<?php

/**
 * @file
 * Wrapper around the tuque library, allows for autoloading of Islandora Tuque
 * Objects.
 *
 * @todo Overload functions and apply pre/post hooks.
 */

// This function may not exist when a batch operation is running from a
// multistep form.
if (function_exists('drupal_get_path')) {
  $islandora_module_path = drupal_get_path('module', 'islandora');
}

// @todo this until we expost these in a module or library
@include_once 'sites/all/libraries/tuque/Datastream.php';
@include_once 'sites/all/libraries/tuque/FedoraApi.php';
@include_once 'sites/all/libraries/tuque/FedoraApiSerializer.php';
@include_once 'sites/all/libraries/tuque/Object.php';
@include_once 'sites/all/libraries/tuque/RepositoryConnection.php';
@include_once 'sites/all/libraries/tuque/Cache.php';
@include_once 'sites/all/libraries/tuque/RepositoryException.php';
@include_once 'sites/all/libraries/tuque/Repository.php';
@include_once 'sites/all/libraries/tuque/FedoraRelationships.php';

@include_once "$islandora_module_path/libraries/tuque/Datastream.php";
@include_once "$islandora_module_path/libraries/tuque/FedoraApi.php";
@include_once "$islandora_module_path/libraries/tuque/FedoraApiSerializer.php";
@include_once "$islandora_module_path/libraries/tuque/Object.php";
@include_once "$islandora_module_path/libraries/tuque/RepositoryConnection.php";
@include_once "$islandora_module_path/libraries/tuque/Cache.php";
@include_once "$islandora_module_path/libraries/tuque/RepositoryException.php";
@include_once "$islandora_module_path/libraries/tuque/Repository.php";
@include_once "$islandora_module_path/libraries/tuque/FedoraRelationships.php";

/**
 * Allow modules to alter an object before a mutable event occurs.
 */
function islandora_alter_object(AbstractObject $object, array &$context) {
  module_load_include('inc', 'islandora', 'includes/utilities');
  drupal_alter(islandora_build_hook_list('islandora_object', $object->models), $object, $context);
}

/**
 * Allow modules to alter a datastream before a mutable event occurs.
 */
function islandora_alter_datastream(AbstractObject $object, AbstractDatastream $datastream, array &$context) {
  module_load_include('inc', 'islandora', 'includes/utilities');
  $types = array();
  foreach ($object->models as $model) {
    $types[] = "{$model}_{$datastream->id}";
  }
  drupal_alter(islandora_build_hook_list('islandora_datastream', $types), $object, $datastream, $context);
}

/**
 * Constructs a list of hooks from the given paramenters and invokes them.
 */
function islandora_invoke_object_hooks($hook, array $models) {
  module_load_include('inc', 'islandora', 'includes/utilities');
  return islandora_invoke_hook_list($hook, $models, array_slice(func_get_args(), 2));
}

/**
 * Constructs a list of hooks from the given paramenters and invokes them.
 */
function islandora_invoke_datastream_hooks($hook, array $models, $dsid) {
  module_load_include('inc', 'islandora', 'includes/utilities');
  $refinements = array();
  foreach ($models as $model) {
    $refinements[] = "{$model}_{$dsid}";
  }
  return islandora_invoke_hook_list($hook, $refinements, array_slice(func_get_args(), 3));
}

class IslandoraFedoraRepository extends FedoraRepository {
  protected $queryClass = 'IslandoraRepositoryQuery';
  protected $newObjectClass = 'IslandoraNewFedoraObject';
  protected $objectClass = 'IslandoraFedoraObject';

  /**
   * Ingest the given object.
   *
   * @see FedoraRepository::ingestObject()
   */
  public function ingestObject(NewFedoraObject &$object) {
    try {
      foreach ($object as $dsid => $datastream) {
        $datastream_context = array(
          'action' => 'ingest',
          'block' => FALSE,
        );
        islandora_alter_datastream($object, $datastream, $datastream_context);
        if ($datastream_context['block']) {
          throw new Exception(t('Object ingest blocked due to ingest of @dsid being blocked.', array(
            '@dsid' => $dsid,
          )));
        }
      }

