using Opc.Ua;
using Serilog;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Core.AlarmHistorian;
using ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms;
using ZB.MOM.WW.OtOpcUa.Core.Scripting;
using ZB.MOM.WW.OtOpcUa.Server.OpcUa;
using ZB.MOM.WW.OtOpcUa.Server.Phase7;

namespace ZB.MOM.WW.OtOpcUa.Server.Tests.Phase7;

/// <summary>
///     Regression for Server-008 — <c>RouteScriptedAlarmMethodCalls</c> must mark a handled
///     <see cref="CallMethodRequest"/> slot as <c>Processed = true</c> so the stack's
///     <c>CustomNodeManager2.Call</c> skips it. The pre-fix code relied on the slot's
///     <c>errors[i]</c> being <c>ServiceResult.Good</c>, but the SDK's actual skip predicate is
///     <see cref="CallMethodRequest.Processed"/>; without setting it, the stack's built-in
///     Part 9 Acknowledge / Confirm handler would also fire, producing a double transition.
/// </summary>
[Trait("Category", "Unit")]
public sealed class ScriptedAlarmMethodRoutingProcessedFlagTests
{
    private static ScriptedAlarmEngine BuildActiveEngine(string alarmId)
    {
        var upstream = new CachedTagUpstreamSource();
        var logger = new LoggerConfiguration().CreateLogger();
        var factory = new ScriptLoggerFactory(logger);
        var engine = new ScriptedAlarmEngine(upstream, new InMemoryAlarmStateStore(), factory, logger);
        var defs = new List<ScriptedAlarmDefinition>
        {
            new(AlarmId: alarmId,
                EquipmentPath: "/eq",
                AlarmName: alarmId,
                Kind: AlarmKind.LimitAlarm,
                Severity: AlarmSeverity.Medium,
                MessageTemplate: "msg",
                PredicateScriptSource: "return true;"),
        };
        engine.LoadAsync(defs, CancellationToken.None).GetAwaiter().GetResult();
        return engine;
    }

    private static ScriptedAlarmEngine BuildEngine(string alarmId)
    {
        var upstream = new CachedTagUpstreamSource();
        var logger = new LoggerConfiguration().CreateLogger();
        var factory = new ScriptLoggerFactory(logger);
        var engine = new ScriptedAlarmEngine(upstream, new InMemoryAlarmStateStore(), factory, logger);
        var defs = new List<ScriptedAlarmDefinition>
        {
            new(AlarmId: alarmId,
                EquipmentPath: "/eq",
                AlarmName: alarmId,
                Kind: AlarmKind.LimitAlarm,
                Severity: AlarmSeverity.Medium,
                MessageTemplate: "msg",
                PredicateScriptSource: "return false;"),
        };
        engine.LoadAsync(defs, CancellationToken.None).GetAwaiter().GetResult();
        return engine;
    }

    private static CallMethodRequest AcknowledgeRequest(string conditionNodeId)
        => new()
        {
            ObjectId = new NodeId(conditionNodeId, 2),
            MethodId = MethodIds.AcknowledgeableConditionType_Acknowledge,
            InputArguments =
            {
                new Variant(new byte[] { 1, 2, 3 }),
                new Variant(new LocalizedText("ack-comment")),
            },
        };

    private static CallMethodRequest AddCommentRequest(string conditionNodeId)
        => new()
        {
            ObjectId = new NodeId(conditionNodeId, 2),
            MethodId = MethodIds.ConditionType_AddComment,
            InputArguments =
            {
                new Variant(new byte[] { 1, 2, 3 }),
                new Variant(new LocalizedText("comment-text")),
            },
        };

    [Fact]
    public void Handled_Acknowledge_marks_Processed_true_so_baseCall_skips_the_slot()
    {
        using var engine = BuildActiveEngine("al-1");
        var calls = new List<CallMethodRequest> { AcknowledgeRequest("al-1.Condition") };
        var results = new List<CallMethodResult> { new CallMethodResult() };
        var errors = new List<ServiceResult> { null! };
        var index = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
        {
            ["al-1.Condition"] = "al-1",
        };

        DriverNodeManager.RouteScriptedAlarmMethodCalls(
            new NamedIdentity("ops-user"), calls, results, errors, engine, index);

        calls[0].Processed.ShouldBeTrue(
            "CustomNodeManager2.Call/CallInternalAsync skips slots with Processed=true. "
            + "Without this flag, base.Call would re-dispatch the Acknowledge to the stack's "
            + "built-in Part 9 handler and the engine would observe a double transition.");
    }

    [Fact]
    public void Handled_AddComment_marks_Processed_true()
    {
        using var engine = BuildEngine("al-1");
        var calls = new List<CallMethodRequest> { AddCommentRequest("al-1.Condition") };
        var results = new List<CallMethodResult> { new CallMethodResult() };
        var errors = new List<ServiceResult> { null! };
        var index = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
        {
            ["al-1.Condition"] = "al-1",
        };

        DriverNodeManager.RouteScriptedAlarmMethodCalls(
            new NamedIdentity("ops-user"), calls, results, errors, engine, index);

        calls[0].Processed.ShouldBeTrue("AddComment handled by the engine must not re-dispatch via base.Call");
    }

    [Fact]
    public void Engine_error_path_also_marks_Processed_so_baseCall_does_not_re_run_the_method()
    {
        using var engine = BuildEngine("al-1");
        var calls = new List<CallMethodRequest>
        {
            // Index maps to an alarm id the engine doesn't know — engine throws
            // ArgumentException, helper sets errors[i] = BadInvalidArgument.
            AcknowledgeRequest("al-1.Condition"),
        };
        var results = new List<CallMethodResult> { new CallMethodResult() };
        var errors = new List<ServiceResult> { null! };
        var index = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
        {
            ["al-1.Condition"] = "al-NOT-IN-ENGINE",
        };

        DriverNodeManager.RouteScriptedAlarmMethodCalls(
            new NamedIdentity("ops-user"), calls, results, errors, engine, index);

        ServiceResult.IsBad(errors[0]).ShouldBeTrue("engine error path");
        calls[0].Processed.ShouldBeTrue(
            "even when the engine returns Bad, the slot was handled — base.Call must not "
            + "re-dispatch the method against the OPC UA built-in handler.");
    }

    [Fact]
    public void Unhandled_slot_leaves_Processed_false_so_baseCall_drives_it()
    {
        using var engine = BuildActiveEngine("al-1");
        var genericMethod = new CallMethodRequest
        {
            ObjectId = new NodeId("some-driver-method", 2),
            MethodId = new NodeId("driver-method", 2),
        };
        var calls = new List<CallMethodRequest> { genericMethod };
        var results = new List<CallMethodResult> { new CallMethodResult() };
        var errors = new List<ServiceResult> { null! };

        DriverNodeManager.RouteScriptedAlarmMethodCalls(
            new NamedIdentity("ops-user"), calls, results, errors, engine,
            conditionIdToAlarmId: new Dictionary<string, string>());

        calls[0].Processed.ShouldBeFalse("non-alarm methods must fall through to base.Call");
        errors[0].ShouldBeNull("unhandled slot's error must stay null for the base implementation");
    }

    private sealed class NamedIdentity(string displayName) : UserIdentity(displayName, "") { }
}