customer-riverside/web/modules/custom/riverside_pt/riverside_pt.module

<?php

use Drupal\Core\Breadcrumb\Breadcrumb;
use Drupal\Core\Link;
use Drupal\Core\Routing\RouteMatchInterface;

function riverside_pt_page_attachments(array &$attachments): void {
  $route = \Drupal::routeMatch()->getRouteName() ?? '';
  if (!str_starts_with($route, 'riverside_pt.')) {
    return;
  }
  $attachments['#attached']['library'][] = 'riverside_pt/app';
}

function riverside_pt_theme(): array {
  return [
    'riverside_pt_header' => [
      'variables' => [
        'site_name'    => NULL,
        'home_url'     => NULL,
        'menu_items'   => [],
        'current_path' => NULL,
      ],
    ],
    'riverside_pt_home' => [
      'variables' => [],
    ],
    'riverside_pt_about' => [
      'variables' => [],
    ],
    'riverside_pt_service' => [
      'variables' => [
        'slug' => NULL,
        'title' => NULL,
        'description' => NULL,
        'long_description' => NULL,
        'what_to_expect' => NULL,
        'benefits' => [],
      ],
    ],
    'riverside_pt_contact' => [
      'variables' => [],
    ],
  ];
}

function riverside_pt_page_top(array &$page_top): void {
  $route = \Drupal::routeMatch()->getRouteName() ?? '';
  if (!str_starts_with($route, 'riverside_pt.')) {
    return;
  }
  $page_top['rpt_header'] = [
    '#theme' => 'riverside_pt_header',
    '#cache' => ['contexts' => ['url.path', 'route']],
  ];
}

function riverside_pt_preprocess_riverside_pt_header(array &$variables): void {
  $variables['site_name'] = \Drupal::config('system.site')->get('name');
  $variables['home_url']  = \Drupal\Core\Url::fromRoute('<front>')->toString();

  $tree_service = \Drupal::service('menu.link_tree');
  $params = new \Drupal\Core\Menu\MenuTreeParameters();
  $params->setMaxDepth(1);
  $tree = $tree_service->load('main', $params);
  $tree = $tree_service->transform($tree, [
    ['callable' => 'menu.default_tree_manipulators:checkAccess'],
    ['callable' => 'menu.default_tree_manipulators:generateIndexAndSort'],
  ]);

  $seen  = [];
  $items = [];
  foreach ($tree as $element) {
    if (!$element->access->isAllowed()) {
      continue;
    }
    $url = $element->link->getUrlObject()->toString();
    if (in_array($url, $seen, TRUE)) {
      continue;
    }
    $seen[]  = $url;
    $title   = (string) $element->link->getTitle();
    $items[] = [
      'title'  => $title,
      'url'    => $url,
      'is_cta' => ($title === 'Book An Appointment' || $title === 'Contact'),
    ];
  }
  $variables['menu_items']   = $items;
  $variables['current_path'] = \Drupal::request()->getPathInfo();
}

function riverside_pt_mail(string $key, array &$message, array $params): void {
  $service_map = [
    'diagnostic' => 'Diagnostic Assessment',
    'sports'     => 'Sports Rehabilitation',
    'surgical'   => 'Surgery Rehabilitation',
    'neuro'      => 'Neurological Therapy',
  ];
  $service_label = $service_map[$params['service'] ?? ''] ?? 'Appointment';

  if ($key === 'booking_request') {
    $start = new \DateTime($params['start']);
    $end   = new \DateTime($params['end']);

    $message['subject'] = 'Booking request — ' . $start->format('M j, Y g:i A');
    $lines = [
      'Name:  ' . ($params['first_name'] ?? '') . ' ' . ($params['last_name'] ?? ''),
      'Email: ' . ($params['email'] ?? ''),
      'Service: ' . $service_label,
      'Phone: ' . ($params['phone'] ?? ''),
      'Slot:  ' . $start->format('l, F j, Y') . ', ' . $start->format('g:i A') . '–' . $end->format('g:i A'),
    ];

    if (!empty($params['comments'])) {
      $lines[] = 'Comments: ' . $params['comments'];
    }

    $message['body'][] = implode("\n", $lines);
    return;
  }

  if ($key === 'booking_confirmation') {
    $start = new \DateTime($params['start']);
    $end   = new \DateTime($params['end']);

    $first = $params['first_name'] ?? 'Patient';
    $message['subject'] = 'Your appointment is confirmed — ' . $start->format('M j, Y g:i A');

    $lines = [
      'Dear ' . $first . ',',
      '',
      'Your appointment is *confirmed* for:',
      $start->format('l, F j, Y') . ', ' . $start->format('g:i A') . '–' . $end->format('g:i A') . ' PST',
      '',
      'Service: ' . $service_label,
    ];

    $full_name = trim(($params['first_name'] ?? '') . ' ' . ($params['last_name'] ?? ''));
    if ($full_name) {
      $lines[] = 'Name: ' . $full_name;
    }
    if (!empty($params['phone'])) {
      $lines[] = 'Phone: ' . $params['phone'];
    }

    $lines[] = '';
    $lines[] = 'We look forward to seeing you at Riverside Physical Therapy.';
    $lines[] = 'If you need to cancel or reschedule, please contact us as soon as possible.';

    $message['body'][] = implode("\n", $lines);
    return;
  }
}