Add group-class scheduling, instructor assignment, and details/invite management

Group classes now carry a specific class time (alongside date and duration)
and an assigned instructor:

- Schema: add `class_time` (TIME) to `us_offerings`; `Offering` gains
  `normalizeTime`/`sessionWindows`. (Rides the pending 1.0.0->1.1.0 dbDelta
  upgrade, so no version bump.)
- Offering form: class-time field, plus a studio-admin instructor picker
  (plain instructors always own their own classes).
- `ClassSlotReconciler`: assigning an instructor clears their open booking
  slots overlapping each session and flags already-booked lessons that clash
  (a booked lesson is never deleted). Uses new
  `AvailabilityRepository::findOverlapping`.
- Front end: `GET /offerings` exposes `instructor_name`; the enrolment page
  shows who teaches each class and when it meets.

Back-office group-class views redesigned:

- Instructor **My Group Classes** and studio-admin **Group Classes** are now
  per-class summaries with enrolment counts, not flat student lists.
- Each links through (`?class_id=<id>`) to a per-class **details page**
  (schedule panel, roster with payment status, and — for invite-only classes
  — the add/make-available/invite-by-email controls). Invite-only membership
  is managed entirely from this page.
- Invite actions are allowed for the class's owning instructor or any
  `view_all_lessons` studio admin, so an owner-operator (studio admin who also
  teaches) can reach every class's roster and invites from the Group Classes
  page.

Tests: composer test (508), composer lint, composer cs all pass.

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

tests/Unit/GroupClass/GroupClassControllerTest.php

@@ -55,6 +55,18 @@ class GroupClassControllerTest extends TestCase
         Functions\when('get_users')->justReturn([]);
         Functions\when('esc_attr')->returnArg();
         Functions\when('esc_attr_e')->returnArg();
+        Functions\when('esc_url')->returnArg();
+        Functions\when('admin_url')->justReturn('admin.php?page=us-my-group-classes');
+        Functions\when('add_query_arg')->alias(
+            static fn ($key, $value, $url) => $url . '&' . $key . '=' . $value
+        );
+        Functions\when('absint')->alias(static fn ($v) => abs((int) $v));
+        Functions\when('mysql2date')->alias(
+            static fn (string $format, string $date) => date($format, (int) strtotime($date))
+        );
+        Functions\when('wp_nonce_field')->justReturn('');
+
+        $_GET = [];
     }
 
     private function offering(int $id, string $title, ?int $capacity): Offering
@@ -76,9 +88,29 @@ class GroupClassControllerTest extends TestCase
         return (string) ob_get_clean();
     }
 
-    public function testInstructorPageListsClassWithCapacityAndRoster(): void
+    public function testInstructorSummaryListsClassWithEnrolmentCountAndRosterLink(): void
+    {
+        $offering = $this->offering(8, 'Choir', 10);
+        $active   = new Enrollment(offeringId: 8, studentId: 5, instructorId: 3, paymentId: 42, id: 1);
+
+        $this->offerings->shouldReceive('findAll')->once()
+            ->with(3, Offering::KIND_GROUP_CLASS)->andReturn([$offering]);
+        $this->enrollments->shouldReceive('findByInstructor')->once()->with(3)->andReturn([$active]);
+        // The summary must not resolve individual students — it is a class list.
+        $this->payments->shouldReceive('findById')->never();
+
+        $html = $this->renderInstructor();
+
+        self::assertStringContainsString('Choir', $html);
+        self::assertStringContainsString('1 / 10', $html);
+        self::assertStringContainsString('View details', $html);
+        self::assertStringContainsString('class_id=8', $html);
+    }
+
+    public function testClassDetailListsRosterWithPaymentStatus(): void
     {
         Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        $_GET = ['class_id' => '8'];
 
         $offering   = $this->offering(8, 'Choir', 10);
         $enrollment = new Enrollment(offeringId: 8, studentId: 5, instructorId: 3, paymentId: 42, id: 1);
@@ -92,15 +124,51 @@ class GroupClassControllerTest extends TestCase
 
         $html = $this->renderInstructor();
 
-        self::assertStringContainsString('Choir', $html);
-        self::assertStringContainsString('(1 / 10 enrolled)', $html);
+        self::assertStringContainsString('1 / 10 enrolled', $html);
         self::assertStringContainsString('Ada Lovelace', $html);
         self::assertStringContainsString('paid', $html);
     }
 
