#include <SPI.h>
#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 SW_PIN 14
#define DT_PIN 13
#define CLK_PIN 12

int ROTARY_VALUE = 0;
int lastClk=0;
int newClk;

#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  Serial.begin(115200);

  pinMode(SW_PIN, INPUT);
  pinMode(DT_PIN, INPUT);
  pinMode(CLK_PIN, INPUT);

  // attachInterrupt(digitalPinToInterrupt(CLK_PIN), readEncoder, FALLING);

  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  display.clearDisplay();
  display.display();
}

void readEncoder() {

  int newClk = digitalRead(CLK_PIN);
  if (newClk != lastClk) {
    // There was a change on the CLK pin
    lastClk = newClk;
    ROTARY_VALUE++;
    int dtValue = digitalRead(DT_PIN);
    if (newClk == LOW && dtValue == HIGH) {
      // ROTARY_VALUE++;
      // Serial.println("Rotated clockwise ⏩");
    }
    if (newClk == LOW && dtValue == LOW) {
      // Serial.println("Rotated counterclockwise ⏪");
      // ROTARY_VALUE--;
    }
  }
  else{
    ROTARY_VALUE--;
  }
}

void loop() {
  readEncoder();
  mainDisplay();
  Serial.println(ROTARY_VALUE);
}

void mainDisplay(){

  display.clearDisplay();

  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.println(F("AMSA"));

  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(10, 10);
  display.println(F(ROTARY_VALUE));
  display.display();

  delay(100);
}