// Create an MQTT Connection
// TCP Connection
// import the WiFi and PubSubClient libraries
//The WiFi library allows ESP32 to establish connections with Wi-Fi networks
//The PubSubClient library enables ESP32 to connect to an MQTT broker for publishing messages and subscribing to topics.
#include <WiFi.h>
#include "PubSubClient.h"
// WiFi
char ssid[]="Wokwi-GUEST";
char pass[]="";
// MQTT Broker
const char *mqtt_broker = "mqtt-dashboard.com";//Public Broker
const char *mqtt_username = "taha.toplu";
const char *mqtt_password = "tahayunus123";
const int mqtt_port = 1883;

// App Protcol ---> Port 
const char *topic_publish = "traffic/light";//Topic ESP32 Pusblish
const char *topic_subsrcibe = "traffic/light";//Topic ESp32 Subs
WiFiClient espClient;//WIFI Opject
PubSubClient client(espClient);

const int red_pin = 2;   
const int yellow_pin = 4; 
const int green_pin = 5;  


const int red_pin_two = 14;   
const int yellow_pin_two = 13; 
const int green_pin_two = 12;  

int state = 0;


// Timing variables
unsigned long previousMillis = 0;
const long interval = 2000; // 2 seconds for each light

enum TrafficLightState {
  RED,
  YELLOW,
  GREEN
};

TrafficLightState currentState = RED;



void callback(char *topic, byte *payload, unsigned int length);
void setTrafficLight(TrafficLightState state);
void switchTrafficLight();

void setup(){
   // Setting LED pin as output
    set_pins();


    //Open a serial connection to display program results and establish a connection to the Wi-Fi network.
    // Set software serial baud to 115200;
    Serial.begin(115200);
    // Connecting to a Wi-Fi network
    WiFi.begin(ssid, pass);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.println("Connecting to WiFi..");
    }
        Serial.println("Connected to the Wi-Fi network");
    // Utilize PubSubClient to establish a connection with the MQTT broker.
    //connecting to a mqtt broker
    Serial.println("Before Connect MQTT");
    //Broker Configuration 
    client.setServer(mqtt_broker, mqtt_port);
    client.setCallback(callback);
   while (!client.connected()) {
        String client_id = "esp32-client-";
        client_id += String(WiFi.macAddress());
        //ESP32-ID -----> esp32-client-macaddress
        //variable.c_str()--->char [] , String
        Serial.printf("The client %s connects to the public MQTT broker\n", client_id.c_str());
        if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
            Serial.println("Public MQTT broker connected");
        } else {
            Serial.print("failed with state ");
            Serial.print(client.state());
            delay(2000);
        }
    }
    Serial.println("After Connect MQTT");
    client.publish(topic_publish, "Hi, I'm ESP32 ^^");
    client.subscribe(topic_subsrcibe);
}

void set_pins(){
  // Set pin modes and initialize the LEDs to be off for the first traffic light

pinMode(red_pin, OUTPUT);
pinMode(yellow_pin, OUTPUT);
pinMode(green_pin, OUTPUT);
digitalWrite(red_pin, HIGH);
digitalWrite(yellow_pin, LOW);
digitalWrite(green_pin, LOW);


// Set pin modes and initialize the LEDs to be off for the fourth traffic light
pinMode(red_pin_two, OUTPUT);
pinMode(yellow_pin_two, OUTPUT);
pinMode(green_pin_two, OUTPUT);
digitalWrite(red_pin_two, HIGH);
digitalWrite(yellow_pin_two, LOW);
digitalWrite(green_pin_two, LOW);

}
void loop() {
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();
  static unsigned long lastSwitchTime = 0;

  if (millis() - lastSwitchTime >= interval) { // Switch every 2 seconds
    lastSwitchTime = millis();
    switch (state) {
      case 0:
        setTrafficLights(red_pin, yellow_pin, green_pin, HIGH, LOW, LOW); // Red
        setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, LOW, HIGH, LOW); // Yellow
        state = 1;
        break;
      case 1:
        setTrafficLights(red_pin, yellow_pin, green_pin, HIGH, LOW, LOW); // Red
        setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, LOW, LOW, HIGH); // Green
        state = 2;
        break;
      case 2:
        setTrafficLights(red_pin, yellow_pin, green_pin, HIGH, LOW, LOW); // RED
        setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, LOW, HIGH, LOW); // Yellow
        state = 3;
        break;
      case 3:
        setTrafficLights(red_pin, yellow_pin, green_pin, LOW, HIGH, LOW); // YELLOW
        setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, HIGH, LOW, LOW); // RED
        state = 4;
        break;
      case 4:
        setTrafficLights(red_pin, yellow_pin, green_pin, LOW, LOW, HIGH); // Green
        setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, HIGH, LOW, LOW); // Red
        state = 5;
        break;
      case 5:
        setTrafficLights(red_pin, yellow_pin, green_pin, LOW, HIGH, LOW); // YELLOW
        setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, HIGH, LOW, LOW); // Red
        state = 0;
        break;
      
    }
  }
}

void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    String client_id = "esp32-client-";
        client_id += String(WiFi.macAddress());
        if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
      Serial.println("connected");
      // Subscribe to topic
    client.subscribe(topic_subsrcibe);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}



void callback(char *topic, byte *payload, unsigned int length) {
    Serial.print("Message arrived in topic: ");
    Serial.println(topic);
    Serial.print("Message:");
     String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  if (message == "FIRST") {
    state = 1;
    setTrafficLights(red_pin, yellow_pin, green_pin, HIGH, LOW, LOW); // Red
    setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, LOW, LOW, HIGH); // GREEN
       
    } else if (message == "SECOND") {
    state = 4;
    setTrafficLights(red_pin, yellow_pin, green_pin, LOW, LOW, HIGH); // Green
    setTrafficLights(red_pin_two, yellow_pin_two, green_pin_two, HIGH, LOW, LOW); // Red
    } 
    Serial.println();
    Serial.println("-----------------------");

}
void setTrafficLights(int redPin, int yellowPin, int greenPin, bool redState, bool yellowState, bool greenState) {
    digitalWrite(redPin, redState);
    digitalWrite(yellowPin, yellowState);
    digitalWrite(greenPin, greenState);
}