<?php
// $Id: spaces.module,v 1.25.4.33.2.18 2009-06-26 13:39:37 yhahn Exp $

define('SPACES_FEATURE_DISABLED', 0);

/**
 * Implementation of hook_init().
 */
function spaces_init() {
  // This is a rather unfortunate and hackish way to get around
  // module weights.
  // @TODO replace this by eliminating spaces_site and instead
  // making it the base space class.
  if (!spaces_get_space() && module_exists('spaces_site')) {
    module_invoke('spaces_site', 'init');
  }

  // We use a menu callback here rather than drupal_access_denied().
  // Using drupal_access_denied() can terminate the page request before
  // bootstrap completes, leading to all sorts of havoc.
  if (!spaces_menu_access()) {
    menu_set_active_item('spaces-access-denied');
  }
  spaces_router('menu');

  // Rebuild spaces menu on page callbacks where there is the
  // potential for the addition/removal/alteration of features.
  $router_item = menu_get_item();
  switch ($router_item['path']) {
    case 'admin/build/context':
    case 'admin/build/features':
    case 'admin/build/modules':
      spaces_features_map(NULL, TRUE);
      break;
  }
}

/**
 * Implementation of hook_perm().
 */
function spaces_perm() {
  return array('administer spaces', 'configure spaces features');
}

/**
 * Implementation of hook_purl_provider().
 */
function spaces_purl_provider() {
  $items = array();
  foreach(spaces_types() as $type => $info) {
    $items['spaces_'. $type] = array(
      'name' => $info['title'],
      'description' => t('Sets a spaces context.'),
      'callback' => 'spaces_init_context',
      'callback arguments' => array($type),
      'example' => 'my-space',
    );
  }
  return $items;
}

/**
 * Context prefix provider callback.
 */
function spaces_init_context($type, $sid) {
  static $once;
  if (empty($once)) {
    $space = spaces_load($type, $sid, TRUE);
    spaces_set_space($space);
    $once = TRUE;
  }
}

/**
 * Implementation of hook_menu().
 */
function spaces_menu() {
  $items = array();
  $items['admin/build/spaces'] = array(
    'title' => 'Spaces presets',
    'description' => 'Create and configure spaces for your site.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('spaces_preset_default_form'),
    'type' => MENU_NORMAL_ITEM,
  );
  $items['admin/build/spaces/presets'] = array(
    'title' => 'Presets',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('spaces_preset_default_form'),
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -1,
  );
  $items['admin/build/spaces/presets/add'] = array(
    'title' => 'Add',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('spaces_preset_form', 'add'),
  );
  $items['admin/build/spaces/presets/edit'] = array(
    'page callback' => 'drupal_get_form',
    'page arguments' => array('spaces_preset_form', 'edit'),
  );
  $items['admin/build/spaces/presets/export'] = array(
    'title' => 'Export preset',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('spaces_preset_export'),
  );
  $items['admin/build/spaces/presets/delete'] = array(
    'page callback' => 'drupal_get_form',
    'page arguments' => array('spaces_preset_delete_form', 5, 6),
  );
  $items['admin/build/spaces/presets/disable'] = array(
    'page callback' => '_spaces_preset_disable_page',
  );
  $items['admin/build/spaces/presets/enable'] = array(
    'page callback' => '_spaces_preset_enable_page',
  );
  foreach ($items as $path => $item) {
    $items[$path]['access callback'] = 'user_access';
    $items[$path]['access arguments'] = array('administer spaces');
    $items[$path]['file'] = 'spaces_admin.inc';
    if (!isset($item['type'])) {
      $items[$path]['type'] = MENU_CALLBACK;
    }
  }
  $items['spaces-access-denied'] = array(
    'title' => 'Access denied',
    'description' => 'Page callback for early-stack spaces router access denied.',
    'page callback' => 'spaces_access_denied',
    'page arguments' => array(),
    'access callback' => FALSE,
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Implementation of hook_menu_alter().
 */
function spaces_menu_alter(&$items) {
  $router_items = array(
    'node/%node',
    'node/%node/edit',
    'user/%user/view',
    'user/%user_uid_optional',
    'user/%user_category/edit',
  );
  foreach (node_get_types('types', NULL, TRUE) as $type) {
    $type_url_str = str_replace('_', '-', $type->type);
    $router_items[] = 'node/add/'. $type_url_str;
  }

  foreach ($router_items as $path) {
    if (isset($items[$path])) {
      $arguments = isset($items[$path]['access arguments']) ? $items[$path]['access arguments'] : array();
      $arguments[] = isset($items[$path]['access callback']) ? $items[$path]['access callback'] : NULL;

      $items[$path]['access callback'] = 'spaces_menu_access';
      $items[$path]['access arguments'] = $arguments;
    }
  }
}

