<?php

/**
 * @file
 * Contains the RapidIllRequestHandler class for submitting ILL requests
 * to RapidILL using the roblib/rapidillrequest package.
 */

use Drupal\Core\Form\FormStateInterface;
use RapidIll\InsertRequest;
use RapidIll\InsertResponse;
use RapidIll\RapidIllClient;
use RapidIll\RapidIllException;
use RapidIll\RequestType;

/**
 * Handles building and submitting RapidILL requests from the ILL loan form.
 *
 * Usage (from the form submit handler):
 * @code
 *   \Drupal::moduleHandler()->loadInclude('upei_roblib_ill', 'inc', 'includes/rapidill');
 *   $handler = new RapidIllRequestHandler();
 *   $response = $handler->submitRequest($form_state);
 * @endcode
 */
class RapidIllRequestHandler {

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

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

  /**
   * Maps a form Genre value to a RapidILL RequestType enum.
   *
   * @param string $genre
   *   The genre value from the ILL form ('article', 'book', or 'chapter').
   *
   * @return \RapidIll\RequestType
   *   The corresponding RequestType enum value.
   */
  public function getRequestType(string $genre): RequestType {
    return match ($genre) {
      'book' => RequestType::Book,
      'chapter' => RequestType::BookChapter,
      default => RequestType::Article,
    };
  }

  /**
   * Builds a RapidILL InsertRequest 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 \RapidIll\InsertRequest
   *   A populated InsertRequest ready to be submitted.
   */
  public function buildInsertRequest(FormStateInterface $form_state): InsertRequest {
    $storage = $form_state->getStorage();
    $biblio = $storage['request'] ?? [];
    $patron = $form_state->getValues();

    $genre = $biblio['Genre'] ?? 'article';
    $request = new InsertRequest();
    $request->setRequestType($this->getRequestType($genre));

    // -- Bibliographic fields --
    if (!empty($biblio['Title'])) {
      $request->setJournalTitle($biblio['Title']);
    }

    if (!empty($biblio['ArticleTitle'])) {
      $request->setArticleTitle($biblio['ArticleTitle']);
    }

    // Use ArticleAuthor for articles/chapters, Author for books.
    $author = '';
    if ($genre !== 'book' && !empty($biblio['ArticleAuthor'])) {
      $author = $biblio['ArticleAuthor'];
    }
    elseif (!empty($biblio['Author'])) {
      $author = $biblio['Author'];
    }
    if (!empty($author)) {
      $request->setArticleAuthor($author);
    }

    if (!empty($biblio['ISSN'])) {
      $issn = is_array($biblio['ISSN']) ? reset($biblio['ISSN']) : $biblio['ISSN'];
      if (!empty($issn)) {
        $request->addIssn($issn);
      }
    }

    if (!empty($biblio['ISBN'])) {
      $isbn = is_array($biblio['ISBN']) ? reset($biblio['ISBN']) : $biblio['ISBN'];
      if (!empty($isbn)) {
        $request->addIsbn($isbn);
      }
    }

    if (!empty($biblio['Volume'])) {
      $request->setJournalVolume($biblio['Volume']);
    }

    if (!empty($biblio['Issue'])) {
      $request->setJournalIssue($biblio['Issue']);
    }

    if (!empty($biblio['PagesRequested'])) {
      $request->setArticlePages($biblio['PagesRequested']);
    }

    if (!empty($biblio['Date'])) {
      $request->setJournalYear($biblio['Date']);
    }

    // -- Patron fields --
    if (!empty($patron['campus_id'])) {
      $request->setPatronId($patron['campus_id']);
    }

    $first_name = $patron['FirstName'] ?? '';
    $surname = $patron['Surname'] ?? '';
    $full_name = trim("$first_name $surname");
    if (!empty($full_name)) {
      $request->setPatronName($full_name);
    }

    if (!empty($patron['DeliveryAddress'])) {
      $request->setPatronEmail($patron['DeliveryAddress']);
    }

    if (!empty($patron['Department'])) {
      $request->setPatronDepartment($patron['Department']);
    }

    // Combine user notes and DOI (if present) into patron notes.
    $notes_parts = [];
    if (!empty($patron['notes'])) {
      $notes_parts[] = $patron['notes'];
    }
    if (!empty($biblio['doi'])) {
      $notes_parts[] = 'DOI: ' . $biblio['doi'];
    }
    if (!empty($notes_parts)) {
      $request->setPatronNotes(implode(' | ', $notes_parts));
    }

    return $request;
  }

  /**
   * Creates a RapidIllClient from the module's Drupal configuration.
   *
   * Reads the following config keys from 'upei_roblib_ill.settings':
   *   - rapid_ill_username
   *   - rapid_ill_password
   *   - rapid_ill_code
   *   - rapid_ill_branch_name
   *
   * @return \RapidIll\RapidIllClient
   *   A configured RapidILL client.
   *
   * @throws \RuntimeException
   *   If any required configuration value is missing.
   */
  protected function createClient(): RapidIllClient {
    $username = $this->config->get('rapid_ill_username');
    $password = $this->config->get('rapid_ill_password');
    $rapid_code = $this->config->get('rapid_ill_code');
    $branch_name = $this->config->get('rapid_ill_branch_name');

    if (empty($username) || empty($password) || empty($rapid_code) || empty($branch_name)) {
      \Drupal::logger('upei_roblib_ill')->error(
        'RapidILL configuration is incomplete. Please set rapid_ill_username, rapid_ill_password, rapid_ill_code, and rapid_ill_branch_name in the ILL settings.'
      );
      throw new \RuntimeException('RapidILL configuration is incomplete.');
    }

    return new RapidIllClient(
      username: $username,
      password: $password,
      rapidCode: $rapid_code,
      branchName: $branch_name,
    );
  }

  /**
   * Builds and submits a RapidILL request from an InsertRequest object.
   *
   * @param \RapidIll\InsertRequest $insert_request
   *   The fully built RapidILL request object.
   *
   * @return array
   *   An associative array with at least a 'ConfirmMessage' key, and
   *   optionally a 'RequestNumber' key on success.
   */
  public function submitRequest(InsertRequest $insert_request): array {
    \Drupal::moduleHandler()->loadInclude('upei_roblib_ill', 'inc', 'includes/db');

    try {
      $client = $this->createClient();
    }
    catch (\RuntimeException $e) {
      $error_response = [
        'ConfirmMessage' => 'RapidILL is not configured. Please contact the library.',
      ];
      upei_roblib_ill_log_request($insert_request, $error_response);
      return $error_response;
    }

    try {
      /** @var \RapidIll\InsertResponse $response */
      $response = $client->insertRequest($insert_request);
    }
    catch (RapidIllException $e) {
      \Drupal::logger('upei_roblib_ill')->error(
        'RapidILL request failed: @message',
        ['@message' => $e->getMessage()]
      );
      $error_response = [
        'ConfirmMessage' => 'Error communicating with RapidILL: ' . $e->getMessage(),
      ];
      upei_roblib_ill_log_request($insert_request, $error_response);
      return $error_response;
    }

    // Build a response array compatible with the existing form redirect.
    if ($response->isSuccessful) {
      $result = [
        'RequestNumber' => $response->rapidRequestId,
        'ConfirmMessage' => 'Your Interlibrary Loan request has been successfully submitted to RapidILL. Your Rapid Request ID is: ' . $response->rapidRequestId,
      ];
    }
    else {
      $message = $response->verificationNote ?? 'Unknown error from RapidILL.';
      $result = [
        'ConfirmMessage' => 'RapidILL could not process your request: ' . $message,
      ];
    }

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

}