add dated assignment endpoint

backend/app/Schedule/UseCases/ListAssignmentsForDate/ListAssignmentsForDate.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace App\Schedule\UseCases\ListAssignmentsForDate;
+
+use App\Exceptions\BadRequestException;
+use App\Schedule\AssignmentForDate;
+use App\Schedule\ScheduleRepository;
+use DateTimeImmutable;
+use DateTimeZone;
+
+class ListAssignmentsForDate
+{
+    public function __construct(
+        private ScheduleRepository $scheduleRepository,
+    ) {}
+
+    /**
+     * @return list<AssignmentForDate>
+     * @throws BadRequestException
+     */
+    public function execute(ListAssignmentsForDateRequest $request): array
+    {
+        $date = $this->parseDate($request->date);
+
+        return $this->scheduleRepository->findAssignmentsForUserOnDate(
+            $request->user,
+            $date,
+        );
+    }
+
+    /**
+     * @throws BadRequestException
+     */
+    private function parseDate(?string $value): DateTimeImmutable
+    {
+        if ($value === null || $value === '') {
+            throw new BadRequestException('date is required');
+        }
+
+        $date = DateTimeImmutable::createFromFormat(
+            '!Y-m-d',
+            $value,
+            new DateTimeZone('UTC'),
+        );
+        $errors = DateTimeImmutable::getLastErrors();
+        if (
+            $date === false
+            || $date->format('Y-m-d') !== $value
+            || ($errors !== false
+                && ($errors['warning_count'] > 0 || $errors['error_count'] > 0))
+        ) {
+            throw new BadRequestException(
+                'date must be a valid date in YYYY-MM-DD format',
+            );
+        }
+
+        return $date;
+    }
+}

backend/app/Schedule/UseCases/ListAssignmentsForDate/ListAssignmentsForDateRequest.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Schedule\UseCases\ListAssignmentsForDate;
+
+use App\User\User;
+
+final readonly class ListAssignmentsForDateRequest
+{
+    public function __construct(
+        public User $user,
+        public ?string $date,
+    ) {}
+}