/**
 * Spaces menu access callback. Allows space types to manage menu
 * access as related to their space workflow. See hook_menu_alter()
 * for how the original menu access callback / argument gets passed
 * to an altered item. 
 */
function spaces_menu_access() {
  $args = func_get_args();
  $op = 'menu';
  $object = NULL;
  if (!empty($args)) {
    $access_callback = array_pop($args);
    if ($access_callback == 'node_access' && $args[0] == 'create') {
      $object = new StdClass();
      $object->type = $args[1];
      $op = 'node';
    }
    else {
      foreach ($args as $arg) {
        if (is_object($arg)) {
          $object = $arg;
          if (isset($object->nid)) {
            $op = 'node';
          }
          else if (isset($object->uid)) {
            $op = 'user';
          }
          break;
        }
      }
    }
  }

  $access = true;
  $types = spaces_types();
  // Check menu access for the active space type
  if ($space = spaces_get_space()) {
    $access = $access && $space->menu_access($op, $object);
    unset($types[$space->type]);
  }
  // Run each non-active space type's menu access check
  foreach ($types as $type => $info) {
    $access = $access && call_user_func(array($info['class'], 'menu_access'), $op, $object, FALSE);
  }

  $standard_access = !empty($access_callback) ? call_user_func_array($access_callback, $args) : TRUE;
  return ($access || user_access('administer spaces')) && $standard_access;
}

/**
 * Menu callback for early access_denied calls. Going through the a menu
 * callback allows Drupal bootstrap to complete.
 */
function spaces_access_denied() {
  drupal_access_denied();
  exit;
}

/**
 * Implementation of hook_help().
 */
function spaces_help($path, $arg) {
  switch ($path) {
    case 'admin/build/spaces/presets/export':
      return "<p>". t('You can use exported presets in your modules by returning an array of presets in <code>hook_spaces_presets()</code>.') ."</p>";
  }
}

/**
 *  Implementation of hook_theme().
 */
function spaces_theme() {
  $items = array();
  $items['spaces_features_form'] =
  $items['spaces_customize_item'] =
  $items['spaces_preset_default_form'] =
  $items['spaces_form_presets'] =
  $items['spaces_block_customizer_settings_form'] = array(
    'file' => 'spaces.theme.inc',
  );
  return $items;
}

/**
 *  Implementation of hook_user().
 */
function spaces_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'view':
    case 'form':
      spaces_router('user', $account);
      break;
  }
}

/**
 * Implementation of hook_nodeapi().
 */
function spaces_nodeapi(&$node, $op, $teaser = NULL, $page = NULL) {
  if ($op == 'view' && $page && menu_get_object() === $node) {
    spaces_router('node', $node);
  }
  if ($op == 'prepare') {
    spaces_router('node', $node);
  }
}

/**
 * Implementation of hook_flush_caches().
 */
function spaces_flush_caches() {
  spaces_features_map(NULL, TRUE);
  return array();
}

/**
 * Implementation of hook_spaces_settings().
 */
function spaces_spaces_settings() {
  return array(
    'home' => array(
      'class' => 'space_setting_home',
      'file' => drupal_get_path('module', 'spaces') .'/spaces.spaces.inc',
    ),
  );
}

/**
 * Implementation of hook_spaces_customizers().
 */
function spaces_spaces_customizers() {
  return array(
    'menu' => array(
      'class' => 'space_customizer_menu',
      'file' => drupal_get_path('module', 'spaces') .'/spaces.spaces.inc',
    ),
    'block' => array(
      'class' => 'space_customizer_block',
      'file' => drupal_get_path('module', 'spaces') .'/spaces.spaces.inc',
    ),
  );
}

/**
 * Implementation of hook_views_api().
 */
function spaces_views_api() {
  return array(
    'api' => 2,
    'path' => drupal_get_path('module', 'spaces') .'/includes',
  );
}

/**
 * Implementation of hook_context_conditions().
 */
function spaces_context_conditions() {
  $type_options = array();
  foreach (spaces_types() as $type => $info) {
    $type_options[$type] = $info['title'];
  }

  $items = array();
  $items['spaces_type'] = array(
    '#title' => t('Spaces type'),
    '#type' => 'checkboxes',
    '#options' => $type_options,
    '#description' => t('Set this context when the selected space types are active.'),
  );
  return $items;
}

/**
 * SPACES API =========================================================
 */

/**
 * Interface for space objects.
 */
interface space {
  /**
   * Core API-related functions
   */
  function __construct($type, $sid = NULL, $is_active = FALSE);
  function save();
  function delete();

  /**
   * Method that defines the feature options available for this space
   * type.
   *
   * @return array
   *   A FormAPI suitable options array of feature options.
   */
  function feature_options();

  /**
   * Method that allows the space type to add to/modify the utility
   * "links" provided to visitors in a space.
   *
   * @param $links
   *   The current space utility links (for use with theme_links) array
   *   passed by reference.
   */
  function links(&$links);

