using Microsoft.Extensions.Logging.Abstractions;
using Opc.Ua;
using Opc.Ua.Client;
using Opc.Ua.Configuration;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Core.Hosting;
using ZB.MOM.WW.OtOpcUa.Server.OpcUa;
using ZB.MOM.WW.OtOpcUa.Server.Security;
// Core.Abstractions.HistoryReadResult (driver-side samples) collides with Opc.Ua.HistoryReadResult
// (service-layer per-node result). Alias the driver type so the stub's interface implementations
// are unambiguous.
using DriverHistoryReadResult = ZB.MOM.WW.OtOpcUa.Core.Abstractions.HistoryReadResult;

namespace ZB.MOM.WW.OtOpcUa.Server.Tests;

/// <summary>
///     End-to-end test that a real OPC UA client's HistoryRead service reaches a fake driver's
///     <see cref="IHistoryProvider"/> via <see cref="DriverNodeManager"/>'s
///     <c>HistoryReadRawModified</c> / <c>HistoryReadProcessed</c> / <c>HistoryReadAtTime</c> /
///     <c>HistoryReadEvents</c> overrides. Boots the full OPC UA stack + a stub
///     <see cref="IHistoryProvider"/> driver, opens a client session, issues each HistoryRead
///     variant, and asserts the client receives the expected per-kind payload.
/// </summary>
[Trait("Category", "Integration")]
public sealed class HistoryReadIntegrationTests : IAsyncLifetime
{
    private static readonly int Port = 48600 + Random.Shared.Next(0, 99);
    private readonly string _endpoint = $"opc.tcp://localhost:{Port}/OtOpcUaHistoryTest";
    private readonly string _pkiRoot = Path.Combine(Path.GetTempPath(), $"otopcua-history-test-{Guid.NewGuid():N}");

    private DriverHost _driverHost = null!;
    private OpcUaApplicationHost _server = null!;
    private HistoryDriver _driver = null!;

    public async ValueTask InitializeAsync()
    {
        _driverHost = new DriverHost();
        _driver = new HistoryDriver();
        await _driverHost.RegisterAsync(_driver, "{}", CancellationToken.None);

        var options = new OpcUaServerOptions
        {
            EndpointUrl = _endpoint,
            ApplicationName = "OtOpcUaHistoryTest",
            ApplicationUri = "urn:OtOpcUa:Server:HistoryTest",
            PkiStoreRoot = _pkiRoot,
            AutoAcceptUntrustedClientCertificates = true, HealthEndpointsEnabled = false,
        };

        _server = new OpcUaApplicationHost(options, _driverHost, new DenyAllUserAuthenticator(),
            NullLoggerFactory.Instance, NullLogger<OpcUaApplicationHost>.Instance);
        await _server.StartAsync(CancellationToken.None);
    }

    public async ValueTask DisposeAsync()
    {
        await _server.DisposeAsync();
        await _driverHost.DisposeAsync();
        try { Directory.Delete(_pkiRoot, recursive: true); } catch { /* best-effort */ }
    }

    [Fact]
    public async Task HistoryReadRaw_round_trips_driver_samples_to_the_client()
    {
        using var session = await OpenSessionAsync();
        var nsIndex = (ushort)session.NamespaceUris.GetIndex("urn:OtOpcUa:history-driver");
        var nodeId = new NodeId("raw.var", nsIndex);

        // The Opc.Ua client exposes HistoryRead via Session.HistoryRead. We construct a
        // ReadRawModifiedDetails (IsReadModified=false → raw path) and a single
        // HistoryReadValueId targeting the driver-backed variable.
        var details = new ReadRawModifiedDetails
        {
            StartTime = new DateTime(2024, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            EndTime = new DateTime(2024, 1, 1, 0, 0, 10, DateTimeKind.Utc),
            NumValuesPerNode = 100,
            IsReadModified = false,
            ReturnBounds = false,
        };
        var extObj = new ExtensionObject(details);
        var nodesToRead = new HistoryReadValueIdCollection { new() { NodeId = nodeId } };

        session.HistoryRead(null, extObj, TimestampsToReturn.Both, false, nodesToRead,
            out var results, out _);

        results.Count.ShouldBe(1);
        results[0].StatusCode.Code.ShouldBe(StatusCodes.Good, $"HistoryReadRaw returned {results[0].StatusCode}");
        var hd = (HistoryData)ExtensionObject.ToEncodeable(results[0].HistoryData);
        hd.DataValues.Count.ShouldBe(_driver.RawSamplesReturned, "one DataValue per driver sample");
        hd.DataValues[0].Value.ShouldBe(_driver.FirstRawValue);
    }

