// https://forum.arduino.cc/t/looping-leds-until/1411057/

#include <Keypad.h>
#include <FastLED.h>

// int last_pressed = 0; // not used. "catched_button" is available
const byte rows = 4; // compiler warning. changed char to byte
const byte columns = 4; // compiler warning. changed char to byte
byte pinrows[rows] = {4, 5, 6, 7}; // compiler warning. changed char to byte
byte pincolumns[columns] = {8, 9, 10, 11}; // compiler warning. changed char to byte
char button[rows][columns] = { // this keypad reqires R1..R4 = 11..8, C1..C4 = 7..4
  {'D', 'C', 'B', 'A'},
  {'#', '9', '6', '3'},
  {'0', '8', '5', '2'},
  {'*', '7', '4', '1'}
};
Keypad k = Keypad(makeKeymap(button), pinrows, pincolumns, rows, columns);

#define LED_PIN     3
#define NUM_LEDS    115
#define BRIGHTNESS  64
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB
CRGB leds[NUM_LEDS];
#define UPDATES_PER_SECOND 100
CRGBPalette16 currentPalette;
TBlendType    currentBlending;

unsigned long timer, timeout = 1000UL / UPDATES_PER_SECOND;
int i;

void setup() {
  delay( 3000 ); // power-up safety delay
  Serial.begin(9600);
  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
  FastLED.setBrightness(BRIGHTNESS );
  currentPalette = RainbowColors_p;
  currentBlending = LINEARBLEND;
}
void loop()
{
  char catched_button = k.getKey();
  if (catched_button) {
    Serial.print("Performed function: ");
    Serial.println(catched_button);
  }
  switch (catched_button) {
    case '1': fun1(); break;
    case '2': fun2(); break;
    case '3': fun3(); break;
    default: fun0(); break;
  }
}

void fun1() {
  fill_solid(leds, NUM_LEDS, CRGB::Black);
  FastLED.show();
  uint8_t colorIndex;
  for ( int i = NUM_LEDS; i > -1; --i) {
    leds[i] = ColorFromPalette( currentPalette, colorIndex, 255, currentBlending);
    FastLED.show();
    FastLED.delay(1000 / UPDATES_PER_SECOND);
    colorIndex += 3;
  }
}

void fun2() {
  fill_solid(leds, NUM_LEDS, CRGB::Black);
  FastLED.show();
  uint8_t colorIndex;
  for ( int i = 0; i < NUM_LEDS; ++i) {
    leds[i] = ColorFromPalette( currentPalette, colorIndex, 255, currentBlending);
    FastLED.show();
    FastLED.delay(1000 / UPDATES_PER_SECOND);
    colorIndex += 3;
  }
}

void fun3() {
  for (uint8_t i = 0; i < 20; i++) {
    for (uint8_t j = 0; j < NUM_LEDS; j++) {
      leds[j] = CRGB(0, 0, BRIGHTNESS);
    }
    FastLED.show();
    delay(UPDATES_PER_SECOND);

    for (uint8_t j = 0; j < NUM_LEDS; j++) {
      leds[j] = CRGB(BRIGHTNESS, BRIGHTNESS, BRIGHTNESS);
    }
    FastLED.show();
    delay(UPDATES_PER_SECOND);
  }
}

void fun0() {
  if (millis() - timer > timeout) { // wait between leds
    timer = millis(); // reset time before next led
    // a random led (0 to NUM_LEDS) will be colored (random red, random green, random blue)
    leds[random(NUM_LEDS)] = CRGB(random(256) * random(2), random(256) * random(2), random(256) * random(2));
    FastLED.show();
  }
}