      $object_context = array(
        'action' => 'ingest',
        'block' => FALSE,
      );
      islandora_alter_object($object, $object_context);
      if ($object_context['block']) {
        throw new Exception('Ingest Object was blocked.');
      }
      $ret = parent::ingestObject($object);
      islandora_invoke_object_hooks(ISLANDORA_OBJECT_INGESTED_HOOK, $object->models, $object);
      // Call the ingested datastream hooks for NewFedoraObject's after the
      // object had been ingested.
      foreach ($object as $dsid => $datastream) {
        islandora_invoke_datastream_hooks(ISLANDORA_DATASTREAM_INGESTED_HOOK, $object->models, $dsid, $object, $datastream);
      }
      // Fire of event if rules is enabled.
      if (module_exists('rules')) {
        rules_invoke_event('islandora_object_ingested', $object);
      }
      return $ret;
    }
    catch (Exception $e) {
      watchdog('islandora', 'Failed to ingest object: @pid</br>code: @code<br/>message: @msg', array(
          '@pid' => $object->id,
          '@code' => $e->getCode(),
          '@msg' => $e->getMessage()), WATCHDOG_ERROR);
      throw $e;
    }
  }
}

class IslandoraRepositoryQuery extends RepositoryQuery {}

class IslandoraNewFedoraObject extends NewFedoraObject {
  protected $newFedoraDatastreamClass = 'IslandoraNewFedoraDatastream';
  protected $fedoraDatastreamClass = 'IslandoraFedoraDatastream';
  protected $fedoraRelsExtClass = 'IslandoraFedoraRelsExt';
}

class IslandoraFedoraObject extends FedoraObject {
  protected $newFedoraDatastreamClass = 'IslandoraNewFedoraDatastream';
  protected $fedoraDatastreamClass = 'IslandoraFedoraDatastream';
  protected $fedoraRelsExtClass = 'IslandoraFedoraRelsExt';

  /**
   * Magical magic, to allow recursive modifications.
   *
   * So... Magic functions in PHP are not re-entrant... Meaning that if you
   * have something which tries to call __set on an object anywhere later in
   * the callstack after it has already been called, it will not call the
   * magic method again; instead, it will set the property on the object
   * proper. Here, we detect the property being set on the object proper, and
   * restore the magic functionality as long as it keeps getting set...
   *
   * Not necessary to try to account for this in Tuque proper, as Tuque itself
   * does not have a mechanism to trigger modifications resulting from other
   * modifications.
   *
   * @param string $name
   *   The name of the property being set.
   * @param mixed $value
   *   The value to which the property should be set.
   */
  public function __set($name, $value) {
    parent::__set($name, $value);

    // Recursion only matters for magic properties... "Plain" properties cannot
    // call other code in order to start recursing, and in fact we would get
    // stuck looping with a "plain" property.
    if ($this->propertyIsMagical($name)) {
      // XXX: Due to the structure of the code, we cannot use property_exists()
      // (because many of the properties are declared in the class, and the
      // magic triggers due them being NULLed), nor can we use isset() (because
      // it is implemented as another magic function...).
      $vars = get_object_vars($this);
      while (isset($vars[$name])) {
        $new_value = $this->$name;
        unset($this->$name);
        parent::__set($name, $new_value);
        $vars = get_object_vars($this);
      }
    }
  }

  /**
   * Ingest the given datastream.
   *
   * @see FedoraObject::ingestDatastream()
   */
  public function ingestDatastream(&$datastream) {
    $object = $datastream->parent;
    $context = array(
      'action' => 'ingest',
      'block' => FALSE,
    );
    islandora_alter_datastream($object, $datastream, $context);
    try {
      if ($context['block']) {
        throw new Exception('Ingest Datastream was blocked.');
      }
      $ret = parent::ingestDatastream($datastream);
      islandora_invoke_datastream_hooks(ISLANDORA_DATASTREAM_INGESTED_HOOK, $object->models, $datastream->id, $object, $datastream);
      return $ret;
    }
    catch (Exception $e) {
      watchdog('islandora', 'Failed to ingest object: @pid</br>code: @code<br/>message: @msg', array(
          '@pid' => $object->id,
          '@dsid' => $datastream->id,
          '@code' => $e->getCode(),
          '@msg' => $e->getMessage()), WATCHDOG_ERROR);
      throw $e;
    }
  }

