DX: Add rolling date converter + unit test

src/Bundle/ChillMainBundle/Service/RollingDate/RollingDate.php

@@ -77,7 +77,7 @@ class RollingDate
      * @param DateTimeImmutable|null $pivotDate Will be "now" if null is given
      * @param DateTimeImmutable|null $fixedDate Only to insert if $roll equals @see{self::T_FIXED_DATE}
      */
-    public function __construct(string $roll, ?DateTimeImmutable $pivotDate = null, ?DateTimeImmutable $fixedDate = null)
+    public function __construct(string $roll, ?DateTimeImmutable $fixedDate = null, ?DateTimeImmutable $pivotDate = null)
     {
         $this->roll = $roll;
         $this->pivotDate = $pivotDate ?? new DateTimeImmutable('now');

src/Bundle/ChillMainBundle/Service/RollingDate/RollingDateConverter.php

@@ -0,0 +1,141 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\MainBundle\Service\RollingDate;
+
+use DateInterval;
+use DateTimeImmutable;
+use LogicException;
+use UnexpectedValueException;
+
+class RollingDateConverter
+{
+    public function convert(RollingDate $rollingDate): DateTimeImmutable
+    {
+        switch ($rollingDate->getRoll()) {
+            case RollingDate::T_MONTH_CURRENT_START:
+                return $this->toBeginOfMonth($rollingDate->getPivotDate());
+
+            case RollingDate::T_MONTH_NEXT_START:
+                return $this->toBeginOfMonth($rollingDate->getPivotDate()->add(new DateInterval('P1M')));
+
+            case RollingDate::T_MONTH_PREVIOUS_START:
+                return $this->toBeginOfMonth($rollingDate->getPivotDate()->sub(new DateInterval('P1M')));
+
+            case RollingDate::T_QUARTER_CURRENT_START:
+                return $this->toBeginOfQuarter($rollingDate->getPivotDate());
+
+            case RollingDate::T_QUARTER_NEXT_START:
+                return $this->toBeginOfQuarter($rollingDate->getPivotDate()->add(new DateInterval('P3M')));
+
+            case RollingDate::T_QUARTER_PREVIOUS_START:
+                return $this->toBeginOfQuarter($rollingDate->getPivotDate()->sub(new DateInterval('P3M')));
+
+            case RollingDate::T_WEEK_CURRENT_START:
+                return $this->toBeginOfWeek($rollingDate->getPivotDate());
+
+            case RollingDate::T_WEEK_NEXT_START:
+                return $this->toBeginOfWeek($rollingDate->getPivotDate()->add(new DateInterval('P1W')));
+
+            case RollingDate::T_WEEK_PREVIOUS_START:
+                return $this->toBeginOfWeek($rollingDate->getPivotDate()->sub(new DateInterval('P1W')));
+
+            case RollingDate::T_YEAR_CURRENT_START:
+                return $this->toBeginOfYear($rollingDate->getPivotDate());
+
+            case RollingDate::T_YEAR_PREVIOUS_START:
+                return $this->toBeginOfYear($rollingDate->getPivotDate()->sub(new DateInterval('P1Y')));
+
+            case RollingDate::T_YEAR_NEXT_START:
+                return $this->toBeginOfYear($rollingDate->getPivotDate()->add(new DateInterval('P1Y')));
+
+            case RollingDate::T_TODAY:
+                return $rollingDate->getPivotDate();
+
+            case RollingDate::T_FIXED_DATE:
+                if (null === $rollingDate->getFixedDate()) {
+                    throw new \LogicException("You must provide a fixed date when selecting a fixed date");
+                }
+                return $rollingDate->getFixedDate();
+
+            default:
+                throw new UnexpectedValueException(sprintf('%s rolling operation not supported', $rollingDate->getRoll()));
+        }
+    }
+
+    private function toBeginOfMonth(DateTimeImmutable $date): DateTimeImmutable
+    {
+        return DateTimeImmutable::createFromFormat(
+            'Y-m-d His',
+            sprintf('%s-%s-01 000000', $date->format('Y'), $date->format('m'))
+        );
+    }
+
+    private function toBeginOfQuarter(DateTimeImmutable $date): DateTimeImmutable
+    {
+        switch ((int) $date->format('n')) {
+            case 1:
+            case 2:
+            case 3:
+                $month = '01';
+
+                break;
+
+            case 4:
+            case 5:
+            case 6:
+                $month = '04';
+
+                break;
+
+            case 7:
+            case 8:
+            case 9:
+                $month = '07';
+
+                break;
+
+            case 10:
+            case 11:
+            case 12:
+                $month = '10';
+
+                break;
+
+            default:
+                throw new LogicException('this month is not valid: ' . $date->format('n'));
+        }
+
+        return DateTimeImmutable::createFromFormat(
+            'Y-m-d His',
+            sprintf('%s-%s-01 000000', $date->format('Y'), $month)
+        );
+    }
+
+    private function toBeginOfWeek(DateTimeImmutable $date): DateTimeImmutable
+    {
+        if (1 === $dayOfWeek = (int) $date->format('N')) {
+            return $date->setTime(0, 0, 0);
+        }
+
+        return $date
+            ->sub(new DateInterval('P' . ($dayOfWeek - 1) . 'D'))
+            ->setTime(0, 0, 0);
+    }
+
+    private function toBeginOfYear(DateTimeImmutable $date): DateTimeImmutable
+    {
+        return DateTimeImmutable::createFromFormat(
+            'Y-m-d His',
+            sprintf('%s-01-01 000000', $date->format('Y'))
+        );
+    }
+}