/*********
  Diyusthad
  Complete project details at https://diyusthad.com
*********/

#include <LiquidCrystal_I2C.h>

// set the LCD number of columns and rows
int lcdColumns = 16;
int lcdRows = 2;

LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);
// if you don't know your display's I2C address, run an I2C scanner sketch
// set LCD address, number of columns and rows

#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <UniversalTelegramBot.h>

// Wifi network station credentials
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
// Telegram BOT Token (Get from Botfather)
#define BOT_TOKEN "6516985274:AAHVZyMkO2_qdzMZ6BJtH07faEQYAqn3tk4"
#define CHAT_ID "6164808768"

const unsigned long BOT_MTBS = 1000; // mean time between scan messages



WiFiClientSecure secured_client;
UniversalTelegramBot bot(BOT_TOKEN, secured_client);
unsigned long bot_lasttime; // last time messages' scan has been done

void handleNewMessages(int numNewMessages)
{
  Serial.print("handleNewMessages ");
  Serial.println(numNewMessages);

  for (int i = 0; i < numNewMessages; i++)
  {
    String chat_id = String(bot.messages[i].chat_id);
    if (chat_id != CHAT_ID )
    {
      bot.sendMessage(chat_id, "Unauthorized user", "");
    }
    else
    {
      String text = bot.messages[i].text;

      String from_name = bot.messages[i].from_name;
      if (from_name == "")
        from_name = "Guest";

      if (text == "/start")
      {
        String welcome = "Welcome to ESP32 IoT display, " + from_name + ".\n";
        welcome += "Just type your message and send .\n\n";
        bot.sendMessage(chat_id, welcome, "Markdown");
      }
      else
      {
//         lcd.clear();
//         lcd.setCursor(1, 0);
//         lcd.print(from_name);
// delay(500);
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("    ");
        lcd.print(text); 
        lcd.print("    ");
      }
    }
  }
}


void setup() {
  // initialize LCD
  lcd.init();
  // turn on LCD backlight
  lcd.backlight();

  Serial.begin(115200);
  Serial.println();

  // attempt to connect to Wifi network:
  Serial.print("Connecting to Wifi SSID ");
  Serial.print(WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  secured_client.setCACert(TELEGRAM_CERTIFICATE_ROOT); // Add root certificate for api.telegram.org
  while (WiFi.status() != WL_CONNECTED)
  {
    Serial.print(".");
    delay(500);
  }
  Serial.print("\nWiFi connected. IP address: ");
  Serial.println(WiFi.localIP());

}

void loop() {

  if (millis() - bot_lasttime > BOT_MTBS)
  {
    int numNewMessages = bot.getUpdates(bot.last_message_received + 1);

    while (numNewMessages)
    {
      Serial.println("got response");
      handleNewMessages(numNewMessages);
      numNewMessages = bot.getUpdates(bot.last_message_received + 1);
    }

    bot_lasttime = millis();
  }

    lcd.scrollDisplayLeft();

}