// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "esp32-hal.h"
#include "lwip/apps/sntp.h"
//#include "tcpip_adapter.h"
#include "esp_netif.h"
#include <time.h>

#ifdef CONFIG_LWIP_TCPIP_CORE_LOCKING
#include "lwip/priv/tcpip_priv.h"
#endif

static void setTimeZone(long offset, int daylight) {
  char cst[21] = {0};
  char cdt[21] = "DST";
  char tz[41] = {0};

  if (offset % 3600) {
    snprintf(cst, sizeof(cst), "UTC%ld:%02u:%02u", offset / 3600, abs((offset % 3600) / 60), abs(offset % 60));
  } else {
    snprintf(cst, sizeof(cst), "UTC%ld", offset / 3600);
  }
  if (daylight != 3600) {
    long tz_dst = offset - daylight;
    if (tz_dst % 3600) {
      snprintf(cdt, sizeof(cdt), "DST%ld:%02u:%02u", tz_dst / 3600, abs((tz_dst % 3600) / 60), abs(tz_dst % 60));
    } else {
      snprintf(cdt, sizeof(cdt), "DST%ld", tz_dst / 3600);
    }
  }
  snprintf(tz, sizeof(tz), "%s%s", cst, cdt);
  setenv("TZ", tz, 1);
  tzset();
}

/*
 * configTime
 * Source: https://github.com/esp8266/Arduino/blob/master/cores/esp8266/time.c
 * */
void configTime(long gmtOffset_sec, int daylightOffset_sec, const char *server1, const char *server2, const char *server3) {
  //tcpip_adapter_init();  // Should not hurt anything if already inited
  esp_netif_init();

#ifdef CONFIG_LWIP_TCPIP_CORE_LOCKING
  if (!sys_thread_tcpip(LWIP_CORE_LOCK_QUERY_HOLDER)) {
    LOCK_TCPIP_CORE();
  }
#endif

  if (sntp_enabled()) {
    sntp_stop();
  }

  sntp_setoperatingmode(SNTP_OPMODE_POLL);
  sntp_setservername(0, (char *)server1);
  sntp_setservername(1, (char *)server2);
  sntp_setservername(2, (char *)server3);
  sntp_init();

#ifdef CONFIG_LWIP_TCPIP_CORE_LOCKING
  if (sys_thread_tcpip(LWIP_CORE_LOCK_QUERY_HOLDER)) {
    UNLOCK_TCPIP_CORE();
  }
#endif

  setTimeZone(-gmtOffset_sec, daylightOffset_sec);
}

/*
 * configTzTime
 * sntp setup using TZ environment variable
 * */
void configTzTime(const char *tz, const char *server1, const char *server2, const char *server3) {
  //tcpip_adapter_init();  // Should not hurt anything if already inited
  esp_netif_init();

#ifdef CONFIG_LWIP_TCPIP_CORE_LOCKING
  if (!sys_thread_tcpip(LWIP_CORE_LOCK_QUERY_HOLDER)) {
    LOCK_TCPIP_CORE();
  }
#endif

  if (sntp_enabled()) {
    sntp_stop();
  }

  sntp_setoperatingmode(SNTP_OPMODE_POLL);
  sntp_setservername(0, (char *)server1);
  sntp_setservername(1, (char *)server2);
  sntp_setservername(2, (char *)server3);
  sntp_init();

#ifdef CONFIG_LWIP_TCPIP_CORE_LOCKING
  if (sys_thread_tcpip(LWIP_CORE_LOCK_QUERY_HOLDER)) {
    UNLOCK_TCPIP_CORE();
  }
#endif

  setenv("TZ", tz, 1);
  tzset();
}

bool getLocalTime(struct tm *info, uint32_t ms) {
  uint32_t start = millis();
  time_t now;
  while ((millis() - start) <= ms) {
    time(&now);
    localtime_r(&now, info);
    if (info->tm_year > (2016 - 1900)) {
      return true;
    }
    delay(10);
  }
  return false;
}
