities.Templates;
using ScadaLink.Commons.Interfaces.Repositories;
using ScadaLink.Commons.Interfaces.Services;
using ScadaLink.Commons.Types.Enums;
using ScadaLink.Communication;
using ScadaLink.DeploymentManager;
using ScadaLink.CentralUI.Components.Shared;
using ScadaLink.TemplateEngine.Services;
using TopologyPage = ScadaLink.CentralUI.Components.Pages.Deployment.Topology;

namespace ScadaLink.CentralUI.Tests;

/// <summary>
/// bUnit rendering tests for the Topology page (Site → Area → Instance tree).
/// Focuses on the behavior that's specific to this page:
/// always-visible empty containers, search dimming, F2 area rename, and the
/// move-dialog destination lists.
/// </summary>
public class TopologyPageTests : BunitContext
{
    private readonly ITemplateEngineRepository _repo = Substitute.For<ITemplateEngineRepository>();
    private readonly ISiteRepository _siteRepo = Substitute.For<ISiteRepository>();
    private readonly IDeploymentManagerRepository _deployRepo = Substitute.For<IDeploymentManagerRepository>();
    private readonly IFlatteningPipeline _pipeline = Substitute.For<IFlatteningPipeline>();
    private readonly IAuditService _audit = Substitute.For<IAuditService>();

    public TopologyPageTests()
    {
        Services.AddSingleton(_repo);
        Services.AddSingleton(_siteRepo);
        Services.AddSingleton(_deployRepo);
        Services.AddSingleton(_pipeline);
        Services.AddSingleton(_audit);

        // DeploymentService has non-mockable concrete deps; instantiate them directly.
        var comms = new CommunicationService(
            Options.Create(new CommunicationOptions()),
            NullLogger<CommunicationService>.Instance);
        Services.AddSingleton(comms);

        Services.AddSingleton(new OperationLockManager());
        Services.AddSingleton(Options.Create(new DeploymentManagerOptions
        {
            OperationLockTimeout = TimeSpan.FromSeconds(5)
        }));
        Services.AddSingleton<ILogger<DeploymentService>>(NullLogger<DeploymentService>.Instance);
        Services.AddScoped<DeploymentService>();
        Services.AddScoped<AreaService>();
        Services.AddScoped<InstanceService>();

        AddTestAuth();

        // The page injects IDialogService for delete confirmations; the host
        // (rendered globally in MainLayout) is not present in bUnit, but the
        // DI registration still has to satisfy the [Inject].
        Services.AddScoped<IDialogService, DialogService>();

        // Site scoping (CentralUI-002): Topology injects SiteScopeService to
        // filter the tree by the user's permitted sites.
        Services.AddScoped<ScadaLink.CentralUI.Auth.SiteScopeService>();

        // TreeView persists expansion state via JS interop. Stub the calls so render doesn't throw.
        JSInterop.Setup<string?>("treeviewStorage.load", _ => true).SetResult(null);
        JSInterop.SetupVoid("treeviewStorage.save", _ => true);
    }

    private void AddTestAuth()
    {
        var claims = new[]
        {
            new Claim("Username", "tester"),
            new Claim(ClaimTypes.Role, "Deployment")
        };
        var user = new ClaimsPrincipal(new ClaimsIdentity(claims, "TestAuth"));
        Services.AddSingleton<AuthenticationStateProvider>(new TestAuthStateProvider(user));
        Services.AddAuthorizationCore();
    }

    private void SeedRepos(
        IEnumerable<Site>? sites = null,
        IEnumerable<Template>? templates = null,
        IEnumerable<Instance>? instances = null,
        Dictionary<int, IReadOnlyList<Area>>? areasBySite = null)
    {
        _siteRepo.GetAllSitesAsync(Arg.Any<CancellationToken>())
            .Returns(Task.FromResult<IReadOnlyList<Site>>(sites?.ToList() ?? new List<Site>()));
        _repo.GetAllTemplatesAsync(Arg.Any<CancellationToken>())
            .Returns(Task.FromResult<IReadOnlyList<Template>>(templates?.ToList() ?? new List<Template>()));
        _repo.GetAllInstancesAsync(Arg.Any<CancellationToken>())
            .Returns(Task.FromResult<IReadOnlyList<Instance>>(instances?.ToList() ?? new List<Instance>()));

