#define BLYNK_TEMPLATE_ID "TMPL39sshMipF"
#define BLYNK_TEMPLATE_NAME "heat controller"
#define BLYNK_AUTH_TOKEN "e8Xm8OQs4QUUITtZawrQiBA-k2H5zdc_"

#include<WiFi.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <esp_timer.h>
#include <BlynkSimpleEsp32.h>
#include <DallasTemperature.h>
#include <OneWire.h>
#include <esp32-hal-ledc.h>


#define ONE_WIRE_BUS 15
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
bool systemon = false;


esp_timer_handle_t periodic_timer;
volatile bool flag = false;
#define VPIN_TEMP V0
#define VPIN_STATE V1
#define VPIN_SLIDE_SWITCH V2

void periodicTimerCallback(void* arg) {
  flag = true;
}

Adafruit_SSD1306 display(128,64,&Wire,-1);
void updateOLED(float temperature, String state); // Declaration


//wifi credentials

const char* ssid="Wokwi-GUEST";
const char* password="";

bool ledStatus = false; // Tracks   LED state

#define   LED 26    //built-in   LED is pin 2

hw_timer_t * timer = NULL;
portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;


float temperature = 0;

#define RELAY_PIN 27
#define BUZZER_PIN 25
#define DS18B20_PIN 15
#define SWITCH_PIN 14



void setup() {
  Serial.begin(115200);
  pinMode(SWITCH_PIN, INPUT);
  pinMode(  LED, OUTPUT);
   pinMode(RELAY_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite( LED, LOW); // Start with  LED off
  digitalWrite(BUZZER_PIN, LOW);  // Add this in setup

sensors.begin();
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Default I2C address
  Serial.println(F("SSD1306 allocation failed"));
  while (true); // Halt
}
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(SSD1306_WHITE);
display.setCursor(0, 0);
display.println("Starting...");
display.display();
delay(1000);

  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nConnected to WiFi");


const esp_timer_create_args_t periodic_timer_args = {
    .callback = &periodicTimerCallback,
    .arg = nullptr,
    .dispatch_method = ESP_TIMER_TASK,
    .name = "periodic_timer"
  };

  esp_timer_create(&periodic_timer_args, &periodic_timer);
  esp_timer_start_periodic(periodic_timer, 1000000);  // 1 second in microseconds

  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, password);
Serial.println("Connecting to Blynk...");
}

BLYNK_WRITE(VPIN_SLIDE_SWITCH) {
  systemon = param.asInt(); // If the slide switch is ON (1), systemOn will be true
}


void loop() {
 
  Blynk.run();
  static bool lastSwitchState = false;
bool currentSwitchState = digitalRead(SWITCH_PIN);

if (currentSwitchState != lastSwitchState) {
  lastSwitchState = currentSwitchState;
  systemon = currentSwitchState;

  // Reflect the new state in Blynk app
  Blynk.virtualWrite(VPIN_SLIDE_SWITCH, systemon);
  Serial.print("Slide switch toggled. System is now: ");
  Serial.println(systemon ? "ON" : "OFF");
}
  if (flag) {
    portENTER_CRITICAL(&timerMux);
    flag = false;
    portEXIT_CRITICAL(&timerMux);
    readAndPublishTemperature();
  }
}



void  readAndPublishTemperature() 
{
  
  sensors.requestTemperatures();  // Request temperature readings
  temperature = sensors.getTempCByIndex(0);

 

  Serial.println(temperature);
  char payload[10]; // buffer array size is proportional to message that wanted to be sent
  snprintf(payload, sizeof(payload), "%.2f",temperature);

String state = "OFF";

   if (systemon) {
    if (temperature < 20) {
      state = "Idle";
      digitalWrite(RELAY_PIN, LOW);
      ledStatus = false;
      noTone(BUZZER_PIN);
    } else if (temperature < 30) {
      state = "Heating";
      digitalWrite(RELAY_PIN, HIGH);
      ledStatus = true;
      noTone(BUZZER_PIN);
    } else if (temperature < 35) {
      state = "Stabilizing";
      digitalWrite(RELAY_PIN, HIGH);
      ledStatus = true;
      noTone(BUZZER_PIN);
    } else if (temperature <= 37) {
      state = "Target Reached";
      digitalWrite( RELAY_PIN, LOW);
      ledStatus = false;
      noTone(BUZZER_PIN);
    } else {
      state = "Overheat";
      digitalWrite( RELAY_PIN, LOW);
      tone(BUZZER_PIN, 2000);
      ledStatus = false;
      Serial.println("Overheat! Turning off heater.");
    }
   }
  if (!systemon) {
  state = "System OFF";
  digitalWrite(RELAY_PIN, LOW);
  ledStatus = false;
  noTone(BUZZER_PIN);
  Serial.println("System is OFF. Heater is disabled.");
}
    updateOLED(temperature, state);


  // Serial log
  
  Serial.print(" | Temp: ");
  Serial.print(temperature, 2);
  Serial.print(" °C | State: ");
  Serial.println(state);

  
Blynk.virtualWrite(VPIN_TEMP, temperature); 
  Blynk.virtualWrite(VPIN_STATE, state); 

  // Printing message value on Serial Monitor and waiting
  Serial.println();
  
}

void updateOLED(float temp, String state) {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Temp: ");
  display.print(temp, 1);
  display.println(" C");

  display.print("State: ");
  display.println(state);

  display.print("WiFi: ");
  display.println(WiFi.isConnected() ? "OK" : "FAIL");

  
  display.display();
}