islandora_iiif.module

<?php

/**
 * @file
 * Main module file for islandora iiif.
 */

/**
 * Implements hook_init().
 */
function islandora_iiif_init() {
  require_once __DIR__ . "/vendor/autoload.php";
}

/**
 * Implements hook_menu().
 */
function islandora_iiif_menu() {
  return array(
    'islandora_iiif/%islandora_object/%/%/%/%' => array(
      'page callback' => 'islandora_iiif_proxied_image_response',
      'page arguments' => array(1, 2, 3, 4, 5),
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 1),
      'load arguments' => array(1),
    ),
    'islandora_iiif/%islandora_object/info.json' => array(
      'page callback' => 'islandora_iiif_proxied_info_response',
      'page arguments' => array(1),
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 1),
      'load arguments' => array(1),
    ),
    'islandora_iiif/%islandora_object/manifest' => array(
      'page callback' => 'islandora_iiif_manifest_callback',
      'page arguments' => array(1),
      'file' => 'includes/manifest.inc',
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 1),
      'load arguments' => array(1),
    ),
    'islandora_iiif/%islandora_object/sequence/%' => array(
      'page callback' => 'islandora_iiif_sequence_callback',
      'page arguments' => array(1),
      'file' => 'includes/sequence.inc',
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 1),
      'load arguments' => array(1),
    ),
    'islandora_iiif/%islandora_object/canvas/%' => array(
      'page callback' => 'islandora_iiif_canvas_callback',
      'page arguments' => array(1),
      'file' => 'includes/canvas.inc',
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 1),
      'load arguments' => array(1),
    ),
    'islandora_iiif/collection/%islandora_object' => array(
      'page callback' => 'islandora_iiif_collection_callback',
      'file' => 'includes/collection.inc',
      'page arguments' => array(2),
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 2),
      'load arguments' => array(2),
    ),
    'islandora_iiif/collection/%islandora_object/%' => array(
      'page callback' => 'islandora_iiif_collection_callback',
      'file' => 'includes/collection.inc',
      'page arguments' => array(2, 3),
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 2),
      'load arguments' => array(2),
    ),
    'admin/islandora/tools/internet_iiif_admin' => array(
      'title' => 'IIIF Module configuration',
      'description' => 'Configure the IIIF Module.',
      'page callback' => 'drupal_get_form',
      'page arguments' => array('islandora_iiif_admin_settings_form'),
      'access arguments' => array('administer site configuration'),
      'file' => 'includes/admin.form.inc',
      'type' => MENU_NORMAL_ITEM,
    ),
  );
}

/**
 *
 */
function islandora_iiif_rootcollection_access($op, $object, $user = NULL) {
  // Get root as we have it configured globally. We can always get
  // islandora:root directly via the PID specific collection manifest.
  $root_pid = variable_get('islandora_repository_pid', 'islandora:root');
  if ($object = islandora_object_load($root_pid)) {
    return islandora_object_access($op, $object, $user);
  }
  return FALSE;
}

/**
 * Our Proxied callback handler()
 */
function islandora_iiif_proxied_image_response(AbstractObject $object, $region, $size, $rotation = 0, $qualityandformat = "default.jp2") {
  global $base_root;
  module_load_include('inc', 'islandora_iiif', 'includes/utils');
  $allowedExtensions = array('png', 'jpg', 'jp2');
  $qualityandformatparsed = islandora_iiif_safefile($qualityandformat, $allowedExtensions);
  // @TODO implement a hook here to allow per CMODEL backend \
  // $hooks = islandora_build_hook_list(ISLANDORA_IMAGESERVER_HOOK, $object->models);
  $iiif_request = array(
    "pid" => $object->id,
    "region" => $region,
    "size" => $size,
    "rotation" => $rotation,
    "quality" => $qualityandformatparsed[0],
    "format" => $qualityandformatparsed[1],
  );

  module_load_include('inc', 'islandora', 'includes/authtokens');
  $uri_params = array(
    'absolute' => TRUE,
    'query' => array(
      'token' => islandora_get_object_token($object->id, "OBJ", 2),
    ),
  );
  $metadata_response = islandora_iiif_djatoka_metadata_request($object->id);
  // dpm($iiif_request);
  // dpm($metadata_response);
  $theresponsecode = (int) $metadata_response->code;
  // dpm($theresponsecode);
  if ($theresponsecode >= 200 && $theresponsecode < 400) {
    $translated_params = islandora_iiif_djatoka_region(json_decode($metadata_response->data, TRUE), $iiif_request);
    drupal_add_http_header('Content-Type', 'image/jp2');
    // @TODO hookify this so others can alter the canonical
    drupal_add_http_header('Link', '<' . $base_root . 'islandora_iiif/' . urlencode($object->id) . 'full/max/0/default.jp2>;rel="canonical"');
    drupal_add_http_header('access-control-allow-origin', '*');
    $djatoka_url = islandora_iiif_djatoka_image_request_url($object->id, $translated_params);
    // Djatoka is terrible at resizing (quality loss) so allow
    // for a setting to override that and resize after via imagemagick.
    if ((variable_get('islandora_iiif_resizeondrupal', FALSE)) &&
      isset($translated_params['scale']) && ($iiif_request['size'] != "max" && $iiif_request['size'] != "full")) {
      // The idea is this:
      // If this is enabled, the right Level will be selected
      // but the final scale should happen via imagemagick just before returning.
      // That should lead to a compromise situation: a bit slower than asking
      // Adored directly, but since level should be close to final, imagemagick
      // overhead will be not that wrong and mostly and better quality.
      $theimage = drupal_http_request($djatoka_url);
      $imagick = new Imagick();

      $imagick->readImageBlob($theimage->data);
      $imagick->setImageFormat('jp2');
      $scale = explode(",", $translated_params['scale']);

      // Make every empty string a 0.
      $scale = array_map(function ($val) {
        if (empty(trim($val))) {
          $val = 0;
        } return $val;
      }, $scale);

      if (count($scale) == 1) {
        $scale[] = 0;
      }

      $imagick->scaleImage($scale[0], $scale[1]);
      print $imagick->getImageBlob();

    }
    else {
      $theimage = drupal_http_request($djatoka_url);
      print $theimage->data;
    }

  }
  else {
    drupal_add_http_header('Status', '404 Not Found');
  }
  
  drupal_page_footer();
}

/**
 * Our Proxied callback handler()
 */
function islandora_iiif_proxied_info_response(AbstractObject $object) {
  module_load_include('inc', 'islandora_iiif', 'includes/utils');
  global $base_root;

  // @TODO implement a hook here to allow per CMODEL/Context backend.
  // $hooks = islandora_build_hook_list(ISLANDORA_IMAGESERVER_HOOK, $object->models);
  $metadata_response = islandora_iiif_djatoka_metadata_request($object->id);

  $theresponsecode = (int) $metadata_response->code;
  if ($theresponsecode >= 200 && $theresponsecode < 400) {
    drupal_add_http_header('Content-Type', 'application/json');
    drupal_add_http_header('access-control-allow-origin', '*');
    
    // @TODO hookify this so others can alter the canonical
    drupal_add_http_header('Link', '<' . $base_root . 'islandora_iiif/' . urlencode($object->id) . 'full/max/0/default.jp2>;rel="canonical"');

    $info = islandora_iiif_adoredjatoka_info_json(json_decode($metadata_response->data, TRUE));
    print json_encode($info, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
  }
  else {
    drupal_add_http_header('Status', '404 Not Found');
  }
}