<?php
/**
 * Horde_Share_Sqlng provides the next-generation SQL backend driver for the
 * Horde_Share library.
 *
 * Copyright 2011-2017 Horde LLC (http://www.horde.org/)
 *
 * See the enclosed file COPYING for license information (LGPL). If you
 * did not receive this file, see http://www.horde.org/licenses/lgpl21.
 *
 * @author  Jan Schneider <jan@horde.org>
 * @package Share
 */

/**
 * @package Share
 */
class Horde_Share_Sqlng extends Horde_Share_Sql
{
    /* Serializable version */
    const VERSION = 1;

    /**
     * The Horde_Share_Object subclass to instantiate objects as
     *
     * @var string
     */
    protected $_shareObject = 'Horde_Share_Object_Sqlng';

    /**
     * A list of available permission.
     *
     * This is necessary to unset certain permission when updating existing
     * share objects.
     *
     * @param array
     */
    protected $_availablePermissions = array();

    /**
     *
     * @see Horde_Share_Base::__construct()
     */
    public function __construct($app, $user, Horde_Perms_Base $perms,
                                Horde_Group_Base $groups)
    {
        parent::__construct($app, $user, $perms, $groups);
        $this->_table = $this->_app . '_sharesng';
    }

    /**
     * Passes the available permissions to the share object.
     *
     * @param Horde_Share_Object $object
     */
    public function initShareObject(Horde_Share_Object $object)
    {
        parent::initShareObject($object);
        $object->availablePermissions = array_keys($this->_availablePermissions);
    }

    /**
     * Returns an array of all shares that $userid has access to.
     *
     * @param string $userid  The userid of the user to check access for.
     * @param array $params   Additional parameters for the search.
     *<pre>
     *  'perm'          Require this level of permissions. Horde_Perms constant.
     *  'attributes'    Restrict shares to these attributes. A hash or username.
     *  'from'          Offset. Start at this share
     *  'count'         Limit.  Only return this many.
     *  'sort_by'       Sort by attribute.
     *  'direction'     Sort by direction.
     *  'parent'        Start at this share in the hierarchy. Either share_id or
     *                  Horde_Share_Object
     *  'all_levels'    List all levels or just the direct children of parent?
     *</pre>
     *
     * @return array  The shares the user has access to.
     * @throws Horde_Share_Exception
     */
    public function listShares($userid, array $params = array())
    {
        $params = array_merge(array('perm' => Horde_Perms::SHOW,
                                    'attributes' => null,
                                    'from' => 0,
                                    'count' => 0,
                                    'sort_by' => null,
                                    'direction' => 0,
                                    'parent' => null,
                                    'all_levels' => true),
                              $params);

        $key = md5(serialize(array($userid, $params)));
        if (isset($this->_listcache[$key])) {
            return $this->_listcache[$key];
        }

        $perms = $this->convertBitmaskToArray($params['perm']);
        $shareids = null;
        if (!empty($userid)) {
            list($users, $groups, $shareids) = $this->_getUserAndGroupShares($userid, $perms);
        }

        if (is_null($params['sort_by'])) {
            $sortfield = 'share_id';
        } elseif ($params['sort_by'] == 'owner' || $params['sort_by'] == 'id') {
            $sortfield = 'share_' . $params['sort_by'];
        } else {
            $sortfield = 'attribute_' . $params['sort_by'];
        }
        $where = $this->_getShareCriteria($userid, $perms, $params['attributes'], $shareids, $params['parent'], $params['all_levels']);
        $query = 'SELECT ' . $this->_getDistinctClause() . ' FROM ' . $this->_table . ' s ' .
            (!empty($where) ? ' WHERE ' . $where : '')
            . ' ORDER BY ' . $sortfield
            . (($params['direction'] == 0) ? ' ASC' : ' DESC');

        $query = $this->_db->addLimitOffset($query, array('limit' => $params['count'], 'offset' => $params['from']));

        try {
            $rows = $this->_db->select($query);
        } catch (Horde_Db_Exception $e) {
            throw new Horde_Share_Exception($e);
        }

