//Write a program to display messages based on the button pressed on the
//web app and assign the OLED display, 3 servo motors, and 4 LEDs pins.

#include <WiFi.h>
#include <PubSubClient.h>
#include <ESP32Servo.h> // used to control the servo motors
#include <Wire.h> // used to enable wire connection in the circuit.
#include <Adafruit_GFX.h> // helps us to write messages on the OLED display.
#include <Adafruit_SSD1306.h> // helps us to write messages on the SSD1306 OLED displa


char clientId[50];  // can store up to 50 characters.
int servoPin1 = 12;
Servo servo1;
int servoPin2 = 4;
Servo servo2;
int servoPin3 = 15;
Servo servo3;

WiFiClient espClient;  //server details
PubSubClient client(espClient);


int ledPin1 = 4;   //red led
int ledPin2 = 12;    //white led
int ledPin3 = 13;   //yellow led
int ledPin4 = 5;   //green led



// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(128, 64, &Wire, 1); //display(width , height of the OLED display, connected to wire , reset=1)


void setup() {
  Serial.begin(9600);  //starts communication
//➔ 500: It is 500 microseconds (pulse width) when the servo angle is 0 degrees. It is a minimum value.
//➔ 2400: It is 2400 microseconds (pulse width) when the servo angle is 180 degrees. It is a maximum value
  servo1.attach(servoPin1, 500, 2400);
  servo2.attach(servoPin2, 500, 2400);
  servo3.attach(servoPin3, 500, 2400);

  //checking  if the OLED display is connected or not-
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64 OLED display
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);  //print only 1 time on console
  }
  delay(2000);  //2 sec
  display.clearDisplay();
  display.setTextSize(1);  //size of the text
  display.setTextColor(WHITE);

  Serial.print("Connecting to …..");

  WiFi.mode(WIFI_STA);  //to search a WiFi station
  WiFi.begin("Wokwi-GUEST","", 6);  //username, password
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
  }
  
  client.setServer("broker.emqx.io", 1883);
  client.setCallback(callback);  //written below
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  pinMode(ledPin4, OUTPUT);

}


//prewritten code
void mqttReconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect(clientId)) {
      Serial.println(" connected");
      client.subscribe("topicName/iot");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());  //state as -2 etc
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}


void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String stMessage;  //message received from MQTT means 1/2/3/4/5/6
  
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);//print message
    stMessage += (char)message[i]; //complete message in terms of numbers
  }


  //class 300 starts
  // starts here
    if(stMessage == "1"){
      Serial.println("1");
      display.clearDisplay();
      display.setTextSize(1);  //set text size on OLED
      display.setTextColor(WHITE);
      display.setCursor(10, 0); //column=10 , row=0
      // Display static text
      display.println("Release Orbital Access Arm");
      display.display();  //display the defined output text on the OLED Screen
      servo1.write(180); //rotate the arm of Servo Motor by 180 Degrees
   }
    else if(stMessage == "2"){
      Serial.println("2");
      digitalWrite(ledPin1, HIGH);  //green LED
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(10, 0);
      // Display static text
      display.println("Main engine gimbal test and lift beanie Cap");
      display.display(); 
      servo2.write(0);  //No rotation
    }
    else if(stMessage == "3"){
      Serial.println("3");
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(10, 0);
      // Display static text
      display.println("Activate Hydrogen Burn off system");
      display.display(); 
      digitalWrite(ledPin2, HIGH);  // yellow LED
    }
    else if(stMessage == "4"){
      Serial.println("4");
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(10, 0);
      // Display static text
      display.println("Main engine ignite");
      display.display(); 
       digitalWrite(ledPin3, HIGH);   //white LED

    }
    else if(stMessage == "5"){
      Serial.println("5");
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(10, 0);
      // Display static text
      display.println("Hydrogen vent Arm | Release tail surface mass | Detonate hold-down bolts");
      display.display(); 
      servo3.write(360); //rotate by 360 degree
      
    }
    else if(stMessage == "6"){
      Serial.println("6");
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(10, 0);
      // Display static text
      display.println("Ignite Both SRBs");
      display.display(); 
     digitalWrite(ledPin4, HIGH);     //red LED  
    }
  }
// ends here


void loop() {
  delay(1000);
  if (!client.connected()) {
    mqttReconnect();
  }
  client.loop();
}