using System.Security.Claims;
using Bunit;
using Microsoft.AspNetCore.Components.Authorization;
using Microsoft.Extensions.DependencyInjection;
using NSubstitute;
using ZB.MOM.WW.ScadaBridge.CentralUI.Auth;
using ZB.MOM.WW.ScadaBridge.CentralUI.Services;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Instances;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Templates;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Services;
using ZB.MOM.WW.ScadaBridge.Commons.Types;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Flattening;
using ZB.MOM.WW.ScadaBridge.DeploymentManager;
using ZB.MOM.WW.ScadaBridge.Security;
using ZB.MOM.WW.ScadaBridge.TemplateEngine.Services;
using InstanceConfigurePage = ZB.MOM.WW.ScadaBridge.CentralUI.Components.Pages.Deployment.InstanceConfigure;

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

/// <summary>
/// Behavioural (bUnit) coverage of the grouped Connection Bindings panel (design
/// 2026-08-20), complementing the structural pins: the rows come from the flattened
/// configuration, a flatten FAILURE falls back to the direct attributes with a banner,
/// a group Apply whose header connection is left at "— mixed —" keeps every member's
/// own connection (review finding: it used to unbind the group, which an upsert Save
/// could never persist), and Save posts the composed rows.
/// </summary>
public class InstanceConfigureBindingBehaviourTests : BunitContext
{
    private readonly ITemplateEngineRepository _templateRepo = Substitute.For<ITemplateEngineRepository>();
    private readonly ISiteRepository _siteRepo = Substitute.For<ISiteRepository>();
    private readonly IFlatteningPipeline _pipeline = Substitute.For<IFlatteningPipeline>();

    public InstanceConfigureBindingBehaviourTests()
    {
        JSInterop.Mode = JSRuntimeMode.Loose;
        Services.AddSingleton(_templateRepo);
        Services.AddSingleton(_siteRepo);
        Services.AddSingleton(new InstanceService(_templateRepo, Substitute.For<IAuditService>()));
        Services.AddSingleton(_pipeline);
        Services.AddSingleton(Substitute.For<IBrowseService>());
        Services.AddSingleton(Substitute.For<IBindingTester>());

        var claims = new[]
        {
            new Claim(JwtTokenService.UsernameClaimType, "deployer"),
            new Claim(JwtTokenService.RoleClaimType, "Deployer"),
        };
        var authProvider = new TestAuthStateProvider(new ClaimsPrincipal(new ClaimsIdentity(claims, "TestAuth")));
        Services.AddSingleton<AuthenticationStateProvider>(authProvider);
        Services.AddSingleton(new SiteScopeService(authProvider));
        Services.AddAuthorizationCore();
        Services.AddTestConfigurationMutations();
        AuthorizationPolicies.AddScadaBridgeAuthorization(Services);
    }

    private void SeedInstance(IReadOnlyList<InstanceConnectionBinding> bindings)
    {
        var instance = new Instance("Z28061") { Id = 42, TemplateId = 1, SiteId = 1,
            State = ZB.MOM.WW.ScadaBridge.Commons.Types.Enums.InstanceState.NotDeployed };
        _templateRepo.GetInstanceByIdAsync(42, Arg.Any<CancellationToken>()).Returns(instance);
        _templateRepo.GetTemplateByIdAsync(1, Arg.Any<CancellationToken>()).Returns(new Template("Reactor") { Id = 1 });
        _siteRepo.GetAllSitesAsync(Arg.Any<CancellationToken>()).Returns(new List<Site> { new("Plant A", "plant-a") { Id = 1 } });
        _templateRepo.GetAreasBySiteIdAsync(1, Arg.Any<CancellationToken>()).Returns(new List<Area>());
        // Direct attributes only — the composed members are NOT here; they only exist in the flattened config.
        _templateRepo.GetAttributesByTemplateIdAsync(1, Arg.Any<CancellationToken>())
            .Returns(new List<TemplateAttribute> { new("ChlorineFlow") { Id = 1, DataSourceReference = "ChlorineFlow" } });
        _siteRepo.GetDataConnectionsBySiteIdAsync(1, Arg.Any<CancellationToken>())
            .Returns(new List<DataConnection> { new("GW-1", "MxGateway", 1) { Id = 1 }, new("GW-2", "MxGateway", 1) { Id = 2 } });
        _templateRepo.GetBindingsByInstanceIdAsync(42, Arg.Any<CancellationToken>()).Returns(bindings);
        _templateRepo.GetOverridesByInstanceIdAsync(42, Arg.Any<CancellationToken>()).Returns(new List<InstanceAttributeOverride>());
        _templateRepo.GetAlarmsByTemplateIdAsync(1, Arg.Any<CancellationToken>()).Returns(new List<TemplateAlarm>());
        _templateRepo.GetAlarmOverridesByInstanceIdAsync(42, Arg.Any<CancellationToken>()).Returns(new List<InstanceAlarmOverride>());
    }

