#define BLYNK_PRINT Serial
// Define Blynk credentials
#define BLYNK_TEMPLATE_ID "TMPL6VrPKQvlx"
#define BLYNK_TEMPLATE_NAME "Quickstart Template"
#define BLYNK_AUTH_TOKEN "-Z1qKckQCir1Mj_pOycTqdpjXZ6Vns6-"

#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <LiquidCrystal_I2C.h>

// WiFi credentials
char ssid[] = "Wokwi-GUEST";  // Your WiFi network name
char pass[] = "";             // Your WiFi password
char auth[] = "-Z1qKckQCir1Mj_pOycTqdpjXZ6Vns6-"; // Your Blynk authentication token

// Ultrasonic sensor pins
int DISTANCIA = 0;
int pinLed = 2;       // LED pin
int pinEco = 12;      // Echo pin
int pinGatillo = 13;  // Trigger pin
int pinBuzzer = 14;   // Buzzer pin

// LCD initialization (I2C address 0x27, 16 columns, 2 rows)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Function to read the distance from the ultrasonic sensor
long readUltrasonicDistance(int triggerPin, int echoPin) {
  pinMode(triggerPin, OUTPUT);
  digitalWrite(triggerPin, LOW);  // Turn off the trigger
  delayMicroseconds(2);           // Wait for 2 microseconds
  digitalWrite(triggerPin, HIGH); // Send the trigger pulse
  delayMicroseconds(10);          // Wait for 10 microseconds
  digitalWrite(triggerPin, LOW);  // End the trigger pulse
  pinMode(echoPin, INPUT);        // Set echoPin as input
  return pulseIn(echoPin, HIGH);  // Measure the pulse duration
}

// Blynk virtual pin handler to control the LED
BLYNK_WRITE(V0) {
  int value = param.asInt();  // Get value from the app (0 or 1)
  digitalWrite(pinLed, value);
}

// Setup function
void setup() {
  Serial.begin(115200);  // Start the serial communication
  
  // Initialize WiFi and Blynk
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);
  
  // Initialize the LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Starting...");
  delay(2000);  // Display "Starting..." for 2 seconds
  lcd.clear();
  
  // Initialize LED and buzzer pins
  pinMode(pinLed, OUTPUT);
  pinMode(pinBuzzer, OUTPUT);
}

// Main loop
void loop() {
  Blynk.run();  // Run Blynk

  // Calculate the distance in centimeters
  DISTANCIA = 0.01723 * readUltrasonicDistance(pinGatillo, pinEco);

  // Send distance to Blynk gauge (Virtual Pin V1)
  Blynk.virtualWrite(V1, DISTANCIA);

  // Check the distance and update the LCD, LED, and buzzer
  if (DISTANCIA < 100) {
    digitalWrite(pinLed, HIGH);    // Turn on the LED
    digitalWrite(pinBuzzer, HIGH); // Turn on the buzzer
    lcd.setCursor(0, 0);
    lcd.print("Stock is low");
    lcd.setCursor(0, 1);
    lcd.print("Please restock");
  } else {
    digitalWrite(pinLed, LOW);     // Turn off the LED
    digitalWrite(pinBuzzer, LOW);  // Turn off the buzzer
    lcd.setCursor(0, 0);
    lcd.print("Stock Available");
    lcd.setCursor(0, 1);
    lcd.print("                ");  // Clear the second row
  }

  delay(500);  // Update every 500ms
}