using System;
using System.Text;
using System.Threading.Tasks;
using MQTTnet.Protocol;
using MQTTnet.Server;
using Newtonsoft.Json.Linq;

namespace MQTTnet.TestApp.NetCore
{
    public static class ServerTest
    {
        public static async Task RunAsync()
        {
            try
            {
                MqttNetConsoleLogger.ForwardToConsole();

                var options = new MqttServerOptions
                {
                    ConnectionValidator = p =>
                    {
                        if (p.ClientId == "SpecialClient")
                        {
                            if (p.Username != "USER" || p.Password != "PASS")
                            {
                                p.ReturnCode = MqttConnectReturnCode.ConnectionRefusedBadUsernameOrPassword;
                            }
                        }
                    },

                    Storage = new RetainedMessageHandler(),

                    ApplicationMessageInterceptor = context =>
                    {
                        if (MqttTopicFilterComparer.IsMatch(context.ApplicationMessage.Topic, "/myTopic/WithTimestamp/#"))
                        {
                            // Replace the payload with the timestamp. But also extending a JSON 
                            // based payload with the timestamp is a suitable use case.
                            context.ApplicationMessage.Payload = Encoding.UTF8.GetBytes(DateTime.Now.ToString("O"));
                        }
                    },
                    SubscriptionInterceptor = context =>
                    {
                        if (context.TopicFilter.Topic.StartsWith("admin/foo/bar") && context.ClientId != "theAdmin")
                        {
                            context.AcceptSubscription = false;
                        }

                        if (context.TopicFilter.Topic.StartsWith("the/secret/stuff") && context.ClientId != "Imperator")
                        {
                            context.AcceptSubscription = false;
                            context.CloseConnection = true;
                        }
                    }
                };

                // Extend the timestamp for all messages from clients.
                // Protect several topics from being subscribed from every client.

                //var certificate = new X509Certificate(@"C:\certs\test\test.cer", "");
                //options.TlsEndpointOptions.Certificate = certificate.Export(X509ContentType.Cert);
                //options.ConnectionBacklog = 5;
                //options.DefaultEndpointOptions.IsEnabled = true;
                //options.TlsEndpointOptions.IsEnabled = false;

                var mqttServer = new MqttFactory().CreateMqttServer();

                mqttServer.ApplicationMessageReceived += (s, e) =>
                {
                    MqttNetConsoleLogger.PrintToConsole(
                        $"'{e.ClientId}' reported '{e.ApplicationMessage.Topic}' > '{Encoding.UTF8.GetString(e.ApplicationMessage.Payload ?? new byte[0])}'",
                        ConsoleColor.Magenta);
                };

                options.ApplicationMessageInterceptor = c =>
                {
                    if (c.ApplicationMessage.Payload == null || c.ApplicationMessage.Payload.Length == 0)
                    {
                        return;
                    }

                    try
                    {
                        var content = JObject.Parse(Encoding.UTF8.GetString(c.ApplicationMessage.Payload));
                        var timestampProperty = content.Property("timestamp");
                        if (timestampProperty != null && timestampProperty.Value.Type == JTokenType.Null)
                        {
                            timestampProperty.Value = DateTime.Now.ToString("O");
                            c.ApplicationMessage.Payload = Encoding.UTF8.GetBytes(content.ToString());
                        }
                    }
                    catch (Exception e)
                    {
                    }
                };

                mqttServer.ClientDisconnected += (s, e) =>
                {
                    Console.Write("Client disconnected event fired.");
                };

                await mqttServer.StartAsync(options);

                Console.WriteLine("Press any key to exit.");
                Console.ReadLine();

                await mqttServer.StopAsync();
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }

            Console.ReadLine();
        }
    }
}