#include <Arduino.h>

#include <Wire.h>
#include <Timezone.h>   // https://github.com/JChristensen/Timezone
#include <TimeLib.h>    // https://github.com/PaulStoffregen/Time
#include <DS1307RTC.h>  // https://github.com/PaulStoffregen/DS1307RTC
#include <NTPClient.h>  // https://github.com/arduino-libraries/NTPClient
#include <TM1637Display.h> // https://github.com/avishorp/TM1637
#include <WiFiManager.h>//https://github.com/tzapu/WiFiManager

#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

// Central European Time (Frankfurt, Paris)
TimeChangeRule CEST = {"CEST", Last, Sun, Mar, 2, 120};     // Central European Summer Time
TimeChangeRule CET = {"CET ", Last, Sun, Oct, 3, 60};       // Central European Standard Time
Timezone CE(CEST, CET);

// NTP
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "europe.pool.ntp.org", 0, 600000);

// timelib
time_t utc;
time_t local;

// display
//TM1637Display display(1, 3);
TM1637Display display(D8, D7); // pinClk, pinDIO

uint8_t data[] = { 0xff, 0xff, 0xff, 0xff };
uint8_t blank[] = { 0x00, 0x00, 0x00, 0x00 };

char buf[4];
char prev[4];

void setup() {
  WiFi.mode(WIFI_STA);

  WiFiManager wifiManager;
  wifiManager.setTimeout(600);

  if(!wifiManager.autoConnect("clock")) {
    ESP.reset();
  }

  ArduinoOTA.begin();
  ESP.wdtEnable(WDTO_8S);

  // put your setup code here, to run once:
  //Wire.begin(0,2); // 00-sda,02-sdl 
  Wire.begin(D2,D1);
  timeClient.begin();
  setSyncProvider(RTC.get);
  display.clear();
}

void loop() {
  ESP.wdtFeed();
  ArduinoOTA.handle();

  yield();

  // put your main code here, to run repeatedly:
  if(timeClient.update()) {
    RTC.set(timeClient.getEpochTime());
  }

  yield();

  utc = now();
  local = CE.toLocal(utc);

  yield();

  sprintf(buf, "%.2d%.2d",hour(local), minute(local));
  data[0] = display.encodeDigit(buf[0] - '0');
  data[1] = display.encodeDigit(buf[1] - '0');
  data[2] = display.encodeDigit(buf[2] - '0');
  data[3] = display.encodeDigit(buf[3] - '0');

  if(strcmp(buf, prev) != 0) {
    display.setSegments(data);
    strcpy(prev , buf);
  }

  yield();
}