/*********
 
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// niet gebruiken: GPI00. (=flash)
// niet gebruiken: GPIO6, GPIO7, GPIO8, GPIO9, GPIO10, en GPIO11

#include <ezButton.h>



const int boardLedPin = 2;    // the number of the LED pin
const int GPIO0 = 0;    //button 1 input, tevens FLASH
const int GPIO2 = 2;    //button 2 input
const int GPIO4 = 4;    //button 3 input
const int GPIO5 = 5;    //button 4 input

const int GPIO12 = 12;    //buton 1 LED
const int GPIO13 = 13;    //buton 2 LED
const int GPIO14 = 14;    //buton 3 LED
const int GPIO16 = 16;    //buton 4 LED

const int BUTTON_1 = GPIO0;
const int BUTTON_2 = GPIO2;
const int BUTTON_3 = GPIO4;
const int BUTTON_4 = GPIO5;

const int BUTTON_CTRL = 15;

const int LED_1 = GPIO12;
const int LED_2 = GPIO13;
const int LED_3 = GPIO14;
const int LED_4 = GPIO16;

const int GPIO15 = 15;    // must be GND   ?

int state = 0;
int prev_state = 0;

int buttonIndex = 0; 
int buttonStates[4]; // To hold button states
unsigned long stateOnAtMillis[4];   // the timing to activate states, 0=none
unsigned long stateOffAtMillis[4];   // the timing to deactivate (blink) states, 0=none
const int blinking_ed_interval = 1500;

ezButton button1(BUTTON_1);  // create ezButton object for button 1
ezButton button2(BUTTON_2);  // create ezButton object for button 2
ezButton button3(BUTTON_3);  // create ezButton object for button 3
ezButton button4(BUTTON_4);  // create ezButton object for button 4
ezButton buttonCTRL(BUTTON_CTRL);  // create ezButton object for button 4


void setup() {
   Serial.begin(9600);
  // initialize GPIO's.
  pinMode(LED_1, OUTPUT);
  pinMode(LED_2, OUTPUT);
  pinMode(LED_3, OUTPUT);
  pinMode(LED_4, OUTPUT);

  button1.setDebounceTime(50); // set debounce time to 50 milliseconds
  button2.setDebounceTime(50); // set debounce time to 50 milliseconds
  button3.setDebounceTime(50); // set debounce time to 50 milliseconds
  button4.setDebounceTime(50); // set debounce time to 50 milliseconds
  buttonCTRL.setDebounceTime(50); // set debounce time to 50 milliseconds
  
  state = -3;
  Serial.println("Setup done.");
}

// the loop function runs over and over again forever
void loop() {
  button1.loop(); // MUST call the loop() function first
  button2.loop(); // MUST call the loop() function first
  button3.loop(); // MUST call the loop() function first
  button4.loop(); // MUST call the loop() function first
  buttonCTRL.loop(); // MUST call the loop() function first

  //show leds are working
  if (state <0 ) {
    state++;

    digitalWrite(LED_1, HIGH);
    delay(100);
    digitalWrite(LED_2, HIGH);
    delay(100);
    digitalWrite(LED_3, HIGH);
    delay(100);
    digitalWrite(LED_4, HIGH);
     delay(100);
    digitalWrite(LED_1, LOW);
    digitalWrite(LED_2, LOW);
    digitalWrite(LED_3, LOW);
    digitalWrite(LED_4, LOW);
     delay(250);
  }

