// A test for the Discord channel.
// Replaced the Adafruit_Liquidcrystal library by the common library.
// Added a I2C bus scanner.

#include <LiquidCrystal_I2C.h>

// LCD Initialization
//Adafruit_LiquidCrystal lcd(0);
LiquidCrystal_I2C lcd(0x27, 16, 2);


// ---------------- PIN DEFINITIONS ----------------
const int BTN_0  = 5;
const int BTN_30 = 4;
const int BTN_45 = 3;
const int BTN_60 = 2;

// L293D Motor Driver Pins
const int MOTOR_EN  = 10;
const int MOTOR_IN1 = 9;
const int MOTOR_IN2 = 8;

// ---------------- VARIABLES ----------------
int targetAngle = 0;
int currentAngle = 0;

unsigned long lastUpdateTime = 0;
const unsigned long updateInterval = 40;

// ---------------- SETUP ----------------
void setup() {

  Serial.begin(9600);

  // Added, a I2C bus scan
  Wire.begin();
  Serial.print("I2C bus scan: ");
  for(int address=1; address<128; address++)
  {
    Wire.beginTransmission(address);
    int error = Wire.endTransmission();
    if(error == 0)
    {
      Serial.print("0x");
      Serial.print(address,HEX);
      Serial.print(", ");
    }
  }
  Serial.println();

//  lcd.begin(16, 2); // this is for the Adafruit display.
  lcd.clear();
  lcd.init();
  lcd.backlight();

  // Button Inputs
  pinMode(BTN_0, INPUT_PULLUP);
  pinMode(BTN_30, INPUT_PULLUP);
  pinMode(BTN_45, INPUT_PULLUP);
  pinMode(BTN_60, INPUT_PULLUP);

  // Motor Outputs
  pinMode(MOTOR_EN, OUTPUT);
  pinMode(MOTOR_IN1, OUTPUT);
  pinMode(MOTOR_IN2, OUTPUT);

  stopActuator();

  updateDisplay();

  Serial.println("System Ready");
}

// ---------------- MAIN LOOP ----------------
void loop() {

  checkButtons();

  // Smooth actuator movement
  if (millis() - lastUpdateTime >= updateInterval) {

    lastUpdateTime = millis();

    if (currentAngle < targetAngle) {

      extendActuator();
      currentAngle++;

      updateDisplay();
    }

    else if (currentAngle > targetAngle) {

      retractActuator();
      currentAngle--;

      updateDisplay();
    }

    else {

      stopActuator();
    }
  }
}

// ---------------- BUTTON HANDLER ----------------
void checkButtons() {

  if (digitalRead(BTN_0) == LOW) {
    setTarget(0);
  }

  else if (digitalRead(BTN_30) == LOW) {
    setTarget(30);
  }

  else if (digitalRead(BTN_45) == LOW) {
    setTarget(45);
  }

  else if (digitalRead(BTN_60) == LOW) {
    setTarget(60);
  }
}

// ---------------- TARGET SETTER ----------------
void setTarget(int angle) {

  if (targetAngle != angle) {

    targetAngle = angle;

    Serial.print("Target set to: ");
    Serial.println(targetAngle);

    updateDisplay();

    delay(200); // debounce
  }
}

// ---------------- MOTOR CONTROLS ----------------
void extendActuator() {

  digitalWrite(MOTOR_EN, HIGH);
  digitalWrite(MOTOR_IN1, HIGH);
  digitalWrite(MOTOR_IN2, LOW);
}

void retractActuator() {

  digitalWrite(MOTOR_EN, HIGH);
  digitalWrite(MOTOR_IN1, LOW);
  digitalWrite(MOTOR_IN2, HIGH);
}

void stopActuator() {

  digitalWrite(MOTOR_EN, LOW);
  digitalWrite(MOTOR_IN1, LOW);
  digitalWrite(MOTOR_IN2, LOW);
}

// ---------------- LCD DISPLAY ----------------
void updateDisplay() {

  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("SETTING:");
  lcd.print(targetAngle);
  lcd.print((char)223); // degree symbol

  lcd.setCursor(0, 1);
  lcd.print("ACTUAL :");
  lcd.print(currentAngle);
  lcd.print((char)223);
}