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

#define ON 1
#define OFF 0

// initial WIFI 
const char* ssid = "Wokwi-GUEST";
const char* password =  "";
WiFiClient espClient;

// initial MQTT client
const char* mqttServer = "mqtt.netpie.io";
const int mqttPort = 1883;
const char* clientID = "153f84a6-486a-443e-9823-18810b8782cf";
const char* mqttUser = "vw5LQagy19eTSwysG6KQAJudVSP8KpWX";
const char* mqttPassword = "ynqRh2deJm4GL1Pacmqp9tSMdTLZ438n";
const char* topic_pub = "@shadow/data/update";
const char* topic_sub = "@msg/lab_ict_kps/command";
// send buffer
String publishMessage;

PubSubClient client(espClient);

// LED initial pin
const int RED_LED_PIN = 33;
const int GREEN_LED_PIN = 32;
const int BUZZER = 25;
int redLED_status = OFF, greenLED_status = OFF, buzzer_status = OFF;

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

  WiFi.begin(ssid, password);

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

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

void reconnectMQTT() {
  // Loop until we're reconnected
  char mqttinfo[80];
  snprintf (mqttinfo, 75, "Attempting MQTT connection at %s:%d (%s/%s)...", mqttServer, mqttPort, mqttUser, mqttPassword);
  while (!client.connected()) {
    Serial.println(mqttinfo);
    String clientId = clientID;
    if (client.connect(clientId.c_str(), mqttUser, mqttPassword)) {
      Serial.println("...Connected");
      client.subscribe(topic_sub);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void messageReceivedCallback(char* topic, byte* payload, unsigned int length) { 
  char payloadMsg[80];
  
  Serial.print("Message arrived in topic: ");
  Serial.println(topic); 
  Serial.print("Message:");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
    payloadMsg[i] = (char) payload[i];
  }
  payloadMsg[length] = '\0';   // put end of string to buffer
  Serial.println();
  Serial.println("-----------------------");
  processMessage(payloadMsg);
}

void processMessage(String recvCommand) {
 
  if (recvCommand == "RED_ON") {
    digitalWrite(RED_LED_PIN, HIGH);
    redLED_status = ON;
  } else  if (recvCommand == "RED_OFF") {
    digitalWrite(RED_LED_PIN, LOW);
     redLED_status = OFF;
  } else  if (recvCommand == "GREEN_ON") {
    digitalWrite(GREEN_LED_PIN, HIGH);
    greenLED_status = ON;
  } else  if (recvCommand == "GREEN_OFF") {
    digitalWrite(GREEN_LED_PIN, LOW);
    greenLED_status = OFF;
  }else  if (recvCommand == "BUZZER_ON") {
    digitalWrite(BUZZER, HIGH);
    BUZZER = ON;
  }else  if (recvCommand == "BUZZER_OFF") {
    digitalWrite(BUZZER, LOW);
    BUZZER = OFF;
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqttServer, mqttPort);
  client.setCallback(messageReceivedCallback); 
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  redLED_status = OFF;
  greenLED_status = OFF;
  buzzer_status = OFF;
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(GREEN_LED_PIN, LOW);
  digitalWrite(BUZZER, LOW);
}

void loop() {
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();
  
  publishMessage = "{\"data\": {\"red_led\": " + String(redLED_status) + ", \"green_led\": "  + String(greenLED_status) + " }}";
  Serial.println(publishMessage);
  client.publish(topic_pub, publishMessage.c_str());
  delay(2000);
  
}