#include <EasyUltrasonic.h>
#include <PubSubClient.h>
#include <WiFi.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16 columns and 2 rows
// Define your WiFi credentials
// const char *ssid = "Mi A3";
// const char *password = "9800bero";
const char *ssid = "Wokwi-GUEST";
const char *password = "";

// Define your MQTT broker information
const char *mqtt_server = "192.168.1.101";
// const char *mqtt_server = "test.mosquitto.org";
const int mqtt_port = 1883;

// Define MQTT topics
const char *distance_topic = "sanu/height_sonar";
const char *volume_topic1 = "sanu/volume_sonar";
const char *volume_topic2 = "sanu/volume_gravity";
const char *height_topic = "sanu/height_gravity";
const char *resetTopic = "sanu/device1/reset";

const float OffSet = 0.465;
const float tankRadius = 0.5;
const float tankLength = 1.5;
float meanDistance = 0;
int count = 0;
int sum = 0;

#define LED_PIN 13
#define TRIGGER_PIN 4
#define ECHO_PIN 5
EasyUltrasonic ultrasonic; // Create the ultrasonic object



WiFiClient espClient;
PubSubClient client(espClient);

unsigned long time_now = 0;
const int period = 10000;

void setup_wifi() {
  Serial.println();
  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    if (millis() >= time_now + period) {
      ESP.restart();
    }
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char *topic, byte *payload, unsigned int length) {
  Serial.print("Message arrived on topic [");
  Serial.print(topic);
  Serial.print("] Payload: ");

  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  String message;
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  // Handle LED control messages
  if (String(topic) == resetTopic) {
    if (message == "reset") {
      Serial.println("Resetting ESP8266...");
      delay(1000);
      // ESP.wdtDisable();  // Disable Watchdog Timer
      ESP.restart();  // Perform a software reset
    }
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("espClient")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

float waterLevel() {
  const int levelDetectionPin = 36;
  const float Vref = 3.3;
  const float g = 9.81;

  float V = analogRead(levelDetectionPin) * Vref / 4096;  // Sensor output voltage
  float P = (V)*250;                                      // Calculate water pressure
  // float P = (V - OffSet) * 250;                           // Calculate water pressure
  Serial.print("Voltage:");
  Serial.print(V, 3);
  Serial.println("V");
  Serial.print(" Pressure:");
  Serial.print(P, 1);
  Serial.println(" KPa");
  float Height = (P / g);
  Serial.print(" Height:");
  Serial.print(Height);
  Serial.println(" Metre");
  return Height;
}

float calculateWaterVolume(float height) {
  // Calculate water volume based on water height
  if (height >= 0 && height <= tankRadius * 2) {
    float angle = acos((tankRadius - height) / tankRadius);
    float waterArea = angle * tankRadius * tankRadius - (tankRadius - height) * sqrt(2 * tankRadius * height - height * height);
    float waterVolume = waterArea * tankLength;
    Serial.print("Volume of water in the tank: ");
    Serial.print(waterVolume * 1000);
    Serial.println("Litre");
    return waterVolume;
  } else {
    Serial.println("Error:calculated height is either '-Ve' or greater than tank diameter");
    return 0;  // Or any other appropriate error code
  }
}

void publishData(const char *topic, float value) {
  char message[20];  // Adjust buffer size as needed
  sprintf(message, "%.2f", value);
  client.publish(topic, message);
}

void setupLCD() {
  lcd.init();       // Initialize the LCD
  lcd.backlight();  // Turn on the backlight
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, mqtt_port);
  client.connect("espClient");
  client.setCallback(callback);
  client.subscribe(resetTopic);
  client.setCallback(callback);
  pinMode(LED_PIN, OUTPUT);
  setupLCD();
  ultrasonic.attach(TRIGGER_PIN, ECHO_PIN); // Attaches the ultrasonic sensor on the specified pins on the ultrasonic object
  // ultrasonic.attach(TRIGGER_PIN, ECHO_PIN, 3, 300); // Uncomment this line and comment the above line if you are using the Ping))) ultrasonic sensor
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();



  // Measure height using pressure sensor
  float height = waterLevel();
  // float distance = sonar.ping_cm();
  float distanceCM = ultrasonic.getDistanceCM(); // Read the distance in centimeters
  float volume_gravity = calculateWaterVolume(height);


  if (distance != 0) {
    count++;
    sum = sum + distance;
    if (count == 100) {
      meanDistance = sum / count;
      float volume_sonar = calculateWaterVolume(tankRadius * 2 - meanDistance / 100);
      count = 0;
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("distance:");
      lcd.print(meanDistance, 2);
      lcd.setCursor(0, 1);
      lcd.print("Water:");
      lcd.print(volume_sonar * 1000, 2);
      publishData(distance_topic, distance);
      publishData(volume_topic1, volume_sonar * 1000);  //m^3->litre
      sum=0;
    }
  }

  // Publish data to MQTT
  publishData(height_topic, height);
  publishData(volume_topic2, volume_gravity*1000);//m^3->litre
  delay(10000);  // Adjust the delay based on your requirements
}