#include <IRremote.hpp>     // Library for IR remote control
#include <LiquidCrystal.h>  // Library for controlling LCD display
#include <Servo.h>          // Library for servo motor control

// Pin Definitions
#define IR_RECEIVE_PIN 2    // Pin for the IR receiver module
#define TEMP_PIN A5         // Pin for temperature sensor (analog input)
#define PHOTO_PIN A0        // Pin for photoresistor (light sensor)
#define SERVO_PIN 3         // Pin for the first servo motor
#define SERVO_PIN2 10       // Pin for the second servo motor
#define PIEZO_PIN 4         // Pin for the piezo buzzer
#define potPin A4           // Pin for the potentiometer (analog input)
#define LED_PIN 13          // Pin for the built-in LED

// Global Variables
int potVal;                 // Stores potentiometer value
int angle;                  // Stores servo angle
bool systemEnabled = false; // System status: ON/OFF

// LCD Initialization (RS, E, D4, D5, D6, D7 pins)
LiquidCrystal lcd(9, 8, 7, 6, 5, 4);
Servo myServo;             // Servo motor object for first servo
Servo myServo2;            // Servo motor object for second servo

// Function Prototypes
void initializeReceiver();           // Initialize the IR receiver
void initializeLCD();                // Initialize the LCD
void lcdPrint(char* text);           // Display text on the LCD
void translateIR();                  // Handle IR remote inputs
int mapPhotoresistorToServo(int);    // Map light sensor value to servo angle
float readTemperature();             // Read temperature sensor value

void setup() {
  // Initialize Components
  initializeReceiver();             // Setup IR receiver
  initializeLCD();                  // Setup LCD display
  pinMode(TEMP_PIN, INPUT);         // Set TEMP_PIN as input
  pinMode(LED_PIN, OUTPUT);         // Set LED_PIN as output
  digitalWrite(LED_PIN, LOW);       // Ensure LED is off initially

  myServo.attach(SERVO_PIN);        // Attach first servo to SERVO_PIN
  myServo2.attach(SERVO_PIN2);      // Attach second servo to SERVO_PIN2

  Serial.begin(9600);               // Start serial communication for debugging

  lcd.setCursor(0, 0);              // Set cursor at first line, first column
  lcd.print("System Ready...");     // Print system ready message
  delay(2000);                      // Wait 2 seconds
  lcd.clear();                      // Clear the LCD display
}

void loop() {
  // Check if IR input is received
  if (IrReceiver.decode()) {
    translateIR();                  // Decode and respond to IR command
    IrReceiver.resume();            // Resume IR receiver for next input
  }

  // Run sensors and logic when the system is enabled
  if (systemEnabled) {
    float temperature = readTemperature();  // Read temperature
    int lightLevel = analogRead(PHOTO_PIN); // Read light level from photoresistor
    potVal = analogRead(potPin);            // Read potentiometer value

    // Map potentiometer value to servo angle (0 to 179 degrees)
    angle = map(potVal, 0, 1023, 0, 179);
    myServo2.write(angle);                 // Move second servo to calculated angle

    // Map light sensor value to servo angle (0 to 90 degrees)
    int servoAngle = mapPhotoresistorToServo(lightLevel);
    myServo.write(servoAngle);             // Move first servo

    // Display temperature and light level on the LCD
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(temperature);
    lcd.print("C   ");

    lcd.setCursor(0, 1);
    lcd.print("Light: ");
    lcd.print(lightLevel);
    lcd.print("    ");
  }
}

// Map photoresistor value (0-1023) to servo angle (0-90 degrees)
int mapPhotoresistorToServo(int lightValue) {
  int servoAngle = map(lightValue, 0, 1023, 0, 90);
  return constrain(servoAngle, 0, 90); // Ensure servo angle is within 0-90 range
}

// Read temperature from TMP36 sensor
float readTemperature() {
  int sensorValue = analogRead(TEMP_PIN);     // Read analog value from temperature sensor
  float voltage = sensorValue * 5.0 / 1023.0; // Convert analog value to voltage
  float temperature = (voltage - 0.5) * 100;  // Convert voltage to temperature in Celsius
  return temperature;
}

// Initialize IR receiver
void initializeReceiver() {
  IrReceiver.begin(IR_RECEIVE_PIN); // Start the IR receiver on defined pin
}

// Initialize the LCD
void initializeLCD() {
  lcd.begin(16, 2);                 // Set up the LCD with 16 columns and 2 rows
  lcd.print("<press a button>");    // Display initial message
}

// Print text on the LCD
void lcdPrint(char* text) {
  lcd.clear();                      // Clear the LCD screen
  lcd.setCursor(0, 0);              // Set cursor at first line
  lcd.print("Button: ");            // Print Button label
  lcd.setCursor(0, 1);              // Set cursor at second line
  lcd.print(text);                  // Print received text
}

// Handle IR remote input and commands
void translateIR() {
  // Turn on LED and print code to Serial Monitor
  digitalWrite(LED_PIN, HIGH);      // Turn on built-in LED
  Serial.print("Button Code: ");
  Serial.println(IrReceiver.decodedIRData.command);

  switch (IrReceiver.decodedIRData.command) {
    case 162: // POWER Button
      systemEnabled = !systemEnabled;  // Toggle system state ON/OFF
      lcdPrint(systemEnabled ? "System ON" : "System OFF");
      break;
    case 226: lcdPrint("MENU"); break;
    case 34:  lcdPrint("TEST"); break;
    case 2:   lcdPrint("PLUS"); break;
    case 194: lcdPrint("BACK"); break;
    case 224: lcdPrint("PREV."); break;
    case 168: lcdPrint("PLAY"); break;
    case 144: lcdPrint("NEXT"); break;
    case 104: lcdPrint("num: 0"); break;
    case 152: lcdPrint("MINUS"); break;
    case 176: lcdPrint("key: C"); break;
    case 48:  lcdPrint("num: 1"); break;
    case 24:  lcdPrint("num: 2"); break;
    case 122: lcdPrint("num: 3"); break;
    case 16:  lcdPrint("num: 4"); break;
    case 56:  lcdPrint("num: 5"); break;
    case 90:  lcdPrint("num: 6"); break;
    case 66:  lcdPrint("num: 7"); break;
    case 74:  lcdPrint("num: 8"); break;
    case 82:  lcdPrint("num: 9"); break;
    default:  // Unknown Command
      lcd.clear();
      lcd.print("Unknown: ");
      lcd.print(IrReceiver.decodedIRData.command);
  }

  delay(200);                        // Keep LED on briefly
  digitalWrite(LED_PIN, LOW);        // Turn off LED
}