#include <Adafruit_GFX.h>
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <TOTP.h>
#include <swRTC.h>
#include <HX711.h>
#include <qrcode.h>

String display_stuff ="{\"token\":\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ3ZWlnaHQiOiIyIiwiaWF0IjoxNjczNjk5MTQxfQ.mXsG3XicF3txetpieWLVRPkJ1uXwVsVzTAivR9Gey0c\",\"dustbinId\":\"63c144b2df1d3f6b0826d25d\",\"timeStamp\":1673699141000}\"";
HX711 scale;
swRTC rtc;

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define PIN_TRIG 12
#define PIN_ECHO 11

#define DETECT_THRESHOLD 30

#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

String id = "someuniqueid";
uint8_t hmacKey[] = {0x4d, 0x79, 0x4c, 0x65, 0x67, 0x6f, 0x44, 0x6f, 0x6f, 0x72};
TOTP totp = TOTP(hmacKey, 6);


void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  rtc.setTime(0,0,0);
  rtc.startRTC();

  scale.begin(A1, A0);

  scale.tare();

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

  }



  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);

  display.display();
  delay(2000);

  display.clearDisplay();

  // Not all the characters will fit on the display. This is normal.
  // Library will draw what it can and the rest will be clipped.

}

int previous_distance = 0;
double previous_weight = 0.0;

void loop() {
  // put your main code here, to run repeatedly:

  // Start a new measurement:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Read the result:
  int duration = pulseIn(PIN_ECHO, HIGH);
  Serial.print("Distance in CM: ");
  Serial.println(duration / 58);
  Serial.print("Distance in inches: ");
  Serial.println(duration / 148);

  int dist_cm = duration / 58;

  double weight = scale.get_units();
  Serial.println(weight);

  if (dist_cm != previous_distance || weight != previous_weight) {
    Serial.println("Something changed");

    previous_weight = weight;
    previous_distance = dist_cm;

    QRCode qrcode;
    uint8_t qrcodeData[qrcode_getBufferSize(7)];

     char *otp = totp.getCode(rtc.getTimestamp(1970));

    String encode = id + String(".") + String(otp) + String(".") + String(weight);

    qrcode_initText(&qrcode, qrcodeData, 7, ECC_HIGH, display_stuff.c_str());

    display.clearDisplay();


    for (uint8_t y = 0; y < qrcode.size; y++) {
        for (uint8_t x = 0; x < qrcode.size; x++) {
            if (qrcode_getModule(&qrcode, x, y)) {
              display.drawPixel(x, y, SSD1306_WHITE);
            }

        }
    }

    display.display();
    delay(30000); 

 

  } else {
    Serial.println("Nothing changed");
    display.clearDisplay();
    display.display();
  }


  delay(1000);

}