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

namespace ZB.MOM.WW.OtOpcUa.Tests.Integration
{
    public class RedundancyTests
    {
        [Fact]
        public async Task Server_WithRedundancyDisabled_ReportsNone()
        {
            var fixture = OpcUaServerFixture.WithFakeMxAccessClient();
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                var redundancySupport = client.Read(VariableIds.Server_ServerRedundancy_RedundancySupport);
                ((int)redundancySupport.Value).ShouldBe((int)RedundancySupport.None);

                var serviceLevel = client.Read(VariableIds.Server_ServiceLevel);
                ((byte)serviceLevel.Value).ShouldBe((byte)255);
            }
            finally
            {
                await fixture.DisposeAsync();
            }
        }

        [Fact]
        public async Task Server_WithRedundancyEnabled_ReportsConfiguredMode()
        {
            var redundancy = new RedundancyConfiguration
            {
                Enabled = true,
                Mode = "Warm",
                Role = "Primary",
                ServiceLevelBase = 200,
                ServerUris = new List<string> { "urn:test:primary", "urn:test:secondary" }
            };

            var fixture = OpcUaServerFixture.WithFakeMxAccessClient(
                redundancy: redundancy,
                applicationUri: "urn:test:primary");
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                var redundancySupport = client.Read(VariableIds.Server_ServerRedundancy_RedundancySupport);
                ((int)redundancySupport.Value).ShouldBe((int)RedundancySupport.Warm);
            }
            finally
            {
                await fixture.DisposeAsync();
            }
        }

        [Fact]
        public async Task Server_Primary_HasHigherServiceLevel_ThanSecondary()
        {
            var sharedUris = new List<string> { "urn:test:primary", "urn:test:secondary" };

            var primaryRedundancy = new RedundancyConfiguration
            {
                Enabled = true, Mode = "Warm", Role = "Primary",
                ServiceLevelBase = 200, ServerUris = sharedUris
            };
            var secondaryRedundancy = new RedundancyConfiguration
            {
                Enabled = true, Mode = "Warm", Role = "Secondary",
                ServiceLevelBase = 200, ServerUris = sharedUris
            };

            var primaryFixture = OpcUaServerFixture.WithFakeMxAccessClient(
                redundancy: primaryRedundancy, applicationUri: "urn:test:primary");
            var secondaryFixture = OpcUaServerFixture.WithFakeMxAccessClient(
                redundancy: secondaryRedundancy, applicationUri: "urn:test:secondary",
                serverName: "TestGalaxy2");

            await primaryFixture.InitializeAsync();
            await secondaryFixture.InitializeAsync();
            try
            {
                using var primaryClient = new OpcUaTestClient();
                await primaryClient.ConnectAsync(primaryFixture.EndpointUrl);
                var primaryLevel = (byte)primaryClient.Read(VariableIds.Server_ServiceLevel).Value;

                using var secondaryClient = new OpcUaTestClient();
                await secondaryClient.ConnectAsync(secondaryFixture.EndpointUrl);
                var secondaryLevel = (byte)secondaryClient.Read(VariableIds.Server_ServiceLevel).Value;

                primaryLevel.ShouldBeGreaterThan(secondaryLevel);
            }
            finally
            {
                await secondaryFixture.DisposeAsync();
                await primaryFixture.DisposeAsync();
            }
        }

        [Fact]
        public async Task Server_WithRedundancyEnabled_ExposesServerUriArray()
        {
            var serverUris = new List<string> { "urn:test:server1", "urn:test:server2" };
            var redundancy = new RedundancyConfiguration
            {
                Enabled = true, Mode = "Warm", Role = "Primary",
                ServiceLevelBase = 200, ServerUris = serverUris
            };

            var fixture = OpcUaServerFixture.WithFakeMxAccessClient(
                redundancy: redundancy, applicationUri: "urn:test:server1");
            await fixture.InitializeAsync();
            try
            {
                using var client = new OpcUaTestClient();
                await client.ConnectAsync(fixture.EndpointUrl);

                var uriArrayValue = client.Read(VariableIds.Server_ServerRedundancy_ServerUriArray);

                // ServerUriArray may not be exposed if the SDK doesn't create the non-transparent
                // redundancy node type automatically. If the value is null, the server logged a
                // warning and the test is informational rather than a hard failure.
                if (uriArrayValue.Value != null)
                {
                    var uris = (string[])uriArrayValue.Value;
                    uris.Length.ShouldBe(2);
                    uris.ShouldContain("urn:test:server1");
                    uris.ShouldContain("urn:test:server2");
                }
            }
            finally
            {
                await fixture.DisposeAsync();
            }
        }

        [Fact]
        public async Task TwoServers_BothExposeSameRedundantSet()
        {
            var sharedUris = new List<string> { "urn:test:a", "urn:test:b" };
            var configA = new RedundancyConfiguration
            {
                Enabled = true, Mode = "Warm", Role = "Primary",
                ServiceLevelBase = 200, ServerUris = sharedUris
            };
            var configB = new RedundancyConfiguration
            {
                Enabled = true, Mode = "Warm", Role = "Secondary",
                ServiceLevelBase = 200, ServerUris = sharedUris
            };

            var fixtureA = OpcUaServerFixture.WithFakeMxAccessClient(
                redundancy: configA, applicationUri: "urn:test:a");
            var fixtureB = OpcUaServerFixture.WithFakeMxAccessClient(
                redundancy: configB, applicationUri: "urn:test:b",
                serverName: "TestGalaxy2");

            await fixtureA.InitializeAsync();
            await fixtureB.InitializeAsync();
            try
            {
                using var clientA = new OpcUaTestClient();
                await clientA.ConnectAsync(fixtureA.EndpointUrl);
                var modeA = (int)clientA.Read(VariableIds.Server_ServerRedundancy_RedundancySupport).Value;

                using var clientB = new OpcUaTestClient();
                await clientB.ConnectAsync(fixtureB.EndpointUrl);
                var modeB = (int)clientB.Read(VariableIds.Server_ServerRedundancy_RedundancySupport).Value;

                modeA.ShouldBe((int)RedundancySupport.Warm);
                modeB.ShouldBe((int)RedundancySupport.Warm);
            }
            finally
            {
                await fixtureB.DisposeAsync();
                await fixtureA.DisposeAsync();
            }
        }
    }
}