    private static Result<FlatteningPipelineResult> Flattened(params ResolvedAttribute[] attrs) =>
        Result<FlatteningPipelineResult>.Success(new FlatteningPipelineResult(
            new FlattenedConfiguration { InstanceUniqueName = "Z28061", Attributes = attrs },
            "hash",
            new ValidationResult()));

    private static ResolvedAttribute DataSourced(string canonical, string dflt, int? conn = null, string? effective = null) =>
        new() { CanonicalName = canonical, DataType = "Boolean", DataSourceReference = effective ?? dflt,
            DefaultDataSourceReference = dflt, BoundDataConnectionId = conn };

    [Fact]
    public void Rows_ComeFromFlattenedConfiguration_ComposedMembersGrouped()
    {
        SeedInstance(new List<InstanceConnectionBinding>());
        _pipeline.FlattenAndValidateAsync(42, Arg.Any<CancellationToken>(), Arg.Any<bool>(), Arg.Any<FlattenSession>())
            .Returns(Flattened(
                DataSourced("ChlorineFlow", "ChlorineFlow"),
                DataSourced("LeftMESReceiver.MoveInFlag", "MoveInFlag"),
                DataSourced("LeftMESReceiver.ScanStateCmd", "ScanStateCmd"),
                DataSourced("RightMESReceiver.MoveInFlag", "MoveInFlag")));

        var cut = Render<InstanceConfigurePage>(p => p.Add(c => c.Id, 42));

        cut.WaitForAssertion(() =>
        {
            var headers = cut.FindAll("[data-test=\"binding-group-header\"]");
            Assert.Equal(3, headers.Count);
            Assert.Contains("(instance)", headers[0].TextContent);
            Assert.Contains("LeftMESReceiver", headers[1].TextContent);
            Assert.Contains("RightMESReceiver", headers[2].TextContent);
            Assert.Equal("4 unbound", cut.Find("[data-test=\"binding-total-unbound\"]").TextContent.Trim());
            Assert.Empty(cut.FindAll("[data-test=\"binding-source-warning\"]"));
        });
    }

    [Fact]
    public void FlattenFailure_FallsBackToDirectAttributes_WithBanner()
    {
        SeedInstance(new List<InstanceConnectionBinding>());
        _pipeline.FlattenAndValidateAsync(42, Arg.Any<CancellationToken>(), Arg.Any<bool>(), Arg.Any<FlattenSession>())
            .Returns(Result<FlatteningPipelineResult>.Failure("Template chain is empty."));

        var cut = Render<InstanceConfigurePage>(p => p.Add(c => c.Id, 42));

        cut.WaitForAssertion(() =>
        {
            Assert.Contains("Template chain is empty.", cut.Find("[data-test=\"binding-source-warning\"]").TextContent);
            var headers = cut.FindAll("[data-test=\"binding-group-header\"]");
            Assert.Single(headers);
            Assert.Contains("(instance)", headers[0].TextContent);
        });
    }

