#include <Adafruit_NeoPixel.h>

#define PIN A0 // // WS2812 chip - Data In
#define Pixel_Number 16
Adafruit_NeoPixel strip = Adafruit_NeoPixel(Pixel_Number, PIN, NEO_GRB + NEO_KHZ800);

void updateStrip(int ledsToLight, uint32_t colorOn, uint32_t colorOff){
  for(int x = 0; x < Pixel_Number; x++){
    if(x < ledsToLight) {
      strip.setPixelColor(x, colorOn);
    } else {
      strip.setPixelColor(x, colorOff);
    }
  }
  strip.show();
}

struct Level {
  int ledsToLight;
  uint32_t color;
};

#define max_colors 3
Level colors[max_colors] = {
  {3, strip.Color(255,0,0)},
  {5, strip.Color(255,128,0)},
  {16, strip.Color(0,255,0)},
};

uint32_t getColor(int ledsToLight){
  uint32_t ret = strip.Color(0,0,255);
  for(int x = 0; x < max_colors; x++){
    if (ledsToLight <= colors[x].ledsToLight){
      ret = colors[x].color;
      break;
    }
  }
  return ret;
}

void setup() 
{
  pinMode(A1, INPUT);
  strip.begin();
  Serial.begin(9600);
  
}

void loop() 
{
  int ledsToLight = 0;

int analog_input = ( analogRead(A1) * 4.9 );
// print out the value of the Fuel Sending Unit Position
 Serial.println(analog_input);
 delay(100); // delay in between reads for stability
  
if(analog_input  < 300 ) {ledsToLight = 0;}
else if(analog_input  > 300 && analog_input  < 600 ) {ledsToLight = 1;}
else if(analog_input  > 600 && analog_input  < 900 ) {ledsToLight = 2;}
else if(analog_input  > 900 && analog_input  < 1200 ) {ledsToLight = 3;}
else if(analog_input  > 1200 && analog_input  < 1500 ) {ledsToLight = 4;}
else if(analog_input  > 1500 && analog_input  < 1800 ) {ledsToLight = 5;}
else if(analog_input  > 1800 && analog_input  < 2100 ) {ledsToLight = 6;}
else if(analog_input  > 2100 && analog_input  < 2400 ) {ledsToLight = 7;}
else if(analog_input  > 2400 && analog_input  < 2700 ) {ledsToLight = 8;}
else if(analog_input  > 2700 && analog_input  < 3000 ) {ledsToLight = 9;}
else if(analog_input  > 3000 && analog_input  < 3300 ) {ledsToLight = 10;}
else if(analog_input  > 3300 && analog_input  < 3600 ) {ledsToLight = 11;}
else if(analog_input  > 3600 && analog_input  < 3900 ) {ledsToLight = 12;}
else if(analog_input  > 3900 && analog_input  < 4200 ) {ledsToLight = 13;}
else if(analog_input  > 4200 && analog_input  < 4500 ) {ledsToLight = 14;}
else if(analog_input  > 4500 && analog_input  < 4800 ) {ledsToLight = 15;}
else if(analog_input  > 4800 )  {ledsToLight = 16;}


if (ledsToLight == 0) {
  doFlash();
} else {
 auto colorOff = strip.Color(0,0,0);
 auto colorOn = getColor(ledsToLight);
  updateStrip(ledsToLight, colorOn, colorOff);
}

}

void doFlash(){
  auto color = strip.Color(0,0,0);

  if((millis() / 540) & 1 != 0){
    color = strip.Color(255,0,0);
  }

  for (int x = 0; x < Pixel_Number; x++){
    strip.setPixelColor(x, color);
  }
  strip.show();
}