#include "neopixel.h"

#define PIXEL_PIN D2
#define PIXEL_COUNT 16
#define PIXEL_TYPE WS2812

Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, PIXEL_TYPE);

// create a global variable to store the time when last performed an action 
unsigned long lastFade = 0;

int brightness = 100;

// store rgb values in global variables
int r = 0; 
int g = 0;
int b = 0;

// store the name of the color in a global variable
String npColor;

void setup(){
    
    strip.begin();
    // initialize all pixels to "off"
    strip.show();
    
    Particle.function("Set color", setColor);
    Particle.function("Fade to white", fadeToWhite);
    
    Particle.variable("brightness", brightness);
    Particle.variable("Neopixel Color", npColor);

    // set default color
    setColor("red");
    
}

void loop(){
    
    //call the function to fade to red (input: given time in minute)
    fadeToWhite("1");

}

// function to fade from red to white
// function input: fading time in minute
int fadeToWhite(String command){
    
    // convert input command to milliseconds
    int totalFadingTime = command.toInt();
    int t = ((totalFadingTime * 60) * 1000) / 100;
    
    unsigned long timeNow = millis();
    
    if(brightness <= 100){
        if (timeNow - lastFade > t){
            for(int i = 0; i < strip.numPixels(); i++){
                strip.setPixelColor(i, r, 100-brightness, 100-brightness);
                }
            strip.show();
            brightness = brightness-1;
            lastFade = timeNow;
        } else{
            return -1;
        }
    }

    return 1;
}


// function to set color to white or red
int setColor(String command){
    
    // update the stored neopixel color value
    npColor = command;
    
    uint16_t i;
    uint32_t white = strip.Color(100, 100, 100);
    uint32_t red = strip.Color(100, 0, 0);
    
    if (npColor  == "white"){
        
        // set rgb values all to 100 (white)
        r = 100;
        g = 100;
        b = 100;
        
        // turn on neopixel using the rgb values of white
        for(i = 0; i < strip.numPixels(); i++){
            strip.setPixelColor(i, r, g, b);
            strip.show();
        }
        delay(100);
        return 1;
        } else if (npColor == "red"){
            // set r=100, g & b = 0 (red)
            r = 100;
            g = 0;
            b = 0;
            
            // turn on neopixel using the rgb values of red
            for(i = 0; i < strip.numPixels(); i++){
                strip.setPixelColor(i, r, g, b);
                strip.show();
            }
            delay(100);
            return 1;
            } else {
              // if the command is neither white or red, return -1 
                return -1;
                }

}