#include <Adafruit_NeoPixel.h>

#include <ESP8266WiFi.h>

#define MAX_BRIGHTNESS 48
#define MIN_BRIGHTNESS 8

// WiFi username and password
const char* ssid     = "Bluffs_Resident";
const char* password = "bluffsresident";

const char* host = "time.nist.gov";
const int port = 13;

const int numLeds = 64;
const int pin = D6;

Adafruit_NeoPixel strip = Adafruit_NeoPixel(numLeds, pin, NEO_GRB + NEO_KHZ800);

WiFiClient client;

void setup() {

    Serial.begin(115200);

    strip.begin();

    int i;

    // initialize matrix
    for (i = 0; i < numLeds; i++)
    {
        strip.setPixelColor(i, 0, 0, 0);
    }

    strip.show();
    strip.setBrightness(MIN_BRIGHTNESS);

    WiFi.begin(ssid, password);

    Serial.println("Wifi started");

    while (WiFi.status() != WL_CONNECTED)
    {
        delay(500);
        Serial.print(".");
    }
    Serial.println(WiFi.localIP());
    Serial.println(WiFi.macAddress());

}

void loop() {
    int i;

    if (!client.connect(host, port))
    {
        Serial.println("Failed to connect to host");
    }

    // API call to get datetime
    client.print("HEAD / HTTP/1.1\r\nAccept: */*\r\nUser-Agent: Mozilla/4.0 (compatible; ESP8266 NodeMcu Lua;)\r\n\r\n");

    delay(100);

    // read all the lines of the reply from server and print them to serial
    // expected line is like : Date: Thu, 01 Jan 2015 22:00:14 GMT
    while (client.available())
    {
        String line = client.readStringUntil('\r');
        Serial.println("RESPONSE: ");
        Serial.println(line);

        if (line.indexOf("Date") != -1)
        {
            Serial.println("Error: Malformed resonse");
        }
        // poorly parse the response into hours and minutes
        // if the response format ever changes, this will break horribly
        else
        {
            String buf = line.substring(16, 18);
            Serial.print("HOUR: ");
            Serial.println(buf);

            int timeHour = buf.toInt();

            buf = line.substring(19, 21);
            Serial.print("MINUTE: ");
            Serial.println(buf);

            int timeMinute = buf.toInt();

            int i;

            // every minute, light up the next LED and increase brightness
            if (timeHour == 10) // 5am
            {
                for (i = 0; i < map(timeMinute, 0, 60, 0, numLeds); i++)
                {
                    strip.setPixelColor(i, 255, 100, 0);
                }
                strip.setBrightness(map(timeMinute, 0, 60, MIN_BRIGHTNESS,
                            MAX_BRIGHTNESS));
                strip.show();
            }
            // reset LEDs
            else if (timeHour > 13) // > 8am
            {
                for (i = 0; i < numLeds; i++)
                {
                    strip.setPixelColor(i, 0, 0, 0);
                }
                strip.setBrightness(MIN_BRIGHTNESS);
                strip.show();
            }
        }
    }
    // only send API request a max of once a minute
    delay(60000);
}