using System.Collections.Generic;
using System.Threading.Tasks;
using Opc.Ua;
using Shouldly;
using Xunit;
using ZB.MOM.WW.LmxOpcUa.Host.Domain;
using ZB.MOM.WW.LmxOpcUa.Tests.Helpers;

namespace ZB.MOM.WW.LmxOpcUa.Tests.Integration
{
    public class AccessLevelTests
    {
        private static FakeGalaxyRepository CreateRepoWithSecurityLevels()
        {
            return new FakeGalaxyRepository
            {
                Hierarchy = new List<GalaxyObjectInfo>
                {
                    new GalaxyObjectInfo { GobjectId = 1, TagName = "TestObj", BrowseName = "TestObj", ParentGobjectId = 0, IsArea = false }
                },
                Attributes = new List<GalaxyAttributeInfo>
                {
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "FreeAttr", FullTagReference = "TestObj.FreeAttr", MxDataType = 5, SecurityClassification = 0 },
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "OperateAttr", FullTagReference = "TestObj.OperateAttr", MxDataType = 5, SecurityClassification = 1 },
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "SecuredAttr", FullTagReference = "TestObj.SecuredAttr", MxDataType = 5, SecurityClassification = 2 },
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "VerifiedAttr", FullTagReference = "TestObj.VerifiedAttr", MxDataType = 5, SecurityClassification = 3 },
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "TuneAttr", FullTagReference = "TestObj.TuneAttr", MxDataType = 5, SecurityClassification = 4 },
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "ConfigAttr", FullTagReference = "TestObj.ConfigAttr", MxDataType = 5, SecurityClassification = 5 },
                    new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestObj", AttributeName = "ViewOnlyAttr", FullTagReference = "TestObj.ViewOnlyAttr", MxDataType = 5, SecurityClassification = 6 },
                }
            };
        }

        /// <summary>
        /// Verifies that writable Galaxy security classifications publish OPC UA variables with read-write access.
        /// </summary>
        [Fact]
        public async Task ReadWriteAttribute_HasCurrentReadOrWrite_AccessLevel()
        {
            var fixture = OpcUaServerFixture.WithFakeMxAccessClient(repo: CreateRepoWithSecurityLevels());
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                foreach (var attrName in new[] { "FreeAttr", "OperateAttr", "TuneAttr", "ConfigAttr" })
                {
                    var nodeId = client.MakeNodeId($"TestObj.{attrName}");
                    var accessLevel = client.ReadAttribute(nodeId, Attributes.AccessLevel);
                    ((byte)accessLevel.Value).ShouldBe(AccessLevels.CurrentReadOrWrite,
                        $"{attrName} should be ReadWrite");
                }
            }
            finally { await fixture.DisposeAsync(); }
        }

        /// <summary>
        /// Verifies that secured and view-only Galaxy classifications publish OPC UA variables with read-only access.
        /// </summary>
        [Fact]
        public async Task ReadOnlyAttribute_HasCurrentRead_AccessLevel()
        {
            var fixture = OpcUaServerFixture.WithFakeMxAccessClient(repo: CreateRepoWithSecurityLevels());
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                foreach (var attrName in new[] { "SecuredAttr", "VerifiedAttr", "ViewOnlyAttr" })
                {
                    var nodeId = client.MakeNodeId($"TestObj.{attrName}");
                    var accessLevel = client.ReadAttribute(nodeId, Attributes.AccessLevel);
                    ((byte)accessLevel.Value).ShouldBe(AccessLevels.CurrentRead,
                        $"{attrName} should be ReadOnly");
                }
            }
            finally { await fixture.DisposeAsync(); }
        }

        /// <summary>
        /// Verifies that the bridge rejects writes against Galaxy attributes whose security classification is read-only.
        /// </summary>
        [Fact]
        public async Task Write_ToReadOnlyAttribute_IsRejected()
        {
            var fixture = OpcUaServerFixture.WithFakeMxAccessClient(repo: CreateRepoWithSecurityLevels());
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                var nodeId = client.MakeNodeId("TestObj.ViewOnlyAttr");
                var result = client.Write(nodeId, "test");
                StatusCode.IsBad(result).ShouldBeTrue("Write to ReadOnly attribute should be rejected");
            }
            finally { await fixture.DisposeAsync(); }
        }

        /// <summary>
        /// Verifies that writes succeed for Galaxy attributes whose security classification permits operator updates.
        /// </summary>
        [Fact]
        public async Task Write_ToReadWriteAttribute_Succeeds()
        {
            var mxClient = new FakeMxAccessClient();
            var fixture = OpcUaServerFixture.WithFakeMxAccessClient(mxClient: mxClient, repo: CreateRepoWithSecurityLevels());
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                var nodeId = client.MakeNodeId("TestObj.OperateAttr");
                var result = client.Write(nodeId, "test");
                StatusCode.IsGood(result).ShouldBeTrue("Write to ReadWrite attribute should succeed");
            }
            finally { await fixture.DisposeAsync(); }
        }
    }
}