#define PIN 25
#define NUM_LEDS 8
#define NUM_MARKS 8
#define MARK_COLOR SwimStrip.Color(0, 0, 255)  // Blue

#include "Adafruit_NeoPixel.h"
#include <LiquidCrystal_I2C.h>

int delayMark = 800;
int CurrentMark = 1;
boolean MarkDirectionUp = true;
int PoolNum=1;

Adafruit_NeoPixel SwimStrip = Adafruit_NeoPixel(NUM_LEDS, PIN, NEO_GRB + NEO_KHZ800);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void TurnOnMark(int mark, uint32_t markColor = MARK_COLOR) {
  // mark = 1 to NUM_MARKS
  SwimStrip.fill(markColor, (mark - 1) * (NUM_LEDS / NUM_MARKS), NUM_LEDS / NUM_MARKS);
  SwimStrip.show();
}

void TurnOffMark(int mark) {
  SwimStrip.fill(SwimStrip.Color(0, 0, 0), (mark - 1) * (NUM_LEDS / NUM_MARKS), NUM_LEDS / NUM_MARKS);
  SwimStrip.show();
}

void SwimTimer() {
  Serial.println("SwimTimer Marker: " + (String)CurrentMark + " " + (String)PoolNum);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("SwimTimer: " + (String)CurrentMark + " " + (String)PoolNum);
  TurnOnMark(CurrentMark);
  if (MarkDirectionUp) {
    TurnOffMark(CurrentMark - 1);
    CurrentMark++;
  } else {
    TurnOffMark(CurrentMark + 1);
    CurrentMark--;
  }

  if ((CurrentMark == NUM_MARKS+1) || (CurrentMark == 0)) {
     PoolNum++;
     Serial.println("change direction: " + (String)CurrentMark);
     if (MarkDirectionUp) {
      CurrentMark-=2;
     } else {
      CurrentMark+=2;
     }
    MarkDirectionUp = not(MarkDirectionUp);
  }
}

void setup() {
  delay(1000);
  Serial.begin(115200);
  Serial.println("Start");

  lcd.init();
  lcd.backlight();  //enables backlight
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Start");
  delay(2000);
  
  SwimStrip.begin();
  SwimStrip.setBrightness(80);
  SwimStrip.clear();
  SwimStrip.show();
}

void loop() {
  SwimTimer();
  delay(delayMark);
}