        $sharelist = array();
        $shares = array();
        foreach ($rows as $share) {
            $shares[(int)$share['share_id']] = $this->_fromDriverCharset($share);
        }
        $this->_fetchClobFields($shares);
        foreach ($shares as $share) {
            $this->_loadPermissions($share);
            $sharelist[$share['share_name']] = $this->_createObject($share);
        }
        unset($shares);

        // Run the results through the callback, if configured.
        if (!empty($this->_callbacks['list'])) {
            $sharelist = $this->runCallback('list', array($userid, $sharelist, $params));
        }
        $this->_listcache[$key] = $sharelist;

        return $this->_listcache[$key];
    }

    /**
     * Returns an array of all system shares.
     *
     * @return array  All system shares.
     * @throws Horde_Share_Exception
     */
    public function listSystemShares()
    {
        $query = 'SELECT * FROM ' . $this->_table . ' WHERE share_owner IS NULL';
        try {
            $rows = $this->_db->select($query);
        } catch (Horde_Db_Exception $e) {
            throw new Horde_Share_Exception($e->getMessage());
        }

        $sharelist = array();
        foreach ($rows as $share) {
            $this->_convertClobs($share);
            $data = $this->_fromDriverCharset($share);
            $this->_loadPermissions($data);
            $sharelist[$data['share_name']] = $this->_createObject($data);
        }

        return $sharelist;
    }

    /**
     * Returns the count of all shares that $userid has access to.
     *
     * @param string  $userid      The userid of the user to check access for.
     * @param integer $perm        The level of permissions required.
     * @param mixed   $attributes  Restrict the shares counted to those
     *                             matching $attributes. An array of
     *                             attribute/values pairs or a share owner
     *                             username.
     * @param mixed  $parent      The share to start searching from
     *                            (Horde_Share_Object, share_id, or null)
     * @param boolean $allLevels  Return all levels, or just the direct
     *                            children of $parent?
     *
     * @return integer  Number of shares the user has access to.
     * @throws Horde_Share_Exception
     */
    public function countShares($userid, $perm = Horde_Perms::SHOW,
        $attributes = null, $parent = null, $allLevels = true)
    {
        $perms = $this->convertBitmaskToArray($perm);
        $shareids = null;
        if (!empty($userid)) {
            list(, , $shareids) = $this->_getUserAndGroupShares($userid, $perms);
        }

        $query = 'SELECT COUNT(DISTINCT share_id) FROM '
            . $this->_table . ' s WHERE '
            . $this->_getShareCriteria($userid, $perms, $attributes, $shareids, $parent, $allLevels);
        try {
            return $this->_db->selectValue($query);
        } catch (Horde_Db_Exception $e) {
            throw new Horde_Share_Exception($e);
        }
    }

    /**
     * Count the number of users who have shares with the given permissions
     * for the current user.
     *
     * @param integer $perm       The level of permissions required.
     * @param mixed $parent       The parent share to start looking in.
     *                            (Horde_Share_Object, share_id, or null).
     * @param boolean $allLevels  Return all levels, or just the direct
     *                            children of $parent?
     *
     * @return integer  Number of users.
     * @throws Horde_Share_Exception
     */
    public function countOwners($perm = Horde_Perms::SHOW, $parent = null, $allLevels = true)
    {
        $perms = self::convertBitmaskToArray($perm);
        $sql = 'SELECT COUNT(DISTINCT(s.share_owner)) FROM ' . $this->_table . ' s WHERE '
            . $this->_getShareCriteria($this->_user, $perms, null, $parent, $allLevels);

        try {
            $results = $this->_db->selectValue($sql);
        } catch (Horde_Db_Exception $e) {
            throw new Horde_Share_Exception($e);
        }

