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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define SCREEN_ADDRESS 0x3C

// size of each character in pixel: 6 x 8
// each line can display 21 characters at most with text size of 1
#define CHAR_WIDTH 6
#define CHAR_HEIGHT 8
unsigned int textSize = 1;

#define RESET_BUTTON 4

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

unsigned int stepCounts = 0;
bool firstRun = true;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  if (!oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println("SSD1306 allocation failed!");
    for(;;);
  }

  pinMode(RESET_BUTTON, INPUT);

  oled.clearDisplay();
  oled.setTextSize(textSize);
  oled.setTextColor(SSD1306_WHITE);

  // date
  oled.setCursor(0, 0);
  oled.print("124-06-2005");

  // temperature
  char ch = 248; // degree symbol
  String temp = "33" + String(ch) + "C";
  oled.setCursor(SCREEN_WIDTH - temp.length() * CHAR_WIDTH * textSize, 0);
  oled.print(temp);

  // total steps
  unsigned int steps = 1234;
  String totalSteps = "Total steps: " + String(steps);
  oled.setCursor((SCREEN_WIDTH - totalSteps.length() * CHAR_WIDTH * textSize) / 2, 10);
  oled.print(totalSteps);

  // current round
  oled.drawFastHLine(0, 24, 128, SSD1306_WHITE);
  oled.drawFastVLine(0, 24, SCREEN_HEIGHT - 24, SSD1306_WHITE);
  oled.drawFastVLine(127, 24, SCREEN_HEIGHT - 24, SSD1306_WHITE);  

  oled.display();

  delay(2000);
}

void loop() {
  int btnResetState = digitalRead(RESET_BUTTON);
  if (btnResetState == HIGH) {
    String startTime = "Start at 07:10";
    oled.setCursor((SCREEN_WIDTH - startTime.length() * CHAR_WIDTH * textSize) / 2, 30);
    oled.print(startTime);

    String counting = "Counting: " + String(stepCounts);
    oled.setCursor((SCREEN_WIDTH - counting.length() * CHAR_WIDTH * textSize) / 2, 50);
    oled.print(counting);
    stepCounts++;
  }
  else {
    if (!firstRun) {
      String endTime = "End at 07:33";
      oled.setCursor((SCREEN_WIDTH - endTime.length() * CHAR_WIDTH * textSize) / 2, 40);
      oled.print(endTime);
    }
    firstRun = false;
    stepCounts = 0;
  }
  oled.display();

  delay(1000); // this speeds up the simulation
}