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

#define OLED_ADDR   0x3C
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

#define SSD1306_128_64
// #define SSD1306_128_32
// #define SSD1306_96_16

// #if (SSD1306_LCDHEIGHT != 64)
// #error("Height incorrect, please fix Adafruit_SSD1306.h!");
// #endif

/*
Code  downoladed  from https://www.hackster.io/yilmazyurdakul/arduino-oled-encoder-simple-menu-system-f9baa1
Original code have bug (little arrow changing continuously) was fixed and slightly improved ... 

*/

#define encoder0PinA  2
#define encoder0PinB  3
volatile unsigned int encoder0Pos = 0;

int valA;
int valB;
int valC;
const byte encoder_switch = 4;
byte clk;
byte menuCount = 1;
byte dir = 0;
bool runState = false;

void setup() {
  pinMode(6, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(encoder_switch,INPUT_PULLUP);
  Serial.begin(9600);
  display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
  display.clearDisplay();
  display.display();
 
  attachInterrupt(0, doEncoder, CHANGE);  // encoder pin on interrupt 0 - pin 2
}

void loop() {
  if (digitalRead(encoder_switch) == LOW){clk = LOW;}
  if (digitalRead(encoder_switch) == HIGH){clk = HIGH;}  
  Serial.println(clk);
  ledControl();
  menuCheck();
  staticMenu();
  display.clearDisplay();
  delay(50);
}

void staticMenu() {
  display.setTextColor(WHITE);
  display.setTextSize(1);
  display.setCursor(10, 10);
  display.println("Value A:");
  display.setCursor(60, 10);
  display.println(valA);

  display.setCursor(10, 20);
  display.println("Value B:");
  display.setCursor(60, 20);
  display.println(valB);

  display.setCursor(10, 30);
  display.println("Value C:");
  display.setCursor(60, 30);
  display.println(valC);
  display.setCursor(10, 40);
  
  if (encoder0Pos > 4 && menuCount == 4) {
    display.println("Push = Clear & OFF");
    runState = true;
  } else {
    display.println("Turn right = ON");
    runState = false;
  }
  display.setCursor(2, (menuCount * 10));
  display.println(">");

  display.display();
}

void ledControl() {
  if (runState == true) {
    analogWrite(6, valA);
    analogWrite(9, valB);
    analogWrite(10, valC);
  }
}
void menuCheck() {
  if (clk == LOW && menuCount < 5) 
  {
    menuCount++;
    encoder0Pos = 0;
  }
  if (clk == LOW && menuCount >= 5) {
    valA =0, valB =0, valC =0;
    analogWrite(6, valA);
    analogWrite(9, valB);
    analogWrite(10,valC);
       
    menuCount = 1;
  }

  if (menuCount == 1) {
    valA = encoder0Pos;
  }
  if (menuCount == 2) {
    valB = encoder0Pos;
  }
  if (menuCount == 3) {
    valC = encoder0Pos;
  }
}

void doEncoder() {
  if (digitalRead(encoder0PinA) == HIGH) {
    if (digitalRead(encoder0PinB) == LOW && encoder0Pos > 0) {
      encoder0Pos = encoder0Pos - 1;
     // dir = 0;
    }
    else {
      encoder0Pos = encoder0Pos + 1;
     // dir = 1;
    }
  }
  else
  {
    if (digitalRead(encoder0PinB) == LOW ) {
      encoder0Pos = encoder0Pos + 1;
     // dir = 1;
    }
    else {
      if (encoder0Pos > 0) {
        encoder0Pos = encoder0Pos - 1;
       // dir = 0;
      }
    }
  }
}