src/user/knob/time.c


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#include <pland/syscall.h>
#include <knob/time.h>
#include <stdint.h>

uint8_t days_in_months[] = {
  31,  0, 31, 30,
  31, 30, 31, 31,
  30, 31, 30, 31
};

struct time get_time() {
  struct time t;

  const uint32_t ts = _get_timestamp();
  t.timestamp = ts;

  const uint32_t time_part = ts % 86400;
  t.hour = time_part / 3600;
  t.minute = (time_part / 60) % 60;
  t.second = time_part % 60;

  uint32_t days = ts / 86400;

  uint32_t year = 2000;
  while (days >= 1461) {
    year += 4;
    days -= 1461;
  }

  days_in_months[1] = 28;
  if (days >= 1096) {
    t.year = year += 3;
    days -= 1096;
  }
  else if (days >= 731) {
    t.year = year += 2;
    days -= 731;
  }
  else if (days >= 366) {
    t.year = ++year;
    days -= 366;
  }
  else {
    t.year = year;
    days_in_months[1] = 29;
  }

  uint8_t m = 0;
  while (days >= days_in_months[m]) {
    days -= days_in_months[m];
    ++m;
  }

  t.month = m + 1;
  t.day = days + 1;
  return t;
}