// https://forum.arduino.cc/t/water-show-with-timing/1207999
// https://wokwi.com/projects/386308181455826945

# include <Adafruit_NeoPixel.h>

const int dataPin = 2;   // DS
const int latchPin = 3;  // STCP
const int clockPin = 4;  // SHCP

#define NUM_SHIFT_REG 4
const int numRegisterPins = NUM_SHIFT_REG * 8;
bool registers[numRegisterPins];

int pattern = 0b10101010;
int delayTime = 133;

# define NUM_LEDS numRegisterPins
# define LED_PIN A0

Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);

  strip.begin();

  setRegisterPin(1, 1);
  setRegisterPin(31, 1);
  writeRegisters();

  delay(777);

  clearRegisters();
}

void loop() {


  // showPattern();
  // showFirstLast();
//  randomrelay();
   cascade();
}

void randomrelay() {
  int i = random(32);
  int j = random(2);

  setRegisterPin(i, j);
  writeRegisters();
  delay(300);
  setRegisterPin(i, !j);
  writeRegisters();
}

void cascade() {
  for (int i = 0; i < numRegisterPins; i++) {
    setRegisterPin(i, 1);
    writeRegisters();
    delay(delayTime);
    setRegisterPin(i, 0);
    writeRegisters();
  }
}

void firstLast() {
  setRegisterPin(0, 1); // set first relay
  setRegisterPin(31, 1); // set last relay
  writeRegisters(); // display
}

void showPattern() {
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, pattern);
  digitalWrite(latchPin, HIGH);
  delay(500);
  pattern = ~pattern; // Invert the pattern
}

void setRegisterPin(int index, int value) {
  // Set an individual pin HIGH or LOW
  registers[index] = value;
  strip.setPixelColor(index, value ? 0xff0000 : 0x010101);
}

void writeRegisters() {
  // Set and display registers
  digitalWrite(latchPin, LOW);

  for (int i = numRegisterPins - 1; i >= 0; i--) {
    digitalWrite(clockPin, LOW);
    digitalWrite(dataPin, registers[i]);
    digitalWrite(clockPin, HIGH);
  }

  digitalWrite(latchPin, HIGH);

  strip.show();
}

void clearRegisters() { // clear all pins
  for (int i = numRegisterPins - 1; i >= 0; i--) {
    registers[i] = LOW;
  }

  strip.clear();
}