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 * Copyright (c) 2005-2025 The OPC Foundation, Inc. All rights reserved.
 *
 * OPC Foundation MIT License 1.00
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
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 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * The complete license agreement can be found here:
 * http://opcfoundation.org/License/MIT/1.00/
 * ======================================================================*/

using System;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using Opc.Ua.Configuration;
using Opc.Ua.Gds.Client;
using Opc.Ua.Security.Certificates;

namespace Opc.Ua.Gds.Tests
{
    public sealed class ServerConfigurationPushTestClient : IDisposable
    {
        public ServerPushConfigurationClient PushClient { get; private set; } = null!;
        public static bool AutoAccept { get; set; }

        public ServerConfigurationPushTestClient(bool autoAccept, ITelemetryContext telemetry)
        {
            AutoAccept = autoAccept;
            m_telemetry = telemetry;
            m_logger = telemetry.CreateLogger<ServerConfigurationPushTestClient>();
        }

        public IUserIdentity AppUser { get; private set; } = null!;
        public IUserIdentity SysAdminUser { get; private set; } = null!;
        public string TempStorePath { get; private set; } = null!;
        public ApplicationConfiguration Config { get; private set; } = null!;
        public string EndpointUrl { get; private set; } = null!;

        public void Dispose()
        {
            PushClient?.Dispose();
            m_application?.DisposeAsync().AsTask().GetAwaiter().GetResult();
            m_application = null!;
        }

        public async Task LoadClientConfigurationAsync(int port = -1)
        {
            ApplicationInstance.MessageDlg = new ApplicationMessageDlg(m_logger);
            await DisconnectClientAsync().ConfigureAwait(false);
            if (m_application != null)
            {
                await m_application.DisposeAsync().ConfigureAwait(false);
                m_application = null!;
            }
            m_application = new ApplicationInstance(m_telemetry)
            {
                ApplicationName = "Server Configuration Push Test Client",
                ApplicationType = ApplicationType.Client,
                ConfigSectionName = "Opc.Ua.ServerConfigurationPushTestClient"
            };
#if USE_FILE_CONFIG
            // load the application configuration.
            Config = await m_application.LoadApplicationConfigurationAsync(false)
                .ConfigureAwait(false);
#else
            string root = Path.Combine(Path.GetTempPath(), "OPC");
            string pkiRoot = Path.Combine(root, "pki");
            var clientConfig = new ServerConfigurationPushTestClientConfiguration
            {
                ServerUrl = "opc.tcp://localhost:58810/GlobalDiscoveryTestServer",
                AppUserName = string.Empty,
                AppPassword = string.Empty,
                SysAdminUserName = "sysadmin",
                SysAdminPassword = "demo",
                TempStorePath = Path.Combine(pkiRoot, "temp")
            };

            var transportQuotas = new TransportQuotas
            {
                OperationTimeout = 120000,
                MaxStringLength = 1048576,
                MaxByteStringLength = 1048576,
                MaxArrayLength = 65535,
                MaxMessageSize = 4194304,
                MaxBufferSize = 65535,
                ChannelLifetime = 300000,
                SecurityTokenLifetime = 3600000
            };

            ArrayOf<CertificateIdentifier> applicationCerts =
                ApplicationConfigurationBuilder.CreateDefaultApplicationCertificates(
                    "CN=Server Configuration Push Test Client, O=OPC Foundation",
                    CertificateStoreType.Directory,
                    pkiRoot);

            // build the application configuration.
            Config = await m_application
                .Build(
                    "urn:localhost:opcfoundation.org:ServerConfigurationPushTestClient",
                    "http://opcfoundation.org/UA/ServerConfigurationPushTestClient")
                .SetTransportQuotas(transportQuotas)
                .AsClient()
                .AddSecurityConfiguration(applicationCerts, pkiRoot, pkiRoot)
                .SetAutoAcceptUntrustedCertificates(true)
                .SetRejectSHA1SignedCertificates(false)
                .SetRejectUnknownRevocationStatus(true)
                .SetMinimumCertificateKeySize(1024)
                .AddExtension(null, clientConfig)
                .CreateAsync()
                .ConfigureAwait(false);
#endif
            // check the application certificate.
            bool haveAppCertificate = await m_application
                .CheckApplicationInstanceCertificatesAsync(true)
                .ConfigureAwait(false);
            if (!haveAppCertificate)
            {
                throw new InvalidOperationException("Application instance certificate invalid!");
            }

            Config.CertificateManager?.AcceptError = AcceptCertificate;

