Add group-class enrolment deadline with instructor late-enrolment override

Group classes gain an instructor-set enrolment deadline (new
us_offerings.enrollment_deadline column) that defaults to the first day of
the class (term_start). Past the deadline students can no longer self-enrol:
the enrolment endpoint rejects it (403 enrollment_closed) and the front-end
class list shows "Enrolment has closed." in place of the Enrol button.

Instructors keep a manual path: the "Add students directly" control on each
class's details page now renders for public classes too (not just
invite-only) and deliberately bypasses the deadline and capacity, so a
student can be added as a late enrolment after the class has closed. Past
the deadline the details page labels these as late enrolments.

Bumps USC_VERSION to 1.1.3 for the schema change.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/Offering/Offering.php

@@ -54,6 +54,7 @@ class Offering {
 		public readonly ?string $termStart = null,
 		public readonly ?string $termEnd = null,
 		public readonly ?string $classTime = null,
+		public readonly ?string $enrollmentDeadline = null,
 		public readonly ?string $scheduleNote = null,
 		public readonly ?string $etransferEmail = null,
 		public readonly ?int $cancellationCutoffHours = null,
@@ -70,6 +71,27 @@ class Offering {
 		return self::ACCESS_INVITE_ONLY === $this->accessMode;
 	}
 
+	/**
+	 * The last day on which a student may enrol in this group class. Defaults to
+	 * the first day of the class (`term_start`) when the instructor has not set an
+	 * explicit deadline; null only when the class has no dates at all.
+	 */
+	public function effectiveEnrollmentDeadline(): ?string {
+		return $this->enrollmentDeadline ?? $this->termStart;
+	}
+
+	/**
+	 * Whether enrolment is still open on `$today` (a `Y-m-d` date). Enrolment stays
+	 * open through the end of the deadline day, so the first class is still
+	 * enrollable under the default deadline. A class with no deadline at all (no
+	 * dates configured) is always open.
+	 */
+	public function isEnrollmentOpen( string $today ): bool {
+		$deadline = $this->effectiveEnrollmentDeadline();
+
+		return null === $deadline || $today <= $deadline;
+	}
+
 	/**
 	 * Normalise a submitted term date to canonical `Y-m-d`, or null when it is
 	 * not a real calendar date. Round-trips through DateTimeImmutable so
@@ -169,6 +191,7 @@ class Offering {
 			termStart:       Val::stringOrNull( $row->term_start ),
 			termEnd:         Val::stringOrNull( $row->term_end ),
 			classTime:       Val::stringOrNull( $row->class_time ?? null ),
+			enrollmentDeadline: Val::stringOrNull( $row->enrollment_deadline ?? null ),
 			scheduleNote:    Val::stringOrNull( $row->schedule_note ),
 			etransferEmail:  Val::stringOrNull( $row->etransfer_email ),
 			cancellationCutoffHours: Val::intOrNull( $row->cancellation_cutoff_hours ),
@@ -203,6 +226,7 @@ class Offering {
 			'term_start'                => $this->termStart,
 			'term_end'                  => $this->termEnd,
 			'class_time'                => $this->classTime,
+			'enrollment_deadline'       => $this->enrollmentDeadline,
 			'schedule_note'             => $this->scheduleNote,
 			'cancellation_cutoff_hours' => $this->cancellationCutoffHours,
 			'access_mode'               => $this->accessMode,

src/Offering/OfferingController.php

@@ -209,6 +209,10 @@ class OfferingController {
 
 		$classTime = Offering::normalizeTime( sanitize_text_field( Val::string( wp_unslash( $_POST['class_time'] ?? '' ) ) ) );
 