  /**
   * Inherits.
   *
   * Calls parent and invokes object modified and deleted(/purged) hooks.
   *
   * @see FedoraObject::modifyObject()
   */
  protected function modifyObject($params) {
    try {
      parent::modifyObject($params);
      islandora_invoke_object_hooks(ISLANDORA_OBJECT_MODIFIED_HOOK, $this->models, $this);
      if ($this->state == 'D') {
        islandora_invoke_object_hooks(ISLANDORA_OBJECT_PURGED_HOOK, $this->models, $this->id);
      }
    }
    catch (Exception $e) {
      watchdog('islandora', 'Failed to modify object: @pid</br>code: @code<br/>message: @msg', array(
          '@pid' => $this->id,
          '@code' => $e->getCode(),
          '@msg' => $e->getMessage()), WATCHDOG_ERROR);
      throw $e;
    }
  }
}

class IslandoraRepositoryConnection extends RepositoryConnection {}

class IslandoraFedoraApi extends FedoraApi {

  /**
   * Instantiate a IslandoraFedoraApi object.
   *
   * @see FedoraApi::__construct()
   */
  public function __construct(IslandoraRepositoryConnection $connection, FedoraApiSerializer $serializer = NULL) {
    if (!$serializer) {
      $serializer = new FedoraApiSerializer();
    }
    $this->a = new FedoraApiA($connection, $serializer);
    $this->m = new IslandoraFedoraApiM($connection, $serializer);
    $this->connection = $connection;
  }
}

class IslandoraFedoraApiM extends FedoraApiM {

  /**
   * Update a datastream.
   *
   * Either changing its metadata, updaing the datastream contents or both.
   *
   * @throws Exception
   *   If the modify datastream request was block by some module.
   *
   * @see FedoraApiM::modifyDatastream
   */
  public function modifyDatastream($pid, $dsid, $params = array()) {
    $object = islandora_object_load($pid);
    $datastream = $object[$dsid];
    $context = array(
      'action' => 'modify',
      'block' => FALSE,
      'params' => $params,
    );
    islandora_alter_datastream($object, $datastream, $context);
    $params = $context['params'];
    if (isset($params['lastModifiedDate'])) {
      $params['lastModifiedDate'] = (string) $object[$dsid]->createdDate;
    }
    if ($context['block']) {
      throw new Exception('Modify Datastream was blocked.');
    }
    return parent::modifyDatastream($pid, $dsid, $params);
  }

  /**
   * Update Fedora Object parameters.
   *
   * @see FedoraApiM::modifyObject
   */
  public function modifyObject($pid, $params = NULL) {
    $object = islandora_object_load($pid);
    $context = array(
      'action' => 'modify',
      'block' => FALSE,
      'params' => $params,
    );
    islandora_alter_object($object, $context);
    $params = $context['params'];
    if ($context['block']) {
      throw new Exception('Modify Object was blocked.');
    }
    return parent::modifyObject($pid, $params);
  }

  /**
   * Purge a datastream from from Fedora.
   *
   * @see FedoraApiM::purgeDatastream
   */
  public function purgeDatastream($pid, $dsid, $params = array()) {
    $object = islandora_object_load($pid);
    $context = array(
      'action' => 'purge',
      'purge' => TRUE,
      'delete' => FALSE,
      'block' => FALSE,
    );
    islandora_alter_datastream($object, $object[$dsid], $context);
    try {
      $action = $context['block'] ? 'block' : FALSE;
      $action = (!$action && $context['delete']) ? 'delete' : $action;
      $action = !$action ? 'purge' : $action;
      switch ($action) {
        case 'block':
          throw new Exception('Purge Datastream was blocked.');

        case 'delete':
          $object[$dsid]->state = 'D';
          return array();

        default:
          $ret = parent::purgeDatastream($pid, $dsid, $params);
          // We need to remove this object from the cache and reload it as
          // Tuque may not have an updated copy. That is the datastream could
          // still be present within the object even though it's purged out of
          // Fedora.
          $tuque = islandora_get_tuque_connection();
          $tuque->cache->delete($pid);
          $non_cached_object = islandora_object_load($pid);
          islandora_invoke_datastream_hooks(ISLANDORA_DATASTREAM_PURGED_HOOK, $non_cached_object->models, $dsid, $non_cached_object, $dsid);
          return $ret;
      }
    }
    catch (Exception $e) {
      watchdog('islandora', 'Failed to purge datastream @dsid from @pid</br>code: @code<br/>message: @msg', array(
          '@pid' => $pid,
          '@dsid' => $dsid,
          '@code' => $e->getCode(),
          '@msg' => $e->getMessage()), WATCHDOG_ERROR);
      throw $e;
    }
  }

