#include <util/atomic.h>
#include <LiquidCrystal_I2C.h>

#define LED_RED 6
#define LED_GREEN 5
#define LED_BLUE 3

#define ENCODER1 A2
#define ENCODER2 A3

#define RED_BUTTON 2
#define GREEN_BUTTON 4

#define DEBOUNCING_PERIOD 30

bool isInMenu = true;
int chosenPosition = 0;

int buttons[] = {RED_BUTTON, GREEN_BUTTON};
int led[] = {LED_RED, LED_BLUE, LED_GREEN};
int intensities[] = {0, 0, 0};
String menu[] = {"Red diode  ", "Blue diode ", "Green diode"};

volatile unsigned long timestamps[] = {0UL, 0UL};
unsigned long previousTimestamps[] = {0UL, 0UL};
volatile int encoder1 = HIGH;
volatile int encoder2 = HIGH;
volatile unsigned long encoderTimestamp = 0UL;

unsigned long redPreviousButtonTimestamp = 0UL;
unsigned long redButtonTimestamp = 0UL;
unsigned long greenPreviousButtonTimestamp = 0UL;
unsigned long greenButtonTimestamp = 0UL;


LiquidCrystal_I2C lcd(0x27, 16, 2);

void initAll()
{
  pinMode(LED_RED, OUTPUT);
  digitalWrite(LED_RED, LOW);
  pinMode(LED_BLUE, OUTPUT);
  digitalWrite(LED_BLUE, LOW);
  pinMode(LED_GREEN, OUTPUT);
  digitalWrite(LED_GREEN, LOW);
  pinMode(ENCODER1, INPUT_PULLUP);
  pinMode(ENCODER2, INPUT_PULLUP);
  pinMode(RED_BUTTON, INPUT_PULLUP);
  pinMode(GREEN_BUTTON, INPUT_PULLUP);
  lcd.init();
  lcd.backlight();
}

void redPressed()
{
  Serial.print("BBB");
  timestamps[0] = millis();
  redButtonTimestamp = millis();
}

void greenPressed()
{
  Serial.print("AAA");
  timestamps[1] = millis();
  greenButtonTimestamp = millis();
}

void printMenu()
{
  lcd.setCursor(2, 0);
  lcd.print(menu[chosenPosition]);
  lcd.setCursor(2, 1);
  lcd.print(menu[(chosenPosition + 1) % 3]);
}

void printValues()
{
  lcd.setCursor(2, 1);
  char buffer[40];
  sprintf(buffer, "Value: %3d  ", intensities[chosenPosition]);
  lcd.print(buffer);
}

void changeLed()
{
  analogWrite(led[chosenPosition], intensities[chosenPosition]);
}

void encoderUpdated(int value){
  if (isInMenu)
  {
    chosenPosition = value % 3;
    printMenu();
  }
  else
  {
    intensities[chosenPosition] = value * 15;
    printValues();
    changeLed();
  }

}

bool isRedPressed(){
  noInterrupts();
    unsigned long localButtonTimestamp = redButtonTimestamp;
    interrupts();

    if (localButtonTimestamp != redPreviousButtonTimestamp && millis() > localButtonTimestamp + DEBOUNCING_PERIOD)
    {
        if (digitalRead(RED_BUTTON) == LOW)
        {
            return true;
        }
        redPreviousButtonTimestamp = localButtonTimestamp;
    }
    return false;
}


bool isGreenPressed(){
  noInterrupts();
    unsigned long localButtonTimestamp = greenButtonTimestamp;
    interrupts();

    if (localButtonTimestamp != greenPreviousButtonTimestamp && millis() > localButtonTimestamp + DEBOUNCING_PERIOD)
    {
        if (digitalRead(GREEN_BUTTON) == LOW)
        {
            return true;
        }
        greenPreviousButtonTimestamp = localButtonTimestamp;
    }
    return false;
}


bool buttonPressed(int buttonID)
{
  noInterrupts();
  unsigned long localButtonTimestamp = timestamps[buttonID];
  interrupts();

    if (localButtonTimestamp != previousTimestamps[buttonID] && millis() > localButtonTimestamp + DEBOUNCING_PERIOD)
    {
        previousTimestamps[buttonID] = localButtonTimestamp;
        return (digitalRead(buttons[buttonID]) == LOW);
    }
  return false;
}

void setup()
{
    initAll();

    lcd.setCursor(0, 0);
    lcd.print(">");
    printMenu();

    attachInterrupt(digitalPinToInterrupt(RED_BUTTON), redPressed, FALLING);

    PCICR |= (1 << PCIE2);
    PCMSK2 |= (1 << PCINT20);
    PCICR |= (1 << PCIE1);
    PCMSK1 |= (1 << PCINT10);

}

ISR(PCINT2_vect)
{
  greenButtonTimestamp = millis();
}
    

ISR(PCINT1_vect)
{
  encoder1 = digitalRead(ENCODER1);
    encoder2 = digitalRead(ENCODER2);
    encoderTimestamp = millis();
}


int encoderValue = 0;
int lastEn1 = LOW;
unsigned long lastChangeTimestamp = 0UL;
void loop()
{
    int en1;
    int en2;
    unsigned long timestamp;

    ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
    {
        en1 = encoder1;
        en2 = encoder2;
        timestamp = encoderTimestamp;
    }

    if (en1 == LOW && timestamp > lastChangeTimestamp + DEBOUNCING_PERIOD)
    {
        if (en2 == HIGH)
        {
          if (encoderValue < 15)
            encoderValue += 1;
        }
        else
        {
          if (encoderValue > 0)
            encoderValue -= 1;
          
        }
        lastChangeTimestamp = timestamp;
        encoderUpdated(encoderValue);
    }
    lastEn1 = en1;


    if(buttonPressed(0))
    {
      if(!isInMenu)
      {
        isInMenu = true;
        encoderValue = chosenPosition;
        printMenu();
      }
    }
    if(buttonPressed(1))
    {
      if(isInMenu)
      {
        isInMenu = false;
        encoderValue = intensities[chosenPosition] / 15;
        printValues();
      }
    }
}