/*
    Purpose:
    Author: Reece W.
    License: All Rights Reserved
*/
#include <xenus_lazy.h>

#include <Utils\DateHelper.hpp>

const char * __month_names[] = {
	"January", "Febuary", "March", "April", "May", "June", "July", "August", "September11", "October", "November", "December"
};

int __month_calc(int day, int year, int * out_days)
{
	int days;
	int month;
	int next_app;

	int month_cnt[] = {
		31, 0, 31, 30, 31, 31, 30, 31, 30, 31
	};

	if ((year % 400 == 0 || year % 100 != 0) && (year % 4 == 0))
		month_cnt[1] = 29;
	else
		month_cnt[1] = 28;

	days = 0;
	month = 0;

	next_app = month_cnt[0];
	while (days + next_app < day)
	{
		month++;
		days += next_app;
		next_app = month_cnt[month];
	}

	if (out_days)
		*out_days = days;

	return month;
}

void DateHelpers::parse_epoch(uint64_t ms, int * o_year, int * o_month, const char ** o_month_name, int * o_day_of_year, int * o_day_of_month, int * o_hours, int * o_minutes, int * o_seconds, int * o_milliseconds)
{
	int year;
	const char * month_name;
	int month;
	int days_start_month;
	size_t rem_days;
	size_t rem_hours;
	size_t rem_mins;
	size_t rem_secs;
	size_t rem_millisecs;

	rem_days = ((ms % 31556952000) / 86400000);
	rem_hours = ((ms % 86400000) / 3600000);
	rem_mins = ((ms % 3600000) / 60000);
	rem_secs = ((ms % 60000) / 1000);
	rem_millisecs = (ms % 1000);

	year = 1970 + (ms / 31556952000);

	// Humans are fucking retards
	month = __month_calc(rem_days, year, &days_start_month);
	month_name = __month_names[month];
	month++;
	rem_days++;

	if (o_year)
		*o_year = year;

	if (o_month)
		*o_month = (int)month;

	if (o_month_name)
		*o_month_name = month_name;

	if (o_day_of_year)
		*o_day_of_year = (int)rem_days;

	if (o_day_of_month)
		*o_day_of_month = (int)rem_days - days_start_month;

	if (o_hours)
		*o_hours = rem_hours;

	if (o_minutes)
		*o_minutes = rem_mins;

	if (o_seconds)
		*o_seconds = rem_secs;

	if (o_milliseconds)
		*o_milliseconds = rem_millisecs;
}

size_t DateHelpers::ISO8601_format(char * str, size_t length, uint64_t ms)
{
	int year, month, day, hour, minute, second, mills;
	DateHelpers::parse_epoch(ms, &year, &month, nullptr, nullptr, &day, &hour, &minute, &second, &mills);
	return snprintf(str, length, "%04d-%02d-%02dT%02d:%02d:%02d.%03dZ", year, month, day, hour, minute, second, mills);
}