using Akka.Configuration;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
using ScadaLink.AuditLog;
using ScadaLink.AuditLog.Site;
using ScadaLink.AuditLog.Site.Telemetry;
using ScadaLink.ClusterInfrastructure;
using ScadaLink.Commons.Interfaces.Services;
using ScadaLink.ConfigurationDatabase;
using ScadaLink.Host;
using ScadaLink.Host.Actors;

namespace ScadaLink.Host.Tests;

/// <summary>
/// Bundle E (M2 Task E1) — verifies the Audit Log (#23) DI surface is wired
/// into both composition roots and that the HOCON document emitted by
/// <see cref="AkkaHostedService.BuildHocon"/> includes the dedicated
/// <c>audit-telemetry-dispatcher</c> the site telemetry actor binds to.
/// </summary>
/// <remarks>
/// <para>
/// Full cluster bring-up is exercised by the existing
/// <see cref="CompositionRootTests"/> pattern — these tests reuse the same
/// <see cref="AkkaHostedServiceRemover"/> trick to short-circuit
/// <see cref="AkkaHostedService.StartAsync"/> so DI resolution is exercised
/// without the actor system actually being created.
/// </para>
/// </remarks>
public class AkkaHostedServiceAuditWiringHoconTests
{
    [Fact]
    public void BuildHocon_Emits_AuditTelemetryDispatcher_Block()
    {
        // Bundle E acceptance: the HOCON document the host parses must declare
        // the dedicated dispatcher the SiteAuditTelemetryActor binds to. A
        // missing dispatcher block would route the actor to the default
        // dispatcher and silently lose the isolation guarantee.
        var nodeOptions = new NodeOptions
        {
            Role = "Site",
            NodeHostname = "site-test-1",
            RemotingPort = 0,
            SiteId = "TestSite",
        };
        var clusterOptions = new ClusterOptions
        {
            SeedNodes = new List<string> { "akka.tcp://scadalink@localhost:2551" },
            SplitBrainResolverStrategy = "keep-oldest",
            MinNrOfMembers = 1,
            StableAfter = TimeSpan.FromSeconds(15),
            HeartbeatInterval = TimeSpan.FromSeconds(2),
            FailureDetectionThreshold = TimeSpan.FromSeconds(10),
        };

        var hocon = AkkaHostedService.BuildHocon(
            nodeOptions,
            clusterOptions,
            new[] { "Site", "site-TestSite" },
            TimeSpan.FromSeconds(5),
            TimeSpan.FromSeconds(15));

        var config = ConfigurationFactory.ParseString(hocon);

        // The dispatcher is declared at the root, so the lookup is by its
        // unqualified name. The HOCON parser must accept the block as a
        // standalone dispatcher definition the actor system can resolve.
        var dispatcherType = config.GetString("audit-telemetry-dispatcher.type");
        Assert.Equal("ForkJoinDispatcher", dispatcherType);

        var throughput = config.GetInt("audit-telemetry-dispatcher.throughput");
        Assert.Equal(100, throughput);

        var threadCount = config.GetInt("audit-telemetry-dispatcher.dedicated-thread-pool.thread-count");
        Assert.Equal(2, threadCount);
    }
}

/// <summary>
/// Verifies Audit Log (#23) services land in the Central composition root.
/// </summary>
public class CentralAuditWiringTests : IDisposable
{
    private readonly WebApplicationFactory<Program> _factory;
    private readonly string? _previousEnv;

    public CentralAuditWiringTests()
    {
        _previousEnv = Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT");
        Environment.SetEnvironmentVariable("DOTNET_ENVIRONMENT", "Central");

