<?php
/**
 * Stores site-side plugin settings as private data.
 *
 * This class is currently a stub, allowing a plugin to
 * save settings in an object's private settings for each site.
 *
 * @package    Elgg.Core
 * @subpackage Plugins.Settings
 */
class ElggPlugin extends ElggObject {
	public $package;
	public $manifest;

	private $path;
	private $pluginID;

	/**
	 * Set subtype to 'plugin'
	 *
	 * @return void
	 */
	protected function initializeAttributes() {
		parent::initializeAttributes();

		$this->attributes['subtype'] = "plugin";

		// plugins must be public.
		$this->access_id = ACCESS_PUBLIC;
	}


	/**
	 * Loads the plugin by GUID or path.
	 *
	 * @warning Unlike other ElggEntity objects, you cannot null instantiate
	 *          ElggPlugin. You must point it to an actual plugin GUID or location.
	 *
	 * @param mixed $plugin The GUID of the ElggPlugin object or the path of
	 *                      the plugin to load.
	 */
	public function __construct($plugin) {
		if (!$plugin) {
			throw new PluginException(elgg_echo('PluginException:NullInstantiated'));
		}

		// ElggEntity can be instantiated with a guid or an object.
		// @todo plugins w/id 12345
		if (is_numeric($plugin) || is_object($plugin)) {
			parent::__construct($plugin);
			$this->path = get_config('plugins_path') . $this->getID();
		} else {
			// not a full path, so assume an id
			// use the default path
			if (substr($plugin, 0, 1) != '/') {
				$plugin = elgg_get_plugin_path() . $plugin;
			}

			// path checking is done in the package
			$plugin = sanitise_filepath($plugin);
			$this->path = $plugin;
			$path_parts = explode('/', rtrim($plugin, '/'));
			$plugin_id = array_pop($path_parts);
			$this->pluginID = $plugin_id;

			// check if we're loading an existing plugin
			$existing_plugin = elgg_get_plugin_from_id($this->pluginID);
			$existing_guid = null;

			if ($existing_plugin) {
				$existing_guid = $existing_plugin->guid;
			}

			// load the rest of the plugin
			parent::__construct($existing_guid);
		}

		// We have to let the entity load so we can manipulate it with the API.
		// If the path is wrong or would cause an exception, catch it,
		// disable the plugin, and emit an error.
		try {
			$this->package = new ElggPluginPackage($this->path, false);
			$this->manifest = $this->package->getManifest();
		} catch (Exception $e) {
			// we always have to allow the entity to load.
		}
	}


	/**
	 * Save the plugin object.  Make sure required values exist.
	 *
	 * @see ElggObject::save()
	 * @return bool
	 */
	public function save() {
		// own by the current site so users can be deleted without affecting plugins
		$site = get_config('site');
		$this->attributes['site_guid'] = $site->guid;
		$this->attributes['owner_guid'] = $site->guid;
		$this->attributes['container_guid'] = $site->guid;
		$this->attributes['title'] = $this->pluginID;

		if (parent::save()) {
			// make sure we have a priority
			$priority = $this->getPriority();
			if ($priority === FALSE || $priority === NULL) {
				return $this->setPriority('last');
			}
		} else {
			return false;
		}
	}


	// Plugin ID

	/**
	 * Returns the ID (dir name) of this plugin
	 *
	 * @return string
	 */
	public function getID() {
		return $this->title;
	}


	/**
	 * Sets the location of this plugin.
	 *
	 * @param path $id The path to the plugin's dir.
	 * @return bool
	 */
	public function setID($id) {
		return $this->attributes['title'] = $id;
	}


	// Load Priority

	/**
	 * Gets the plugin's load priority.
	 *
	 * @return int
	 */
	public function getPriority() {
		$name = elgg_namespace_plugin_private_setting('internal', 'priority');
		return $this->$name;
	}