    [Fact]
    public async Task ApplyOnMixedConnectionGroup_KeepsEachMembersConnection_AndSavePostsComposedRows()
    {
        SeedInstance(new List<InstanceConnectionBinding>
        {
            new("LeftMESReceiver.MoveInFlag") { Id = 1, InstanceId = 42, DataConnectionId = 1, DataSourceReferenceOverride = "Old.MoveInFlag" },
            new("LeftMESReceiver.ScanStateCmd") { Id = 2, InstanceId = 42, DataConnectionId = 2, DataSourceReferenceOverride = "Old.ScanStateCmd" },
        });
        _pipeline.FlattenAndValidateAsync(42, Arg.Any<CancellationToken>(), Arg.Any<bool>(), Arg.Any<FlattenSession>())
            .Returns(Flattened(
                DataSourced("LeftMESReceiver.MoveInFlag", "MoveInFlag", 1, "Old.MoveInFlag"),
                DataSourced("LeftMESReceiver.ScanStateCmd", "ScanStateCmd", 2, "Old.ScanStateCmd")));

        var cut = Render<InstanceConfigurePage>(p => p.Add(c => c.Id, 42));
        cut.WaitForAssertion(() => Assert.Single(cut.FindAll("[data-test=\"binding-group-header\"]")));

        // Connections differ (1 vs 2) → header select reads "— mixed —" (value 0); inferred object is "Old".
        var header = cut.Find("[data-test=\"binding-group-header\"]");
        Assert.Contains("— mixed —", header.QuerySelector("[data-test=\"binding-group-connection\"]")!.TextContent);
        Assert.Equal("Old", header.QuerySelector("[data-test=\"binding-group-object\"]")!.GetAttribute("value"));

        await cut.InvokeAsync(() => cut.Find("[data-test=\"binding-group-object\"]").Change("MESReceiver_022"));
        await cut.InvokeAsync(() => cut.Find("[data-test=\"binding-group-apply\"]").Click());

        cut.WaitForAssertion(() =>
        {
            // Still bound — Apply with the header at "— mixed —" must not unbind anyone.
            Assert.Empty(cut.FindAll("[data-test=\"binding-group-unbound\"]"));
            Assert.Contains("2 changed", cut.Find("[data-test=\"binding-group-header\"]").TextContent);
            // Object unified → header pre-fills the new prefix; the group still reads
            // "mixed" because the CONNECTIONS were deliberately left different (1 vs 2).
            Assert.Equal("MESReceiver_022", cut.Find("[data-test=\"binding-group-object\"]").GetAttribute("value"));
            Assert.Single(cut.FindAll("[data-test=\"binding-group-mixed\"]"));
            Assert.Contains("— mixed —", cut.Find("[data-test=\"binding-group-connection\"]").TextContent);
        });

        // Save posts both composed rows with their ORIGINAL connections and the rewritten overrides.
        var existing = await _templateRepo.GetBindingsByInstanceIdAsync(42);
        _templateRepo.GetBindingsByInstanceIdAsync(42, Arg.Any<CancellationToken>()).Returns(existing);
        await cut.InvokeAsync(() => cut.FindAll("button").Single(b => b.TextContent.Trim() == "Save Bindings").Click());

        await _templateRepo.Received(1).UpdateInstanceConnectionBindingAsync(
            Arg.Is<InstanceConnectionBinding>(b => b.AttributeName == "LeftMESReceiver.MoveInFlag" && b.DataConnectionId == 1 && b.DataSourceReferenceOverride == "MESReceiver_022.MoveInFlag"),
            Arg.Any<CancellationToken>());
        await _templateRepo.Received(1).UpdateInstanceConnectionBindingAsync(
            Arg.Is<InstanceConnectionBinding>(b => b.AttributeName == "LeftMESReceiver.ScanStateCmd" && b.DataConnectionId == 2 && b.DataSourceReferenceOverride == "MESReceiver_022.ScanStateCmd"),
            Arg.Any<CancellationToken>());
    }
}