<?php

/**
 * Returns a CMIS repository properties, based on local configuration.
 * 
 * Config sample:
 *  $conf['cmis_repositories'] = array(
 *    'default' => array (
 *      'label' => 'Local',
 *      'url' => 'http://127.0.0.1:8080/alfresco/s/cmis',
 *      'transport' => 'cmis_headerswing', 
 *      'headerswing_headers' => array (
 *        // headers copied from $_SERVER[] to CMIS repository curl call
 *        'HTTP_HOST' => 'FRONTENT_HOST',
 *        'HTTP_HOST' => 'FRONTENT_HOST_AGAIN',
 *        'HTTP_USER' => 'FRONTENT_USER',
 *        'PHP_AUTH_USER' => 'FRONTENT_USER'
 *        'PHP_AUTH_DIGEST' => 'FRONTEND_AUTH'
 *      )
 *    ),
 *    
 *    'demo cmis alfresco' => array(
 *      'label' => 'cmis.alfresco.com',
 *      'user' => 'admin',
 *      'password' => 'admin',
 *      'url' => 'http://cmis.alfresco.com/s/cmis'
 *    ),
 *    
 *    'demo cmis nuxeo' => array(
 *      'label' => 'cmis.demo.nuxeo.org',
 *      'user' => 'Administrator',
 *      'password' => 'Administrator',
 *      'url' => 'http://cmis.demo.nuxeo.org/nuxeo/site/cmis',
 *      'repository_id' => '8006e8e1-2298-4764-998c-5800383ac88a'
 *    )
 *  );
 * 
 * Usage:
 *   // get default CMIS repository info
 *   $cmis_repo = cmis_get_repository();
 *
 *   // get CMIS repository info based on config alias
 *   $cmis_repo = cmis_get_repository('demo cmis alfresco');
 *
 *   // get CMIS repository info based on repository id.
 *   // INTERNAL USE ONLY!
 *   $cmis_repo = cmis_get_repository('8006e8e1-22...');
 *
 *   // CMIS getRepositoryInfo result
 *   print_r($cmis_repo->info)
 *
 *   // repository id
 *   print $cmis_repo->repositoryId
 *
 *   // config settings
 *   print_r($cmis_repo->settings)
 * 
 * @param $id_or_alias 
 * @return stdClass
 */
function cmis_get_repository($id_or_alias = NULL) {
  static $repositories_cache;
  $cmis_repository = NULL;

  if(empty($id_or_alias)) {
    global $user;
    $id_or_alias = isset($user->cmis_repository)?$user->cmis_repository:'default';
  }
  
  // init repository cache
  if (is_null($repositories_cache)) {
    $repositories_cache = array();
  }

  // lookup repository in cache
  if (array_key_exists($id_or_alias, $repositories_cache)) {
    $cmis_repository = $repositories_cache[$id_or_alias];
  }
  else {
    $config_cmis_repos = variable_get('cmis_repositories', array());
    
    if (array_key_exists($id_or_alias, $config_cmis_repos)) {
      // setup temp repository details
      $cmis_repository = new stdClass();      
      $repositories_cache[$id_or_alias] = $cmis_repository;
      
      // setup settings
      $cmis_repository->settings = $config_cmis_repos[$id_or_alias];
      
      // merge in defaults.
      $cmis_repository->settings += array('transport' => 'cmis_common');
      
      // init cmis repository
      $cmis_repository->info = cmisapi_getRepositoryInfo($id_or_alias);
      $cmis_repository->repositoryId = $cmis_repository->info->repositoryInfo['cmis:repositoryId'];
        
      // save repo description in cache
      $repositories_cache[$cmis_repository->repositoryId] = & $repositories_cache[$id_or_alias];
    }
    else {
      throw new CMISException(t('Unable to lookup CMIS repository [@cmis_id_or_alias]',
                                array('@cmis_id_or_alias' => $id_or_alias)));
    }
  }
  
  return $cmis_repository;
}

/**
 * CMIS invoke service. This method should return a stdClass with
 * the following form:
 *      $return = new stdClass();
 *      $return->code = 200; // HTTP return code
 *      $return->body = 'data'; // result body
 *      $return->content_type = 'text/html'; //result content type
 *      $return->content_lenght = 200;
 *
 * @return stdClass
 */
function cmis_service($repositry_id, $url = '', $properties = array()) {
  // merge in defaults
  $properties += array(
    'headers' => array(),
    'method' => 'GET',
    'data' => NULL,
    'retry' => 3
  );
  