        return $results;
    }

    /**
     * Return a list of users who have shares with the given permissions
     * for the current user.
     *
     * @param integer $perm       The level of permissions required.
     * @param mixed  $parent      The parent share to start looking in.
     *                            (Horde_Share_Object, share_id, or null)
     * @param boolean $allLevels  Return all levels, or just the direct
     *                            children of $parent? Defaults to all levels.
     * @param integer $from       The user to start listing at.
     * @param integer $count      The number of users to return.
     *
     * @return array  List of users.
     * @throws Horde_Share_Exception
     */
    public function listOwners($perm = Horde_Perms::SHOW, $parent = null, $allLevels = true,
                               $from = 0, $count = 0)
    {
        $perms = self::convertBitmaskToArray($perm);
        $sql = 'SELECT DISTINCT(s.share_owner) FROM ' . $this->_table . ' s WHERE '
            . $this->_getShareCriteria($this->_user, $perms, null, $parent, $allLevels);

        if ($count) {
            $sql = $this->_db->addLimitOffset($sql, array('limit' => $count, 'offset' => $from));
        }

        try {
            $allowners = $this->_db->selectValues($sql);
        } catch (Horde_Db_Exception $e) {
            throw new Horde_Share_Exception($e);
        }

        $owners = array();
        foreach ($allowners as $owner) {
            if ($this->countShares($this->_user, $perm, $owner, $parent, $allLevels)) {
                $owners[] = $owner;
            }
        }

        return $owners;
    }

    /**
     * Converts a bit mask number to a bit mask array.
     *
     * @param integer  A bit mask.
     *
     * @return array  The bit mask as an array.
     */
    public static function convertBitmaskToArray($perm)
    {
        $perms = array();
        for ($bit = 1; $perm; $bit *= 2, $perm >>= 1) {
            if ($perm % 2) {
                $perms[] = $bit;
            }
        }
        return $perms;
    }

    /**
     * Builds a permission bit mask from all columns in a data row prefixed
     * with "perm_".
     *
     * @param array $row     A data row including permission columns.
     *
     * @return integer  A permission mask.
     */
    protected function _buildPermsFromRow($row)
    {
        $perms = 0;
        foreach ($row as $column => $value) {
            if (substr($column, 0, 5) != 'perm_') {
                continue;
            }
            $perm = (int)substr($column, 5);
            $this->_availablePermissions[$perm] = true;
            if ($value) {
                $perms |= $perm;
            }
        }
        return $perms;
    }

    /**
     * Converts the permissions from the database table format into the
     * Horde_Share format.
     *
     * @param array $data  The share object data to convert.
     */
    protected function _getSharePerms(&$data)
    {
        $data['perm']['type'] = 'matrix';
        $data['perm']['default'] = $data['perm']['guest'] = $data['perm']['creator'] = 0;
        foreach ($data as $column => $value) {
            $perm = explode('_', $column, 3);
            if ($perm[0] != 'perm' || count($perm) != 3) {
                continue;
            }
            $permvalue = (int)$perm[2];
            $this->_availablePermissions[$permvalue] = true;
            if ($value) {
                $data['perm'][$perm[1]] |= $permvalue;
            }
            unset($data[$column]);
        }
    }

    /**
     * Returns the records and share IDs from the user and group tables that
     * match the search criteria.
     *
     * @param string $userid     The userid of the user to check access for.
     * @param array $perms       The level of permissions required.
     *
     * @return array  A set of user, groups, and shareids.
     */
    protected function _getUserAndGroupShares($userid, array $perms)
    {
        $shareids = array();

        // Get users permissions.
        $query = 'SELECT * FROM ' . $this->_table
            . '_users WHERE user_uid = ' .  $this->_db->quote($userid)
            . ' AND (' . $this->_getPermsCriteria('perm', $perms) . ')';
        try {
            $users = $this->_db->select($query);
        } catch (Horde_Db_Exception $e) {
            throw new Horde_Share_Exception($e->getMessage());
        }
        foreach ($users as $user) {
            $shareids[] = $user['share_id'];
        }

