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

#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 64 

Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;

int ledR = 14;
int ledY = 12;
int ledG = 13;


void setup_wifi() 
{
  delay(10);

  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

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

  randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) 
{
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) 
  {
    //Serial.print((char)payload[i]);
  }
  Serial.println();

  // if ((char)payload[0] == '1') 
  // {
  //   digitalWrite(2, LOW); 
  // } 
  // else 
  // {
  //   digitalWrite(2, HIGH);
  // }
}

void reconnect() 
{ 
  while (!client.connected()) 
  {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) 
    {
      Serial.println("Connected");
      client.publish("KDR5B2023", "SELAMAT DATANG DI QUIZ KDR"); 
      delay(500);
      client.publish("KDR5B2023", "JIKA KALIAN MENERIMA PESAN INI");
      delay(500);
      client.publish("KDR5B2023", "HARAP MENGIRIMKAN KALIMAT SIAP");
      delay(500);
      client.publish("KDR5B2023", "SIAP?");
      client.subscribe("KDR5B2023"); 
    } 
    else 
    {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() 
{
  pinMode(2, OUTPUT); 

  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) 
  {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }
  oled.clearDisplay();

  oled.setTextSize(1);         
  oled.setTextColor(WHITE);   
  oled.setCursor(0, 2);      
  oled.println("Robotronix"); 
  oled.display();

  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  reconnect();
}

void loop() 
{
  // if (!client.connected()) 
  // {
  //   reconnect();
  // }
  client.loop();
  delay(500);

  // unsigned long now = millis();
  // if (now - lastMsg > 2000) 
  // {
  //   lastMsg = now;
  // }
}