#include "clock.h"

#include <WiFi.h>

#include "log.h"
#include "wifi.h"

#define CLOCK_GMT_OFFSET_SECONDS        3600
#define CLOCK_DST_OFFSET_SECONDS        3600
#define CLOCK_NTP_SERVER2_URL           "de.pool.ntp.org"
#define CLOCK_EPOCH_SECONDS_MIN         1735686000

time_t clockOffset = 0;

time_t startupTime = 0;

auto ntpSet = false;

void clockLoop() {
  if (isClockSet()) {
    return;
  }

  if (!ntpSet && isWiFiConnected()) {
    configTime(CLOCK_GMT_OFFSET_SECONDS, CLOCK_DST_OFFSET_SECONDS, CLOCK_NTP_SERVER2_URL, WiFi.gatewayIP().toString().c_str());
    ntpSet = true;
  }

  const auto now = time(nullptr);
  if (isCorrectTime(now)) {
    clockOffset = now;
  } else {
    startupTime = now - clockOffset;
    info("clock set after %ld seconds! So startup was at %s", clockOffset, getStartupStr());
  }
}

bool isClockSet() {
  return startupTime != 0;
}


char *getClockStr(const time_t epoch) {
  auto now = epoch;
  if (now == 0) {
    now = time(nullptr);
  }

  tm t{};
  localtime_r(&now, &t);

  static char buffer[20];
  snprintf(buffer, sizeof buffer, "%04d-%02d-%02d %02d:%02d:%02d", t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, t.tm_hour, t.tm_min, t.tm_sec);
  return buffer;
}

char *getStartupStr() {
  return getClockStr(startupTime);
}

time_t getUptimeSeconds() {
  return time(nullptr) - startupTime;
}

char *getUptimeStr() {
  const auto totalSeconds = getUptimeSeconds();
  const auto totalMinutes = totalSeconds / 60;
  const auto totalHours = totalMinutes / 60;

  const auto partSeconds = totalSeconds % 60;
  const auto partMinutes = totalMinutes % 60;
  const auto partHours = totalHours % 24;
  const auto partDays = totalHours / 24;

  static char buffer[20];
  snprintf(buffer, sizeof buffer, "%dd %2dh %2dm %2ds", partDays, partHours, partMinutes, partSeconds);
  return buffer;
}

bool isCorrectTime(const time_t now) {
  return now < CLOCK_EPOCH_SECONDS_MIN;
}

time_t clockCorrect(const time_t t) {
  if (!isClockSet() || isCorrectTime(t)) {
    return t;
  }
  return t + clockOffset;
}

void clockCorrect(time_t *t) {
  if (!isClockSet() || isCorrectTime(*t)) {
    return;
  }
  *t += clockOffset;
}