  /**
   * Method that provides a space-type specific check for whether the
   * provided feature is accessible by the current user.
   *
   * @param $feature
   *   The feature identifier string.
   *
   * @return bool
   *   TRUE if the user has access to this feature. FALSE if not.
   */
  function feature_access($feature = NULL);

  /**
   * Method that provides a space-type specific check for whether the
   * the space can be administered by the current user.
   *
   * @return bool
   *   TRUE if the user has admin access to this space. FALSE if not.
   */
  function admin_access();

  /**
   * Master router method that allows the space type to define routing
   * workflow rules. Currently called at the following hooks:
   *
   * hook_menu(), where $may_cache == FALSE
   * hook_nodeapi(), where $op == 'view'
   * hook_form_alter(), when editing a node
   * hook_user(), where $op == 'view'
   *
   * @param $op
   *   The current hook from which the router is being called.
   *   Can be one of the following: 'menu', 'node view', 'node form',
   *   'user view'
   * @param $object
   *   The object relevant to the current $op called. e.g. when
   *   $op == 'node view', $object is the node object.
   * @param $is_active
   *   Boolean for whether this router has been called as part of a
   *   fully instantiated space object. If FALSE, the router should
   *   not assume the space has been fully constructed and should take
   *   the appropriate actions as necessary.
   *
   * @return bool
   *   TRUE to allow the user to pass through. FALSE to return a
   *   drupal_access_denied() page to the user.
   */
  function router($op, $object = NULL, $is_active = TRUE);

  /**
   * Redirect handler that abstracts redirect logic and allows space
   * types to define their own definitions of various spaces concepts.
   *
   * @param $op
   *   The page being redirected to. Currently only $op value is 'home'
   */
  function redirect($op = 'home');

  /**
   * Allows the space type to implement custom form options on the
   * feature/preset form.
   *
   * @return array
   *   A FormAPI element array. It will be included as a child element
   *   of the master space feature form.
   */
  function form();

  /**
   * Validate handler for the space type's custom form.
   *
   * @param $values
   *   The submitted values.
   */
  function validate($values);

  /**
   * Custom submit handler for the space type's custom form. For
   * example, allows the space type to process values in preparation
   * for spaces_save().
   *
   * @param $values
   *   The submitted values.
   * 
   * @return array
   *   An array of values.
   */
  function submit($values);

  /**
   * Views filter callback that allows the space type to filter views
   * when it is the current active space.
   *
   * @param $query
   *   The views query object.
   */
  function views_filter(&$query, $base_table = '', $relationship = '');

  /**
   * Allows the space type to take additional action when enforcing a
   * preset against the current space.
   *
   * @param $preset
   *   A spaces preset definition.
   */
  function preset_enforce($preset);
}

/**
 * Interface for space settings.
 */
interface space_setting {
  function __construct($id = NULL);
  function form($space, $value = array());
  function validate($space, $value);
  function submit($space, $value);
}

/**
 * Interface for space customizers.
 */
interface space_customizer {
  function form($space, $feature);
  function validate($space, $feature, $value);
  function submit($space, $feature, $value);
}

/**
 * Implementation of hook_context_active_contexts_alter().
 */
function spaces_context_active_contexts_alter(&$contexts) {
  $space = spaces_get_space();
  foreach ($contexts as $identifier => $context) {
    if (!empty($context->block)) {
      spaces_customizers();
      space_customizer_block::customize($space, $identifier, $context->block);
    }
  }
}

/**
 * Load a space.
 *
 * @param $type
 *   The type of the space to be loaded. Must be one of the keys in the
 *   array returned by spaces_types(). 
 * @param $sid
 *   The id of the space to be loaded. If omitted, a "prototype" space
 *   will be constructed.
 * @param $is_active
 *   Optional boolean flag for whether this space is active or not.
 *   Defaults to FALSE.
 *
 * @return
 *   The requested space object or FALSE if something went wrong.
 */
function spaces_load($type, $sid = NULL, $is_active = FALSE) {
  $types = spaces_types();
  if (isset($types[$type])) {
    if (!empty($types[$type]['file']) && is_file($types[$type]['file'])) {
      require_once $types[$type]['file'];
    }
    $class = $types[$type]['class'];

    // Create a new space object
    $space = new $class($type, $sid, $is_active);

    // Initialize various space variables
    $space->type = $type;
    $space->features = array();
    $space->settings = array();
    $space->customizer = array();

    // Initialize space specific settings if $sid is provided
    if ($sid) {
      $space->sid = $sid;

      // Load the PURL modifier
      if ($modifier = purl_load(array('provider' => "spaces_{$type}", 'id' => $sid))) {
        $space->purl = $modifier['value'];
      }

      // Load features
      $result = db_query("SELECT id, value FROM {spaces_features} WHERE sid = %d AND type = '%s' ORDER BY weight ASC", $sid, $type);
      while ($row = db_fetch_object($result)) {
        $space->features[$row->id] = $row->value;
      }

