#include <Servo.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <DHT.h>

#define DHTPIN 6 // Pin connected to the DHT sensor
#define DHTTYPE DHT22 // DHT 22 

// Initialize variables
int mode = 0;
int axe = 0;
int buttonState1 = 0;
int buttonState2 = 0;
int prevButtonState1 = 1;
int prevButtonState2 = 1;
const int ldrPin = A0; // LDR sensor pin
const int fun_buttonPin = 13; // Pin for the functional push button
int fun_buttonState = HIGH;       // Variable to store the button state
int fun_lastButtonState = HIGH;   // Variable to store the last button state
int functionState = 0;       // Variable to store the current equipment state

// LDR Characteristics
const float GAMMA = 0.7;
const float RL10 = 50;

int ldrtopr = A1; // top-right LDR
int ldrtopl = A2; // top-left LDR
int ldrbotr = A3; // bottom-right LDR
int ldrbotl = A4; // bottom-left LDR
int topl = 0;
int topr = 0;
int botl = 0;
int botr = 0;

// Declare servos
Servo servo_updown;
Servo servo_rightleft;
Servo servo_finalDirection_updown; // New servo motor for final direction in auto mode
Servo servo_finalDirection_rightleft; // New servo motor for final direction in auto mode

int threshold_value = 10; // Measurement sensitivity

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 20, 4);

void setup() {
  // Initialize the LCD
  lcd.init();
  // Turn on the backlight
  lcd.backlight();
  // Start the DHT sensor
  dht.begin();
  // Clear the LCD
  lcd.clear();
  printWelcomeMessage();
  delay(4000);
  lcd.clear();
  // Initialize serial communication
  pinMode(ldrPin, INPUT);
  // Set pin modes with internal pull-ups
  pinMode(13, INPUT_PULLUP); // Mode switch Button
  pinMode(12, INPUT_PULLUP); // Axis switch
  pinMode(A5, INPUT); // Potentiometer for right-left movement and for up-down movement
  // Attach servos
  servo_updown.attach(9); // Servo motor up-down movement
  servo_rightleft.attach(10); // Servo motor right-left movement
  servo_finalDirection_updown.attach(8); // New servo motor
  servo_finalDirection_rightleft.attach(7); // New servo motor

  pinMode(fun_buttonPin, INPUT_PULLUP); // Set button pin as input with pull-up resistor
}

void loop() {
  if (buttonState1 != prevButtonState1) {
      ButtonState();
      }
      else{
      lcd.noBacklight();
      lcd.clear();
     }
      State();
}

void ButtonState(){
  char Mode[16];
  buttonState1 = digitalRead(13);
  if (buttonState1 ==LOW && prevButtonState1 == HIGH) {
    lcd.backlight();
    delay(50); // Debounce delay
    if (digitalRead(13) == LOW) {// Confirm the button is still pressed
      // Change mode 
      mode = !mode;
    }
  }
  if (mode == 0) {
    strcpy(Mode, "  Manual Mode");
    Serial.println(Mode);   // Send Mode "Manual" to serial port
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(Mode);
    manualsolartracker();
  } else { // mode automatic
    strcpy(Mode, "  Auto Mode");
    Serial.println(Mode);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(Mode);
    automaticsolartracker(); // Send Mode "Automatic" to serial port
  }
 prevButtonState1 = buttonState1;
}

void automaticsolartracker() {
  // Capture analog values of each LDR
  topr = analogRead(ldrtopr); // Capturing analog value of top right LDR
  topl = analogRead(ldrtopl); // Capturing analog value of top left LDR
  botr = analogRead(ldrbotr); // Capturing analog value of bot right LDR
  botl = analogRead(ldrbotl); // Capturing analog value of bot left LDR

  // calculating average
  int avgtop = (topr + topl) / 2; // average of top LDRs
  int avgbot = (botr + botl) / 2; // average of bottom LDRs
  int avgleft = (topl + botl) / 2; // average of left LDRs
  int avgright = (topr + botr) / 2; // average of right LDRs

  // Get the difference
  int diffelev = avgtop - avgbot; // Get the difference average between LDRs top and LDRs bot
  int diffazi = avgright - avgleft; // Get the difference average between LDRs right and LDRs left