	/**
	 * Sets the priority of the plugin
	 *
	 * @param mixed $priority  The priority to set. One of +1, -1, first, last, or a number.
	 *                         If given a number, this will displace all plugins at that number
	 *                         and set their priorities +1
	 * @param mixed $site_guid Optional site GUID.
	 * @return bool
	 */
	public function setPriority($priority, $site_guid = null) {
		if (!$this->guid) {
			return false;
		}

		$db_prefix = get_config('dbprefix');
		$name = elgg_namespace_plugin_private_setting('internal', 'priority');
		// if no priority assume a priority of 0
		$old_priority = (int) $this->getPriority();
		$max_priority = elgg_get_max_plugin_priority();

		if ($priority == $old_priority) {
			return false;
		}

		// there's nothing above the max.
		if ($priority > $max_priority) {
			$priority = $max_priority;
		}

		// there's nothing below 1.
		if ($priority < 1) {
			$priority = 1;
		}

		// (int) 0 matches (string) first, so cast to string.
		$priority = (string) $priority;

		switch ($priority) {
			case '+1':
				$priority = $old_priority + 1;
				break;

			case '-1':
				$priority = $old_priority - 1;
				break;

			case 'first':
				$priority = 1;
				break;

			case 'last':
				$priority = $max_priority;
				break;
		}

		// should be a number by now
		if ($priority) {
			if (!is_numeric($priority)) {
				return false;
			}

			if ($priority > $old_priority) {
				$op = '-';
				$where = "CAST(value as unsigned) BETWEEN $old_priority AND $priority";
			} else {
				$op = '+';
				$where = "CAST(value as unsigned) BETWEEN $priority AND $old_priority";
			}

			// displace the ones affected by this change
			$q = "UPDATE {$db_prefix}private_settings
				SET value = CAST(value as unsigned) $op 1
				WHERE entity_guid != $this->guid
				AND name = '$name'
				AND $where";

			if (!update_data($q)) {
				return false;
			}

			// set this priority
			if ($this->set($name, $priority)) {
				//return elgg_plugins_reindex_priorities();
				return true;
			} else {
				return false;
			}
		}

		return false;
	}


	// Plugin settings

	/**
	 * Returns a plugin setting
	 *
	 * @todo These need to be namespaced
	 *
	 * @param string $name The setting name
	 * @return mixed
	 */
	public function getSetting($name) {
		return $this->$name;
	}


	/**
	 * Set a plugin setting for the plugin
	 *
	 * @todo This will only work once the plugin has a GUID.
	 * @todo These need to be namespaced.
	 *
	 * @param string $name  The name to set
	 * @param string $value The value to set
	 *
	 * @return bool
	 */
	public function setSetting($name, $value) {
		if ($this->guid) {
			return false;
		}
		// Hook to validate setting
		$value = elgg_trigger_plugin_hook('plugin:setting', 'plugin', array(
			'plugin' => $this->pluginID,
			'plugin_object' => $this,
			'name' => $name,
			'value' => $value
		), $value);

		return $this->$name = $value;
	}


	/**
	 * Removes a plugin setting name and value.
	 *
	 * @param string $name The setting name to remove
	 *
	 * @return bool
	 */
	public function removeSetting($name) {
		return remove_private_setting($this->guid, $name);
	}


	/**
	 * Removes all settings for this plugin.
	 *
	 * @todo Should be a better way to do this without dropping to raw SQL.
	 * @todo If we could namespace the plugin settings this would be cleaner.
	 * @return bool
	 */
	public function removeAllSettings() {
		$db_prefix = get_config('dbprefix');
		$ps_prefix = elgg_namespace_plugin_private_setting('setting', '');

		$q = "DELETE FROM {$db_prefix}private_settings
			WHERE entity_guid = $this->guid
			AND name NOT LIKE '$ps_prefix%'";

		return delete_data($q);
	}


	// User settings

	/**
	 * Returns a user's setting for this plugin
	 *
	 * @param int    $user_guid The user GUID
	 * @param string $name      The setting name
	 *
	 * @return mixed The setting string value or false
	 */
	public function getUserSetting($user_guid, $name) {
		$name = elgg_namespace_plugin_private_setting('user_setting', $name, $this->getID());
		return get_private_setting($user_guid, $name);
	}

