#define BLYNK_TEMPLATE_ID "TMPL6qwDGZBSu" // Template ID for Blynk IoT platform
#define BLYNK_TEMPLATE_NAME "HomeAutomation" // Project name on Blynk
#define BLYNK_AUTH_TOKEN "lfu1Mh4IwQHstzn8a0StAM9yusmVvLwb" // Authentication token to connect the ESP32 to Blynk

#define BLYNK_PRINT Serial // Enables debugging via Serial Monitor

#include <LiquidCrystal_I2C.h> // Library for I2C LCD
#include <WiFi.h> // Wi-Fi library for ESP32
#include <WiFiClient.h> // Supports Wi-Fi client
#include <BlynkSimpleEsp32.h> // Blynk library for ESP32

// Create an LCD object (I2C address, 16 columns, 2 rows)
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2); 

char auth[] = BLYNK_AUTH_TOKEN; // Blynk authentication token
char ssid[] = "Wokwi-GUEST";    // Wi-Fi network name
char pass[] = "";               // Wi-Fi password (empty for this network)

BlynkTimer timer; // Timer to handle periodic tasks

// GPIO pins for buttons and relays
#define button1_pin 26
#define button2_pin 25
#define button3_pin 33
#define button4_pin 32

#define relay1_pin 13
#define relay2_pin 12
#define relay3_pin 14
#define relay4_pin 27

// Variables to store the state of each relay
int relay1_state = 0;
int relay2_state = 0;
int relay3_state = 0;
int relay4_state = 0;

// Virtual pins for Blynk (used to control relays)
#define button1_vpin V1
#define button2_vpin V2
#define button3_vpin V3
#define button4_vpin V4

// Sync relay states with the Blynk server when connected
BLYNK_CONNECTED() {
  Blynk.syncVirtual(button1_vpin);
  Blynk.syncVirtual(button2_vpin);
  Blynk.syncVirtual(button3_vpin);
  Blynk.syncVirtual(button4_vpin);
}

// Handle button presses from the Blynk app for relay 1
BLYNK_WRITE(button1_vpin) {
  relay1_state = param.asInt(); // Get button state from Blynk app
  digitalWrite(relay1_pin, relay1_state); // Set relay state
  update_lcd(1, relay1_state); // Update the LCD
}

// Handle button presses from the Blynk app for relay 2
BLYNK_WRITE(button2_vpin) {
  relay2_state = param.asInt(); 
  digitalWrite(relay2_pin, relay2_state); 
  update_lcd(2, relay2_state); 
}

// Handle button presses from the Blynk app for relay 3
BLYNK_WRITE(button3_vpin) {
  relay3_state = param.asInt(); 
  digitalWrite(relay3_pin, relay3_state); 
  update_lcd(3, relay3_state); 
}

// Handle button presses from the Blynk app for relay 4
BLYNK_WRITE(button4_vpin) {
  relay4_state = param.asInt(); 
  digitalWrite(relay4_pin, relay4_state); 
  update_lcd(4, relay4_state); 
}

void setup() {
  Serial.begin(115200); // Start Serial communication

  // Initialize the LCD
  LCD.init();
  LCD.backlight();
  LCD.setCursor(0, 0);
  LCD.print("Connecting to");
  LCD.setCursor(0, 1);
  LCD.print("WiFi...");

  // Configure button pins as inputs with pull-up resistors
  pinMode(button1_pin, INPUT_PULLUP);
  pinMode(button2_pin, INPUT_PULLUP);
  pinMode(button3_pin, INPUT_PULLUP);
  pinMode(button4_pin, INPUT_PULLUP);

  // Configure relay pins as outputs
  pinMode(relay1_pin, OUTPUT);
  pinMode(relay2_pin, OUTPUT);
  pinMode(relay3_pin, OUTPUT);
  pinMode(relay4_pin, OUTPUT);

  // Set all relays to OFF initially (HIGH in this setup means OFF)
  digitalWrite(relay1_pin, HIGH);
  digitalWrite(relay2_pin, HIGH);
  digitalWrite(relay3_pin, HIGH);
  digitalWrite(relay4_pin, HIGH);

  // Connect to Wi-Fi and Blynk
  Blynk.begin(auth, ssid, pass);

  // Update the LCD display when Wi-Fi is connected
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print("WiFi Connected!");
  delay(2000); // Delay for visibility
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print("Home Automation");
}

void loop() {
  Blynk.run(); // Handle Blynk communication
  timer.run(); // Handle Blynk timers
  listen_push_buttons(); // Check for physical button presses
}

// Function to detect button presses and toggle relays
void listen_push_buttons() {
  if (digitalRead(button1_pin) == LOW) { // Button 1 pressed
    delay(200); // Debounce delay
    control_relay(1); // Toggle relay 1
    Blynk.virtualWrite(button1_vpin, relay1_state); // Update Blynk app
  } else if (digitalRead(button2_pin) == LOW) { // Button 2 pressed
    delay(200);
    control_relay(2);
    Blynk.virtualWrite(button2_vpin, relay2_state);
  } else if (digitalRead(button3_pin) == LOW) { // Button 3 pressed
    delay(200);
    control_relay(3);
    Blynk.virtualWrite(button3_vpin, relay3_state);
  } else if (digitalRead(button4_pin) == LOW) { // Button 4 pressed
    delay(200);
    control_relay(4);
    Blynk.virtualWrite(button4_vpin, relay4_state);
  }
}

// Function to toggle the relay state
void control_relay(int relay) {
  if (relay == 1) {
    relay1_state = !relay1_state; // Toggle state
    digitalWrite(relay1_pin, relay1_state); // Set relay state
    update_lcd(1, relay1_state); // Update LCD
  } else if (relay == 2) {
    relay2_state = !relay2_state;
    digitalWrite(relay2_pin, relay2_state);
    update_lcd(2, relay2_state);
  } else if (relay == 3) {
    relay3_state = !relay3_state;
    digitalWrite(relay3_pin, relay3_state);
    update_lcd(3, relay3_state);
  } else if (relay == 4) {
    relay4_state = !relay4_state;
    digitalWrite(relay4_pin, relay4_state);
    update_lcd(4, relay4_state);
  }
}

// Function to update the LCD with the relay status
void update_lcd(int relay, int state) {
  LCD.clear(); // Clear the LCD
  LCD.setCursor(0, 0); // First row
  LCD.print("Bulb ");
  LCD.print(relay);
  if (state) {
    LCD.print(" is ON"); // Display ON if state is 1
  } else {
    LCD.print(" is OFF"); // Display OFF if state is 0
  }
  LCD.setCursor(0, 1); // Second row
  LCD.print("Home Automation");
}