            ServerConfigurationPushTestClientConfiguration clientConfiguration =
                m_application.ApplicationConfiguration!
                    .ParseExtension<ServerConfigurationPushTestClientConfiguration>()!;
            PushClient = new ServerPushConfigurationClient(m_application.ApplicationConfiguration);
            EndpointUrl = TestUtils.PatchOnlyGDSEndpointUrlPort(
                clientConfiguration!.ServerUrl,
                port);
            if (string.IsNullOrEmpty(clientConfiguration.AppUserName))
            {
                AppUser = new UserIdentity();
            }
            else
            {
                AppUser = new UserIdentity(
                    clientConfiguration.AppUserName,
                    Encoding.UTF8.GetBytes(clientConfiguration.AppPassword));
            }
            SysAdminUser = new UserIdentity(
                clientConfiguration.SysAdminUserName,
                Encoding.UTF8.GetBytes(clientConfiguration.SysAdminPassword));
            TempStorePath = clientConfiguration.TempStorePath;
        }

        public async Task DisconnectClientAsync()
        {
            m_logger.LogInformation("Disconnect Session. Waiting for exit...");

            if (PushClient != null)
            {
                ServerPushConfigurationClient pushClient = PushClient;
                PushClient = null!;
                try
                {
                    await pushClient.DisconnectAsync().ConfigureAwait(false);
                }
                finally
                {
                    await pushClient.DisposeAsync().ConfigureAwait(false);
                }
            }
        }

        private bool AcceptCertificate(Certificate certificate, ServiceResult error)
        {
            if (error.StatusCode == StatusCodes.BadCertificateUntrusted)
            {
                if (AutoAccept)
                {
                    if (m_logger.IsEnabled(LogLevel.Information))
                    {
                        m_logger.LogInformation("Accepted Certificate: {Subject}", certificate.Subject);
                    }
                    return true;
                }
                if (m_logger.IsEnabled(LogLevel.Information))
                {
                    m_logger.LogInformation("Rejected Certificate: {Subject}", certificate.Subject);
                }
            }
            return false;
        }

        /// <summary>
        /// Sets the PushClient's endpoint by SecurityPolicy URI and optional MessageSecurityMode.
        /// </summary>
        /// <exception cref="ArgumentException"></exception>
        /// <exception cref="InvalidOperationException"></exception>
        public async Task ConnectAsync(
            string securityPolicyUri,
            MessageSecurityMode securityMode = MessageSecurityMode.SignAndEncrypt)
        {
            if (Config == null)
            {
                throw new InvalidOperationException("Client configuration must be loaded before setting endpoint.");
            }
            await PushClient.DisconnectAsync().ConfigureAwait(false);
            var endpointConfiguration = EndpointConfiguration.Create(Config);
            using DiscoveryClient discoveryClient = await DiscoveryClient.CreateAsync(
                new Uri(EndpointUrl),
                endpointConfiguration,
                m_telemetry).ConfigureAwait(false);
            ArrayOf<EndpointDescription> endpoints =
                await discoveryClient.GetEndpointsAsync(default).ConfigureAwait(false);
            await discoveryClient.CloseAsync().ConfigureAwait(false);
            EndpointDescription? selectedEndpoint = null;
            foreach (EndpointDescription ep in endpoints)
            {
                if (ep.SecurityPolicyUri == securityPolicyUri && ep.SecurityMode == securityMode)
                {
                    selectedEndpoint = ep;
                    break;
                }
            }
            if (selectedEndpoint == null)
            {
                throw new ArgumentException(
                    $"No endpoint found for SecurityPolicyUri '{securityPolicyUri}' and SecurityMode '{securityMode}'.");
            }
            PushClient.Endpoint = new ConfiguredEndpoint(null, selectedEndpoint, endpointConfiguration);

            await PushClient.ConnectAsync().ConfigureAwait(false);
        }

        private ApplicationInstance m_application = null!;
        private readonly ITelemetryContext m_telemetry;
        private readonly ILogger m_logger;
    }

    /// <summary>
    /// Stores the configuration the data access node manager.
    /// </summary>
    [DataType(Namespace = Ua.Namespaces.OpcUaConfig)]
    public partial class ServerConfigurationPushTestClientConfiguration
    {
        [DataTypeField(Order = 1)]
        public string ServerUrl { get; set; } = null!;

        [DataTypeField(Order = 2)]
        public string AppUserName { get; set; } = null!;

        [DataTypeField(Order = 3)]
        public string AppPassword { get; set; } = null!;

        [DataTypeField(Order = 4)]
        public string SysAdminUserName { get; set; } = null!;

        [DataTypeField(Order = 5)]
        public string SysAdminPassword { get; set; } = null!;

        [DataTypeField(Order = 6)]
        public string TempStorePath { get; set; } = null!;
    }
}