#include <Servo.h>
#include <SD.h>
#include <SPI.h>
#include <SoftwareSerial.h>
#include <LiquidCrystal.h>

// Pin definitions
const int trigPins[] = {22, 24, 26, 28}; // Ultrasonic sensor trigger pins
const int echoPins[] = {23, 25, 27, 29}; // Ultrasonic sensor echo pins
const int servoPins[] = {2, 3, 4};       // Servo motor pins
const int buttonPins[] = {5, 6, 7, 19, 20}; // Push button pins (including Continue and Go Back)
const int proximitySensorPins[] = {32, 33}; // Inductive proximity sensor pins
const int buzzerPins[] = {34, 35}; // Buzzer pins
const int chipSelect = 10;               // SD card chip select pin
const int servo4Pin = 36;
const int servo5Pin = 37;

// GSM Module Pins
SoftwareSerial sim(15, 16); // TX, RX (Use Pins 30 and 31 for the GSM module)

// LCD2004 Pins (Parallel Mode)
LiquidCrystal lcd2004(8, 9, 11, 12, 13, 14);

bool useLCD2004 = true; // Set to true for LCD2004, false for ST7920

// Variables
long duration[4];
int distance[4];
int buttonState[5];
int lastButtonState[5] = {LOW, LOW, LOW, LOW, LOW};
int servoCount[3] = {0, 0, 0};
int selectedItem = -1; // -1 means no item selected
bool waitingForContinue = false; // True when waiting for Continue button
bool countingBottles = false; // True when counting PET bottles
int PET_BottleCount = 0;
const int PET_BOTTLE_COUNT_LIMIT = 10; // Set your PET bottle count limit
Servo servos[3];
Servo servo4; // Only declare once
Servo servo5; // Only declare once
File dataFile;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  sim.begin(9600);
  delay(1000);

  // Initialize pins
  for (int i = 0; i < 4; i++) {
    pinMode(trigPins[i], OUTPUT);
    pinMode(echoPins[i], INPUT);
  }
  for (int i = 0; i < 3; i++) {
    pinMode(buttonPins[i], INPUT);
    servos[i].attach(servoPins[i]);
  }
  pinMode(buttonPins[3], INPUT); // Continue button
  pinMode(buttonPins[4], INPUT); // Go Back button

  // Initialize SD card
  if (!SD.begin(chipSelect)) {
    Serial.println("SD card initialization failed!");
    return;
  }
  Serial.println("SD card initialized.");

  // Initialize LCD
    lcd2004.begin(20, 4);
    lcd2004.clear();
    lcd2004.setCursor(0, 0);
    lcd2004.print("Select an item");
    lcd2004.setCursor(0, 1);
    lcd2004.print("1) Distilled Water");
    lcd2004.setCursor(0, 2);
    lcd2004.print("2) Skyflakes");
    lcd2004.setCursor(0, 3);
    lcd2004.print("3) Instant noodles");
}

void loop() {
  for (int i = 0; i < 3; i++) {
    int reading = digitalRead(buttonPins[i]);
    if (reading != lastButtonState[i]) {
      lastButtonState[i] = reading;
      if (reading == HIGH && !waitingForContinue) {
        selectedItem = i;
        displayItemConfirmation(i);
        waitingForContinue = true;
      }
    }

    // Ultrasonic distance measurement
    digitalWrite(trigPins[i], LOW);
    delayMicroseconds(2);
    digitalWrite(trigPins[i], HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPins[i], LOW);
    duration[i] = pulseIn(echoPins[i], HIGH);
    distance[i] = duration[i] * 0.034 / 2;

    // Check distances and display messages
    if (distance[i] > 20 && servoCount[i] >= 3) {
      switch (i) {
        case 0:
          displayMessage(i, "Low on supply: Lucky Me noodles");
          break;
        case 1:
          displayMessage(i, "Low on supply: Mineral water");
          break;
        case 2:
          displayMessage(i, "Low on supply: Sky Flakes");
          break;
      }
      SendMessage();
      servoCount[i] = 0;
    }
  }

  // Check the 4th ultrasonic sensor for critical level
  digitalWrite(trigPins[3], LOW);
  delayMicroseconds(2);
  digitalWrite(trigPins[3], HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPins[3], LOW);
  duration[3] = pulseIn(echoPins[3], HIGH);
  distance[3] = duration[3] * 0.034 / 2;

  if (distance[3] < 150) {
    SendMessageCriticalLevel();
  }

  // Check for Continue and Go Back button presses
  for (int i = 3; i < 5; i++) {
    int reading = digitalRead(buttonPins[i]);
    if (reading != lastButtonState[i]) {
      lastButtonState[i] = reading;
      if (reading == HIGH) {
        if (i == 3) {
          // Continue button action
          if (selectedItem != -1) {
            lcd2004.clear();
            lcd2004.setCursor(0, 1);
            lcd2004.print("Bottles Inserted");
            countingBottles = true;
            PET_BottleCount = 0;
            waitingForContinue = false;
            while (countingBottles) {
              checkProximitySensor();
              if (PET_BottleCount >= getPETBottleCountLimit(selectedItem)) {
                lcd2004.clear();
                lcd2004.setCursor(0, 0);
                lcd2004.print("The Right amount of");
                lcd2004.setCursor(0, 1);
                lcd2004.print("PET bottles has been");
                lcd2004.setCursor(0, 2);
                lcd2004.print("inserted");
                delay(2000);
                rotateServo(selectedItem);
                logToSD(selectedItem);
                returnToSelectItem();
                selectedItem = -1;
                countingBottles = false;
                break;
              }
            }
          }
        } else if (i == 4) {
          // Go Back button action
          selectedItem = -1;
          waitingForContinue = false;
          returnToSelectItem();
        }
      }
    }
  }

  delay(500); // Short delay to avoid spamming the loop
}

void rotateServo(int index) {
  servos[index].write(180); // Rotate to 180 degrees
  delay(500);
  servos[index].write(0);   // Rotate back to 0 degrees
  delay(500);

