//#include <spi.h>
#include <Wire.h> 
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
//#define ENCODER_OPTIMIZE_INTERRUPTS
#include <Encoder.h>

// screen specifics
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for SSD1306 display connected using I2C
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);


Encoder myEnc(3, 4);
String timeStr = "";
long oldPosition  = -999;
long initPosition = -999;
unsigned long menuTriggeredTime = 0;
const int numOfScreens = 5;
int currentScreen = -1;
String screens[numOfScreens][2] = {
  {"Ignition Time","Minutes"}, 
  {"Stabilization", "Minutes"}, 
  {"Cleaning","Minutes"},
  {"Start dose","Seconds"}, 
  {"Cut-off Temperature","Celsius"}, 
};
int parameters[numOfScreens];
bool updateScreen = true;

void setup() {
  //Wire.begin(D1, D2);
  pinMode(2, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(2), triggerMenu, FALLING);
  initScreen();
  delay(2000);
}

void loop() {
  long newPosition = myEnc.read();
  if (newPosition != oldPosition && newPosition % 2 == 0) {
    if(menuTriggeredTime != 0 && currentScreen != -1) {
      if(newPosition > oldPosition) {
        parameters[currentScreen]++;
      } else {
        parameters[currentScreen]--;
      }
      //reset menu trigger time on parameter change
      menuTriggeredTime = millis();
      updateScreen = true;
    }
    oldPosition = newPosition;
  }

  if(menuTriggeredTime != 0 && currentScreen != -1) {
    displayMenu();
    if(menuTriggeredTime + 4000 < millis()) {
      menuTriggeredTime = 0;
      currentScreen = -1;
      myEnc.write(initPosition);
      oldPosition = initPosition;
      newPosition = initPosition;
      initPosition = -999;
      // put code to display the initial screen with updated values
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.setCursor(40,16);
      display.print("Main menu");
      display.display();
      display.setCursor(24,24);
      display.print("Taste The Code");
      display.display();
    }
  }   

  delay(10);
}

void initScreen() {
  
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(24,0);
  display.print("PELLET BURNER");
  display.display();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(32,8);
  display.print("LCD Example");
  display.display();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(40,16);
  display.print("Subscribe!");
  display.display();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(24,24);
  display.print("Taste The Code");
  display.display();
}


void triggerMenu()
{
  if(menuTriggeredTime + 50 < millis()){
    if(menuTriggeredTime == 0) {
      initPosition = oldPosition;
    }
    menuTriggeredTime = millis();
    currentScreen++;
    if(currentScreen >= numOfScreens) {
      currentScreen = 0;
    }
    updateScreen = true;
  }
}

void displayMenu() {
  if(updateScreen) {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0,8); 
    display.print(" ***  SETTINGS  *** ");
    display.display();
    display.setCursor(0,16);
    display.print(screens[currentScreen][0]);
    display.display();
    display.print(parameters[currentScreen]);
    display.display();
    display.print(" ");
    display.display();
    display.print(screens[currentScreen][1]);
    display.display();
    updateScreen = false;
  }
}