      // Load settings
      $result = db_query("SELECT id, value FROM {spaces_settings} WHERE sid = %d AND type = '%s'", $sid, $type);
      while ($row = db_fetch_object($result)) {
        $space->settings[$row->id] = unserialize($row->value);
      }

      // Load customizer & preset
      $row = db_fetch_object(db_query("SELECT customizer, preset FROM {spaces} WHERE sid = %d AND type = '%s'", $space->sid, $space->type));
      $space->customizer = $row ? unserialize($row->customizer) : array();

      // Enforce preset or use default if not found
      $default_presets = variable_get('spaces_default_presets', array());
      if ($row) {
        $space->preset = $row->preset;
      }
      else if (empty($space->preset) && isset($default_presets[$type])) {
        $space->preset = $default_presets[$type];
      }
      if (!empty($space->preset)) {
        spaces_preset_enforce($space);
      }
    }

    return $space;
  }
  return false;
}

/**
 * Saves a space object's feature/setting values.
 *
 * @param $space
 *   The space object to save.
 *
 * @return
 *   Returns TRUE on success, FALSE on failure.
 */
function spaces_save($space) {
  if (!empty($space->sid) && !empty($space->type)) {

    // Force the preset if it is has changed
    $existing = spaces_load($space->type, $space->sid);
    if ($space->preset != $existing->preset) {
      spaces_preset_enforce($space, TRUE);
    }
    else {
      spaces_preset_enforce($space);
    }

    // Update features
    db_query("DELETE FROM {spaces_features} WHERE sid = %d AND type = '%s'", $space->sid, $space->type);
    $valid_features = spaces_features($space->type);
    $weight = -10;
    foreach ($space->features as $feature => $value) {
      if (isset($valid_features[$feature])) {
        $values = array($space->sid, $space->type, $feature, $value, $weight);
        db_query("INSERT INTO {spaces_features} (sid, type, id, value, weight) VALUES (%d, '%s', '%s', '%s', %d)", $values);
        $weight++;
      }
    }

    // Update settings
    db_query("DELETE FROM {spaces_settings} WHERE sid = %d AND type = '%s'", $space->sid, $space->type);
    // Build list of valid settings including those associated with features.
    $valid_settings = spaces_settings($space->type);
    foreach (spaces_feature_settings() as $feature => $settings) {
      foreach ($settings as $id => $class) {
        $valid_settings[$id] = $class;
      }
    }
    foreach ($space->settings as $setting => $value) {
      if (isset($valid_settings[$setting]) && !empty($value)) {
        $value = serialize($value);
        $values = array($space->sid, $space->type, $setting, $value);
        db_query("INSERT INTO {spaces_settings} (sid, type, id, value) VALUES (%d, '%s', '%s', '%s')", $values);
      }
    }

    // Update preset & customizer
    $exists = db_result(db_query("SELECT count(sid) FROM {spaces} WHERE sid = %d AND type = '%s'", $space->sid, $space->type));
    if ($exists) {
      db_query("UPDATE {spaces} SET preset = '%s', customizer = '%s' WHERE sid = %d AND type = '%s'", $space->preset, serialize($space->customizer), $space->sid, $space->type);
    }
    else {
      db_query("INSERT INTO {spaces} (sid, type, preset, customizer) VALUES(%d, '%s', '%s', '%s')", $space->sid, $space->type, $space->preset, serialize($space->customizer));
    }

    // Save context prefix if space type allows prefix customization
    $types = spaces_types();
    $save_purl = isset($types[$space->type]['custom purl']) && $types[$space->type]['custom purl'];
    if ($space->purl && $save_purl) {
      // We need to concatenate the type/sid so that collisions between space types do not occur.
      $modifier = array(
        'provider' => 'spaces_'. $space->type,
        'id' => $space->sid,
        'value' => $space->purl,
      );
      purl_save($modifier);
    }

    // Allow space type to do its own saving
    $space->save();

    return true;
  }
  return false;
}

/**
 * Deletes a space object's records in the database.
 *
 * @param $space
 *   The space object to delete.
 *
 * @return
 *   Returns TRUE for now.
 */
function spaces_delete($space) {
  // Remove all features and settings
  db_query("DELETE FROM {spaces} WHERE sid = %d AND type = '%s'", $space->sid, $space->type);
  db_query("DELETE FROM {spaces_features} WHERE sid = %d AND type = '%s'", $space->sid, $space->type);
  db_query("DELETE FROM {spaces_settings} WHERE sid = %d AND type = '%s'", $space->sid, $space->type);

  // Delete the purl modifier
  $modifier = array('provider' => 'spaces_'. $space->type, 'id'   => $space->sid);
  purl_delete($modifier);

  // Allow space type to do its own deleting
  $space->delete();

  return true;
}

/**
 * Enforces a spaces preset.
 */
function spaces_preset_enforce(&$space, $force = FALSE) {
  $presets = spaces_presets($space->type);
  if (isset($space->preset) && isset($presets[$space->preset])) {
    $preset = $presets[$space->preset]['preset'];