  $cmis_repository = cmis_get_repository((string) $repositry_id);
  $cmis_transport = $cmis_repository->settings['transport'];

  // invoke hook_cmis_service()
  if (module_exists($cmis_transport)) {
    return module_invoke($cmis_transport, 'cmis_service', $url, $properties, $cmis_repository->settings);  
  }
  else {
    throw new CMISException(t('Unable to lookup CMIS transport [@cmis_transport] for [@cmis_id_or_alias]',
                              array('@cmis_id_or_alias' => $repositry_id,
                                    '@cmis_transport' => $cmis_transport)));
  }
}

/**
 * Utility function that returns all known vendors
 * 
 * @return array
 */
function cmis_get_vendors() {
  $vendors = array();
  $info_array = module_invoke_all('cmis_info');
  foreach ($info_array as $type => $info) {
    $info['type'] = $type;
    $vendors[$type] = $info;
  }
  return $vendors;
}

/**
 * Utility function used to call a CMIS method, 
 * using the CMIS vendor selected in config.  
 *
 * @return mixed
 */
function cmis_vendor_invoke() {
  $vendor = variable_get('cmis_vendor', 'cmis_common');

  $args = func_get_args();
  $cmis_method = $args[0];

  $vendors = cmis_get_vendors();
  if (array_key_exists($vendor, $vendors)) {
    if (function_exists($vendor .'_cmisapi_invoke')) {
        return call_user_func_array($vendor .'_cmisapi_invoke', $args);
    }
    else {
        unset($args[0]);
        $function = $vendor .'_cmisapi_'. $cmis_method;
        if (function_exists($function)) {
          return call_user_func_array($function, $args);
        }
        throw new CMISException(t('@function not implemented by @vendor CMIS vendor', array('@function' => $function, '@vendor' => $vendor)));
    }
  }
  throw new CMISException(t('Unknown CMIS vendor: @vendor', array('@vendor' => $vendor)));
}

/**
 * Return permissions for the CMIS module.
 * 
 */
function cmis_permission() {
  $perms = array(
    'administer cmis',
    'access cmis',
  );
  return $perms;
}

/**
 * CMIS Exception class.
 *  
 */
class CMISException extends Exception {
  
}

/**
 * Utility for handling CMIS errors. 
 * 
 * @param $e Exception
 */
function cmis_error_handler($type, $e) {
  watchdog($type, $e->getMessage(), NULL, WATCHDOG_ERROR);
  drupal_set_message($e->getMessage(), 'error');
}

/**
 * Implements hook_block_info
 */
function cmis_block_info() {
  $blocks['cmis_switcher'] = array(
    'info' => t('CMIS repository switcher'),
    'cache' => DRUPAL_CACHE_GLOBAL,
  );
  
  return $blocks;
}

/**
 * Implements hook_block_info
 */
function cmis_block_view($delta = '') {
  $block = array();
  switch($delta) {
    case 'cmis_switcher':
      $block['subject'] = t('CMIS repositories');
      $block['content'] = drupal_get_form('cmis_repository_switcher_form');
      break;
  }
  return $block;
}

/**
 * Implementation of hook_boot()
 * 
 */
function cmis_boot() {
  if (isset($_SESSION['cmis_repository'])) {
    global $user;
    $user->cmis_repository = $_SESSION['cmis_repository'];
  }
}

/**
 * CMIS repository switcher form.
 * 
 */
function cmis_repository_switcher_form(& $form_state) {
  $repositories = array();
  foreach(variable_get('cmis_repositories', array()) as $repository_name => $repository_info) {
    $repositories[$repository_name] = array_key_exists('label', $repository_info)?$repository_info['label']:$repository_name;
  }

  $form = array();
  $form['cmis_repository'] = array(
    '#type' => 'select',
    '#title' => t('CMIS repositories'),
    '#default_value' => $_SESSION['cmis_repository'],
    '#options' => $repositories 
  );
  
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('OK'), 
  );

  return $form;
}

/**
 * CMIS repository switcher form submit.
 *
 */
function cmis_repository_switcher_form_submit($form, & $form_state) {
  // saving current CMIS repository
  $_SESSION['cmis_repository'] = $form_state['values']['cmis_repository'];
  
  // redirect to the source page
  $form_state['redirect'] = $_GET['q'];
}