<?php

/*
    Copyright 2012-2020 OpenBroadcaster, Inc.

    This file is part of OpenBroadcaster Server.

    OpenBroadcaster Server is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenBroadcaster Server is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with OpenBroadcaster Server.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * Group and user permissions model.
 *
 * @package Model
 */
class PermissionsModel extends OBFModel
{

  var $permission_cache=FALSE;

  /**
   * Get group permissions from group ID.
   *
   * @param id
   *
   * @return permissions
   */
  function get_group_permissions($id) {

    $r = array();

    // special handling for admin group.  admins get all permissions.
    if($id==1)
    {
      $permissions = $this->db->get('users_permissions');
      foreach($permissions as $permission) $r[] = $permission['name'];
      return $r;
    }

    // handling for non-admin groups..
    $this->db->what('users_permissions_to_groups.item_id','item_id');
    $this->db->what('users_permissions.name','name');
    $this->db->leftjoin('users_permissions','users_permissions_to_groups.permission_id','users_permissions.id');
    $this->db->where('users_permissions_to_groups.group_id',$id);

    $permissions = $this->db->get('users_permissions_to_groups');

    if(!empty($permissions)) foreach($permissions as $permission) $r[]=$permission['name'].($permission['item_id'] ? ':'.$permission['item_id'] : '');

    return $r;


  }

  /**
   * Determine the permissions for the user ID. This is the most liberal set of
   * permissions when combined with the groups they are in.
   *
   * @param id
   *
   * @return permissions
   */
  function get_user_permissions($id) {

    if(!isset($this->permission_cache[$id])) {

      $this->db->what('group_id');
      $this->db->where('user_id',$id);
      $groups = $this->db->get('users_to_groups');

      // everyone should be considered part of base (new user, no assigned groups)...
      $groups[]=array('group_id'=>0);

      $result = array();

      foreach($groups as $group) {
        $p=$this('get_group_permissions',$group['group_id']);
        foreach($p as $pname) $result[]=$pname;
      }

      $this->permission_cache[$id]=$result;

    }

    return $this->permission_cache[$id];

  }

  /**
   * Get names of groups user ID is in.
   *
   * @param id
   *
   * @return group_names
   */
  function get_user_groups($id)
  {

    $this->db->what('users_groups.name','name');
    $this->db->where('users_to_groups.user_id',$id);
    $this->db->leftjoin('users_groups','users_to_groups.group_id','users_groups.id');
    $groups = $this->db->get('users_to_groups');

    $return = array();

    if($groups) foreach($groups as $group) $return[] = $group['name'];

    return $return;

  }

  /**
   * Check if user has a permission. Return the first found permission or FALSE
   * if none can be found.
   *
   * @param permission
   * @param userid
   *
   * @return permission
   */ 
  function check_permission($permission,$userid)
  {

    $p=$this('get_user_permissions',$userid);

    $permission_array=explode(' or ',$permission);

    foreach($permission_array as $check_permission) {

      // if we are looking for an item specific permission, then we will also accept the permission without the item id specified.
      // in this case the permission is valid for all items.
      $check_permission_array = explode(':',$check_permission);
      if(count($check_permission_array)>1)
      {
        if(array_search($check_permission_array[0], $p)!==false) return true;

        // in this case we will accept any item ID.
        if($check_permission_array[1]=='*') foreach($p as $pname)
        {
          $pname_array = explode(':',$pname);
          if($pname_array[0]==$check_permission_array[0]) return true;
        }

      }

      // check regular permission or item-specific permission.  (permission as specified)
      if(array_search($check_permission, $p)!==false) return true;

    }

    return FALSE;

  }

}