    // Enforce features, settings, customizer
    $keys = array('features', 'settings', 'customizer');
    foreach ($keys as $key) {
      if (isset($preset[$key]) && is_array($preset[$key])) {
        // If forced, completely replace any existing settings.
        if ($force) {
          $space->{$key} = $preset[$key];
        }
        // Otherwise, attempt to preserve user-chosen settings.
        else {
          foreach ($preset[$key] as $k => $v) {
            if (!empty($preset['locked'][$key][$k]) || !isset($space->{$key}[$k])) {
              $space->{$key}[$k] = $v;
            }
          }
        }
      }
    }

    // Type-specific presets
    $space->preset_enforce($preset);
  }
}

/**
 * Invokes hook_spaces_types() to gather an array of space types and
 * associated classes.
 *
 * Implementing modules should provide an associate array in
 * hook_spaces_types() of the following format:
 *
 * return array(
 *   $id => array(
 *     'class' => $space_class,
 *     'title' => $space_type_name,
 *     'purl modifier' => $bool,
 *     'file' => $direct_path_to_file
 *   ),
 * );
 *
 * Where:
 *
 * $id: A unique string identifier for this space type. e.g. "og"
 * $space_class: The PHP class to construct for this space. e.g. "spaces_og"
 * $space_type_name: The human-readable name of your space type. e.g. "Group space"
 * $bool: TRUE or FALSE for whether spaces should provide a UI for
 *   users to provide a custom URL modifier for each space. If FALSE,
 *   the implementing module should implement
 *   hook_purl_modifiers() in order to provide PURL modifiers programatically.
 * $direct_path_to_file: the relative path from the Drupal root to the file that
 *   defines the PHP class. (Optional)
 *
 * @param $reset
 *   Optional reset flag for clearing the static cache.
 *
 * @return
 *   An array of space types where $key => $value corresponds to the space type => space class.
 */
function spaces_types($reset = false) {
  static $spaces_types;
  if (!isset($spaces_types) || $reset) {
    $spaces_types = module_invoke_all('spaces_types');
  }
  return $spaces_types;
}

/**
 * Gather an array of spaces presets from the DB.
 *
 * @param $type
 *   Optional space type to filter results by.
 * @param $include_disabled
 *   Optional flag to return all presets, including disabled ones.
 * @param $reset
 *   Optional reset flag for clearing the static cache.
 *
 * @return
 *   An array of space types where $key => $value corresponds to the space type => space class.
 */
function spaces_presets($type = NULL, $include_disabled = FALSE, $reset = FALSE) {
  static $presets;
  if (!isset($presets)) {
    $presets = array();
    $disabled = variable_get('spaces_disabled_presets', array());

    // Collect presets provided by modules in code
    foreach(module_implements('spaces_presets') as $module) {
      $items = call_user_func($module .'_spaces_presets');
      foreach($items as $id => $preset) {
        $preset['disabled'] = isset($disabled[$preset['type']][$id]);
        $presets[$preset['type']][$id] = $preset;
      }
    }
    $result = db_query("SELECT * FROM {spaces_presets}");
    while ($row = db_fetch_object($result)) {
      $presets[$row->type][$row->id] = array(
        'name' => $row->name,
        'description' => $row->description,
        'preset' => unserialize($row->value),
        'disabled' => isset($disabled[$row->type][$row->id]),
      );
    }
  }
  // Move filtering outside main condition in order to hit the DB only once
  $return = $presets;
  if (!$include_disabled) {
    foreach (array_keys($return) as $preset_type) {
      foreach ($return[$preset_type] as $id => $preset) {
        if ($preset['disabled']) {
          unset($return[$preset_type][$id]);
        }
      }
    }
  }
  if ($type) {
    return isset($return[$type]) ? $return[$type] : array();
  }
  return $return;
}

/**
 * Wrapper function around spaces_set_space(). Retrieves the current
 * active space.
 */
function spaces_get_space() {
  return spaces_set_space();
}

/**
 * Sets the specified space as the current active space. Returns the
 * active space if no space is provided.
 *
 * @param $space
 *   The space object to set as the active space. Optional.
 * @param $reset
 *   Optional flag to reset the static cache.
 *
 * @return
 *   The active space object or FALSE if there is no active space.
 */
function spaces_set_space($space = NULL, $reset = FALSE) {
  static $current_space;
  if (!isset($current_space) || $reset) {
    $current_space = $space;

    if ($space) {
      // Context integration with spaces_type setter.
      context_set_by_condition('spaces_type', $space->type);
    }
  }
  return is_object($current_space) ? $current_space : FALSE;
}

