<?php

/**
 * @file
 * Contains the SharePointRequestHandler class for submitting ILL requests
 * to a SharePoint list via a Power Automate webhook.
 */

use Drupal\Core\Form\FormStateInterface;

/**
 * Handles building and submitting ILL requests to SharePoint via Power Automate.
 *
 * Usage (from the form submit handler):
 * @code
 *   \Drupal::moduleHandler()->loadInclude('upei_roblib_ill', 'inc', 'includes/sharepoint');
 *   $handler = new SharePointRequestHandler();
 *   $payload = $handler->buildPayload($form_state);
 *   $response = $handler->submitRequest($payload);
 * @endcode
 */
class SharePointRequestHandler
{

  /**
   * Drupal config object for upei_roblib_ill.settings.
   *
   * @var \Drupal\Core\Config\ImmutableConfig
   */
  protected $config;

  /**
   * Constructs a new SharePointRequestHandler.
   */
  public function __construct()
  {
    $this->config = \Drupal::config('upei_roblib_ill.settings');
  }

  /**
   * Builds the webhook payload from the Drupal form state.
   *
   * Reads bibliographic data from form storage (step 1) and patron data
   * from the current form values (step 2).
   *
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current form state containing both steps of the ILL form.
   *
   * @return array
   *   An associative array matching the Power Automate webhook payload schema.
   */
  public function buildPayload(FormStateInterface $form_state): array
  {
    $storage = $form_state->getStorage();
    $biblio = $storage['request'] ?? [];
    $patron = $form_state->getValues();

    $genre = $biblio['Genre'] ?? 'article';

    // Determine the author: use ArticleAuthor for articles/chapters, Author for books.
    $author = '';
    if ($genre !== 'book' && !empty($biblio['ArticleAuthor'])) {
      $author = $biblio['ArticleAuthor'];
    }
    elseif (!empty($biblio['Author'])) {
      $author = $biblio['Author'];
    }

    // Combine DOI and ISBN into a single field.
    $doi_isbn_parts = [];
    if (!empty($biblio['doi'])) {
      $doi_isbn_parts[] = $biblio['doi'];
    }
    if (!empty($biblio['ISBN'])) {
      $doi_isbn_parts[] = $biblio['ISBN'];
    }
    if (!empty($biblio['ISSN'])) {
      $doi_isbn_parts[] = $biblio['ISSN'];
    }
    $doi_isbn = implode('; ', $doi_isbn_parts);

    // Build patron full name.
    $first_name = $patron['FirstName'] ?? '';
    $surname = $patron['Surname'] ?? '';
    $patron_name = trim("$first_name $surname");

    // Build notes — pack all extra info that doesn't have its own schema field.
    $notes_parts = [];
    if (!empty($biblio['ArticleTitle'])) {
      $notes_parts[] = 'Article/Chapter: ' . $biblio['ArticleTitle'];
    }
    if (!empty($biblio['Volume'])) {
      $notes_parts[] = 'Vol: ' . $biblio['Volume'];
    }
    if (!empty($biblio['Issue'])) {
      $notes_parts[] = 'Issue: ' . $biblio['Issue'];
    }
    if (!empty($biblio['PagesRequested'])) {
      $notes_parts[] = 'Pages: ' . $biblio['PagesRequested'];
    }
    if (!empty($patron['patron_type'])) {
      $notes_parts[] = 'Patron Type: ' . $patron['patron_type'];
    }
    if (!empty($patron['Department'])) {
      $notes_parts[] = 'Dept: ' . $patron['Department'];
    }
    if (!empty($patron['notes'])) {
      $notes_parts[] = $patron['notes'];
    }

    // All values MUST be strings — Power Automate rejects the request
    // if any value type does not match the trigger's JSON schema.
    return [
      'title' => (string)($biblio['Title'] ?? ''),
      'author' => (string)$author,
      'year' => (string)($biblio['Date'] ?? ''),
      'doi_isbn' => (string)$doi_isbn,
      'format' => (string)$genre,
      'patronName' => (string)$patron_name,
      'patronEmail' => (string)($patron['DeliveryAddress'] ?? ''),
      'patronBarcode' => (string)($patron['campus_id'] ?? ''),
      'notes' => (string)implode(' | ', $notes_parts),
      'submittedAt' => (string)gmdate('Y-m-d\TH:i:s') . '.000Z',
    ];
  }

  /**
   * Submits the payload to the configured Power Automate webhook.
   *
   * @param array $payload
   *   The payload array as built by buildPayload().
   *
   * @return array
   *   An associative array with at least a 'ConfirmMessage' key, and
   *   optionally a 'RequestNumber' key on success.
   */
  public function submitRequest(array $payload): array
  {
    \Drupal::moduleHandler()->loadInclude('upei_roblib_ill', 'inc', 'includes/db');

    $webhook_url = $this->config->get('sharepoint_webhook_url');
    if (empty($webhook_url)) {
      \Drupal::logger('upei_roblib_ill')->error(
        'SharePoint webhook URL is not configured. Please set it in the ILL settings.'
      );
      $error_response = [
        'ConfirmMessage' => 'SharePoint integration is not configured. Please contact the library.',
      ];
      upei_roblib_ill_log_request($payload, $error_response);
      return $error_response;
    }

    // Log the outgoing payload for debugging.
    \Drupal::logger('upei_roblib_ill')->notice(
      'Submitting ILL request to SharePoint webhook. Payload: @payload',
    ['@payload' => json_encode($payload)]
    );

    try {
      // Use 'json' option which handles JSON encoding and Content-Type automatically.
      $response = \Drupal::httpClient()->post($webhook_url, [
        'json' => $payload,
        'timeout' => 30,
      ]);

      $status_code = $response->getStatusCode();
      $body = (string)$response->getBody();
      $response_data = json_decode($body, TRUE) ?: [];

      if ($status_code >= 200 && $status_code < 300) {
        $result = [
          'RequestNumber' => $response_data['request_number'] ?? date('YmdHis'),
          'ConfirmMessage' => 'Your Interlibrary Loan request has been successfully submitted.',
        ];
      }
      else {
        $message = $response_data['error'] ?? 'Unexpected response from SharePoint (HTTP ' . $status_code . ').';
        $result = [
          'ConfirmMessage' => 'SharePoint could not process your request: ' . $message,
        ];
      }
    }
    catch (\Exception $e) {
      \Drupal::logger('upei_roblib_ill')->error(
        'SharePoint webhook request failed: @message',
      ['@message' => $e->getMessage()]
      );
      $result = [
        'ConfirmMessage' => 'Error communicating with SharePoint: ' . $e->getMessage(),
      ];
    }

    upei_roblib_ill_log_request($payload, $result);
    return $result;
  }

}