<?php
/**
 * PHP 5
 *
 * @copyright http://www.4webby.com
 * @author Daniel Vecchiato
 * @author Mark Scherer
 * @author Marc Würth
 * @version 1.3
 * @license MIT License (http://www.opensource.org/licenses/mit-license.php)
 * @link https://github.com/dereuromark/tools
 */

App::uses('CakeSession', 'Model/Datasource');
App::uses('ModelBehavior', 'Model');

/**
 * WhoDidIt Behavior
 *
 * Handles created_by, modified_by fields for a given Model, if they exist in the Model DB table.
 * It's similar to the created, modified automagic, but it stores the id of the logged in user
 * in the models that have $actsAs = array('WhoDidIt').
 *
 * This is useful to track who created records, and the last user that has changed them.
 *
 * @link http://book.cakephp.org/2.0/en/models/saving-your-data.html#using-created-and-modified
 */
class WhoDidItBehavior extends ModelBehavior {

	/**
	 * Default settings for a model that has this behavior attached.
	 *
	 * Setting force_modified to true will have the same effect as overriding the save method as
	 * described in the code example for "Using created and modified" in the Cookbook.
	 *
	 * @var array
	 * @link http://book.cakephp.org/2.0/en/models/saving-your-data.html#using-created-and-modified
	 */
	protected $_defaults = array(
		'auth_session' => 'Auth', // Name of Auth session key
		'user_model' => 'User', // Name of the User model
		'created_by_field' => 'created_by', // Name of the "created_by" field in the model
		'modified_by_field' => 'modified_by', // Name of the "modified_by" field in the model
		'confirmed_by_field' => 'confirmed_by', // Name of the "confirmed by" field in the model
		'auto_bind' => true, // Automatically bind the model to the User model (default true)
		'force_modified' => false // Force update of the "modified" field even if not empty
	);

	/**
	 * Initiate WhoDidIt Behavior.
	 *
	 * Checks if the configured fields are available in the model.
	 * Also binds the User model as association for each available field.
	 *
	 * @param Model $Model The model.
	 * @param array $config Behavior settings you would like to override.
	 * @return void
	 */
	public function setup(Model $Model, $config = array()) {
		$this->settings[$Model->alias] = array_merge($this->_defaults, (array)$config);

		$hasFieldCreatedBy = $Model->hasField($this->settings[$Model->alias]['created_by_field']);
		$hasFieldModifiedBy = $Model->hasField($this->settings[$Model->alias]['modified_by_field']);
		$hasFieldConfirmedBy = $Model->hasField($this->settings[$Model->alias]['confirmed_by_field']);

		$this->settings[$Model->alias]['has_created_by'] = $hasFieldCreatedBy;
		$this->settings[$Model->alias]['has_modified_by'] = $hasFieldModifiedBy;
		$this->settings[$Model->alias]['has_confirmed_by'] = $hasFieldConfirmedBy;

		// Handles model binding to the User model according to the auto_bind settings (default true).
		if ($this->settings[$Model->alias]['auto_bind']) {
			if ($hasFieldCreatedBy) {
				$commonBelongsTo = array(
					'CreatedBy' => array(
						'className' => $this->settings[$Model->alias]['user_model'],
						'foreignKey' => $this->settings[$Model->alias]['created_by_field']));
				$Model->bindModel(array('belongsTo' => $commonBelongsTo), false);
			}

			if ($hasFieldModifiedBy) {
				$commonBelongsTo = array(
					'ModifiedBy' => array(
						'className' => $this->settings[$Model->alias]['user_model'],
						'foreignKey' => $this->settings[$Model->alias]['modified_by_field']));
				$Model->bindModel(array('belongsTo' => $commonBelongsTo), false);
			}

			if ($hasFieldConfirmedBy) {
				$commonBelongsTo = array(
					'ConfirmedBy' => array(
						'className' => $this->settings[$Model->alias]['user_model'],
						'foreignKey' => $this->settings[$Model->alias]['confirmed_by_field']));
				$Model->bindModel(array('belongsTo' => $commonBelongsTo), false);
			}
		}
	}

	/**
	 * Before save callback.
	 *
	 * Checks if at least one field is available.
	 * Reads the current user id from the session.
	 * If a user id is set it will fill...
	 * ... the created_by field only when creating a record
	 * ... the modified by field only if it is not in the data array
	 * or the "force_modified" setting is set to true.
	 *
	 * @param Model $Model The model using this behavior.
	 * @return boolean True if the operation should continue, false if it should abort.
	 */
	public function beforeSave(Model $Model, $options = array()) {
		if ($this->settings[$Model->alias]['has_created_by'] || $this->settings[$Model->alias]['has_modified_by']) {
			$authSession = $this->settings[$Model->alias]['auth_session'];
			list($plugin, $userSession) = pluginSplit($this->settings[$Model->alias]['user_model']);

			$userId = CakeSession::read($authSession . '.' . $userSession . '.id');

			if ($userId) {
				$data = array();
				$modifiedByField = $this->settings[$Model->alias]['modified_by_field'];

				if (!isset($Model->data[$Model->alias][$modifiedByField]) || $this->settings[$Model->alias]['force_modified']) {
					$data[$this->settings[$Model->alias]['modified_by_field']] = $userId;
				} else {
					$pos = strpos($this->settings[$Model->alias]['modified_by_field'], '_');
					$field = substr($this->settings[$Model->alias]['modified_by_field'], 0, $pos);
					$data[$field] = false;
				}

				if (!$Model->exists()) {
					$data[$this->settings[$Model->alias]['created_by_field']] = $userId;
				}
				if ($data) {
					$Model->set($data);
				}
			}
		}
		return true;
	}

}