/**
 * Wrapper around implementations of $space->router. Provides
 * additional intelligence, including a global killswitch and routing
 * when no spaces are active.
 *
 * @param $op
 *   The current "hook" or "hook op" identifier for the $space->router
 *   to act on.
 * @param $object
 *   Optional object to pass to the $space->router.
 */
function spaces_router($op, $object = NULL) {
  // Check global killswitch
  if (spaces_router_get()) {
    $types = spaces_types();
    // Run the router for the active space
    if ($space = spaces_get_space()) {
      $space->router($op, $object);
      unset($types[$space->type]);
    }
    // Run each non-active space type's router
    foreach ($types as $type => $info) {
      call_user_func(array($info['class'], 'router'), $op, $object, FALSE);
    }
  }
}

/**
 * Wrapper around spaces_router_get().
 */
function spaces_router_set($status) {
  return spaces_router_get($status, TRUE);
}

/**
 * Sets a static variable that is used to disable spaces routing
 * altogether -- e.g. for install/update scripts, migrations, etc.
 *
 * @param $enabled
 *   Optional boolean for enabling/disabling spaces routing.
 * @param $reset
 *   Optional boolean for resetting the static cache.
 *
 * @return
 *   Returns a boolean for whether routing is enabled/disabled.
 */
function spaces_router_get($enabled = 1, $reset = FALSE) {
  static $status;
  if (!isset($status) || $reset) {
    $status = $enabled;
  }
  return $status;
}

/**
 * Retrieve all available features.
 *
 * @param $type
 *   Optional type flag by which to filter available features.
 * @param $reset
 *   Optional boolean flag for resetting the static cache.
 *
 * @return
 *   Keyed array of potential features.
 */
function spaces_features($type = NULL, $reset = FALSE) {
  static $spaces_features;
  if (!isset($spaces_features) || $reset) {
    $spaces_features = array('all' => array(), 'common' => array());
    $features = features_get_features();
    foreach ($features as $feature) {
      if (module_exists($feature->name) && !empty($feature->info['spaces'])) {
        if (!empty($feature->info['spaces']['types']) && is_array($feature->info['spaces']['types'])) {
          foreach ($feature->info['spaces']['types'] as $t) {
            $spaces_features[$t][$feature->name] = $feature;
          }
        }
        else {
          $spaces_features['common'][$feature->name] = $feature;
        }
        $spaces_features['all'][$feature->name] = $feature;
      }
    }
    foreach (array_keys($spaces_features) as $t) {
      if ($t != 'all' && $t != 'common') {
        $spaces_features[$t] = array_merge($spaces_features[$t], $spaces_features['common']);
      }
    }
  }
  if ($type) {
    return !empty($spaces_features[$type]) ? $spaces_features[$type] : $spaces_features['common'];
  }
  return $spaces_features['all'];
}

/**
 * Retrieve settings provided by a given feature.
 *
 * @param $feature
 *   Optional feature name whose settings should be returned.
 * @param $reset
 *   Boolean flag to reset static cache.
 *
 * @return
 *   An array of instantiated setting classes.
 */
function spaces_feature_settings($feature = NULL, $reset = FALSE) {
  static $feature_settings;
  if (!isset($feature_settings) || $reset) {
    $feature_settings = array();

    // Exclude feature-specific settings here
    $features = spaces_features();
    foreach (module_implements('spaces_settings') as $module) {
      if (isset($features[$module])) {
        $settings = module_invoke($module, 'spaces_settings');
        foreach ($settings as $id => $info) {
          // Load any setting includes before instantiating its class.
          if (is_array($info)) {
            if (isset($info['file']) && is_file($info['file'])) {
              require_once($info['file']);
            }
            if (isset($info['class']) && class_exists($info['class'])) {
              $class = $info['class'];
              $setting = new $class();
            }
          }
          // This format is deprecated -- included for backwards compatibility.
          else if (is_string($info) && class_exists($info)) {
            $setting = new $info();
          }
          $feature_settings[$module][$id] = new $setting;
        }
      }
    }
  }
  if ($feature) {
    return isset($feature_settings[$feature]) ? $feature_settings[$feature] : array();
  }
  return $feature_settings;
}

/**
 * Retrieve all available settings.
 *
 * @param $type
 *   Optional space type to return a subset of settings that only apply
 *   to the given space type.
 * @param $reset
 *   Optional boolean flag for resetting the static cache.
 *
 * @return
 *   Keyed array of potential settings.
 */
function spaces_settings($type = NULL, $reset = FALSE) {
  static $spaces_settings;
  if (!isset($spaces_settings) || $reset) {
    $spaces_settings = array('all' => array(), 'common' => array());

