using System.Collections.Concurrent;
using System.Text.Json;
using Akka.Actor;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging.Abstractions;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
using ZB.MOM.WW.OtOpcUa.Commons.Types;
using ZB.MOM.WW.OtOpcUa.Configuration;
using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
using ZB.MOM.WW.OtOpcUa.OpcUaServer;
using ZB.MOM.WW.OtOpcUa.Runtime.OpcUa;
using ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;

namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.OpcUa;

public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
{
    /// <summary>Tests that RebuildAddressSpace with dbFactory loads artifact, composes, and applies.</summary>
    [Fact]
    public void RebuildAddressSpace_with_dbFactory_loads_artifact_composes_and_applies()
    {
        var db = NewInMemoryDbFactory();
        var sink = new RecordingSink();
        var applier = new Phase7Applier(sink, NullLogger<Phase7Applier>.Instance);

        SeedDeployment(db, equipmentIds: new[] { "eq-1", "eq-2" }, driverIds: new[] { "drv-1" });

        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
            sink: sink,
            dbFactory: db,
            applier: applier));

        actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));

        AwaitAssert(() =>
        {
            // Add path: Equipment + Driver + Alarm — but only Equipment/Alarm topology triggers
            // RebuildAddressSpace. With 2 new equipment we expect one Rebuild call.
            sink.RebuildCalls.ShouldBe(1);
        }, duration: TimeSpan.FromSeconds(2));
    }

    /// <summary>Tests that rebuild with no artifact is idempotent no-op.</summary>
    [Fact]
    public void Rebuild_with_no_artifact_is_idempotent_no_op()
    {
        var db = NewInMemoryDbFactory();
        var sink = new RecordingSink();
        var applier = new Phase7Applier(sink, NullLogger<Phase7Applier>.Instance);

        // No deployment seeded — LoadLatestArtifact returns empty blob.
        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
            sink: sink,
            dbFactory: db,
            applier: applier));

        actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
        Thread.Sleep(200);

        sink.RebuildCalls.ShouldBe(0);
    }

    /// <summary>Tests that second rebuild with same artifact is empty plan no-op.</summary>
    [Fact]
    public void Second_rebuild_with_same_artifact_is_empty_plan_no_op()
    {
        var db = NewInMemoryDbFactory();
        var sink = new RecordingSink();
        var applier = new Phase7Applier(sink, NullLogger<Phase7Applier>.Instance);
        SeedDeployment(db, equipmentIds: new[] { "eq-1" }, driverIds: Array.Empty<string>());

        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
            sink: sink, dbFactory: db, applier: applier));

        actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: TimeSpan.FromSeconds(2));

        actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));
        Thread.Sleep(200);
        // Same composition ⇒ plan IsEmpty ⇒ applier not called again.
        sink.RebuildCalls.ShouldBe(1);
    }

    /// <summary>Tests that rebuild without dbFactory falls back to raw sink rebuild.</summary>
    [Fact]
    public void Rebuild_without_dbFactory_falls_back_to_raw_sink_rebuild()
    {
        // Pre-#109 behavior: no dbFactory wired ⇒ RebuildAddressSpace calls _sink.RebuildAddressSpace
        // directly. The dev/Mac path before the full integration is bound.
        var sink = new RecordingSink();
        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(sink: sink));

        actor.Tell(new OpcUaPublishActor.RebuildAddressSpace(CorrelationId.NewId()));

        AwaitAssert(() => sink.RebuildCalls.ShouldBe(1), duration: TimeSpan.FromMilliseconds(500));
    }

    private static void SeedDeployment(
        IDbContextFactory<OtOpcUaConfigDbContext> dbFactory,
        string[] equipmentIds,
        string[] driverIds)
    {
        var artifact = JsonSerializer.SerializeToUtf8Bytes(new
        {
            Equipment = equipmentIds.Select(id => new
            {
                EquipmentId = id,
                MachineCode = id.ToUpperInvariant(),
                UnsLineId = "line-1",
                Name = id,
            }).ToArray(),
            DriverInstances = driverIds.Select(id => new
            {
                DriverInstanceId = id,
                DriverType = "Modbus",
                Enabled = true,
                DriverConfig = "{}",
            }).ToArray(),
            ScriptedAlarms = Array.Empty<object>(),
        });

        using var ctx = dbFactory.CreateDbContext();
        ctx.Deployments.Add(new Deployment
        {
            DeploymentId = Guid.NewGuid(),
            RevisionHash = new string('a', 64),
            Status = DeploymentStatus.Sealed,
            CreatedBy = "test",
            SealedAtUtc = DateTime.UtcNow,
            ArtifactBlob = artifact,
        });
        ctx.SaveChanges();
    }

    private sealed class RecordingSink : IOpcUaAddressSpaceSink
    {
        /// <summary>Gets the list of recorded sink calls.</summary>
        public ConcurrentQueue<string> Calls { get; } = new();
        /// <summary>Gets or sets the count of rebuild address space calls.</summary>
        public int RebuildCalls;
        /// <summary>Records a value write call.</summary>
        /// <param name="nodeId">The OPC UA node ID.</param>
        /// <param name="value">The value to write.</param>
        /// <param name="quality">The OPC UA quality code.</param>
        /// <param name="ts">The timestamp of the write.</param>
        public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime ts)
            => Calls.Enqueue($"WV:{nodeId}");
        /// <summary>Records an alarm state write call.</summary>
        /// <param name="alarmNodeId">The alarm node ID.</param>
        /// <param name="active">Whether the alarm is active.</param>
        /// <param name="acknowledged">Whether the alarm is acknowledged.</param>
        /// <param name="ts">The timestamp of the state change.</param>
        public void WriteAlarmState(string alarmNodeId, bool active, bool acknowledged, DateTime ts)
            => Calls.Enqueue($"WA:{alarmNodeId}");
        /// <summary>Records a folder ensure call.</summary>
        /// <param name="folderNodeId">The folder node ID.</param>
        /// <param name="parentNodeId">The parent node ID, or null if this is a root folder.</param>
        /// <param name="displayName">The display name of the folder.</param>
        public void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName)
            => Calls.Enqueue($"EF:{folderNodeId}");
        /// <summary>Records a variable ensure call.</summary>
        /// <param name="variableNodeId">The variable node ID.</param>
        /// <param name="parentFolderNodeId">The parent folder node ID, or null if this is a root variable.</param>
        /// <param name="displayName">The display name of the variable.</param>
        /// <param name="dataType">The OPC UA built-in type name.</param>
        public void EnsureVariable(string variableNodeId, string? parentFolderNodeId, string displayName, string dataType)
            => Calls.Enqueue($"EV:{variableNodeId}");
        /// <summary>Records a rebuild address space call.</summary>
        public void RebuildAddressSpace() => Interlocked.Increment(ref RebuildCalls);
    }
}