	/**
	 * Sets a user setting for a plugin
	 *
	 * @param int    $user_guid The user GUID
	 * @param string $name      The setting name
	 * @param string $value     The setting value
	 *
	 * @return mixed The new setting ID or false
	 */
	public function setUserSetting($user_guid, $name, $value) {
		$name = elgg_namespace_plugin_private_setting('user_setting', $name, $this->getID());
		return set_private_setting($user_guid, $name, $value);
	}


	/**
	 * Removes a user setting name and value.
	 *
	 * @param int    $user_guid The user GUID
	 * @param string $name      The user setting name
	 *
	 * @return bool
	 */
	public function removeUserSetting($user_guid, $name) {
		$name = elgg_namespace_plugin_private_setting('user_setting', $name, $this->getID());
		return remove_private_setting($user_guid, $name);
	}


	/**
	 * Removes all User Settings for this plugin
	 *
	 * Use {@link removeAllUsersSettings()} to remove all user
	 * settings for all users.  (Note the plural 'Users'.)
	 *
	 * @param int $user_guid The user GUID to remove user settings.
	 * @return bool
	 */
	public function removeAllUserSettings($user_guid) {
		$db_prefix = get_config('dbprefix');
		$ps_prefix = elgg_namespace_plugin_private_setting('user_setting', '', $this->getID());

		$q = "DELETE FROM {$db_prefix}private_settings
			WHERE entity_guid = $user_guid
			AND name LIKE '$ps_prefix%'";

		return delete_data($q);
	}


	/**
	 * Removes this plugin's user settings for all users.
	 *
	 * Use {@link removeAllUserSettings()} if you just want to remove
	 * settings for a single user.
	 *
	 * @return bool
	 */
	public function removeAllUsersSettings() {
		$db_prefix = get_config('dbprefix');
		$ps_prefix = elgg_namespace_plugin_private_setting('user_setting', '', $this->getID());

		$q = "DELETE FROM {$db_prefix}private_settings
			WHERE name LIKE '$ps_prefix%'";

		return delete_data($q);
	}


	// validation

	/**
	 * Returns if the plugin is complete, meaning has all required files
	 * and Elgg can read them and they make sense.
	 *
	 * @todo bad name? This could be confused with isValid() from ElggPackage.
	 *
	 * @return bool
	 */
	public function isValid() {
		if (!$this->getID()) {
			return false;
		}

		if (!$this->package instanceof ElggPluginPackage) {
			return false;
		}

		if (!$this->package->isValid()) {
			return false;
		}

		return true;
	}


	/**
	 * Is this plugin active?
	 *
	 * @param int $site_guid Optional site guid.
	 * @return bool
	 */
	public function isActive($site_guid = null) {
		if (!$this->guid) {
			return false;
		}

		if ($site_guid) {
			$site = get_entity($site_guid);

			if (!($site instanceof ElggSite)) {
				return false;
			}
		} else {
			$site = get_config('site');
		}

		return check_entity_relationship($this->guid, 'active_plugin', $site->guid);
	}


	/**
	 * Checks if this plugin can be activated on the current
	 * Elgg installation.
	 *
	 * @param mixed $site_guid Optional site guid
	 * @return bool
	 */
	public function canActivate($site_guid = null) {
		if ($this->package) {
			return $this->package->isValid() && $this->package->checkDependencies();
		}

		return false;
	}


	// activating and deactivating

	/**
	 * Actives the plugin for the current site.
	 *
	 * @param mixed $site_guid Optional site GUID.
	 * @return bool
	 */
	public function activate($site_guid = null) {
		if ($this->isActive($site_guid)) {
			return false;
		}
		// set in the db, now perform tasks and emit events
		if ($this->setStatus(true, $site_guid)) {
			// emit an event. returning false will make this not be activated.
			// we need to do this after it's been fully activated
			// or the deactivate will be confused.
			$params = array(
				'plugin_id' => $this->pluginID,
				'plugin_entity' => $this
			);

