<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Access
 *
 * @copyright   Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

jimport('joomla.access.rule');

/**
 * @package     Joomla.Platform
 * @subpackage  Access
 * @since       11.1
 */
class JRules
{
    /**
     * @var array   A named array
     */
    protected $_data = array();

    /**
     * Constructor.
     *
     * The input array must be in the form: array('action' => array(-42 => true, 3 => true, 4 => false))
     * or an equivalent JSON encoded string, or an object where properties are arrays.
     *
     * @param   mixed   A JSON format string (probably from the database), or a nested array.
     */
    public function __construct($input = '')
    {
        // Convert in input to an array.
        if (is_string($input)) {
            $input = json_decode($input, true);
        }
        else if (is_object($input)) {
            $input = (array) $input;
        }

        if (is_array($input))
        {
            // Top level keys represent the actions.
            foreach ($input as $action => $identities) {
                $this->mergeAction($action, $identities);
            }
        }
    }

    /**
     * Get the data for the action.
     *
     * @return  array   A named array of JRule objects.
     */
    public function getData()
    {
        return $this->_data;
    }

    /**
     * Method to merge a collection of JRules.
     *
     * @param   mixed
     */
    public function mergeCollection($input)
    {
        // Check if the input is a
        if (is_array($input))
        {
            foreach ($input as $actions) {
                $this->merge($actions);
            }
        }
    }

    /**
     * Method to merge actions with this object.
     *
     * @param   mixed
     */
    public function merge($actions)
    {
        if (is_string($actions)) {
            $actions = json_decode($actions, true);
        }

        if (is_array($actions))
        {
            foreach ($actions as $action => $identities) {
                $this->mergeAction($action, $identities);
            }
        }
        else if ($actions instanceof JRules)
        {
            $data = $actions->getData();

            foreach ($data as $name => $identities) {
                $this->mergeAction($name, $identities);
            }
        }
    }

    /**
     * @param   string  The name of the action.
     */
    public function mergeAction($action, $identities)
    {
        if (isset($this->_data[$action]))
        {
            // If exists, merge the action.
            $this->_data[$action]->mergeIdentities($identities);
        }
        else
        {
            // If new, add the action.
            $this->_data[$action] = new JRule($identities);
        }
    }

    /**
     * Checks that an action can be performed by an identity.
     *
     * The identity is an integer where +ve represents a user group,
     * and -ve represents a user.
     *
     * @param   string  The name of the action.
     * @param   mixed   An integer representing the identity, or an array of identities
     *
     * @return  mixed
     */
    public function allow($action, $identity)
    {
        // Check we have information about this action.
        if (isset($this->_data[$action])) {
            return $this->_data[$action]->allow($identity);
        }
        return null;
    }

    /**
     * Get the allowed actions for an identity.
     *
     * @param   mixed   An integer representing the identity, or an array of identities
     */
    function getAllowed($identity)
    {
        // Sweep for the allowed actions.
        $allowed = new JObject;
        foreach ($this->_data as $name => &$action)
        {
            if ($action->allow($identity)) {
                $allowed->set($name, true);
            }
        }
        return $allowed;
    }

    /**
     * Magic method to convert the object to JSON string representation.
     *
     * @return  string
     */
    public function __toString()
    {
        $temp = array();
        foreach ($this->_data as $name => $rule)
        {
            // Convert the action to JSON, then back into an array otherwise
            // re-encoding will quote the JSON for the identities in the action.
            $temp[$name] = json_decode((string) $rule);
        }
        return json_encode($temp);
    }
}