    // Exclude feature-specific settings.
    // Use spaces_feature_settings() to retrieve these.
    $settings = array();
    $features = spaces_features();
    foreach (module_implements('spaces_settings') as $module) {
      if (!isset($features[$module])) {
        $settings = array_merge($settings, module_invoke($module, 'spaces_settings'));
      }
    }

    foreach ($settings as $setting_name => $info) {
      // Load any setting includes before instantiating its class.
      if (is_array($info)) {
        if (isset($info['file']) && is_file($info['file'])) {
          require_once($info['file']);
        }
        if (isset($info['class']) && class_exists($info['class'])) {
          $class = $info['class'];
          $setting = new $class();
        }
      }
      // This format is deprecated -- included for backwards compatibility.
      else if (is_string($info) && class_exists($info)) {
        $setting = new $info();
      }
      if (!empty($setting->types)) {
        foreach ($setting->types as $t) {
          if (!isset($spaces_settings[$t])) {
            $spaces_settings[$t] = array();
          }
          $spaces_settings[$t][$setting_name] = $setting;
        }
      }
      else {
        $spaces_settings['common'][$setting_name] = $setting;
      }
      $spaces_settings['all'][$setting_name] = $setting;
    }
    foreach (array_keys($spaces_settings) as $t) {
      if ($t != 'all' && $t != 'common') {
        $spaces_settings[$t] = array_merge($spaces_settings[$t], $spaces_settings['common']);
      }
    }
  }
  if ($type) {
    return !empty($spaces_settings[$type]) ? $spaces_settings[$type] : $spaces_settings['common'];
  }
  return $spaces_settings['all'];
}

/**
 * Retrieve all available customizers.
 *
 * @param $reset
 *   Optional boolean flag for resetting the static cache.
 *
 * @return
 *   Keyed array of customizers.
 */
function spaces_customizers($reset = FALSE) {
  static $spaces_customizers;
  if (!isset($spaces_customizers) || $reset) {
    $customizers = module_invoke_all('spaces_customizers');
    foreach ($customizers as $customizer_name => $info) {
      // Load any includes before instantiating its class.
      if (is_array($info)) {
        if (isset($info['file']) && is_file($info['file'])) {
          require_once($info['file']);
        }
        if (isset($info['class']) && class_exists($info['class'])) {
          $class = $info['class'];
          $customizer = new $class();
        }
      }
      // This format is deprecated -- included for backwards compatibility.
      else if (is_string($info) && class_exists($info)) {
        $customizer = new $info();
      }
      $spaces_customizers[$customizer_name] = $customizer;
    }
  }
  return $spaces_customizers;
}

/**
 * Caches a map of feature component => feature name
 */
function spaces_features_map($type = NULL, $reset = FALSE) {
  static $map;
  if (!isset($map) || $reset) {
    $map = array();
    $cache = cache_get('spaces_map', 'cache');

    if ($cache && !$reset) {
      $map = $cache->data;
    }
    else {
      $features = spaces_features();
      foreach ($features as $feature) {
        foreach ($feature->info['features'] as $component => $items) {
          if (is_array($items)) {
            foreach ($items as $item) {
              $map[$component][$item] = $feature->name;
            }
          }
        }
      }
      // Go through contexts and add relevant context components in as well
      $contexts = context_enabled_contexts();
      $components = array('node', 'views');
      if (!empty($map['context'])) {
        foreach ($map['context'] as $identifier => $feature_name) {
          $context = $contexts[$identifier];
          if (!empty($context)) {
            foreach ($components as $component) {
              if (!empty($context->{$component})) {
                foreach ($context->{$component} as $item) {
                  $map[$component][$item] = $feature_name;
                }
              }
            }
          }
        }
      }
      cache_set('spaces_map', $map, 'cache');
    }
  }
  if (!empty($type)) {
    return isset($map[$type]) ? $map[$type] : array();
  }
  return $map;
}

/**
 * Returns an array of items of a given type that belong to a given feature.
 */
function spaces_features_items($type, $feature) {
  $features = spaces_features();
  if (!empty($features[$feature]) && !empty($features[$feature]->info['features'][$type])) {
    return $features[$feature]->info['features'][$type];
  }
  return array();
}

/**
 * Implementation of hook_features_menu_links_alter().
 */
function spaces_features_menu_links_alter(&$links) {
  $space = empty($space) ? spaces_get_space() : $space;

  // Sanity check on our space object.
  if ($space && !empty($space->sid)) {
    // Load up the spaces menu links
    spaces_customizers();
    space_customizer_menu::customize($space, $links);

    // Retrieve the menu cache for a path to feature mapping
    $map = spaces_features_map('menu');

    // Sort the menu by feature weight & hide any items for features
    // that are not available (this **should**) be handled by access
    // control on the links' respective menu callbacks, but awkward
    // permissioning (e.g. user 1)  makes it nice for these to be
    // hidden manually.
    $weights = array_flip(array_keys($space->features));
    $weighted = array();
    foreach ($links as $k => $item) {
      $feature = '';
      if (!empty($map[$item['href']])) {
        $feature = $map[$item['href']];
      }
      if (!empty($feature) && $space->feature_access($feature)) {
        // Retrieve path > feature > weight
        $links[$k]['#weight'] = $weights[$feature];
      }
      else {
        unset($links[$k]);
      }
    }
    uasort($links, 'element_sort');
  }
}

