using System.Security.Claims;
using Akka.Actor;
using Bunit;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Components.Authorization;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using NSubstitute;
using ScadaLink.CentralUI.Components.Shared;
using ScadaLink.Commons.Entities.Sites;
using ScadaLink.Commons.Interfaces.Repositories;
using ScadaLink.Commons.Messages.Audit;
using ScadaLink.Communication;
using ScadaLink.Security;
using SiteCallsReportPage = ScadaLink.CentralUI.Components.Pages.SiteCalls.SiteCallsReport;

namespace ScadaLink.CentralUI.Tests.Pages;

/// <summary>
/// bUnit rendering tests for the Site Calls report page (Site Call Audit #22).
///
/// Testability note: <see cref="CommunicationService"/> is a concrete class with
/// non-virtual methods, so NSubstitute cannot intercept it. The page's calls all
/// route through an injected <see cref="IActorRef"/> (the Site Call Audit proxy),
/// so the tests wire a real, lightweight <see cref="ActorSystem"/> with a scripted
/// <see cref="ReceiveActor"/> that replies with fixed responses — the same seam
/// <c>SetSiteCallAudit</c> exists for. Mirrors <see cref="NotificationReportPageTests"/>.
/// </summary>
public class SiteCallsReportPageTests : BunitContext
{
    private readonly ActorSystem _system = ActorSystem.Create("site-calls-report-tests");
    private readonly CommunicationService _comms;

    private static readonly Guid ParkedId = Guid.Parse("11111111-1111-1111-1111-111111111111");
    private static readonly Guid FailedId = Guid.Parse("22222222-2222-2222-2222-222222222222");

    // Mutable scripted reply — individual tests can override before rendering.
    private SiteCallQueryResponse _queryReply = new(
        "q", true, null,
        new List<SiteCallSummary>
        {
            new(ParkedId, "plant-a", "ApiOutbound", "ERP.GetOrder", "Parked",
                RetryCount: 3, LastError: "HTTP 503 from ERP", HttpStatus: 503,
                CreatedAtUtc: DateTime.UtcNow.AddMinutes(-30), UpdatedAtUtc: DateTime.UtcNow.AddMinutes(-5),
                TerminalAtUtc: null, IsStuck: true),
            new(FailedId, "plant-b", "DbOutbound", "Historian.Write", "Failed",
                RetryCount: 1, LastError: "constraint violation", HttpStatus: null,
                CreatedAtUtc: DateTime.UtcNow.AddHours(-2), UpdatedAtUtc: DateTime.UtcNow.AddHours(-2),
                TerminalAtUtc: DateTime.UtcNow.AddHours(-2), IsStuck: false),
        },
        NextAfterCreatedAtUtc: null,
        NextAfterId: null);

    // Records the most recent retry/discard requests the actor received.
    private readonly List<SiteCallQueryRequest> _queryRequests = new();
    private readonly List<RetrySiteCallRequest> _retryRequests = new();
    private readonly List<DiscardSiteCallRequest> _discardRequests = new();

    // Scripted relay responses — overridable per test.
    private RetrySiteCallResponse _retryReply =
        new("q", SiteCallRelayOutcome.Applied, true, true, null);
    private DiscardSiteCallResponse _discardReply =
        new("q", SiteCallRelayOutcome.Applied, true, true, null);

    public SiteCallsReportPageTests()
    {
        _comms = new CommunicationService(
            Options.Create(new CommunicationOptions()),
            NullLogger<CommunicationService>.Instance);

        var auditProxy = _system.ActorOf(Props.Create(() => new ScriptedSiteCallAuditActor(this)));
        _comms.SetSiteCallAudit(auditProxy);

        Services.AddSingleton(_comms);
        Services.AddSingleton<IDialogService>(new AlwaysConfirmDialogService());

        var siteRepo = Substitute.For<ISiteRepository>();
        siteRepo.GetAllSitesAsync(Arg.Any<CancellationToken>())
            .Returns(Task.FromResult<IReadOnlyList<Site>>(new List<Site>
            {
                new("Plant A", "plant-a") { Id = 1 },
                new("Plant B", "plant-b") { Id = 2 },
            }));
        Services.AddSingleton(siteRepo);

        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();
    }

    [Fact]
    public void Page_RequiresDeploymentPolicy()
    {
        var attr = typeof(SiteCallsReportPage)
            .GetCustomAttributes(typeof(AuthorizeAttribute), true)
            .Cast<AuthorizeAttribute>()
            .FirstOrDefault();

        Assert.NotNull(attr);
        Assert.Equal(AuthorizationPolicies.RequireDeployment, attr!.Policy);
    }

    [Fact]
    public void Renders_SiteCallRows()
    {
        var cut = Render<SiteCallsReportPage>();

        cut.WaitForAssertion(() =>
        {
            Assert.Contains("ERP.GetOrder", cut.Markup);
            Assert.Contains("Historian.Write", cut.Markup);
        });
    }