			$return = elgg_trigger_event('activate', 'plugin', $params);

			// if there are any on_enable functions, start the plugin now and run them
			// Note: this will not run re-run the init hooks!
			$functions = $this->manifest->getOnActivate();
			if ($return && $functions) {
				$flags = ELGG_PLUGIN_INCLUDE_START | ELGG_PLUGIN_REGISTER_CLASSES
						| ELGG_PLUGIN_REGISTER_LANGUAGES | ELGG_PLUGIN_REGISTER_VIEWS;

				$this->start($flags);
				foreach ($functions as $function) {
					if (!is_callable($function)) {
						$return = false;
					} else {
						$on_enable = call_user_func($function);
						// allow null to mean "I don't care" like other subsystems
						$return = ($on_disable === false) ? false: true;
					}

					if ($return === false) {
						break;
					}
				}
			}

			if ($return === false) {
				$this->deactivate($site_guid);
			}

			return $return;
		}

		return false;
	}


	/**
	 * Deactivates the plugin.
	 *
	 * @param mixed $site_guid Optional site GUID.
	 * @return bool
	 */
	public function deactivate($site_guid = null) {
		if (!$this->isActive($site_guid)) {
			return false;
		}

		// emit an event. returning false will cause this to not be deactivated.
		$params = array(
			'plugin_id' => $this->pluginID,
			'plugin_entity' => $this
		);

		$return = elgg_trigger_event('deactivate', 'plugin', $params);

		// run any deactivate functions
		// check for the manifest in case we haven't fully loaded the plugin.
		if ($this->manifest) {
			$functions = $this->manifest->getOnDeactivate();
		} else {
			$functions = array();
		}

		if ($return && $functions) {
			foreach ($functions as $function) {
				if (!is_callable($function)) {
					$return = false;
				} else {
					$on_enable = call_user_func($function);
					// allow null to mean "I don't care" like other subsystems
					$return = ($on_disable === false) ? false : true;
				}

				if ($return === false) {
					break;
				}
			}
		}

		if ($return === false) {
			return false;
		} else {
			return $this->setStatus(false, $site_guid);
		}
	}


	/**
	 * Start the plugin.
	 *
	 * @param int $flags Start flags for the plugin. See the constants in lib/plugins.php for details.
	 * @return true
	 * @throws PluginException
	 */
	public function start($flags) {
		if (!$this->canActivate()) {
			return false;
		}

		// include start file
		if ($flags & ELGG_PLUGIN_INCLUDE_START) {
			$this->includeStart();
		}

		// include views
		if ($flags & ELGG_PLUGIN_REGISTER_VIEWS) {
			$this->registerViews();
		}

		// include languages
		if ($flags & ELGG_PLUGIN_REGISTER_LANGUAGES) {
			$this->registerLanguages();
		}

		// include classes
		if ($flags & ELGG_PLUGIN_REGISTER_CLASSES) {
			$this->registerClasses();
		}

		return true;
	}


	// start helpers

	/**
	 * Includes the plugin's start file
	 *
	 * @throws PluginException
	 * @return true
	 */
	protected function includeStart() {
		$start = "$this->path/start.php";
		if (!include($start)) {
			$msg = elgg_echo('ElggPlugin:Exception:CannotIncludeStart',
							array($this->getID(), $this->guid, $this->path));
			throw new PluginException($msg);
		}

		return true;
	}

	/**
	 * Registers the plugin's views
	 *
	 * @throws PluginException
	 * @return true
	 */
	protected function registerViews() {
		$view_dir = "$this->path/views/";

		// plugins don't have to have views.
		if (!is_dir($view_dir)) {
			return true;
		}