  // left-right movement of solar tracker
  if (abs(diffazi) >= threshold_value) { // Change position only if light difference is bigger then the threshold_value
    if (diffazi > 0) {
      if (servo_rightleft.read() < 180) {
        servo_rightleft.write(servo_rightleft.read() + 2);
        servo_finalDirection_rightleft.write(servo_rightleft.read() + 2);
      }
    } else {
      if (servo_rightleft.read() > 0) {
        servo_rightleft.write(servo_rightleft.read() - 2);
        servo_finalDirection_rightleft.write(servo_rightleft.read() - 2);
      }
    }
  }

  // up-down movement of solar tracker
  if (abs(diffelev) >= threshold_value) { // Change position only if light difference is bigger then the threshold_value
    if (diffelev > 0) {
      if (servo_updown.read() < 180) {
        servo_updown.write(servo_updown.read() - 2);
        servo_finalDirection_updown.write(servo_updown.read() - 2);
      }
    } else {
      if (servo_updown.read() > 0) {
        servo_updown.write(servo_updown.read() + 2);
        servo_finalDirection_updown.write(servo_updown.read() + 2);
      }
    }
  }
}

void manualsolartracker() {
  buttonState2 = digitalRead(12);
  if (buttonState2 != prevButtonState2 && buttonState2 == LOW) {
    delay(50); // Debounce delay
    if (buttonState2 == LOW) {
      // Change axis and light up the correct indicator  
      axe = !axe;
    }
  }
  prevButtonState2 = buttonState2;

  if (axe == 0) {     // Control right-left movement
    servo_finalDirection_rightleft.write(map(analogRead(A5), 0, 1023, 0, 180));
  } else { // Control up-down movement
    servo_finalDirection_updown.write(map(analogRead(A5), 0, 1023, 0, 180));
  } 
}

void State() {
   fun_buttonState = digitalRead(fun_buttonPin); // Read the state of the button

  if (fun_buttonState == LOW && fun_lastButtonState == HIGH) {
    lcd.backlight();
    delay(50); // Debounce delay
    functionState++;
    if (functionState > 3) {
      functionState = 1; // Reset to 1 after the last equipment
    }
    updatefunctionState();
  }

  fun_lastButtonState = fun_buttonState; // Update the last button state

}


void updatefunctionState() {
  // Turn off all previous print
  lcd.clear();
  // Turn on the current equipment based on the state
  switch (functionState) {
    case 1:
     printDHTData();
      break;
    case 2:
     printVisibility();
      break;
    case 3:
     printWelcomeMessage();
      break;
  }
}


void printDHTData() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  // Check if any reads failed and exit early (to try again).
  if (isnan(humidity) || isnan(temperature)) {
    lcd.setCursor(0, 1);
    lcd.print("Failed to read from");
    lcd.setCursor(0, 2);
    lcd.print("DHT sensor!");
    delay(1000);
    return;
  }
  // Display temperature and humidity on LCD
  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C");
  lcd.setCursor(0, 2);
  lcd.print("Humidity: ");
  lcd.print(humidity);
  lcd.print("%");
  delay(1000);
}

void printVisibility() {
  lcd.setCursor(0, 1);
  lcd.print("Checking Visibility"); // Initial message on LCD
  lcd.setCursor(0, 2);
  lcd.print(" Loading....");
  lcd.setCursor(0, 3);
  lcd.print(" please wait");
  delay(1000); // Delay for stability
  int analogValue = analogRead(ldrPin);
  float voltage = analogValue / 1024.0 * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
  lcd.setCursor(0, 3);
  lcd.print("                     "); // Clear previous message
  lcd.setCursor(0, 2);
  lcd.print("Visibility:");
  if (lux > 50) {
    lcd.print("clear");
    delay(1000);
  } else {
    lcd.print("Not Clear");

    delay(1000);
  }
  lcd.clear(); // Clear previous message
  lcd.setCursor(0, 1);
  lcd.print("Lux: ");
  lcd.print(lux);
  lcd.setCursor(0,2);
  lcd.print("Thank You.....");
  delay(1000);
  lcd.clear();
}

void printWelcomeMessage() {
  lcd.setCursor(0, 0);
  lcd.print("Welcome to CSIR NAL");
  lcd.setCursor(0, 1);
  lcd.print("It is Solar Tracking");
  lcd.setCursor(0, 2);
  lcd.print("and power management");
  lcd.setCursor(0, 3);
  lcd.print("system");
  delay(2000);
}