    [Fact]
    public void StuckRow_IsBadged()
    {
        var cut = Render<SiteCallsReportPage>();

        cut.WaitForAssertion(() =>
        {
            var stuckRow = cut.FindAll("tbody tr")
                .First(r => r.TextContent.Contains("ERP.GetOrder"));
            Assert.Contains("badge", stuckRow.InnerHtml);
            Assert.Contains("Stuck", stuckRow.TextContent);
        });
    }

    [Fact]
    public void RetryDiscardButtons_ShownOnlyOnParkedRows()
    {
        var cut = Render<SiteCallsReportPage>();

        cut.WaitForState(() => cut.Markup.Contains("ERP.GetOrder"));

        var parkedRow = cut.FindAll("tbody tr")
            .First(r => r.TextContent.Contains("ERP.GetOrder"));
        var failedRow = cut.FindAll("tbody tr")
            .First(r => r.TextContent.Contains("Historian.Write"));

        // The Parked row carries Retry + Discard buttons.
        Assert.Contains(parkedRow.QuerySelectorAll("button"),
            b => b.TextContent.Contains("Retry"));
        Assert.Contains(parkedRow.QuerySelectorAll("button"),
            b => b.TextContent.Contains("Discard"));

        // The Failed row carries neither — Retry/Discard are Parked-only.
        Assert.DoesNotContain(failedRow.QuerySelectorAll("button"),
            b => b.TextContent.Contains("Retry"));
        Assert.DoesNotContain(failedRow.QuerySelectorAll("button"),
            b => b.TextContent.Contains("Discard"));
    }

    [Fact]
    public void ClickRetry_OnParkedRow_RelaysRetryToOwningSite()
    {
        var cut = Render<SiteCallsReportPage>();

        cut.WaitForState(() => cut.Markup.Contains("ERP.GetOrder"));

        var parkedRow = cut.FindAll("tbody tr")
            .First(r => r.TextContent.Contains("ERP.GetOrder"));
        var retryButton = parkedRow.QuerySelectorAll("button")
            .First(b => b.TextContent.Contains("Retry"));

        retryButton.Click();

        cut.WaitForAssertion(() =>
        {
            Assert.Single(_retryRequests);
            Assert.Equal(ParkedId, _retryRequests[0].TrackedOperationId);
            // The relay carries the owning site so central can route it.
            Assert.Equal("plant-a", _retryRequests[0].SourceSite);
        });
    }

    [Fact]
    public void ClickDiscard_OnParkedRow_RelaysDiscardToOwningSite()
    {
        var cut = Render<SiteCallsReportPage>();

        cut.WaitForState(() => cut.Markup.Contains("ERP.GetOrder"));

        var parkedRow = cut.FindAll("tbody tr")
            .First(r => r.TextContent.Contains("ERP.GetOrder"));
        var discardButton = parkedRow.QuerySelectorAll("button")
            .First(b => b.TextContent.Contains("Discard"));

        discardButton.Click();

        cut.WaitForAssertion(() =>
        {
            Assert.Single(_discardRequests);
            Assert.Equal(ParkedId, _discardRequests[0].TrackedOperationId);
            Assert.Equal("plant-a", _discardRequests[0].SourceSite);
        });
    }

    [Fact]
    public void RetryRelay_SiteUnreachable_ShowsDistinctMessage()
    {
        // The relay never reached the owning site — a transient transport
        // condition, surfaced distinctly from a generic failure.
        _retryReply = new RetrySiteCallResponse(
            "q", SiteCallRelayOutcome.SiteUnreachable, Success: false, SiteReachable: false,
            ErrorMessage: "Site plant-a is offline — relay not delivered.");

        var cut = Render<SiteCallsReportPage>();
        cut.WaitForState(() => cut.Markup.Contains("ERP.GetOrder"));

        var parkedRow = cut.FindAll("tbody tr")
            .First(r => r.TextContent.Contains("ERP.GetOrder"));
        parkedRow.QuerySelectorAll("button")
            .First(b => b.TextContent.Contains("Retry"))
            .Click();

        cut.WaitForAssertion(() =>
            Assert.Contains("offline", cut.Markup));
    }

    [Fact]
    public void QueryFailure_ShowsErrorMessage()
    {
        _queryReply = new SiteCallQueryResponse(
            "q", false, "site call query backend unavailable",
            new List<SiteCallSummary>(), null, null);

        var cut = Render<SiteCallsReportPage>();

        cut.WaitForAssertion(() =>
            Assert.Contains("site call query backend unavailable", cut.Markup));
    }

    // ─────────────────────────────────────────────────────────────────────────
    // Drill-in — every row carries a "View audit history" link to
    // /audit/log?correlationId={TrackedOperationId}.
    // ─────────────────────────────────────────────────────────────────────────

