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

// Constants
const char *ssid = "Wokwi-GUEST";
const char *password = "";
const char *mqtt_server = "broker.emqx.io";
const char *mqtt_username = "";
const char *mqtt_password = "";
const char *mqtt_topic = "parsing";

// OLED Setup
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Function prototypes
void setupWiFi();
void setupMQTT();
void callback(char *topic, byte *payload, unsigned int length);
void displayPoints(int points);

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);

  // Setup OLED
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }

  display.display();
  delay(2000);
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);

  setupWiFi();
  setupMQTT();
}

void loop() {
  if (!client.connected()) {
    setupMQTT();
  }

  client.loop();
}

void setupWiFi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to WiFi");

  WiFi.begin(ssid, password);

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

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

void setupMQTT() {
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client", mqtt_username, mqtt_password)) {
      Serial.println("connected");
      client.subscribe(mqtt_topic);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void callback(char *topic, byte *payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");

  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  Serial.println(message);

  // Parsing message
  int separatorIndex = message.indexOf(',');
  if (separatorIndex != -1) {
    String trigger = message.substring(0, separatorIndex);
    String pointsStr = message.substring(separatorIndex + 1);

    if (trigger.equals("yes")) {
      int points = pointsStr.toInt();
      displayPoints(points);
    }
  }
}

void displayPoints(int points) {
  display.clearDisplay();
  display.setTextSize(3);
  display.setCursor(0, 0);
  display.print("Points: ");
  display.print(points);
  display.display();
}