#include <WiFi.h>
#include <string.h>
#include <PubSubClient.h>
#include <WiFiClientSecure.h>

#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
#define WIFI_CHANNEL 6

namespace led
{
  constexpr uint8_t pin = 33;
  constexpr uint8_t minValue = 0;
  constexpr uint8_t maxValue = 255;
}

// MQTT Broker
namespace mqtt
{
  namespace broker
  {
    constexpr auto url = "b8c171f53af94fddbf33ee09ab2fe0e5.s1.eu.hivemq.cloud";
    constexpr auto port = 8883;
  };
  namespace client
  {
    constexpr auto username = "lab7.3-actuator";
    constexpr auto password = "Lab7.3-actuator";
  };

  const String subject("intensity");
}; // MQTT

void callback(char* topic, byte* payload, unsigned int length);
void reconnect();
void setLightIntensity(uint8_t intensity);

WiFiClientSecure wifiClient;
PubSubClient pubSubClient(wifiClient);

void setup() {
  pinMode(led::pin, OUTPUT);

  Serial.begin(9600);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD, WIFI_CHANNEL);
  while (WiFi.status() != WL_CONNECTED)
    delay(100);

  wifiClient.setInsecure();
  pubSubClient.setServer(mqtt::broker::url, mqtt::broker::port)
    .setCallback(callback);
}

void loop() {
  if (!pubSubClient.connected()) reconnect();  
  pubSubClient.loop();
  delay(500);
}

void callback(char* topic, byte* payload, unsigned int length)
{
  String incommingMessage;
  for (unsigned int i = 0; i < length; ++i)
    incommingMessage += static_cast<char>(payload[i]);

  const uint8_t intensity = incommingMessage.toInt();
  setLightIntensity(intensity);
}

void reconnect()
{
  while (!pubSubClient.connected())
  {
    Serial.println("Try to connect to MQTT server.");
    if (pubSubClient.connect("1", mqtt::client::username, mqtt::client::password))
    {
      Serial.println("Connected.");
      pubSubClient.subscribe(mqtt::subject.c_str());
    }
    else
    {
      Serial.println("Fail to connect. Retry in 3 sec.");
      delay(3000);
    }
  }
}

void setLightIntensity(uint8_t intensity)
{
  Serial.println(String("Set intensity to ") + intensity + "%");
  const auto value = map(intensity, 0, 100, led::minValue, led::maxValue);
  analogWrite(led::pin, value);
}