-    public function testEnrolmentCountExcludesCancelledButRosterKeepsThem(): void
+    public function testClassDetailShowsClassSettingsAndInviteControlsForInviteOnly(): void
+    {
+        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        $_GET = ['class_id' => '8'];
+
+        $offering = new Offering(
+            instructorId: 3,
+            kind:         Offering::KIND_GROUP_CLASS,
+            title:        'Private Choir',
+            price:        120.0,
+            description:  'A year of choir.',
+            durationMinutes: 60,
+            termStart:    '2026-09-08',
+            termEnd:      '2026-09-08',
+            classTime:    '16:00:00',
+            accessMode:   Offering::ACCESS_INVITE_ONLY,
+            id:           8,
+        );
+
+        $this->offerings->shouldReceive('findAll')->once()
+            ->with(3, Offering::KIND_GROUP_CLASS)->andReturn([$offering]);
+        $this->enrollments->shouldReceive('findByInstructor')->once()->with(3)->andReturn([]);
+        $this->access->shouldReceive('findByOffering')->once()->with(8)->andReturn([]);
+
+        $html = $this->renderInstructor();
+
+        // The details section.
+        self::assertStringContainsString('Class details', $html);
+        self::assertStringContainsString('Ada Lovelace', $html);
+        self::assertStringContainsString('120.00', $html);
+        self::assertStringContainsString('A year of choir.', $html);
+        // The invite/add controls are reached from this page.
+        self::assertStringContainsString('Add students directly', $html);
+        self::assertStringContainsString('Invite by email', $html);
+    }
+
+    public function testClassDetailEnrolmentCountExcludesCancelledButRosterKeepsThem(): void
     {
         Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Grace Hopper']);
+        $_GET = ['class_id' => '8'];
 
         $offering  = $this->offering(8, 'Band', null);
         $active    = new Enrollment(offeringId: 8, studentId: 5, instructorId: 3, id: 1);
@@ -112,14 +180,15 @@ class GroupClassControllerTest extends TestCase
         $html = $this->renderInstructor();
 
         // Unlimited capacity offering counts only the active enrolment.
-        self::assertStringContainsString('(1 enrolled)', $html);
+        self::assertStringContainsString('1 enrolled', $html);
         // But the roster still shows the cancelled row.
         self::assertStringContainsString('cancelled', $html);
     }
 
-    public function testFreeEnrolmentShowsDashForPayment(): void
+    public function testClassDetailFreeEnrolmentShowsDashForPayment(): void
     {
         Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Alan Turing']);
+        $_GET = ['class_id' => '8'];
 
         $offering   = $this->offering(8, 'Theory', 5);
         $enrollment = new Enrollment(offeringId: 8, studentId: 5, instructorId: 3, paymentId: null, id: 1);
@@ -135,8 +204,6 @@ class GroupClassControllerTest extends TestCase
 
     public function testEnrolmentsForOtherClassesAreNotMixedIn(): void
     {
-        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Katherine Johnson']);
-
         $offering = $this->offering(8, 'Choir', 5);
         $mine     = new Enrollment(offeringId: 8, studentId: 5, instructorId: 3, id: 1);
         $other    = new Enrollment(offeringId: 9, studentId: 6, instructorId: 3, id: 2);
@@ -146,11 +213,14 @@ class GroupClassControllerTest extends TestCase
 
         $html = $this->renderInstructor();
 
-        self::assertStringContainsString('(1 / 5 enrolled)', $html);
+        self::assertStringContainsString('1 / 5', $html);
     }
 
-    public function testClassWithNoEnrolmentsShowsEmptyMessage(): void
+    public function testClassDetailWithNoEnrolmentsShowsEmptyMessage(): void
     {
+        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        $_GET = ['class_id' => '8'];
+
         $offering = $this->offering(8, 'Jazz', 5);
 
         $this->offerings->shouldReceive('findAll')->once()->andReturn([$offering]);
@@ -171,6 +241,64 @@ class GroupClassControllerTest extends TestCase
         self::assertStringContainsString('You have no group classes.', $html);
     }
 