}

void logToSD(int index) {
  dataFile = SD.open("data.txt", FILE_WRITE);
  if (dataFile) {
    switch (index) {
      case 0:
        dataFile.println("Lucky Me noodles dispensed");
        break;
      case 1:
        dataFile.println("Mineral water dispensed");
        break;
      case 2:
        dataFile.println("Sky Flakes dispensed");
        break;
    }
    dataFile.close();
    Serial.println("Data logged to SD card.");
  } else {
    Serial.println("Error opening data.txt");
  }
}

void SendMessage() {
  sim.println("AT+CMGF=1");
  delay(1000);
  sim.println("AT+CMGS=\"+YOUR_NUMBER_HERE\"\r"); // Replace with your phone number
  delay(1000);
  sim.println("Low on supply, please resupply!");
  delay(100);
  sim.println((char)26);
  delay(1000);
}

void SendMessageCriticalLevel() {
  sim.println("AT+CMGF=1");
  delay(1000);
  sim.println("AT+CMGS=\"+YOUR_NUMBER_HERE\"\r"); // Replace with your phone number
  delay(1000);
  sim.println("Bottles storage in critical level!");
  delay(100);
  sim.println((char)26);
  delay(1000);
}

void displayItemConfirmation(int itemIndex) {
  if (useLCD2004) {
    lcd2004.clear();
    lcd2004.setCursor(0, 1);
    switch (itemIndex) {
      case 0:
        lcd2004.print("Distilled Water = ");
        lcd2004.print(PET_BOTTLE_COUNT_LIMIT);
        break;
      case 1:
        lcd2004.print("Skyflakes = ");
        lcd2004.print(PET_BOTTLE_COUNT_LIMIT + 2);
        break;
      case 2:
        lcd2004.print("Instant Noodles = ");
        lcd2004.print(PET_BOTTLE_COUNT_LIMIT + 5);
        break;
    }
    lcd2004.setCursor(0, 2);
    lcd2004.print("Continue or Go Back?");
  } 
}

void displayMessage(int index, const char* message) {
  if (useLCD2004) {
    lcd2004.clear();
    lcd2004.setCursor(0, 0);
    lcd2004.print(message);
  } 
}

void returnToSelectItem() {
    lcd2004.clear();
    lcd2004.setCursor(0, 0);
    lcd2004.print("Select an item");
    lcd2004.setCursor(0, 1);
    lcd2004.print("1) Distilled Water");
    lcd2004.setCursor(0, 2);
    lcd2004.print("2) Skyflakes");
    lcd2004.setCursor(0, 3);
    lcd2004.print("3) Instant noodles");
}

void checkProximitySensor() {
  // Check both slide switches (proximity sensors)
  int sensorValue1 = digitalRead(proximitySensorPins[0]);
  int sensorValue2 = digitalRead(proximitySensorPins[1]);

  // Only count the bottle if both sensors are LOW (indicating both switches are on)
  if (sensorValue1 == LOW && sensorValue2 == LOW) {
    // Detected a PET bottle
    PET_BottleCount++;
    if (PET_BottleCount <= getPETBottleCountLimit(selectedItem)) {
      lcd2004.setCursor(0, 2);
      lcd2004.print("PET Bottle Count: ");
      lcd2004.print(PET_BottleCount);
    }
    delay(1000); // Delay to prevent counting the same bottle multiple times
  }

     // Rotate Servo 4 if slide switch 1 is turned on
  if (sensorValue1 == LOW) {
    rotateServo4();
  }

  // Rotate Servo 5 if slide switch 2 is turned on
  if (sensorValue2 == LOW) {
    rotateServo5();
  }
}

void rotateServo4() {
  servo4.attach(servo4Pin);
  servo4.write(180);
  delay(1500); // Rotate for 1.5 seconds
  servo4.write(0);
  delay(500); // Hold the position before detaching
  servo4.detach();
}

void rotateServo5() {
  servo5.attach(servo5Pin);
  servo5.write(180);
  delay(1500); // Rotate for 1.5 seconds
  servo5.write(0);
  delay(500); // Hold the position before detaching
  servo5.detach();
}


int getPETBottleCountLimit(int itemIndex) {
  switch (itemIndex) {
    case 0:
      return PET_BOTTLE_COUNT_LIMIT;
    case 1:
      return PET_BOTTLE_COUNT_LIMIT + 2;
    case 2:
      return PET_BOTTLE_COUNT_LIMIT + 5;
    default:
      return PET_BOTTLE_COUNT_LIMIT;
  }
}