    [Fact]
    public async Task HistoryReadProcessed_maps_Average_aggregate_and_routes_to_ReadProcessedAsync()
    {
        using var session = await OpenSessionAsync();
        var nsIndex = (ushort)session.NamespaceUris.GetIndex("urn:OtOpcUa:history-driver");
        var nodeId = new NodeId("proc.var", nsIndex);

        var details = new ReadProcessedDetails
        {
            StartTime = new DateTime(2024, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            EndTime = new DateTime(2024, 1, 1, 0, 1, 0, DateTimeKind.Utc),
            ProcessingInterval = 10_000, // 10s buckets
            AggregateType = [ObjectIds.AggregateFunction_Average],
        };
        var extObj = new ExtensionObject(details);
        var nodesToRead = new HistoryReadValueIdCollection { new() { NodeId = nodeId } };

        session.HistoryRead(null, extObj, TimestampsToReturn.Both, false, nodesToRead,
            out var results, out _);

        results[0].StatusCode.Code.ShouldBe(StatusCodes.Good);
        _driver.LastProcessedAggregate.ShouldBe(HistoryAggregateType.Average,
            "MapAggregate must translate ObjectIds.AggregateFunction_Average → driver enum");
        _driver.LastProcessedInterval.ShouldBe(TimeSpan.FromSeconds(10));
    }

    [Fact]
    public async Task HistoryReadProcessed_returns_BadAggregateNotSupported_for_unmapped_aggregate()
    {
        using var session = await OpenSessionAsync();
        var nsIndex = (ushort)session.NamespaceUris.GetIndex("urn:OtOpcUa:history-driver");
        var nodeId = new NodeId("proc.var", nsIndex);

        var details = new ReadProcessedDetails
        {
            StartTime = new DateTime(2024, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            EndTime = new DateTime(2024, 1, 1, 0, 1, 0, DateTimeKind.Utc),
            ProcessingInterval = 10_000,
            // TimeAverage is a valid OPC UA aggregate NodeId but not one the driver implements —
            // the override returns BadAggregateNotSupported per Part 13 rather than coercing.
            AggregateType = [ObjectIds.AggregateFunction_TimeAverage],
        };
        var extObj = new ExtensionObject(details);
        var nodesToRead = new HistoryReadValueIdCollection { new() { NodeId = nodeId } };

        session.HistoryRead(null, extObj, TimestampsToReturn.Both, false, nodesToRead,
            out var results, out _);

        results[0].StatusCode.Code.ShouldBe(StatusCodes.BadAggregateNotSupported);
    }

    [Fact]
    public async Task HistoryReadAtTime_forwards_timestamp_list_to_driver()
    {
        using var session = await OpenSessionAsync();
        var nsIndex = (ushort)session.NamespaceUris.GetIndex("urn:OtOpcUa:history-driver");
        var nodeId = new NodeId("atTime.var", nsIndex);

        var t1 = new DateTime(2024, 3, 1, 10, 0, 0, DateTimeKind.Utc);
        var t2 = new DateTime(2024, 3, 1, 10, 0, 30, DateTimeKind.Utc);
        var details = new ReadAtTimeDetails { ReqTimes = new DateTimeCollection { t1, t2 } };
        var extObj = new ExtensionObject(details);
        var nodesToRead = new HistoryReadValueIdCollection { new() { NodeId = nodeId } };

        session.HistoryRead(null, extObj, TimestampsToReturn.Both, false, nodesToRead,
            out var results, out _);

        results[0].StatusCode.Code.ShouldBe(StatusCodes.Good);
        _driver.LastAtTimeRequestedTimes.ShouldNotBeNull();
        _driver.LastAtTimeRequestedTimes!.Count.ShouldBe(2);
        _driver.LastAtTimeRequestedTimes[0].ShouldBe(t1);
        _driver.LastAtTimeRequestedTimes[1].ShouldBe(t2);
    }

    [Fact]
    public async Task HistoryReadEvents_returns_HistoryEvent_with_BaseEventType_field_list()
    {
        using var session = await OpenSessionAsync();
        // Events target the driver-root notifier (not a specific variable) which is the
        // conventional pattern for alarm-history browse.
        var nsIndex = (ushort)session.NamespaceUris.GetIndex("urn:OtOpcUa:history-driver");
        var nodeId = new NodeId("history-driver", nsIndex);

