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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1    // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C // I2C address of the OLED display

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

//Global variables
int days = 0;
int hours = 0;
int minutes = 0;
int seconds = 0;
unsigned long timeNow = 0;
unsigned long timeLast = 0;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;)
      ;
  }
  display.display();
  delay(2000);

  display.clearDisplay();
  print_line("Welcome to Medibox!", 10, 20, 2);
}

void loop() {
  update_time();
  print_time_now();
}

void print_line(String text, int column, int row, int textsize) {
  display.setTextSize(textsize);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(column, row);
  display.println(text);
  display.display();
}

void print_time_now() {
  display.clearDisplay();
  print_line(String(days), 0, 0, 2);
  print_line(":", 20, 0, 2);
  print_line(String(hours), 30, 0, 2);
  print_line(":", 50, 0, 2);
  print_line(String(minutes), 60, 0, 2);
  print_line(":", 80, 0, 2);
  print_line(String(seconds), 90, 0, 2);
}

void update_time() {
  timeNow = millis() / 1000; //seconds passed from bootup
  seconds = timeNow - timeLast;

  if (seconds >= 60) {
    minutes += 1; //minutes = minutes +1
    timeLast += 60;
  }

  if (minutes == 60) {
    hours += 1;
    minutes = 0;
  }

  if (hours == 24) {
    days += 1;
    hours = 0;
  }
}