Attainly/backend/app/Schedule/EvenDistributionScheduler.php

114 lines
3.1 KiB
PHP

<?php
namespace App\Schedule;
use DateTimeImmutable;
class EvenDistributionScheduler
{
/**
* @return list<DateTimeImmutable>
*/
public function scheduledDates(
int $assignmentCount,
DateTimeImmutable $startDate,
DateTimeImmutable $targetDate,
WorkloadPlacement $workloadPlacement,
): array {
$differenceInDays = $startDate->diff($targetDate)->days;
$dayCount = $differenceInDays + 1;
if ($workloadPlacement === WorkloadPlacement::Spread) {
return $this->sparseDates(
assignmentCount: $assignmentCount,
dayCount: $dayCount,
startDate: $startDate,
);
}
return $this->groupedDates(
assignmentCount: $assignmentCount,
dayCount: $dayCount,
startDate: $startDate,
workloadPlacement: $workloadPlacement,
);
}
/**
* @return list<DateTimeImmutable>
*/
private function sparseDates(
int $assignmentCount,
int $dayCount,
DateTimeImmutable $startDate,
): array {
if ($assignmentCount === 1) {
return [$startDate];
}
$dates = [];
for ($assignmentIndex = 0;
$assignmentIndex < $assignmentCount;
$assignmentIndex++
) {
$scaledIndex = $assignmentIndex * ($dayCount - 1)
/ ($assignmentCount - 1);
$dayIndex = (int) floor($scaledIndex + 0.5);
$dates[] = $startDate->modify("+{$dayIndex} days");
}
return $dates;
}
/**
* @return list<DateTimeImmutable>
*/
private function groupedDates(
int $assignmentCount,
int $dayCount,
DateTimeImmutable $startDate,
WorkloadPlacement $workloadPlacement,
): array {
$assignmentsPerDay = intdiv($assignmentCount, $dayCount);
$remainderDayCount = $assignmentCount % $dayCount;
$remainderBlockStart = $this->remainderBlockStart(
dayCount: $dayCount,
remainderDayCount: $remainderDayCount,
workloadPlacement: $workloadPlacement,
);
$dates = [];
for ($dayIndex = 0; $dayIndex < $dayCount; $dayIndex++) {
$assignmentCountForDay = $assignmentsPerDay;
if (
$dayIndex >= $remainderBlockStart
&& $dayIndex < $remainderBlockStart + $remainderDayCount
) {
$assignmentCountForDay++;
}
$date = $startDate->modify("+{$dayIndex} days");
for ($index = 0; $index < $assignmentCountForDay; $index++) {
$dates[] = $date;
}
}
return $dates;
}
private function remainderBlockStart(
int $dayCount,
int $remainderDayCount,
WorkloadPlacement $workloadPlacement,
): int {
if ($workloadPlacement === WorkloadPlacement::Start) {
return 0;
}
if ($workloadPlacement === WorkloadPlacement::End) {
return $dayCount - $remainderDayCount;
}
return intdiv($dayCount - $remainderDayCount, 2);
}
}