        // EventFilter must carry at least one SelectClause or the stack rejects it as
        // BadEventFilterInvalid before our override runs — empty filters are spec-forbidden.
        // We populate the standard BaseEventType selectors any real client would send; my
        // override's BuildHistoryEvent ignores the specific clauses and emits the canonical
        // field list anyway (the richer "respect exact SelectClauses" behavior is on the PR 38
        // follow-up list).
        var filter = new EventFilter();
        filter.AddSelectClause(ObjectTypeIds.BaseEventType, BrowseNames.EventId);
        filter.AddSelectClause(ObjectTypeIds.BaseEventType, BrowseNames.SourceName);
        filter.AddSelectClause(ObjectTypeIds.BaseEventType, BrowseNames.Message);
        filter.AddSelectClause(ObjectTypeIds.BaseEventType, BrowseNames.Severity);
        filter.AddSelectClause(ObjectTypeIds.BaseEventType, BrowseNames.Time);
        filter.AddSelectClause(ObjectTypeIds.BaseEventType, BrowseNames.ReceiveTime);

        var details = new ReadEventDetails
        {
            StartTime = new DateTime(2024, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            EndTime = new DateTime(2024, 12, 31, 0, 0, 0, DateTimeKind.Utc),
            NumValuesPerNode = 10,
            Filter = filter,
        };
        var extObj = new ExtensionObject(details);
        var nodesToRead = new HistoryReadValueIdCollection { new() { NodeId = nodeId } };

        session.HistoryRead(null, extObj, TimestampsToReturn.Both, false, nodesToRead,
            out var results, out _);

        results[0].StatusCode.Code.ShouldBe(StatusCodes.Good);
        var he = (HistoryEvent)ExtensionObject.ToEncodeable(results[0].HistoryData);
        he.Events.Count.ShouldBe(_driver.EventsReturned);
        he.Events[0].EventFields.Count.ShouldBe(6, "BaseEventType default field layout is 6 entries");
    }

    private async Task<ISession> OpenSessionAsync()
    {
        var cfg = new ApplicationConfiguration
        {
            ApplicationName = "OtOpcUaHistoryTestClient",
            ApplicationUri = "urn:OtOpcUa:HistoryTestClient",
            ApplicationType = ApplicationType.Client,
            SecurityConfiguration = new SecurityConfiguration
            {
                ApplicationCertificate = new CertificateIdentifier
                {
                    StoreType = CertificateStoreType.Directory,
                    StorePath = Path.Combine(_pkiRoot, "client-own"),
                    SubjectName = "CN=OtOpcUaHistoryTestClient",
                },
                TrustedIssuerCertificates = new CertificateTrustList { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(_pkiRoot, "client-issuers") },
                TrustedPeerCertificates = new CertificateTrustList { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(_pkiRoot, "client-trusted") },
                RejectedCertificateStore = new CertificateTrustList { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(_pkiRoot, "client-rejected") },
                AutoAcceptUntrustedCertificates = true,
                AddAppCertToTrustedStore = true,
            },
            TransportConfigurations = new TransportConfigurationCollection(),
            TransportQuotas = new TransportQuotas { OperationTimeout = 15000 },
            ClientConfiguration = new ClientConfiguration { DefaultSessionTimeout = 60000 },
        };
        await cfg.Validate(ApplicationType.Client);
        cfg.CertificateValidator.CertificateValidation += (_, e) => e.Accept = true;

        var instance = new ApplicationInstance { ApplicationConfiguration = cfg, ApplicationType = ApplicationType.Client };
        await instance.CheckApplicationInstanceCertificate(true, CertificateFactory.DefaultKeySize);

        var selected = CoreClientUtils.SelectEndpoint(cfg, _endpoint, useSecurity: false);
        var endpointConfig = EndpointConfiguration.Create(cfg);
        var configuredEndpoint = new ConfiguredEndpoint(null, selected, endpointConfig);

        return await Session.Create(cfg, configuredEndpoint, false, "OtOpcUaHistoryTestClientSession", 60000,
            new UserIdentity(new AnonymousIdentityToken()), null);
    }