		// but if they do, they have to be readable
		$handle = opendir($view_dir);
		if (!$handle) {
			$msg = elgg_echo('ElggPlugin:Exception:CannotRegisterViews',
							array($this->getID(), $this->guid, $view_dir));
			throw new PluginException($msg);
		}

		while (FALSE !== ($view_type = readdir($handle))) {
			$view_type_dir = $view_dir . $view_type;

			if ('.' !== substr($view_type, 0, 1) && is_dir($view_type_dir)) {
				if (autoregister_views('', $view_type_dir, $view_dir, $view_type)) {
					elgg_register_viewtype($view_type);
				} else {
					$msg = elgg_echo('ElggPlugin:Exception:CannotRegisterViews',
									array($this->getID(), $view_type_dir));
					throw new PluginException($msg);
				}
			}
		}

		return true;
	}

	/**
	 * Registers the plugin's languages
	 *
	 * @throws PluginException
	 * @return true
	 */
	protected function registerLanguages() {
		$languages_path = "$this->path/languages";

		// don't need to have classes
		if (!is_dir($languages_path)) {
			return true;
		}

		// but need to have working ones.
		if (!register_translations($languages_path)) {
			$msg = elgg_echo('ElggPlugin:Exception:CannotRegisterLanguages',
							array($this->getID(), $this->guid, $languages_path));
			throw new PluginException($msg);
		}

		return true;
	}

	/**
	 * Registers the plugin's classes
	 *
	 * @throws PluginException
	 * @return true
	 */
	protected function registerClasses() {
		$classes_path = "$this->path/classes";

		// don't need to have classes
		if (!is_dir($classes_path)) {
			return true;
		}

		// but need to have working ones.
		if (!elgg_register_classes($classes_path)) {
			$msg = elgg_echo('ElggPlugin:Exception:CannotRegisterClasses',
							array($this->getID(), $this->guid, $classes_path));
			throw new PluginException($msg);
		}

		return true;
	}


	// generic helpers and overrides

	/**
	 * Get a value from private settings.
	 *
	 * @param string $name Name
	 *
	 * @return mixed
	 */
	public function get($name) {
		// rewrite for old and inaccurate plugin:setting
		if (strstr($name, 'plugin:setting:')) {
			$msg = 'Direct access of user settings is deprecated. Use ElggPlugin->getUserSetting()';
			elgg_deprecated_notice($msg, 1.8);
			$name = str_replace('plugin:setting:', '', $name);
			$name = elgg_namespace_plugin_private_setting('user_setting', $name);
		}

		// See if its in our base attribute
		if (array_key_exists($name, $this->attributes)) {
			return $this->attributes[$name];
		}

		// No, so see if its in the private data store.
		// get_private_setting() returns false if it doesn't exist
		$meta = get_private_setting($this->guid, $name);

		if ($meta === false) {
			// Can't find it, so return null
			return NULL;
		}

		return $meta;
	}

	/**
	 * Save a value to private settings.
	 *
	 * @param string $name  Name
	 * @param mixed  $value Value
	 *
	 * @return bool
	 */
	public function set($name, $value) {
		if (array_key_exists($name, $this->attributes)) {
			// Check that we're not trying to change the guid!
			if ((array_key_exists('guid', $this->attributes)) && ($name == 'guid')) {
				return false;
			}

			$this->attributes[$name] = $value;
		} else {
			return set_private_setting($this->guid, $name, $value);
		}

		return true;
	}

	/**
	 * Sets the plugin to active or inactive for $site_guid.
	 *
	 * @param bool  $active    Set to active or inactive
	 * @param mixed $site_guid Int for specific site, null for current site.
	 *
	 * @return bool
	 */
	private function setStatus($active, $site_guid = null) {
		if (!$this->guid) {
			return false;
		}

		if ($site_guid) {
			$site = get_entity($site_guid);

			if (!($site instanceof ElggSite)) {
				return false;
			}
		} else {
			$site = get_config('site');
		}

		if ($active) {
			return add_entity_relationship($this->guid, 'active_plugin', $site->guid);
		} else {
			return remove_entity_relationship($this->guid, 'active_plugin', $site->guid);
		}
	}
}