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

// --- Stepper Driver Pins (ESP32) ---
#define DIR_PIN 27
#define STEP_PIN 26

// --- DS18B20 setup ---
#define ONE_WIRE_BUS 25
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// --- LCD I2C setup ---
LiquidCrystal_I2C lcd(0x27, 16, 2); // use 0x3F if display doesn't show

// --- Variables ---
int tempReadCount = 0;
bool systemDeactivated = false;
unsigned long deactivationTime = 0;

// --- Motor Position Tracker ---
int motorPosition = 0; // absolute steps (0, 3, 6, 50)

// --- Functions ---
void stepMotor(int steps) {
  if (steps > 0) {
    digitalWrite(DIR_PIN, HIGH); // forward
  } else {
    digitalWrite(DIR_PIN, LOW);  // backward
    steps = -steps;
  }
  for (int i = 0; i < steps; i++) {
    digitalWrite(STEP_PIN, HIGH);
    delayMicroseconds(800);
    digitalWrite(STEP_PIN, LOW);
    delayMicroseconds(800);
  }
}

void moveToPosition(int target) {
  int delta = target - motorPosition;
  stepMotor(delta);
  motorPosition = target;
}

void setup() {
  Serial.begin(115200);   // ESP32 default baud
  sensors.begin();
  lcd.init();
  lcd.backlight();

  pinMode(DIR_PIN, OUTPUT);
  pinMode(STEP_PIN, OUTPUT);

  // System loading
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("System Loading");
  Serial.println("System Loading");
  delay(2000);

  // System activated
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("System Activated");
  Serial.println("System Activated");

  // Move motor to 50 steps initially
  moveToPosition(50);
  delay(500);
}

void loop() {
  sensors.requestTemperatures();
  float tempC = sensors.getTempCByIndex(0);

  // Always display temperature
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(tempC);
  lcd.print((char)223);
  lcd.print("C");

  Serial.print("Temperature: ");
  Serial.print(tempC);
  Serial.println("°C");

  if (!systemDeactivated) {
    // --- Control logic reordered from lowest → highest ---
    if (tempC > 62 && tempC <= 71.9) {
      moveToPosition(6);
      lcd.setCursor(0, 1);
      lcd.print("Motor at 10");
      lcd.print((char)223);
    }
    else if (tempC >= 72 && tempC < 77) {
      Serial.print("Alert: Temp at ");
      Serial.print(tempC);
      Serial.println("°C");
      lcd.setCursor(0, 1);
      lcd.print("Alert: T at ");
      lcd.print(int(tempC));
      lcd.print((char)223);
      lcd.println("C");
    }
    else if (tempC >= 77) {
      Serial.println("Alert: Temp > 77°C");
      lcd.setCursor(0, 1);
      lcd.print("ALERT: T > 77");
      lcd.print((char)223);
      lcd.print("C");
      tempReadCount++;

      if (tempReadCount >= 5) {
        moveToPosition(0);
        Serial.println("Alert: T > 77°C; system Deactivated");
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("System Deactivated");
        systemDeactivated = true;
        deactivationTime = millis();
      }
    }
  }
  else {
    if (tempC <= 60) { // Temperature falls below 60
      systemDeactivated = false;
      tempReadCount = 0;

      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("System");
      lcd.setCursor(0,1);
      lcd.print("Reactivated");
      Serial.println("System Reactivated");

      moveToPosition(50);
      delay(1000);
    }
  }

  delay(2000);
}