// Include necessary libraries
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// Define pin connections
#define TRIGGER_PIN  32
#define ECHO_PIN     33
#define RELAY_PIN    3
#define BUZZER_PIN   18
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// OLED display setup
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Blynk authentication token
char auth[] = "YourAuthToken";

// Your WiFi credentials
char ssid[] = "YourNetworkName";
char pass[] = "YourPassword";

// Variables to store water level and distance
long duration;
float distance;
float waterLevel;
const float maxDistance = 200.0; // Maximum distance your sensor can measure

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

  // Initialize the OLED display
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 10);
  display.println(F("Water Level Monitoring"));
  display.display();

  // Initialize pin modes
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW); // Ensure pump is off initially

  // Connect to WiFi and Blynk
  WiFi.begin(ssid, pass);
  Blynk.begin(auth, ssid, pass);
}

void loop() {
  // Measure water level
  measureWaterLevel();

  // Display water level on OLED
  displayWaterLevel();

  // Send water level to Blynk app
  Blynk.virtualWrite(V1, waterLevel);

  // Control water pump based on water level
  controlPump();

  // Run Blynk
  Blynk.run();
}

void measureWaterLevel() {
  // Clear the trigger pin
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);

  // Sets the trigger pin on HIGH state for 10 microseconds
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);

  // Reads the echo pin, returns the sound wave travel time in microseconds
  duration = pulseIn(ECHO_PIN, HIGH);

  // Calculating the distance
  distance = duration * 0.034 / 2;
  waterLevel = maxDistance - distance;
}

void displayWaterLevel() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print(F("Water Level: "));
  display.print(waterLevel);
  display.println(F(" cm"));

  if (digitalRead(RELAY_PIN) == HIGH) {
    display.println(F("Pump: ON"));
  } else {
    display.println(F("Pump: OFF"));
  }
  display.display();
}

void controlPump() {
  // Thresholds for turning the pump on/off
  const float upperThreshold = 180.0; // cm
  const float lowerThreshold = 20.0;  // cm

  if (waterLevel < lowerThreshold) {
    digitalWrite(RELAY_PIN, HIGH); // Turn pump on
  } else if (waterLevel > upperThreshold) {
    digitalWrite(RELAY_PIN, LOW); // Turn pump off
    tone(BUZZER_PIN, 1000); // Alert with buzzer
    delay(1000);
    noTone(BUZZER_PIN);
  }
}