// Adafruit_MQTT_noTLS.ino
// https://wokwi.com/projects/399507534924937217

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

// Configure WiFi
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Configure MQTT
const char* mqtt_server = "io.adafruit.com";
const int mqtt_port = 1883;
const char* mqtt_username = "kelvinw"; // Username MQTT (if needed)
const char* mqtt_password = "aio_ChRX18oS4MyxhPGBDg6Oe61iNOUF"; // Password MQTT (if needed)
const char* mqtt_client_id = "ESP32_LED_Client";
const int retry_interval = 5000;
const int publish_interval = 2000;

WiFiClient espClient;
PubSubClient mqttClient(espClient);
unsigned long lastMsg = 0;

#define MSG_BUFFER_SIZE (50)
char msg[MSG_BUFFER_SIZE];
int value = 0;

// MQTT topics for sensors and LED lights
const char* sensor1_topic = "kelvinw/feeds/test.temp";
// const char* sensor2_topic = "user/kelvinw/humd";
const char* command1_topic = "kelvinw/feeds/test.led1";
// const char* command2_topic = "user/kelvinw/led2";

// GPIO pins for LED light
#define LED1 12
// #define LED2 13

void setup_wifi() {
  // delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.print(ssid);
  Serial.print(" ");

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("");
}

void reconnect() {
  // Loop until we're reconnected
  while (!mqttClient.connected()) {
    Serial.print("Attempting MQTT connection ... ");
    Serial.print(mqtt_client_id);
    Serial.print(" ... ");
    // Attempt to connect
    if (mqttClient.connect(mqtt_client_id, mqtt_username, mqtt_password)) {
      Serial.println("MQTT connected!");
      // Once connected, subscribe to the topic
      mqttClient.subscribe(sensor1_topic);   // subscribe the topics here
      // mqttClient.subscribe(sensor2_topic);   // subscribe the topics here
      mqttClient.subscribe(command1_topic);   // subscribe the topics here
      // mqttClient.subscribe(command2_topic);   // subscribe the topics here
    } else {
      Serial.print("failed, rc = ");
      Serial.print(mqttClient.state());
      Serial.print("; try again in ");
      Serial.print(retry_interval);
      Serial.println(" ms");
      // Wait 5 seconds before retrying
      delay(retry_interval);
    }
  }
}

void setup() {
  Serial.begin(9600);

  setup_wifi();
  mqttClient.setServer(mqtt_server, mqtt_port);
  mqttClient.setCallback(callback);

  pinMode(LED1, OUTPUT);
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived   [");
  Serial.print(topic);
  Serial.print("]: ");

  String message;
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println(message);

  // If the message is “on”, turn on the LED light
  if (message == "on") {
    digitalWrite(LED1, HIGH);
  }
  // If the message is “off”, turn off the LED light
  else if (message == "off") {
    digitalWrite(LED1, LOW);
  }
}

void loop() {
  if (!mqttClient.connected()) {
    reconnect();
  }
  mqttClient.loop();

  unsigned long now = millis();
  if (now - lastMsg >= publish_interval) {
    lastMsg = now;
    ++value;
    // snprintf(msg, MSG_BUFFER_SIZE, "Hello World! #%ld", value);
    // Serial.print("Publish message: ");
    // Serial.println(msg);
    // mqttClient.publish(mqtt_topic, msg);
    // publishMessage(sensor1_topic, msg, false);
    // publishMessage(sensor2_topic, msg, false);
    publishMessage(sensor1_topic, String(value) + String("°C"), false);
    // publishMessage(sensor2_topic, String(value) + String("%"), false);

    // publishMessage(command1_topic, String("13579"), true);  // Send a retained message
    // publishMessage(command1_topic, String(""), true);  // Delete a retained message
  }
}

void publishMessage(const char* topic, String payload, boolean retained) {
  // if (mqttClient.publish(topic, payload.c_str(), true))
  if (mqttClient.publish(topic, payload.c_str(), retained))
    Serial.println("Message published [" + String(topic) + "]: " + payload);
}