  //combine buttons already pressed
  int prev_pressed = 0;
  for (int i=0; i<buttonIndex; i++)
    prev_pressed = prev_pressed | buttonStates[i];

  int buttons_pressed = readButtons() & (prev_pressed ^ 0x0F);
  if (buttons_pressed > 0) {
    //register the button pressed
    if (buttonIndex < 4) {
        buttonStates[buttonIndex] = buttons_pressed;
        if (buttonIndex == 0) {
//          showPressed(buttonStates[0], HIGH);
          stateOnAtMillis[0] = millis();      //to activate LED of first button pressed
          stateOffAtMillis[0] = 0;            //and keep on
        } else {
          stateOnAtMillis[buttonIndex] = stateOnAtMillis[0] + buttonIndex *200; //to activate LED of second/next button pressed
          stateOffAtMillis[buttonIndex] = stateOnAtMillis[buttonIndex] + 50;    //and turn off after 100 millis
        }
    }
      buttonIndex++;
      state = buttons_pressed;
  }

  updateStatesOnOff(blinking_ed_interval);

  if (state !=  prev_state) {
    Serial.print("prev_pressed=");
    Serial.println(prev_pressed);

    Serial.print("buttons pressed:");
    Serial.print(buttonStates[0]);
    Serial.print(",");
    Serial.print(buttonStates[1]);
    Serial.print(",");
    Serial.print(buttonStates[2]);
    Serial.print(",");
    Serial.println(buttonStates[3]);
    Serial.print("state=");
    Serial.println(state);
  }

  checkControl();
   
  prev_state = state;
 // delay(10);

  
}

int readButtons() {
  int result = 0;
  if(button1.isPressed())
    result = 1;
  if(button2.isPressed())
    result = result + 2;
  if(button3.isPressed())
    result = result + 4;
  if(button4.isPressed())
    result = result + 8;
  return result;
}

int showPressed(int actives, int onoff) {
  if ((actives & 0x01) > 0)
    digitalWrite(LED_1, onoff);
  if ((actives & 0x02) > 0)
    digitalWrite(LED_2, onoff);
  if ((actives & 0x04) > 0)
    digitalWrite(LED_3, onoff);
  if ((actives & 0x08) > 0)
    digitalWrite(LED_4, onoff);
  return 0;
}

void updateStatesOnOff(int interval) {
  unsigned long currentMillis = millis();
  for (int i=0; i<buttonIndex; i++) {
    if (stateOnAtMillis[i] > 0) {
      if (stateOnAtMillis[i] < currentMillis) {
        stateOnAtMillis[i] += interval; //set next
        showPressed(buttonStates[i], HIGH);
      }
    }
    if (stateOffAtMillis[i] > 0) {
      if (stateOffAtMillis[i] < currentMillis) {
        stateOffAtMillis[i] += interval; //set next
        showPressed(buttonStates[i], LOW);
      } 
    }
  }
}


void checkControl() {
  //check for control button to be pressed
  if(buttonCTRL.isPressed()) {

  
    if (buttonIndex > 0) {
      buttonIndex--;
      buttonStates[0] =  buttonStates[1];
      buttonStates[1] =  buttonStates[2];
      buttonStates[2] =  buttonStates[3];
      buttonStates[3] =  0;
      stateOnAtMillis[0] =  stateOnAtMillis[1];
      stateOnAtMillis[1] =  stateOnAtMillis[2];
      stateOnAtMillis[2] =  stateOnAtMillis[3];
      stateOnAtMillis[3] =  0;
      stateOffAtMillis[0] =  0;
      stateOffAtMillis[1] =  stateOffAtMillis[2];
      stateOffAtMillis[2] =  stateOffAtMillis[3];
      stateOffAtMillis[3] =  0;
      digitalWrite(LED_1, LOW);
      digitalWrite(LED_2, LOW);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);

    }

    if (buttonIndex == 0) {
      //reset, back to init
      digitalWrite(LED_1, LOW);
      digitalWrite(LED_2, LOW);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);
      delay(250);
      digitalWrite(LED_1, HIGH);
      digitalWrite(LED_2, HIGH);
      digitalWrite(LED_3, HIGH);
      digitalWrite(LED_4, HIGH);
      delay(100);
      digitalWrite(LED_1, LOW);
      digitalWrite(LED_2, LOW);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);
      delay(250);

      for (int i=0; i<4; i++) {
        buttonStates[i] = 0;
        stateOnAtMillis[i] = 0;
        stateOffAtMillis[i] = 0;
      }
      buttonIndex =0;
      state = 0;
    } 
  }
}