        areasBySite ??= new();
        _repo.GetAreasBySiteIdAsync(Arg.Any<int>(), Arg.Any<CancellationToken>())
            .Returns(call =>
            {
                var sid = call.Arg<int>();
                return Task.FromResult(areasBySite.TryGetValue(sid, out var list)
                    ? list
                    : (IReadOnlyList<Area>)new List<Area>());
            });
    }

    [Fact]
    public void Renders_EmptyState_WhenNoSites()
    {
        SeedRepos();

        var cut = Render<TopologyPage>();

        Assert.Contains("No sites configured", cut.Markup);
    }

    [Fact]
    public void Renders_EmptySite_AsTopLevelNode()
    {
        // An always-show-empty container is a hard requirement: a site with nothing
        // under it must still appear so users can move/create into it.
        SeedRepos(sites: new[] { new Site("Plant-A", "plant-a") { Id = 1 } });

        var cut = Render<TopologyPage>();

        Assert.Contains("Plant-A", cut.Markup);
        Assert.Contains("bi-building", cut.Markup);
    }

    private static AngleSharp.Dom.IElement? FindToggleForLabel(IRenderedComponent<TopologyPage> cut, string label) =>
        cut.FindAll(".tv-row")
            .FirstOrDefault(row => row.QuerySelector(".tv-label")?.TextContent == label)
            ?.QuerySelector(".tv-toggle");

    [Fact]
    public void Renders_SiteAreaInstance_Nesting()
    {
        var areasBySite = new Dictionary<int, IReadOnlyList<Area>>
        {
            [1] = new List<Area>
            {
                new("Line-1") { Id = 10, SiteId = 1, ParentAreaId = null }
            }
        };
        SeedRepos(
            sites: new[] { new Site("Plant-A", "plant-a") { Id = 1 } },
            instances: new[]
            {
                new Instance("Pump-001") { Id = 100, SiteId = 1, AreaId = 10, State = InstanceState.NotDeployed }
            },
            areasBySite: areasBySite);

        var cut = Render<TopologyPage>();

        // Expand the site, then the area, to render the instance leaf. The
        // helper scopes by the row's own label so we don't match outer rows
        // whose TextContent transitively contains the inner label.
        FindToggleForLabel(cut, "Plant-A")!.Click();
        FindToggleForLabel(cut, "Line-1")!.Click();

        Assert.Contains("Pump-001", cut.Markup);
        Assert.Contains("bi-diagram-3", cut.Markup);
        Assert.Contains("bi-box", cut.Markup);
        Assert.Contains("NotDeployed", cut.Markup);
    }

    [Fact]
    public void Search_DimsNonMatches_PreservesShape()
    {
        var areasBySite = new Dictionary<int, IReadOnlyList<Area>>
        {
            [1] = new List<Area>
            {
                new("Line-1") { Id = 10, SiteId = 1 },
                new("Boilers") { Id = 11, SiteId = 1 }
            }
        };
        SeedRepos(
            sites: new[] { new Site("Plant-A", "plant-a") { Id = 1 } },
            areasBySite: areasBySite);

        var cut = Render<TopologyPage>();
        FindToggleForLabel(cut, "Plant-A")!.Click();

        var search = cut.Find("input[type='text']");
        search.Input("Line");

        // Both areas remain in the DOM (shape preserved). 'Boilers' gets the dim style.
        Assert.Contains("Line-1", cut.Markup);
        Assert.Contains("Boilers", cut.Markup);
        var dimmedNodes = cut.FindAll("span.tv-label[style*='opacity']");
        Assert.Contains(dimmedNodes, n => n.TextContent.Contains("Boilers"));
    }

