#include <WiFi.h>
#include <EEPROM.h>
#include <PubSubClient.h>
#include <Adafruit_SSD1306.h>

#define MQTT_SERVER "104.214.189.245"
#define MQTT_PORT 1883
#define MQTT_USERNAME ""
#define MQTT_PASSWORD ""
#define MQTT_NAME "ESP32_1"
#define LED_PIN 25
#define POT 34
#define sw 5
#define EEPROM_SIZE 4056
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32

WiFiClient client;
PubSubClient mqtt(client);
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire);

const char* send_pot = "/ESP32_1/POT";
String text, textclone;
bool toggle = true;
int pot, timecount, cov;

int suit(int value) {
  return (value * 255) / 4095;
}
void callback(char *topic, byte *payload, unsigned int length) {
  for (int i = 0; i < length; i++) {
    text += (char)payload[i];
  }
  textclone = text;
  text = "";
  Serial.println("text is");
  Serial.println(textclone);
}
void showoled(int add, int value, int cov, bool key) {
  display.clearDisplay();
  display.display();
  display.setTextSize(0.5);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  if (key) {

    display.println(F("ON"));
    display.setCursor(60, 0);
    display.println(F("ADC : "));
    display.setCursor(80, 0);
    display.println(value);
    display.setCursor(0, 15);
    display.println(F("Address : "));
    display.setCursor(60, 15);
    display.println(add);
    display.setCursor(0, 25);
    display.println(F("Data : "));
    display.setCursor(40, 25);
    display.println(cov);
    display.display();
  } else {
    display.println(F("OFF"));
    display.setCursor(60, 0);
    display.println(F("ADC : "));
    display.setCursor(80, 0);
    display.println(value);
    display.setCursor(0, 15);
    display.println(F("Address : "));
    display.setCursor(60, 15);
    display.println(add);
    display.setCursor(0, 25);
    display.println(F("Data : "));
    display.setCursor(40, 25);
    display.println(cov);
    display.display();
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  pinMode(sw, INPUT_PULLUP);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true); 
  }

  if (!EEPROM.begin(EEPROM_SIZE)) {
    Serial.println("Failed to initialize EEPROM");
    delay(1000);
    ESP.restart(); 
  }


  WiFi.mode(WIFI_STA);
  WiFi.begin("Wokwi-GUEST", ""); 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("WiFi connected");

  EEPROM.writeUChar(82, 0);
  EEPROM.commit();

  mqtt.setServer(MQTT_SERVER, MQTT_PORT);
  mqtt.setCallback(callback);
}

void loop() {
  if (!mqtt.connected()) {
    if (mqtt.connect(MQTT_NAME, MQTT_USERNAME, MQTT_PASSWORD)) {
      Serial.println("Connected to MQTT");
      mqtt.subscribe("/ESP32_1/POT");
      mqtt.subscribe("/ESP32_1/LED"); 
    } else {
      delay(5000); 
      return;
    }
  }
  
  mqtt.loop(); 
  pot = analogRead(POT);
  cov = suit(pot);

  if (digitalRead(sw) == LOW) {
    delay(1000); 
    mqtt.publish("/ESP32_1/POT",String(EEPROM.readUChar(82)).c_str());    
    EEPROM.writeUChar(82, cov);
    EEPROM.commit();
    Serial.println("Commit success");
  }

  if (textclone == "on") {

    showoled(82, pot, cov, true); 
    analogWrite(LED_PIN, EEPROM.readUChar(82));
  } 
  else if (textclone == "off") 
  {
    showoled(82, pot, cov, false); 
    analogWrite(LED_PIN, 0); 
  }
  else
  {
    showoled(82, pot, cov, false); 
    analogWrite(LED_PIN, 0); 
  }
}