    /// <summary>
    ///     Stub driver that implements <see cref="IHistoryProvider"/> so the service dispatch
    ///     can be verified without bringing up a real Galaxy or Historian. Captures the last-
    ///     seen arguments so tests can assert what the service handler forwarded.
    /// </summary>
    private sealed class HistoryDriver : IDriver, ITagDiscovery, IReadable, IHistoryProvider
    {
        public string DriverInstanceId => "history-driver";
        public string DriverType => "HistoryStub";

        public int RawSamplesReturned => 3;
        public int FirstRawValue => 100;
        public int EventsReturned => 2;

        public HistoryAggregateType? LastProcessedAggregate { get; private set; }
        public TimeSpan? LastProcessedInterval { get; private set; }
        public IReadOnlyList<DateTime>? LastAtTimeRequestedTimes { get; private set; }

        public Task InitializeAsync(string driverConfigJson, CancellationToken ct) => Task.CompletedTask;
        public Task ReinitializeAsync(string driverConfigJson, CancellationToken ct) => Task.CompletedTask;
        public Task ShutdownAsync(CancellationToken ct) => Task.CompletedTask;
        public DriverHealth GetHealth() => new(DriverState.Healthy, DateTime.UtcNow, null);
        public long GetMemoryFootprint() => 0;
        public Task FlushOptionalCachesAsync(CancellationToken ct) => Task.CompletedTask;

        public Task DiscoverAsync(IAddressSpaceBuilder builder, CancellationToken ct)
        {
            // Every variable must be Historized for HistoryRead to route — the node-manager's
            // stack base class checks the bit before dispatching.
            builder.Variable("raw", "raw",
                new DriverAttributeInfo("raw.var", DriverDataType.Int32, false, null,
                    SecurityClassification.FreeAccess, IsHistorized: true, IsAlarm: false));
            builder.Variable("proc", "proc",
                new DriverAttributeInfo("proc.var", DriverDataType.Float64, false, null,
                    SecurityClassification.FreeAccess, IsHistorized: true, IsAlarm: false));
            builder.Variable("atTime", "atTime",
                new DriverAttributeInfo("atTime.var", DriverDataType.Int32, false, null,
                    SecurityClassification.FreeAccess, IsHistorized: true, IsAlarm: false));
            return Task.CompletedTask;
        }

        public Task<IReadOnlyList<DataValueSnapshot>> ReadAsync(
            IReadOnlyList<string> fullReferences, CancellationToken cancellationToken)
        {
            var now = DateTime.UtcNow;
            IReadOnlyList<DataValueSnapshot> r =
                [.. fullReferences.Select(_ => new DataValueSnapshot(0, 0u, now, now))];
            return Task.FromResult(r);
        }

        public Task<DriverHistoryReadResult> ReadRawAsync(
            string fullReference, DateTime startUtc, DateTime endUtc, uint maxValuesPerNode,
            CancellationToken cancellationToken)
        {
            var samples = new List<DataValueSnapshot>();
            for (var i = 0; i < RawSamplesReturned; i++)
            {
                samples.Add(new DataValueSnapshot(
                    Value: FirstRawValue + i,
                    StatusCode: StatusCodes.Good,
                    SourceTimestampUtc: startUtc.AddSeconds(i),
                    ServerTimestampUtc: startUtc.AddSeconds(i)));
            }
            return Task.FromResult(new DriverHistoryReadResult(samples, null));
        }

        public Task<DriverHistoryReadResult> ReadProcessedAsync(
            string fullReference, DateTime startUtc, DateTime endUtc, TimeSpan interval,
            HistoryAggregateType aggregate, CancellationToken cancellationToken)
        {
            LastProcessedAggregate = aggregate;
            LastProcessedInterval = interval;
            return Task.FromResult(new DriverHistoryReadResult(
                [new DataValueSnapshot(1.0, StatusCodes.Good, startUtc, startUtc)],
                null));
        }

        public Task<DriverHistoryReadResult> ReadAtTimeAsync(
            string fullReference, IReadOnlyList<DateTime> timestampsUtc,
            CancellationToken cancellationToken)
        {
            LastAtTimeRequestedTimes = timestampsUtc;
            var samples = timestampsUtc
                .Select(t => new DataValueSnapshot(42, StatusCodes.Good, t, t))
                .ToArray();
            return Task.FromResult(new DriverHistoryReadResult(samples, null));
        }

        public Task<HistoricalEventsResult> ReadEventsAsync(
            string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents,
            CancellationToken cancellationToken)
        {
            var events = new List<HistoricalEvent>();
            for (var i = 0; i < EventsReturned; i++)
            {
                events.Add(new HistoricalEvent(
                    EventId: $"e{i}",
                    SourceName: sourceName,
                    EventTimeUtc: startUtc.AddHours(i),
                    ReceivedTimeUtc: startUtc.AddHours(i).AddSeconds(1),
                    Message: $"Event {i}",
                    Severity: (ushort)(500 + i)));
            }
            return Task.FromResult(new HistoricalEventsResult(events, null));
        }
    }
}