/**
* 計算
*
* @return \Month
*/
public function calc()
{
$day = 1;
// 先月用
$lastMonthLastDay = $this->lastMonthLastDay() - $this->firstDayWeekCode;
// 来月開始日用
$nextMonthDay = 1;
$weekCnt = $this->haveWeeksCount();
for ($i = 1; $i <= $weekCnt; $i++) {
$week = new Week();
for ($j = 0; $j < 7; $j++) {
// 先月
if ($i === 1 && $j < $this->firstDayWeekCode) {
$week->setDays(Day::forge($this->lastMonthFullDate($lastMonthLastDay + $j + 1), Day::LAST_MONTH)->calc());
continue;
}
// 当月
if ($day <= $this->lastDay) {
$week->setDays(Day::forge($this->fullDate($day++))->calc());
continue;
}
// 来月
$week->setDays(Day::forge($this->nextMonthFullDate($nextMonthDay++), Day::NEXT_MONTH)->calc());
}
$this->weeks[$i] = $week;
}
return $this;
}