  /**
   * Purge an object.
   *
   * @see FedoraApiM::purgeObject
   */
  public function purgeObject($pid, $log_message = NULL) {
    $object = islandora_object_load($pid);
    $context = array(
      'action' => 'purge',
      'purge' => TRUE,
      'delete' => FALSE,
      'block' => FALSE,
    );
    islandora_alter_object($object, $context);
    try {
      $action = $context['block'] ? 'block' : FALSE;
      $action = (!$action && $context['delete']) ? 'delete' : $action;
      $action = !$action ? 'purge' : $action;
      $models = $object->models;
      switch ($action) {
        case 'block':
          throw new Exception('Purge object was blocked.');

        case 'delete':
          $object->state = 'D';
          return '';

        default:
          $ret = parent::purgeObject($pid, $log_message);
          islandora_invoke_object_hooks(ISLANDORA_OBJECT_PURGED_HOOK, $models, $pid);
          return $ret;
      }
    }
    catch (Exception $e) {
      watchdog('islandora', 'Failed to purge object @pid</br>code: @code<br/>message: @msg', array(
          '@pid' => $pid,
          '@code' => $e->getCode(),
          '@msg' => $e->getMessage()), WATCHDOG_ERROR);
      throw $e;
    }
  }

}

class IslandoraSimpleCache extends SimpleCache {}

class IslandoraNewFedoraDatastream extends NewFedoraDatastream {
  protected $fedoraRelsIntClass = 'IslandoraFedoraRelsInt';
  protected $fedoraDatastreamVersionClass = 'IslandoraFedoraDatastreamVersion';
}

class IslandoraFedoraDatastream extends FedoraDatastream {
  protected $fedoraRelsIntClass = 'IslandoraFedoraRelsInt';
  protected $fedoraDatastreamVersionClass = 'IslandoraFedoraDatastreamVersion';

  /**
   * Magical magic, to allow recursive modifications.
   *
   * So... Magic functions in PHP are not re-entrant... Meaning that if you
   * have something which tries to call __set on an object anywhere later in
   * the callstack after it has already been called, it will not call the
   * magic method again; instead, it will set the property on the object
   * proper. Here, we detect the property being set on the object proper, and
   * restore the magic functionality as long as it keeps getting set...
   *
   * Not necessary to try to account for this in Tuque proper, as Tuque itself
   * does not have a mechanism to trigger modifications resulting from other
   * modifications.
   *
   * @param string $name
   *   The name of the property being set.
   * @param mixed $value
   *   The value to which the property should be set.
   */
  public function __set($name, $value) {
    parent::__set($name, $value);

    // Recursion only matters for magic properties... "Plain" properties cannot
    // call other code in order to start recursing, and in fact we would get
    // stuck looping with a "plain" property.
    if ($this->propertyIsMagical($name)) {
      // XXX: Due to the structure of the code, we cannot use property_exists()
      // (because many of the properties are declared in the class, and the
      // magic triggers due them being NULLed), nor can we use isset() (because
      // it is implemented as another magic function...).
      $vars = get_object_vars($this);
      while (isset($vars[$name])) {
        $new_value = $this->$name;
        unset($this->$name);
        parent::__set($name, $new_value);
        $vars = get_object_vars($this);
      }
    }
  }

  /**
   * Inherits.
   *
   * Calls parent and invokes modified and purged hooks.
   *
   * @see FedoraDatastream::modifyDatastream()
   */
  protected function modifyDatastream(array $args) {
    try {
      parent::modifyDatastream($args);
      islandora_invoke_datastream_hooks(ISLANDORA_DATASTREAM_MODIFIED_HOOK, $this->parent->models, $this->id, $this->parent, $this);
      if ($this->state == 'D') {
        islandora_invoke_datastream_hooks(ISLANDORA_DATASTREAM_PURGED_HOOK, $this->parent->models, $this->id, $this->parent, $this->id);
      }
    }
    catch (Exception $e) {
      watchdog('islandora', 'Failed to modify datastream @dsid from @pid</br>code: @code<br/>message: @msg', array(
          '@pid' => $this->parent->id,
          '@dsid' => $this->id,
          '@code' => $e->getCode(),
          '@msg' => $e->getMessage()), WATCHDOG_ERROR);
      throw $e;
    }
  }
}

class IslandoraFedoraDatastreamVersion extends FedoraDatastreamVersion {
  protected $fedoraRelsIntClass = 'IslandoraFedoraRelsInt';
  protected $fedoraDatastreamVersionClass = 'IslandoraFedoraDatastreamVersion';
}

class IslandoraFedoraRelsExt extends FedoraRelsExt {}

class IslandoraFedoraRelsInt extends FedoraRelsInt {}