        _factory = new WebApplicationFactory<Program>()
            .WithWebHostBuilder(builder =>
            {
                builder.ConfigureAppConfiguration((_, config) =>
                {
                    config.AddInMemoryCollection(new Dictionary<string, string?>
                    {
                        ["ScadaLink:Node:NodeHostname"] = "localhost",
                        ["ScadaLink:Node:RemotingPort"] = "0",
                        ["ScadaLink:Cluster:SeedNodes:0"] = "akka.tcp://scadalink@localhost:2551",
                        ["ScadaLink:Cluster:SeedNodes:1"] = "akka.tcp://scadalink@localhost:2552",
                        ["ScadaLink:Database:SkipMigrations"] = "true",
                        ["ScadaLink:Security:JwtSigningKey"] = "test-signing-key-must-be-at-least-32-chars-long!",
                        ["ScadaLink:Security:LdapServer"] = "localhost",
                        ["ScadaLink:Security:LdapPort"] = "3893",
                        ["ScadaLink:Security:LdapUseTls"] = "false",
                        ["ScadaLink:Security:AllowInsecureLdap"] = "true",
                        ["ScadaLink:Security:LdapSearchBase"] = "dc=scadalink,dc=local",
                        ["ScadaLink:InboundApi:ApiKeyPepper"] = "test-inbound-api-key-pepper-at-least-32-chars!",
                    });
                });
                builder.UseSetting("ScadaLink:Node:Role", "Central");
                builder.UseSetting("ScadaLink:Database:SkipMigrations", "true");
                builder.ConfigureServices(services =>
                {
                    var descriptorsToRemove = services
                        .Where(d =>
                            d.ServiceType == typeof(DbContextOptions<ScadaLinkDbContext>) ||
                            d.ServiceType == typeof(DbContextOptions) ||
                            d.ServiceType == typeof(ScadaLinkDbContext) ||
                            d.ServiceType.FullName?.Contains("EntityFrameworkCore") == true)
                        .ToList();
                    foreach (var d in descriptorsToRemove)
                        services.Remove(d);

                    services.AddDbContext<ScadaLinkDbContext>(options =>
                        options.UseInMemoryDatabase($"CentralAuditWiringTests_{Guid.NewGuid()}"));

                    AkkaHostedServiceRemover.RemoveAkkaHostedServiceOnly(services);
                });
            });

        _ = _factory.Server;
    }

    public void Dispose()
    {
        _factory.Dispose();
        Environment.SetEnvironmentVariable("DOTNET_ENVIRONMENT", _previousEnv);
    }

    [Fact]
    public void Central_Resolves_IAuditWriter_AsFallbackAuditWriter()
    {
        // Central nodes still register the writer chain because AddAuditLog is
        // shared between roles — the registrations are lazy singletons and the
        // writer is never resolved on a central node in production. Asserting
        // it resolves here confirms the chain is intact and ready for the
        // future case where a central-only actor needs to emit audit events.
        var writer = _factory.Services.GetService<IAuditWriter>();
        Assert.NotNull(writer);
        Assert.IsType<FallbackAuditWriter>(writer);
    }

    [Fact]
    public void Central_Resolves_AuditLogOptions()
    {
        var opts = _factory.Services.GetService<IOptions<ScadaLink.AuditLog.Configuration.AuditLogOptions>>();
        Assert.NotNull(opts);
        Assert.NotNull(opts!.Value);
    }

    [Fact]
    public void Central_Resolves_SqliteAuditWriterOptions()
    {
        var opts = _factory.Services.GetService<IOptions<SqliteAuditWriterOptions>>();
        Assert.NotNull(opts);
        Assert.NotNull(opts!.Value);
    }

    [Fact]
    public void Central_Resolves_SiteAuditTelemetryOptions()
    {
        var opts = _factory.Services.GetService<IOptions<SiteAuditTelemetryOptions>>();
        Assert.NotNull(opts);
        Assert.NotNull(opts!.Value);
    }

    [Fact]
    public void Central_Resolves_ISiteStreamAuditClient_AsNoOpDefault()
    {
        var client = _factory.Services.GetService<ISiteStreamAuditClient>();
        Assert.NotNull(client);
        Assert.IsType<NoOpSiteStreamAuditClient>(client);
    }
}

