using Akka.Actor;
using Akka.TestKit.Xunit2;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using ScadaLink.AuditLog;
using ScadaLink.AuditLog.Central;
using ScadaLink.AuditLog.Payload;

namespace ScadaLink.AuditLog.Tests.Central;

/// <summary>
/// Bundle E (M6-T9) coverage for the central-side payload-filter redactor
/// failure bridge. M5 wired the SITE bridge
/// (<c>HealthMetricsAuditRedactionFailureCounter</c>) that pushes increments
/// into the site health report; M6 mirrors that with
/// <see cref="CentralAuditRedactionFailureCounter"/> so the same payload
/// filter — when it runs on the central writer paths — surfaces failures on
/// the central <see cref="AuditCentralHealthSnapshot"/>.
/// </summary>
public class CentralAuditRedactionFailureCounterTests : TestKit
{
    [Fact]
    public void Increment_Routes_To_Snapshot()
    {
        var snapshot = new AuditCentralHealthSnapshot();
        var counter = new CentralAuditRedactionFailureCounter(snapshot);

        counter.Increment();
        counter.Increment();
        counter.Increment();

        Assert.Equal(3, snapshot.AuditRedactionFailure);
    }

    [Fact]
    public void Construction_With_Null_Snapshot_Throws()
    {
        Assert.Throws<ArgumentNullException>(
            () => new CentralAuditRedactionFailureCounter(null!));
    }

    [Fact]
    public void AddAuditLogCentralMaintenance_Replaces_IAuditRedactionFailureCounter_With_CentralImpl()
    {
        // AddAuditLog registers NoOp; AddAuditLogCentralMaintenance is the
        // override path. The replaced binding MUST resolve to the central
        // bridge — a site host that wires AddAuditLogHealthMetricsBridge
        // instead would resolve to the site bridge (covered in
        // AddAuditLogTests).
        var config = new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                ["AuditLog:SiteWriter:DatabasePath"] = ":memory:",
            })
            .Build();

        var services = new ServiceCollection();
        services.AddSingleton<ILoggerFactory, NullLoggerFactory>();
        services.AddSingleton(typeof(ILogger<>), typeof(NullLogger<>));
        // AuditCentralHealthSnapshot no longer takes a tracker dependency —
        // the tracker is constructed later by the Akka bootstrap because its
        // ctor needs an ActorSystem (not a DI-resolvable singleton). The
        // snapshot itself composes purely from primitives.
        services.AddAuditLog(config);
        services.AddAuditLogCentralMaintenance(config);
        using var provider = services.BuildServiceProvider();

        var counter = provider.GetRequiredService<IAuditRedactionFailureCounter>();

        Assert.IsType<CentralAuditRedactionFailureCounter>(counter);
    }

    [Fact]
    public void AddAuditLog_Default_IAuditRedactionFailureCounter_Is_NoOp()
    {
        // Sanity check: without AddAuditLogCentralMaintenance the default
        // remains the NoOp from M5 — the central bridge only takes effect
        // when the central-only registration runs.
        var config = new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                ["AuditLog:SiteWriter:DatabasePath"] = ":memory:",
            })
            .Build();

        var services = new ServiceCollection();
        services.AddSingleton<ILoggerFactory, NullLoggerFactory>();
        services.AddSingleton(typeof(ILogger<>), typeof(NullLogger<>));
        services.AddAuditLog(config);
        using var provider = services.BuildServiceProvider();

        var counter = provider.GetRequiredService<IAuditRedactionFailureCounter>();

        Assert.IsType<NoOpAuditRedactionFailureCounter>(counter);
    }
}