using System;
using System.Threading.Tasks;
using UnityEngine;
using MQTTnet;
using MQTTnet.Server;
using MQTTnet.Protocol;

public class MQTTBroker : MonoBehaviour
{
    public int port = 1883;
    public string username = "";
    public string password = "";
    public bool allowAnonymousConnections = true;

    private MqttServer mqttServer;

    private async void Start()
    {
        var optionsBuilder = new MqttServerOptionsBuilder()
            .WithDefaultEndpoint()
            .WithDefaultEndpointPort(port);

        mqttServer = new MqttFactory().CreateMqttServer(optionsBuilder.Build());

        mqttServer.ValidatingConnectionAsync += args =>
        {
            if (string.IsNullOrEmpty(args.Username))
            {
                if (allowAnonymousConnections)
                {
                    args.ReasonCode = MqttConnectReasonCode.Success;
                    //Debug.Log($"[MQTT] Anonymous client connected: {args.ClientId}");
                }
                else
                {
                    args.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
                    Debug.LogWarning($"[MQTT] Anonymous not allowed: {args.ClientId}");
                }
            }
            else if (args.Username == username && args.Password == password)
            {
                args.ReasonCode = MqttConnectReasonCode.Success;
                Debug.Log($"[MQTT] Authenticated client: {args.ClientId}");
            }
            else
            {
                args.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
                Debug.LogWarning($"[MQTT] Invalid credentials: {args.ClientId}");
            }

            return Task.CompletedTask;
        };

        mqttServer.ClientConnectedAsync += e =>
        {
            //Debug.Log($"[MQTT] Client connected: {e.ClientId}");
            return Task.CompletedTask;
        };

        mqttServer.InterceptingPublishAsync += e =>
        {
            string payload = e.ApplicationMessage?.Payload == null
                ? ""
                : System.Text.Encoding.UTF8.GetString(e.ApplicationMessage.Payload);

            //Debug.Log($"[MQTT] Topic: {e.ApplicationMessage.Topic} - Payload: {payload}");
            return Task.CompletedTask;
        };

        await mqttServer.StartAsync();
        //Debug.Log($"MQTT broker started on port {port}");
    }

    private async void OnApplicationQuit()
    {
        if (mqttServer != null)
        {
            await mqttServer.StopAsync();
            Debug.Log("MQTT broker stopped.");
        }
    }
}