+		// A blank (or invalid) deadline means "use the default" — the first class
+		// day (term_start), applied by Offering::effectiveEnrollmentDeadline().
+		$enrollmentDeadline = Offering::normalizeDate( sanitize_text_field( Val::string( wp_unslash( $_POST['enrollment_deadline'] ?? '' ) ) ) );
+
 		return new Offering(
 			instructorId:    $this->resolveInstructorId( $instructorId, $manageAll, $existing ),
 			kind:            $kind,
@@ -223,6 +227,7 @@ class OfferingController {
 			termStart:       $termStart,
 			termEnd:         $termEnd,
 			classTime:       $classTime,
+			enrollmentDeadline: $enrollmentDeadline,
 			scheduleNote:    $this->nullableText( sanitize_text_field( Val::string( wp_unslash( $_POST['schedule_note'] ?? '' ) ) ) ),
 			etransferEmail:  $this->nullableText( sanitize_email( Val::string( wp_unslash( $_POST['etransfer_email'] ?? '' ) ) ) ),
 			cancellationCutoffHours: $cutoffHours,

src/Offering/OfferingEndpoint.php

@@ -161,6 +161,7 @@ class OfferingEndpoint {
 			capacity:        $this->nullableInt( $request->get_param( 'capacity' ) ),
 			termStart:       $this->nullableText( $request->get_param( 'term_start' ) ),
 			termEnd:         $this->nullableText( $request->get_param( 'term_end' ) ),
+			enrollmentDeadline: $this->nullableText( $request->get_param( 'enrollment_deadline' ) ),
 			scheduleNote:    $this->nullableText( $request->get_param( 'schedule_note' ) ),
 			etransferEmail:  $this->nullableEmail( $request->get_param( 'etransfer_email' ) ),
 			cancellationCutoffHours: $this->nullableInt( $request->get_param( 'cancellation_cutoff_hours' ) ),
@@ -208,6 +209,7 @@ class OfferingEndpoint {
 			capacity:        $request->has_param( 'capacity' ) ? $this->nullableInt( $request->get_param( 'capacity' ) ) : $existing->capacity,
 			termStart:       $request->has_param( 'term_start' ) ? $this->nullableText( $request->get_param( 'term_start' ) ) : $existing->termStart,
 			termEnd:         $request->has_param( 'term_end' ) ? $this->nullableText( $request->get_param( 'term_end' ) ) : $existing->termEnd,
+			enrollmentDeadline: $request->has_param( 'enrollment_deadline' ) ? $this->nullableText( $request->get_param( 'enrollment_deadline' ) ) : $existing->enrollmentDeadline,
 			scheduleNote:    $request->has_param( 'schedule_note' ) ? $this->nullableText( $request->get_param( 'schedule_note' ) ) : $existing->scheduleNote,
 			etransferEmail:  $request->has_param( 'etransfer_email' ) ? $this->nullableEmail( $request->get_param( 'etransfer_email' ) ) : $existing->etransferEmail,
 			cancellationCutoffHours: $request->has_param( 'cancellation_cutoff_hours' ) ? $this->nullableInt( $request->get_param( 'cancellation_cutoff_hours' ) ) : $existing->cancellationCutoffHours,

src/Offering/OfferingRepository.php

@@ -14,12 +14,13 @@ class OfferingRepository {
 	/**
 	 * Column formats aligned to {@see columns()} (instructor_id, kind, title,
 	 * description, duration_minutes, price, currency, billing_mode, allow_weekly,
-	 * capacity, term_start, term_end, class_time, schedule_note, etransfer_email,
-	 * cancellation_cutoff_hours, access_mode, is_active).
+	 * capacity, term_start, term_end, class_time, enrollment_deadline,
+	 * schedule_note, etransfer_email, cancellation_cutoff_hours, access_mode,
+	 * is_active).
 	 *
 	 * @var list<string>
 	 */
-	private const COLUMN_FORMATS = [ '%d', '%s', '%s', '%s', '%d', '%f', '%s', '%s', '%d', '%d', '%s', '%s', '%s', '%s', '%s', '%d', '%s', '%d' ];
+	private const COLUMN_FORMATS = [ '%d', '%s', '%s', '%s', '%d', '%f', '%s', '%s', '%d', '%d', '%s', '%s', '%s', '%s', '%s', '%s', '%d', '%s', '%d' ];
 
 	public function insert( Offering $offering ): int {
 		$this->db->insert(
@@ -61,6 +62,7 @@ class OfferingRepository {
 			'term_start'                => $offering->termStart,
 			'term_end'                  => $offering->termEnd,
 			'class_time'                => $offering->classTime,
+			'enrollment_deadline'       => $offering->enrollmentDeadline,
 			'schedule_note'             => $offering->scheduleNote,
 			'etransfer_email'           => $offering->etransferEmail,
 			'cancellation_cutoff_hours' => $offering->cancellationCutoffHours,