using Opc.Ua;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Core.Authorization;
using ZB.MOM.WW.OtOpcUa.Server.OpcUa;
using ZB.MOM.WW.OtOpcUa.Server.Security;

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

/// <summary>
///     Unit tests for <see cref="DriverNodeManager.GateCallMethodRequests"/> and
///     <see cref="DriverNodeManager.MapCallOperation"/> — Phase 6.2 Stream C method-Call
///     gating covering the Part 9 alarm Acknowledge / Confirm methods plus generic
///     driver-exposed method nodes.
/// </summary>
[Trait("Category", "Unit")]
public sealed class CallGatingTests
{
    [Fact]
    public void MapCallOperation_Acknowledge_maps_to_AlarmAcknowledge()
    {
        DriverNodeManager.MapCallOperation(MethodIds.AcknowledgeableConditionType_Acknowledge)
            .ShouldBe(OpcUaOperation.AlarmAcknowledge);
    }

    [Fact]
    public void MapCallOperation_Confirm_maps_to_AlarmConfirm()
    {
        DriverNodeManager.MapCallOperation(MethodIds.AcknowledgeableConditionType_Confirm)
            .ShouldBe(OpcUaOperation.AlarmConfirm);
    }

    [Fact]
    public void MapCallOperation_generic_method_maps_to_Call()
    {
        // Arbitrary driver-exposed method NodeId — falls through to generic Call.
        DriverNodeManager.MapCallOperation(new NodeId("driver-method", 2))
            .ShouldBe(OpcUaOperation.Call);
    }

    [Fact]
    public void Gate_null_leaves_errors_untouched()
    {
        var calls = new List<CallMethodRequest> { NewCall("c1/area/line/eq/alarm1", MethodIds.AcknowledgeableConditionType_Acknowledge) };
        var errors = new List<ServiceResult> { (ServiceResult)null! };

        DriverNodeManager.GateCallMethodRequests(calls, errors, new UserIdentity(), gate: null, scopeResolver: null);

        errors[0].ShouldBeNull();
    }

    [Fact]
    public void Denied_Acknowledge_call_gets_BadUserAccessDenied()
    {
        var calls = new List<CallMethodRequest>
        {
            NewCall("c1/area/line/eq/alarm1", MethodIds.AcknowledgeableConditionType_Acknowledge),
        };
        var errors = new List<ServiceResult> { (ServiceResult)null! };
        var gate = MakeGate(strict: true, rows: []); // no grants → deny

        DriverNodeManager.GateCallMethodRequests(calls, errors, NewIdentity("alice"), gate, new NodeScopeResolver("c1"));

        ServiceResult.IsBad(errors[0]).ShouldBeTrue();
        errors[0].StatusCode.ShouldBe((StatusCode)StatusCodes.BadUserAccessDenied);
    }

    [Fact]
    public void Allowed_Acknowledge_passes_through()
    {
        var calls = new List<CallMethodRequest>
        {
            NewCall("c1/area/line/eq/alarm1", MethodIds.AcknowledgeableConditionType_Acknowledge),
        };
        var errors = new List<ServiceResult> { (ServiceResult)null! };
        var gate = MakeGate(strict: true, rows: [Row("grp-ops", NodePermissions.AlarmAcknowledge)]);

        DriverNodeManager.GateCallMethodRequests(calls, errors, NewIdentity("alice", "grp-ops"), gate, new NodeScopeResolver("c1"));

        errors[0].ShouldBeNull();
    }

    [Fact]
    public void Mixed_batch_gates_per_item()
    {
        var calls = new List<CallMethodRequest>
        {
            NewCall("c1/area/line/eq/alarm1", MethodIds.AcknowledgeableConditionType_Acknowledge),
            NewCall("c1/area/line/eq/alarm1", MethodIds.AcknowledgeableConditionType_Confirm),
        };
        var errors = new List<ServiceResult> { (ServiceResult)null!, (ServiceResult)null! };
        // Grant Acknowledge but not Confirm — mixed outcome per item.
        var gate = MakeGate(strict: true, rows: [Row("grp-ops", NodePermissions.AlarmAcknowledge)]);

        DriverNodeManager.GateCallMethodRequests(calls, errors, NewIdentity("alice", "grp-ops"), gate, new NodeScopeResolver("c1"));

        errors[0].ShouldBeNull("Acknowledge granted");
        ServiceResult.IsBad(errors[1]).ShouldBeTrue("Confirm not granted");
    }

    [Fact]
    public void Pre_populated_error_is_preserved()
    {
        var calls = new List<CallMethodRequest> { NewCall("c1/area/line/eq/alarm1", NodeId.Null) };
        var errors = new List<ServiceResult> { new(StatusCodes.BadMethodInvalid) };
        var gate = MakeGate(strict: true, rows: []);

        DriverNodeManager.GateCallMethodRequests(calls, errors, NewIdentity("alice"), gate, new NodeScopeResolver("c1"));

        errors[0].StatusCode.ShouldBe((StatusCode)StatusCodes.BadMethodInvalid);
    }

    // ---- helpers -----------------------------------------------------------

    private static CallMethodRequest NewCall(string objectFullRef, NodeId methodId) => new()
    {
        ObjectId = new NodeId(objectFullRef, 2),
        MethodId = methodId,
    };

    private static NodeAcl Row(string group, NodePermissions flags) => new()
    {
        NodeAclRowId = Guid.NewGuid(),
        NodeAclId = Guid.NewGuid().ToString(),
        GenerationId = 1,
        ClusterId = "c1",
        LdapGroup = group,
        ScopeKind = NodeAclScopeKind.Cluster,
        ScopeId = null,
        PermissionFlags = flags,
    };

    private static AuthorizationGate MakeGate(bool strict, NodeAcl[] rows)
    {
        var cache = new PermissionTrieCache();
        cache.Install(PermissionTrieBuilder.Build("c1", 1, rows));
        var evaluator = new TriePermissionEvaluator(cache);
        return new AuthorizationGate(evaluator, strictMode: strict);
    }

    private static IUserIdentity NewIdentity(string name, params string[] groups) => new FakeIdentity(name, groups);

    private sealed class FakeIdentity : UserIdentity, ILdapGroupsBearer
    {
        public FakeIdentity(string name, IReadOnlyList<string> groups)
        {
            DisplayName = name;
            LdapGroups = groups;
        }
        public new string DisplayName { get; }
        public IReadOnlyList<string> LdapGroups { get; }
    }
}