    [Fact]
    public void SiteCallRow_ViewAuditHistory_Link_HasCorrectHref()
    {
        var cut = Render<SiteCallsReportPage>();

        cut.WaitForAssertion(() =>
        {
            // Both rows (Parked + Failed) surface the link — the drill-in is
            // row-scope, not status-scope.
            var parkedRow = cut.FindAll("tbody tr")
                .First(r => r.TextContent.Contains("ERP.GetOrder"));
            var link = parkedRow.QuerySelector("a[data-test^=\"audit-link-\"]");
            Assert.NotNull(link);
            Assert.Equal(
                $"/audit/log?correlationId={ParkedId}",
                link!.GetAttribute("href"));
            Assert.Contains("View audit history", link.TextContent);

            var failedRow = cut.FindAll("tbody tr")
                .First(r => r.TextContent.Contains("Historian.Write"));
            var failedLink = failedRow.QuerySelector("a[data-test^=\"audit-link-\"]");
            Assert.NotNull(failedLink);
            Assert.Equal(
                $"/audit/log?correlationId={FailedId}",
                failedLink!.GetAttribute("href"));
        });
    }

    // ─────────────────────────────────────────────────────────────────────────
    // Keyset paging — Next is driven by the response's NextAfter* cursor, not by
    // page numbers; the request echoes the cursor back to the actor.
    // ─────────────────────────────────────────────────────────────────────────

    [Fact]
    public void Paging_NextButton_HiddenWhenNoFurtherPage()
    {
        // The default reply returns 2 rows and no NextAfter* cursor — there is no
        // further page, so Next is disabled.
        var cut = Render<SiteCallsReportPage>();
        cut.WaitForState(() => cut.Markup.Contains("ERP.GetOrder"));

        var next = cut.Find("[data-test='site-calls-next']");
        Assert.True(next.HasAttribute("disabled"));
        var prev = cut.Find("[data-test='site-calls-prev']");
        Assert.True(prev.HasAttribute("disabled"));
    }

    [Fact]
    public void Paging_NextButton_AdvancesUsingKeysetCursor()
    {
        // A full page (PageSize=50 rows) plus a NextAfter* cursor: Next is live
        // and, when clicked, the follow-up query carries that cursor.
        var firstPage = new List<SiteCallSummary>();
        for (var i = 0; i < 50; i++)
        {
            firstPage.Add(new SiteCallSummary(
                Guid.NewGuid(), "plant-a", "ApiOutbound", $"ERP.Op{i}", "Delivered",
                RetryCount: 0, LastError: null, HttpStatus: 200,
                CreatedAtUtc: DateTime.UtcNow.AddMinutes(-i), UpdatedAtUtc: DateTime.UtcNow.AddMinutes(-i),
                TerminalAtUtc: DateTime.UtcNow.AddMinutes(-i), IsStuck: false));
        }

        var cursorCreated = new DateTime(2026, 5, 20, 12, 0, 0, DateTimeKind.Utc);
        var cursorId = Guid.Parse("99999999-9999-9999-9999-999999999999");
        _queryReply = new SiteCallQueryResponse(
            "q", true, null, firstPage,
            NextAfterCreatedAtUtc: cursorCreated,
            NextAfterId: cursorId);

        var cut = Render<SiteCallsReportPage>();
        cut.WaitForState(() => cut.Markup.Contains("ERP.Op0"));

        var next = cut.Find("[data-test='site-calls-next']");
        Assert.False(next.HasAttribute("disabled"));

        next.Click();

        cut.WaitForAssertion(() =>
        {
            // Two queries fired: the initial load and the Next click. The second
            // carries the keyset cursor echoed by the first response.
            Assert.Equal(2, _queryRequests.Count);
            Assert.Equal(cursorCreated, _queryRequests[1].AfterCreatedAtUtc);
            Assert.Equal(cursorId, _queryRequests[1].AfterId);
        });
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            _system.Terminate().Wait(TimeSpan.FromSeconds(5));
        }
        base.Dispose(disposing);
    }

    /// <summary>
    /// Stand-in for the Site Call Audit actor. Replies to each message type with
    /// the test's currently-scripted response.
    /// </summary>
    private sealed class ScriptedSiteCallAuditActor : ReceiveActor
    {
        public ScriptedSiteCallAuditActor(SiteCallsReportPageTests test)
        {
            Receive<SiteCallQueryRequest>(r =>
            {
                test._queryRequests.Add(r);
                Sender.Tell(test._queryReply);
            });
            Receive<RetrySiteCallRequest>(r =>
            {
                test._retryRequests.Add(r);
                Sender.Tell(test._retryReply);
            });
            Receive<DiscardSiteCallRequest>(r =>
            {
                test._discardRequests.Add(r);
                Sender.Tell(test._discardReply);
            });
        }
    }

    /// <summary>A dialog service that auto-confirms, so action paths run end-to-end.</summary>
    private sealed class AlwaysConfirmDialogService : IDialogService
    {
        public Task<bool> ConfirmAsync(string title, string message, bool danger = false)
            => Task.FromResult(true);

        public Task<string?> PromptAsync(
            string title, string label, string initialValue = "", string? placeholder = null)
            => Task.FromResult<string?>(null);
    }
}