using MQTTnet;
using System.Text;
using System.Buffers;

namespace GuilhermesApp.Pages;

public partial class SensorPage : ContentPage
{
    private IMqttClient? _mqttClient;
    private MqttClientOptions? _options;
    private bool _isLedOn = false;

    public SensorPage()
    {
        InitializeComponent();
        ConfigurarMqtt();
    }

    private async void ConfigurarMqtt()
    {
        try 
        {
            // TENTATIVA A: MqttClientFactory (Novo padrão em algumas versões v5)
            // Se der erro aqui, tenta mudar para: var factory = new MqttFactory();
            var factory = new MqttClientFactory();
            _mqttClient = factory.CreateMqttClient();

            _options = new MqttClientOptionsBuilder()
                .WithTcpServer("broker.hivemq.com", 1883)
                .Build();

            _mqttClient.ApplicationMessageReceivedAsync += e =>
            {
                // Extração manual de bytes para evitar o erro do ToArray
                var buffer = e.ApplicationMessage.Payload;
                byte[] payloadBytes = new byte[buffer.Length];
                buffer.CopyTo(payloadBytes);
                
                string payload = Encoding.UTF8.GetString(payloadBytes);
                
                MainThread.BeginInvokeOnMainThread(() =>
                {
                    if (payload == "PRESSIONADO")
                    {
                        StatusLabel.Text = $"Último clique: {DateTime.Now:HH:mm:ss}";
                        StatusLabel.TextColor = Colors.Green;
                    }
                });

                return Task.CompletedTask;
            };

            await _mqttClient.ConnectAsync(_options);
            await _mqttClient.SubscribeAsync("guilherme/app/botao");
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine($"Erro crítico MQTT: {ex.Message}");
        }
    }

    private async void OnLedClicked(object sender, EventArgs e)
    {
        if (_mqttClient == null || !_mqttClient.IsConnected)
        {
            await DisplayAlert("Erro", "O MQTT não está ligado.", "OK");
            return;
        }

        _isLedOn = !_isLedOn;
        string comando = _isLedOn ? "ON" : "OFF";

        var message = new MqttApplicationMessageBuilder()
            .WithTopic("guilherme/app/led")
            .WithPayload(comando)
            .Build();

        await _mqttClient.PublishAsync(message);

        LedBtn.Text = _isLedOn ? "DESLIGAR LED" : "LIGAR LED";
        LedBtn.BackgroundColor = _isLedOn ? Colors.Red : Colors.DarkSlateGray;
    }
}