#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define OLED_RESET 0  // GPIO0
Adafruit_SSD1306 display(OLED_RESET);

#if (SSD1306_LCDHEIGHT != 48)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif

const char* ssid = "IoT-Zecevic";
const char* password =  "IoTSifra123456!";
const char* mqttServer = "192.168.1.11";
const int mqttPort = 1883;
const char* mqttUser = "yourMQTTuser";
const char* mqttPassword = "yourMQTTpassword";
 
WiFiClient espClient;
PubSubClient client(espClient);
 
void callback(char* topic, byte* payload, unsigned int length) {
 
  Serial.print("Message arrived in topic: ");
  Serial.println(topic);
 
  Serial.print("Message:");
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println("Power: ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
    display.setTextSize(2);
    display.print((char)payload[i]);
  }
  
  display.display();
  Serial.println();
  Serial.println("-----------------------");
 
}
 
void setup() {

  Serial.begin(115200);

  // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize with the I2C addr 0x3C (for the 64x48)
  // init done

  // Clear the buffer.
  display.clearDisplay();

   WiFi.begin(ssid, password);
 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi..");
  }
  Serial.println("Connected to WiFi");
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println("Connected to the WiFi network!");
  display.display(); 
 
  client.setServer(mqttServer, mqttPort);
  client.setCallback(callback);
 
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
 
    if (client.connect("ESP32Client", mqttUser, mqttPassword )) {
 
      Serial.println("connected");
      Serial.println("Connected to mqtt!");
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.println("Connected to mqtt!");
      display.println("No data yet");
      display.display();   
 
    } else {
 
      Serial.print("failed with state ");
      Serial.print(client.state());
      delay(2000);
 
    }
  }
  //solar power
  client.subscribe("solar/114182126368/0/power");
  
  /*client.subscribe("tele/tasmota_server_C32969/SENSOR");
  client.subscribe("tele/tasmota_LR-C23E87/SENSOR");
  client.subscribe("tele/tasmota_OfficeNET_17A00F/SENSOR");
  client.subscribe("tele/tasmota_OfficePC1856E2/SENSOR");*/
 
}
 
void loop() {
  client.loop();
}