// Smart Surgical Laser Guide
// Wokwi Simulation - Arduino Uno
// Components: 2x Servo, LDR, LCD I2C, 2x LED, Potentiometer

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

// Pin Definitions
#define PIN_SERVO_M1   9
#define PIN_SERVO_M2   10
#define PIN_LDR        A0
#define PIN_POT        A1
#define PIN_BTN        4
#define PIN_LED_GREEN  7
#define PIN_LED_RED    6
#define LDR_THRESHOLD  600

Servo servoM1;
Servo servoM2;
LiquidCrystal_I2C lcd(0x27, 16, 2);

int theta1 = 45;
int theta2 = 45;
bool targetHit = false;
int servoSteps = 0;
unsigned long lastPrint = 0;

byte checkChar[8] = {
  0b00000, 0b00001, 0b00011, 0b10110,
  0b11100, 0b01000, 0b00000, 0b00000
};

void computeAngles(int targetDeg, int &t1, int &t2) {
  targetDeg = constrain(targetDeg, 10, 170);
  t1 = targetDeg / 2;
  t2 = 90 - t1;
  t1 = constrain(t1, 10, 85);
  t2 = constrain(t2, 10, 85);
}

void moveSmooth(Servo &srv, int &current, int target) {
  if (current == target) return;
  int step = (target > current) ? 1 : -1;
  while (current != target) {
    current += step;
    srv.write(current);
    delay(12);
    servoSteps++;
  }
}

void updateLCD(int t1, int t2, bool hit, int ldr) {
  lcd.setCursor(0, 0);
  lcd.print("M1:"); lcd.print(t1); lcd.print((char)223);
  lcd.print(" M2:"); lcd.print(t2); lcd.print((char)223);
  lcd.print("   ");
  lcd.setCursor(0, 1);
  if (hit) {
    lcd.print("TARGET HIT!     ");
  } else {
    lcd.print("LDR:"); lcd.print(ldr); lcd.print(" SCAN    ");
  }
}

void printSerial(int t1, int t2, int ldr, bool hit) {
  Serial.println("--------------------------------");
  Serial.print("  Theta1 (M1) : "); Serial.print(t1);   Serial.println(" deg");
  Serial.print("  Theta2 (M2) : "); Serial.print(t2);   Serial.println(" deg");
  Serial.print("  LDR value   : "); Serial.println(ldr);
  Serial.print("  Status      : "); Serial.println(hit ? "TARGET HIT!" : "Searching...");
  Serial.print("  Servo steps : "); Serial.println(servoSteps);
}

void setup() {
  Serial.begin(9600);
  servoM1.attach(PIN_SERVO_M1);
  servoM2.attach(PIN_SERVO_M2);
  servoM1.write(45);
  servoM2.write(45);
  pinMode(PIN_LED_GREEN, OUTPUT);
  pinMode(PIN_LED_RED,   OUTPUT);
  pinMode(PIN_BTN, INPUT_PULLUP);
  digitalWrite(PIN_LED_RED, HIGH);
  lcd.init();
  lcd.backlight();
  lcd.createChar(0, checkChar);
  lcd.clear();
  lcd.setCursor(0, 0); lcd.print("LASER GUIDE SYS ");
  lcd.setCursor(0, 1); lcd.print("Initializing... ");
  delay(1000);
  lcd.setCursor(0, 1); lcd.print("Self-test...    ");
  moveSmooth(servoM1, theta1, 75);
  moveSmooth(servoM2, theta2, 75);
  delay(200);
  moveSmooth(servoM1, theta1, 20);
  moveSmooth(servoM2, theta2, 20);
  delay(200);
  moveSmooth(servoM1, theta1, 45);
  moveSmooth(servoM2, theta2, 45);
  lcd.clear();
  Serial.println("=== SMART SURGICAL LASER GUIDE ===");
  Serial.println("System ready. Turn potentiometer to aim.");
  Serial.println("");
}

void loop() {
  int ldrValue    = analogRead(PIN_LDR);
  int potValue    = analogRead(PIN_POT);
  int targetAngle = map(potValue, 0, 1023, 10, 170);
  int newT1, newT2;
  computeAngles(targetAngle, newT1, newT2);
  if (abs(newT1 - theta1) >= 2) moveSmooth(servoM1, theta1, newT1);
  if (abs(newT2 - theta2) >= 2) moveSmooth(servoM2, theta2, newT2);
  targetHit = (ldrValue > LDR_THRESHOLD);
  digitalWrite(PIN_LED_GREEN, targetHit ? HIGH : LOW);
  digitalWrite(PIN_LED_RED,   targetHit ? LOW  : HIGH);
  updateLCD(theta1, theta2, targetHit, ldrValue);
  if (millis() - lastPrint > 600) {
    printSerial(theta1, theta2, ldrValue, targetHit);
    lastPrint = millis();
  }
  delay(40);
}