/// <summary>
/// Verifies Audit Log (#23) services land in the Site composition root.
/// </summary>
public class SiteAuditWiringTests : IDisposable
{
    private readonly WebApplication _host;
    private readonly string _tempDbPath;

    public SiteAuditWiringTests()
    {
        _tempDbPath = Path.Combine(Path.GetTempPath(), $"scadalink_audit_wiring_{Guid.NewGuid()}.db");

        var builder = WebApplication.CreateBuilder();
        builder.Configuration.Sources.Clear();
        builder.Configuration.AddInMemoryCollection(new Dictionary<string, string?>
        {
            ["ScadaLink:Node:Role"] = "Site",
            ["ScadaLink:Node:NodeHostname"] = "test-site",
            ["ScadaLink:Node:SiteId"] = "TestSite",
            ["ScadaLink:Node:RemotingPort"] = "0",
            ["ScadaLink:Node:GrpcPort"] = "0",
            ["ScadaLink:Database:SiteDbPath"] = _tempDbPath,
            ["ScadaLink:Cluster:SeedNodes:0"] = "akka.tcp://scadalink@localhost:2551",
            ["ScadaLink:Cluster:SeedNodes:1"] = "akka.tcp://scadalink@localhost:2552",
            // SqliteAuditWriter would attempt to open a SQLite file when first
            // resolved; point it at an in-memory connection so the test doesn't
            // pollute the working directory.
            ["AuditLog:SiteWriter:DatabasePath"] = ":memory:",
        });

        builder.Services.AddGrpc();
        builder.Services.AddSingleton<ScadaLink.Communication.Grpc.SiteStreamGrpcServer>();
        SiteServiceRegistration.Configure(builder.Services, builder.Configuration);
        AkkaHostedServiceRemover.RemoveAkkaHostedServiceOnly(builder.Services);

        _host = builder.Build();
    }

    public void Dispose()
    {
        (_host as IDisposable)?.Dispose();
        try { File.Delete(_tempDbPath); } catch { /* best effort */ }
    }

    [Fact]
    public void Site_Resolves_IAuditWriter_AsFallbackAuditWriter()
    {
        var writer = _host.Services.GetService<IAuditWriter>();
        Assert.NotNull(writer);
        Assert.IsType<FallbackAuditWriter>(writer);
    }

    [Fact]
    public void Site_Resolves_SqliteAuditWriter_AsSingleton()
    {
        var a = _host.Services.GetService<SqliteAuditWriter>();
        var b = _host.Services.GetService<SqliteAuditWriter>();
        Assert.NotNull(a);
        Assert.NotNull(b);
        Assert.Same(a, b);
    }

    [Fact]
    public void Site_ISiteAuditQueue_AndSqliteAuditWriter_AreSameInstance()
    {
        // The telemetry actor reads from ISiteAuditQueue while ScriptRuntimeContext
        // writes through IAuditWriter → SqliteAuditWriter. If these don't resolve
        // to the same instance, pending rows are invisible to the actor.
        var queue = _host.Services.GetService<ISiteAuditQueue>();
        var writer = _host.Services.GetService<SqliteAuditWriter>();
        Assert.NotNull(queue);
        Assert.NotNull(writer);
        Assert.Same(writer, queue);
    }

    [Fact]
    public void Site_Resolves_RingBufferFallback()
    {
        var ring = _host.Services.GetService<RingBufferFallback>();
        Assert.NotNull(ring);
    }

    [Fact]
    public void Site_Resolves_IAuditWriteFailureCounter_AsNoOpDefault()
    {
        var counter = _host.Services.GetService<IAuditWriteFailureCounter>();
        Assert.NotNull(counter);
        Assert.IsType<NoOpAuditWriteFailureCounter>(counter);
    }

    [Fact]
    public void Site_Resolves_ISiteStreamAuditClient_AsNoOpDefault()
    {
        var client = _host.Services.GetService<ISiteStreamAuditClient>();
        Assert.NotNull(client);
        Assert.IsType<NoOpSiteStreamAuditClient>(client);
    }

    [Fact]
    public void Site_Resolves_SiteAuditTelemetryOptions_WithDefaults()
    {
        var opts = _host.Services.GetService<IOptions<SiteAuditTelemetryOptions>>();
        Assert.NotNull(opts);
        Assert.Equal(256, opts!.Value.BatchSize);
        Assert.Equal(5, opts.Value.BusyIntervalSeconds);
        Assert.Equal(30, opts.Value.IdleIntervalSeconds);
    }
}