/**
 * Preset options form that can be reused by implementing modules.
 *
 * @param $space
 *   A space object.
 *
 * @return
 *   A FormAPI array structure.
 */
function spaces_form_presets($space) {
  $presets = spaces_presets($space->type);
  if ($presets) {
    // If there's one preset, then select it and don't show the form.
    if (count($presets) == 1) {
      $form['preset'] = array('#type' => 'value', '#value' => array_shift(array_keys($presets)));
    }
    else {
      $default_presets = variable_get('spaces_default_presets', array());
      if (isset($space->preset) && !empty($presets[$space->preset])) {
        $default_preset = $space->preset;
      }
      else if (isset($default_presets[$space->type])) {
        $default_preset = $default_presets[$space->type];
      }
      else {
        $default_preset = NULL;
      }

      // Radios for presets
      $form = array(
        '#tree' => false,
        '#theme' => 'spaces_form_presets',
      );
      $form['preset'] = array(
        '#title' => t('Preset'),
        '#type' => 'radios',
        '#required' => true,
        '#options' => array(),
        '#default_value' => $default_preset,
      );
      $form['info'] = array();
      foreach ($presets as $id => $preset) {
        $form['preset']['#options'][$id] = $preset['name'];
        $form['info'][$id] = array(
          '#type' => 'item',
          '#title' => $preset['name'],
          '#description' => $preset['description'],
        );
      }
    }
    return $form;
  }
  return array();
}

/**
 * Menu admin access wrapper.
 */
function spaces_admin_access($type = NULL, $op = NULL) {
  $return = false;
  $space = spaces_get_space();
  if ($space && $type == $space->type) {
    $return = $space->admin_access();
  }
  if ($op == 'features') {
    return $return && (user_access('administer spaces') || user_access('configure spaces features'));
  }
  return $return;
}

/**
 * Menu feature access wrapper.
 */
function spaces_feature_access($feature = NULL) {
  if ($space = spaces_get_space()) {
    return user_access('access content') && ($space->feature_access($feature) || user_access('administer spaces'));
  }
  return user_access('access content');
}

/**
 * A mild abstraction of hook_menu() items that can be used by
 * implementing modules to embed/graft relevant spaces items into the
 * menu tree. Should only be used when the $may_cache argument of
 * hook_menu() is false.
 *
 * @param $space
 *   A space object.
 * @param $local_tasks
 *   Optional boolean flag for whether the items are fully rendered as
 *   local tasks.
 * @param $path_prefix
 *   A path to prefix the menu item paths by.
 *
 * @return
 *   An array of menu items.
 */
function spaces_active_space_menu($type, $local_tasks = FALSE, $path_prefix = '') {
  $types = spaces_types();
  $arg_count = !empty($path_prefix) ? count(explode('/', $path_prefix)) : 0;
  $path_prefix = !empty($path_prefix) ? $path_prefix .'/' : '';
  $spaces_path = drupal_get_path('module', 'spaces');

  $items[$path_prefix. 'spaces/features'] = array(
    'title' => 'Features',
    'page arguments' => array('spaces_features_form'),
    'access arguments' => array($type, 'features'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 1,
  );
  $items[$path_prefix. 'spaces/features/%'] = array(
    'title' => 'Features',
    'page arguments' => array('spaces_customize_form', NULL, 2 + $arg_count),
    'access arguments' => array($type, 'features'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 1,
  );
  foreach ($items as $path => $item) {
    $items[$path]['page callback'] = 'drupal_get_form';
    $items[$path]['access callback'] = 'spaces_admin_access';
    $items[$path]['file'] = 'spaces_admin.inc';
    $items[$path]['file path'] = $spaces_path;
  }
  return $items;
}

/**
 * THEME FUNCTIONS ====================================================
 */

/**
 * Generates an array of utility links for the current space suitable
 * for use in theme_links().
 */
function spaces_space_links() {
  $links = array();
  if ($space = spaces_get_space()) {
    $space->links($links);
    drupal_alter('space_links', $links);
  }
  return $links;
}

/**
 * theme_block() preprocessor.
 */
function spaces_preprocess_block(&$vars) {
  $space = spaces_get_space();
  if (!empty($vars['block'])) {
    spaces_customizers();
    space_customizer_block::customize_subject($space, $vars['block']);
  }
}

/**
 * theme_page() preprocessor.
 */
function spaces_preprocess_page(&$vars) {
  $space = spaces_get_space();
  if ($space) {
    if ($links = spaces_space_links()) {
      $vars['space_links'] = theme('links', $links, array('class' => 'links space-links'));
    }
    if (!empty($space->title)) {
      $vars['space_title'] = l($space->title, '<front>');
    }
    $vars['body_classes'] .= " spaces-{$space->type}";
  }
}