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

LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin definitions
#define RSSI_PIN PA0
#define MOTOR_PIN PA8
#define BUZZER_PIN PB10
#define LASER_PIN PB11
#define EMG_BTN PB12

void setup() {
  pinMode(MOTOR_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LASER_PIN, OUTPUT);
  pinMode(EMG_BTN, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();

  lcd.setCursor(0,0);
  lcd.print("Border Alert");
  lcd.setCursor(0,1);
  lcd.print("System Ready");
  delay(2000);
  lcd.clear();
}

void loop() {

  int rssiValue = analogRead(RSSI_PIN);  // 0–4095 STM32
  int emergency = digitalRead(EMG_BTN);

  // Emergency Mode
  if (emergency == LOW) {
    analogWrite(MOTOR_PIN, 0);
    digitalWrite(BUZZER_PIN, HIGH);
    digitalWrite(LASER_PIN, HIGH);

    lcd.setCursor(0,0);
    lcd.print("EMERGENCY !!! ");
    lcd.setCursor(0,1);
    lcd.print("STOP BOAT    ");
    delay(500);
    return;
  }

  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(LASER_PIN, LOW);

  // SAFE ZONE
  if (rssiValue > 2500) {
    analogWrite(MOTOR_PIN, 255);
    lcd.setCursor(0,0);
    lcd.print("Status: SAFE ");
    lcd.setCursor(0,1);
    lcd.print("Speed: HIGH ");
  }

  // WARNING ZONE
  else if (rssiValue > 1500) {
    analogWrite(MOTOR_PIN, 120);
    digitalWrite(BUZZER_PIN, HIGH);

    lcd.setCursor(0,0);
    lcd.print("Status: WARN ");
    lcd.setCursor(0,1);
    lcd.print("Slow Down    ");
  }

  // DANGER ZONE
  else {
    analogWrite(MOTOR_PIN, 0);
    digitalWrite(BUZZER_PIN, HIGH);
    digitalWrite(LASER_PIN, HIGH);

    lcd.setCursor(0,0);
    lcd.print("DANGER ZONE  ");
    lcd.setCursor(0,1);
    lcd.print("STOP BOAT   ");
  }

  delay(500);
}