// Include libraries
#include <Wire.h>               // For I2C communication (included in ESp32 by default)
#include <Adafruit_GFX.h>       // Provides functions for drawing graphics and text on the display
#include <Adafruit_SSD1306.h>   // Handles communication and control of the SSD1306 OLED display driver chip

// Define OLED parameters
#define SCREEN_WIDTH 128     // OLED display width, in pixels
#define SCREEN_HEIGHT 64     // OLED display height, in pixels
#define OLED_RESET -1        // Set it to -1 if your module doesn't have a separate reset pin and shares the reset pin with the ESP32.
#define SCREEN_ADDRESS 0x3C  // I2C address of your OLED display (Some have 0x3D)

// This line creates an instance named display, of the class Adafruit_SSD1306, which will be used to control the OLED display.
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup(){
  Serial.begin(115200);
  // SSD1306_SWITCHCAPVCC, tells the library to use the ESP32's internal 3.3V supply to generate the necessary voltage for the display
  // If the initialization fails, an error message is printed, and the code enters an infinite loop.
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)){     // (! = not)
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);     // Infinite loop (To stop the program from proceeding further)
  }

  display.display();        // Shows initial display buffer contents on the screen (Adafruit boot screen)
  delay(2000);              // Pause for 2 seconds
  display.clearDisplay();   // Clears the buffer

  display.setTextSize(1);   // Normal text size (1:1 pixel scale)
  display.setTextColor(SSD1306_WHITE);    
  display.setCursor(0,0);   // (column, row) Sets the cursor position to the top-left corner
  display.println(F("Welcome to Medibox!"));  // The F macro tells the compiler to store a string directly in flash memory (program memory) instead of RAM. Hence load on RAM is reduced.
  display.display();
}

void loop(){
  delay(10);  // this speeds up the simulation
  // Simulation environments often run at an accelerated pace compared to real-time hardware.
  // This means that the code executes and updates the simulated display much faster than it would on an actual physical device.
  // By introducing a small delay, the code execution slows down slightly within the simulation.
  // This allows the simulated OLED display to catch up and update at a more observable rate, making it easier to see the changes happening on the display.
}