    [Fact]
    public void SiteScoping_ScopedDeploymentUser_OnlySeesPermittedSites()
    {
        // Regression test for CentralUI-002. The SiteId claims issued at login were
        // never read, so a Deployment user scoped to one site could view (and act
        // on) every site's topology. Topology now filters the tree by the user's
        // permitted sites via SiteScopeService.
        var scopedUser = new ClaimsPrincipal(new ClaimsIdentity(new[]
        {
            new Claim("Username", "scoped-tester"),
            new Claim(ScadaLink.Security.JwtTokenService.RoleClaimType, "Deployment"),
            // Permitted on site 1 only.
            new Claim(ScadaLink.Security.JwtTokenService.SiteIdClaimType, "1"),
        }, "TestAuth"));
        // Last AuthenticationStateProvider registration wins on resolution.
        Services.AddSingleton<AuthenticationStateProvider>(new TestAuthStateProvider(scopedUser));

        SeedRepos(sites: new[]
        {
            new Site("Plant-A", "plant-a") { Id = 1 },
            new Site("Plant-B", "plant-b") { Id = 2 },
        });

        var cut = Render<TopologyPage>();

        // The permitted site is rendered; the non-permitted site is not.
        Assert.Contains("Plant-A", cut.Markup);
        Assert.DoesNotContain("Plant-B", cut.Markup);
    }

    [Fact]
    public void SiteScoping_SystemWideDeploymentUser_SeesAllSites()
    {
        // A Deployment user with no SiteId claims is system-wide and sees every site.
        SeedRepos(sites: new[]
        {
            new Site("Plant-A", "plant-a") { Id = 1 },
            new Site("Plant-B", "plant-b") { Id = 2 },
        });

        var cut = Render<TopologyPage>();

        Assert.Contains("Plant-A", cut.Markup);
        Assert.Contains("Plant-B", cut.Markup);
    }

    [Fact]
    public void DoubleClick_OnAreaLabel_EntersRenameMode()
    {
        var areasBySite = new Dictionary<int, IReadOnlyList<Area>>
        {
            [1] = new List<Area> { new("Line-1") { Id = 10, SiteId = 1 } }
        };
        SeedRepos(sites: new[] { new Site("Plant-A", "plant-a") { Id = 1 } }, areasBySite: areasBySite);

        var cut = Render<TopologyPage>();
        FindToggleForLabel(cut, "Plant-A")!.Click();

        var areaLabel = cut.FindAll("span.tv-label").First(s => s.TextContent == "Line-1");
        areaLabel.DoubleClick();

        // Inline rename input replaces the label.
        Assert.NotNull(cut.Find("input.form-control-sm.d-inline-block"));
    }

    [Fact]
    public void InstanceRows_DoNotHaveDoubleClickRename()
    {
        // Instance rename is out of scope; the label should not have @ondblclick wired.
        // bUnit throws MissingEventHandlerException when dispatching to an element
        // that has no handler — that's the assertion: the dblclick event is not bound.
        SeedRepos(
            sites: new[] { new Site("Plant-A", "plant-a") { Id = 1 } },
            instances: new[]
            {
                new Instance("Pump-001") { Id = 100, SiteId = 1, State = InstanceState.NotDeployed }
            });

        var cut = Render<TopologyPage>();
        FindToggleForLabel(cut, "Plant-A")!.Click();

        var instanceLabel = cut.FindAll("span.tv-label").First(s => s.TextContent == "Pump-001");
        Assert.Throws<Bunit.MissingEventHandlerException>(() => instanceLabel.DoubleClick());
    }

    [Fact]
    public void LegacyInstancesRoute_IsDeclaredOnTopologyPage()
    {
        // Old bookmarks to /deployment/instances must still resolve. Reflection
        // check: the Topology component carries both @page directives.
        var pageAttrs = typeof(TopologyPage).GetCustomAttributes(
            typeof(Microsoft.AspNetCore.Components.RouteAttribute), inherit: false)
            .Cast<Microsoft.AspNetCore.Components.RouteAttribute>()
            .Select(a => a.Template)
            .ToList();

        Assert.Contains("/deployment/topology", pageAttrs);
        Assert.Contains("/deployment/instances", pageAttrs);
    }
}