#include "FastLED.h";

bool On         = false;
bool NightOrDay = false;

CRGB LED;

enum ledPin: byte {
  red   = 3,
  green = 5,
  blue  = 6,
  white = 9
};

byte button[4] = {12, 11, 10, 8};

bool buttonPressed[5] = {false, false, false, false, false};

byte Br = 10;


// https://stackoverflow.com/questions/1952175/how-can-i-call-a-function-using-a-function-pointer
//
// void A() { Serial.println("first");}; // declare three functions
// void B() { Serial.println("second");};
// void C() { Serial.println("third");};

//  void (*choice) ();   // defines a pointer "choice"
//  choice = B;          // "choice" points to function "B()""
//  choice();            // this calls function "B()", prints "second"

// functions associated with the four buttons
// placed in an array so that a "for" loop could be used to scan buttons
// and call the functions directly, without using "if" or "switch-case"
void f0() { On = !On;                 Serial.print("on " ); Serial.println(On); delay(500); }
void f1() { NightOrDay = !NightOrDay; Serial.print("n/d "); Serial.println(NightOrDay); delay(500); }
void f2() { Br--;                     Serial.print("br  "); Serial.println(Br); delay(50); }
void f3() { Br++;                     Serial.print("br  "); Serial.println(Br); delay(50); }

// https://stackoverflow.com/questions/1952175/how-can-i-call-a-function-using-a-function-pointer
typedef void (*func_ptr)();
func_ptr function[4] = {f0, f1, f2, f3};  // array of functions

//  function[0] ();  // functions are called this way
//  function[1] ();


void setup() {

  Serial.begin(9600);

  for (int i = 0; i<4; i++) {
    pinMode(button[i], INPUT_PULLUP);
  }
}

byte buttonTick() {
  byte a = 0;
  for (int i = 0; i<4; i++) {
    if (buttonPressed[i]) return i;
  }
}

void loop() {
  // Read the button inputs
  
  for (int i = 0; i<4; i++) {
  
    buttonPressed[i] = digitalRead(button[i]) == LOW;

    // do debouncing here

    if (buttonPressed[i]) {
      buttonPressed[i] = false;
      function[i] ();    // call function directly
    }
  }

  if(On) {
    if(NightOrDay){
      analogWrite (ledPin::white, Br);
      digitalWrite(ledPin::red,    0);
      digitalWrite(ledPin::green,  0);
      digitalWrite(ledPin::blue,   0);
    }

    else {
      LED = ColorFromPalette(HeatColors_p,inoise8(millis()/16));

      analogWrite (ledPin::red,   LED.r);
      analogWrite (ledPin::green, LED.g);
      analogWrite (ledPin::blue,  LED.b);
      digitalWrite(ledPin::white,     0);
    }
  }
  else {
    digitalWrite(ledPin::red,   0);
    digitalWrite(ledPin::green, 0);
    digitalWrite(ledPin::blue,  0);
    digitalWrite(ledPin::white, 0);
  }
}