#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// Initialize the LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);

// DS18B20 Temperature sensor
#define ONE_WIRE_BUS 4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// Sensor pins
const int currentSensorPin = A0; // Potentiometer simulating current sensor
const int voltageSensorPin = A1; // Potentiometer simulating voltage sensor

// LED pins
const int chargingLED = 7;
const int fullChargeLED = 8;

// Button pins
const int startButton = 2;
const int stopButton = 3;

// Variables for sensor readings
float currentReading = 0.0;
float voltageReading = 0.0;
float tempReading = -127.0;  // Initialize to an invalid temperature

// Optimal values
const float optimalTempLow = 20.0;
const float optimalTempHigh = 25.0;
const float optimalCurrent = 10.0;  // Example optimal current in amps
const float optimalVoltage = 12.6;  // Example optimal voltage in volts

// Function prototypes
void readSensors();
void updateDisplay();
void handleButtons();
void checkChargingStatus();

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

  // Initialize the LCD
  lcd.begin(16, 2);
  lcd.print("Smart Charging");

  // Initialize the temperature sensor
  sensors.begin();

  // Set LED pins as output
  pinMode(chargingLED, OUTPUT);
  pinMode(fullChargeLED, OUTPUT);

  // Set button pins as input
  pinMode(startButton, INPUT_PULLUP);
  pinMode(stopButton, INPUT_PULLUP);

  // Initial LED state
  digitalWrite(chargingLED, LOW);
  digitalWrite(fullChargeLED, LOW);
}

void loop() {
  readSensors();
  updateDisplay();
  handleButtons();
  checkChargingStatus();
  delay(1000);  // Update every second
}

void readSensors() {
  // Read current sensor (potentiometer)
  int currentSensorValue = analogRead(currentSensorPin);
  currentReading = (currentSensorValue * 5.0 / 1023.0) * 10.0;  // Example conversion

  // Read voltage sensor (potentiometer)
  int voltageSensorValue = analogRead(voltageSensorPin);
  voltageReading = (voltageSensorValue * 5.0 / 1023.0) * 11.0;  // Example conversion

  // Read temperature sensor
  sensors.requestTemperatures();
  tempReading = sensors.getTempCByIndex(0);
}

void updateDisplay() {
  lcd.clear();
  
  // Check if readings are valid
  bool validCurrent = currentReading > 0;
  bool validVoltage = voltageReading > 0;
  bool validTemp = tempReading != -127.0;

  if (validCurrent && validVoltage && validTemp) {
    lcd.setCursor(0, 0);
    lcd.print("Cur: ");
    lcd.print(currentReading);
    lcd.print(" A");

    lcd.setCursor(0, 1);
    lcd.print("Volt: ");
    lcd.print(voltageReading);
    lcd.print(" V");

    delay(2000); // Display current readings for 2 seconds
    lcd.clear();
    
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(tempReading);
    lcd.print(" C");

    delay(2000); // Display temperature reading for 2 seconds
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Opt Temp: ");
    lcd.print(optimalTempLow);
    lcd.print("-");
    lcd.print(optimalTempHigh);
    lcd.print("C");
    
    Serial.print("Optimal Temperature: ");
    Serial.print(optimalTempLow);
    Serial.print(" - ");
    Serial.print(optimalTempHigh);
    Serial.println(" C");

    lcd.setCursor(0, 1);
    lcd.print("Opt Cur: ");
    lcd.print(optimalCurrent);
    lcd.print("A ");

    delay(2000); // Display optimal temperature and current for 2 seconds
    lcd.clear();

    lcd.setCursor(0, 0);
    lcd.print("Opt Volt: ");
    lcd.print(optimalVoltage);
    lcd.print(" V");

    delay(2000); // Display optimal voltage for 2 seconds
  }
}

void handleButtons() {
  if (digitalRead(startButton) == LOW) {
    digitalWrite(chargingLED, HIGH);
    digitalWrite(fullChargeLED, LOW);
  }

  if (digitalRead(stopButton) == LOW) {
    digitalWrite(chargingLED, LOW);
    digitalWrite(fullChargeLED, HIGH);
  }
}

void checkChargingStatus() {
  // Simple condition for full charge based on voltage level
  if (voltageReading > 12.6) {
    digitalWrite(chargingLED, LOW);
    digitalWrite(fullChargeLED, HIGH);
  } else {
    digitalWrite(chargingLED, HIGH);
    digitalWrite(fullChargeLED, LOW);
  }
}