+    public function testStudioAdminPageSummarisesClassesNotStudents(): void
+    {
+        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+
+        $offering = new Offering(
+            instructorId: 3,
+            kind: Offering::KIND_GROUP_CLASS,
+            title: 'Choir',
+            capacity: 10,
+            termStart: '2026-09-08',
+            termEnd: '2026-09-08',
+            classTime: '16:00:00',
+            id: 8,
+        );
+
+        $this->offerings->shouldReceive('findAll')->once()
+            ->with(0, Offering::KIND_GROUP_CLASS)->andReturn([$offering]);
+        $this->enrollments->shouldReceive('countActiveForOffering')->once()->with(8)->andReturn(4);
+
+        ob_start();
+        $this->controller->renderPage();
+        $html = (string) ob_get_clean();
+
+        self::assertStringContainsString('Choir', $html);
+        self::assertStringContainsString('Ada Lovelace', $html);
+        self::assertStringContainsString('4 / 10', $html);
+    }
+
+    public function testStudioAdminCanOpenClassDetailWithInviteControls(): void
+    {
+        // A studio admin (view_all_lessons) opens a class taught by instructor 7.
+        Functions\when('get_userdata')->justReturn((object) ['display_name' => 'Ada Lovelace']);
+        $_GET = ['class_id' => '8'];
+
+        $offering = new Offering(
+            instructorId: 7,
+            kind:         Offering::KIND_GROUP_CLASS,
+            title:        'Private Choir',
+            price:        120.0,
+            accessMode:   Offering::ACCESS_INVITE_ONLY,
+            id:           8,
+        );
+
+        $this->offerings->shouldReceive('findAll')->once()
+            ->with(0, Offering::KIND_GROUP_CLASS)->andReturn([$offering]);
+        // Detail rosters are looked up by the class's own instructor (7).
+        $this->enrollments->shouldReceive('findByInstructor')->once()->with(7)->andReturn([]);
+        $this->access->shouldReceive('findByOffering')->once()->with(8)->andReturn([]);
+
+        ob_start();
+        $this->controller->renderPage();
+        $html = (string) ob_get_clean();
+
+        self::assertStringContainsString('Class details', $html);
+        self::assertStringContainsString('Add students directly', $html);
+        self::assertStringContainsString('Invite by email', $html);
+    }
+
     public function testDeniesUsersWithoutViewLessonsCapability(): void
     {
         Functions\when('current_user_can')->justReturn(false);
@@ -184,6 +312,7 @@ class GroupClassControllerTest extends TestCase
     protected function tearDown(): void
     {
         $_POST = [];
+        $_GET  = [];
         parent::tearDown();
     }
 
@@ -332,8 +461,13 @@ class GroupClassControllerTest extends TestCase
         self::assertStringContainsString('1 student(s) granted access.', $html);
     }
 
-    public function testActionRejectedForClassNotOwnedByInstructor(): void
+    public function testActionRejectedForClassNotOwnedByPlainInstructor(): void
     {
+        // A plain instructor (no view_all_lessons) may only manage their own classes.
+        Functions\when('current_user_can')->alias(
+            static fn (string $cap) => 'view_all_lessons' !== $cap
+        );
+
         $_POST = ['usc_action' => 'add_direct', 'offering_id' => 8, 'student_ids' => [5]];
         $this->stubActionContext();
 
@@ -346,4 +480,36 @@ class GroupClassControllerTest extends TestCase
 
         self::assertStringContainsString('That group class was not found.', $html);
     }
+
+    public function testStudioAdminCanManageInviteForAnotherInstructorsClass(): void
+    {
+        // current_user_can returns true for everything (incl. view_all_lessons),
+        // so the studio admin may add students to a class they do not own.
+        $_POST = ['usc_action' => 'add_direct', 'offering_id' => 8, 'student_ids' => [5]];
+        $this->stubActionContext();
+
+        $foreign = new Offering(instructorId: 7, kind: Offering::KIND_GROUP_CLASS, title: 'Other', price: 100.0, accessMode: Offering::ACCESS_INVITE_ONLY, id: 8);
+        $this->offerings->shouldReceive('findById')->with(8)->andReturn($foreign);
+        $this->enrollments->shouldReceive('hasActiveEnrollment')->with(8, 5)->andReturn(false);
+        $this->enrollments->shouldReceive('insert')->once()->andReturn(44);
+
+        // The enrolment and payment use the class's own instructor (7), not the admin.
+        $payment = new Payment(
+            studentId:        5,
+            instructorId:     7,
+            registrationType: Payment::REG_ENROLLMENT,
+            registrationId:   44,
+            amount:           100.0,
+            status:           Payment::STATUS_PENDING,
+            id:               12,
+        );
+        $this->paymentService->shouldReceive('createForRegistration')
+            ->once()->with(Payment::REG_ENROLLMENT, 44, 5, 7, 100.0, 'CAD', null)->andReturn($payment);
+        $this->enrollments->shouldReceive('setPaymentId')->once()->with(44, 12)->andReturn(true);
+        $this->access->shouldReceive('markEnrolled')->once()->with(8, 5);
+
+        $html = $this->renderInstructor();
+
+        self::assertStringContainsString('1 student(s) added to the class.', $html);
+    }
 }