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

#define ON 1
#define OFF 0

#define BUZZER_ON_STATUS "TRUE"
#define BUZZER_OFF_STATUS "FALSE"

// command for LED
#define RED_LED_ON "RED_ON"
#define RED_LED_OFF "RED_OFF"
#define GREEN_LED_ON "GREEN_ON"
#define GREEN_LED_OFF "GREEN_OFF"
#define BUZZER_ON "BUZZER_ON"
#define BUZZER_OFF "BUZZER_OFF"

// 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 = "f894f914-11d9-4252-a7e1-aea0c34ec9d5";
const char* mqttUser = "agJ7NVtzYftwyWLGn4WX4QzEkq5oUnmG";
const char* mqttPassword = "v1Aw3MkS3x17mYFKMhDeovufzxXdFFHj";
const char* data_pub = "@shadow/data/update";
const char* topic_pub = "@msg/lab_ict_kps/iot/status";
const char* topic_sub = "@msg/lab_ict_kps/iot/commands";
// send buffer
String publishMessage;

PubSubClient client(espClient);

// LED initial pin
const int RED_LED_PIN = 32;  // change pin number here
const int GREEN_LED_PIN = 33; // change pin number here
const int BUZZER_PIN = 35;
int redLED_status = OFF, greenLED_status = OFF;
String buzzer_status = BUZZER_OFF_STATUS;

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

  WiFi.begin(ssid, password);

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

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

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); // DEBUG: 
    String clientId = clientID;
    if (client.connect(clientId.c_str(), mqttUser, mqttPassword)) {
      Serial.println("...MQTT Broker Connected"); // DEBUG: 
      client.subscribe(topic_sub);
    } else {
      Serial.print("failed, rc="); // DEBUG: 
      Serial.print(client.state()); // DEBUG: 
      Serial.println(" try again in 5 seconds"); // DEBUG: 
      // 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: "); // DEBUG: 
  Serial.println(topic); // DEBUG: 
  Serial.print("Message:"); // DEBUG: 
  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();  // DEBUG: 
  Serial.println("-----------------------");  // DEBUG: show line
  processMessage(payloadMsg);
}

void processMessage(String recvCommand) {
 
  if (recvCommand == RED_LED_ON) {
    digitalWrite(RED_LED_PIN, HIGH);
    redLED_status = ON;
  } else  if (recvCommand == RED_LED_OFF) {
    digitalWrite(RED_LED_PIN, LOW);
     redLED_status = OFF;
  } else  if (recvCommand == GREEN_LED_ON) {
    digitalWrite(GREEN_LED_PIN, HIGH);
    greenLED_status = ON;
  } else  if (recvCommand == GREEN_LED_OFF) {
    digitalWrite(GREEN_LED_PIN, LOW);
    greenLED_status = OFF;
  } else if (recvCommand == BUZZER_ON) {
    digitalWrite(BUZZER_PIN, HIGH);
    buzzer_status = BUZZER_ON_STATUS;
  }else if (recvCommand == BUZZER_OFF) {
    digitalWrite(BUZZER_PIN, LOW);
    buzzer_status = BUZZER_OFF_STATUS;
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqttServer, mqttPort);
  client.setCallback(messageReceivedCallback); 
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  redLED_status = OFF;
  greenLED_status = OFF;
  // turn off all LED at start
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(GREEN_LED_PIN, LOW);
}

void loop() {

  if(WiFi.status() != WL_CONNECTED){
    setup_wifi();
  }else{
    reconnectMQTT();
  }
  client.loop();
  // prepare publish message
  publishMessage = "{\"data\": {\"red_led\": " + String(redLED_status) + ", \"green_led\": "  + String(greenLED_status) + " , \"buzzer\": "  +buzzer_status + " }}";
  Serial.println(publishMessage);  // DEBUG: show publish message
  // publishing message 
  client.publish(topic_pub, publishMessage.c_str());
  delay(1000);
  client.publish(data_pub, publishMessage.c_str());
  delay(1000);
  
}