        // Get groups permissions.
        $groups = array();
        try {
            $groupNames = $this->_groups->listGroups($userid);
            if ($groupNames) {
                $group_ids = array();
                foreach (array_keys($groupNames) as $id) {
                    $group_ids[] = $this->_db->quote((string)$id);
                }
                $query = 'SELECT * FROM ' . $this->_table
                    . '_groups WHERE group_uid IN ('
                    . implode(',', $group_ids) . ') AND ('
                    . $this->_getPermsCriteria('perm', $perms) . ')';
                try {
                    $groups = $this->_db->select($query);
                } catch (Horde_Db_Exception $e) {
                    throw new Horde_Share_Exception($e->getMessage());
                }
                foreach ($groups as $group) {
                    $shareids[] = $group['share_id'];
                }
            }
        } catch (Horde_Group_Exception $e) {
            $this->_logger->err($e);
        }

        return array($users, $groups, array_unique($shareids));
    }

    /**
     * Returns a criteria statement for querying shares.
     *
     * @param string $userid     The userid of the user to check access for.
     * @param array $perms       The level of permissions required.
     * @param array $attributes  Restrict the shares returned to those who
     *                           have these attribute values.
     * @param array $shareids    Additional share IDs from user and group
     *                           permissions.
     *
     * @return string  The criteria string for fetching this user's shares.
     */
    protected function _getShareCriteria($userid, array $perms, $attributes,
                                         $shareids = null, $parent = null,
                                         $allLevels = true)
    {
        /* Convert to driver's keys */
        $attributes = $this->_toDriverKeys($attributes);

        /* ...and to driver charset */
        $attributes = $this->toDriverCharset($attributes);

        $where = '';
        if (empty($userid)) {
            $where = $this->_getPermsCriteria('perm_guest', $perms);
        } else {
            // (owner == $userid)
            $where .= 'share_owner = ' . $this->_db->quote($userid);

            // (name == perm_creator and val & $perm)
            $where .= ' OR ' . $this->_getPermsCriteria('perm_creator', $perms);

            // (name == perm_default and val & $perm)
            $where .= ' OR ' . $this->_getPermsCriteria('perm_default', $perms);

            if ($shareids) {
                $where .= ' OR share_id IN (' . implode(',', $shareids) . ')';
            }
        }

        if (is_array($attributes)) {
            // Build attribute/key filter.
            $where = '(' . $where . ') ';
            foreach ($attributes as $key => $value) {
                if (is_array($value)) {
                    $value = array_map(array($this->_db, 'quote'), $value);
                    $where .= ' AND ' . $key . ' IN (' . implode(', ', $value) . ')';
                } else {
                    $where .= ' AND ' . $key . ' = ' . $this->_db->quote($value);
                }
            }
        } elseif (!empty($attributes)) {
            // Restrict to shares owned by the user specified in the
            // $attributes string.
            $where = '(' . $where . ') AND share_owner = ' . $this->_db->quote($attributes);
        }

        // See if we need to filter by parent or get the parent object
        if ($parent != null) {
            if (!($parent instanceof Horde_Share_Object)) {
                $parent = $this->getShareById($parent);
            }

            // Need to append the parent's share id to the list of parents in
            // order to search the share_parents field.
            $parents = $parent->get('parents') . ':' . $parent->getId();
            if ($allLevels) {
                $where_parent = '(share_parents = ' . $this->_db->quote($parents)
                    . ' OR share_parents LIKE ' . $this->_db->quote($parents . ':%') . ')';
            } else {
                $where_parent = 's.share_parents = ' . $this->_db->quote($parents);
            }
        } elseif (!$allLevels) {
            // No parents, and we only want the root.
            $where_parent = "(s.share_parents = '' OR s.share_parents IS NULL)";
        }
        if (!empty($where_parent)) {
            if (empty($where)) {
                $where = $where_parent;
            } else {
                $where = '(' . $where . ') AND ' . $where_parent;
            }
        }

        return $where;
    }

    /**
     * Builds an ANDed criteria snippet for a set or permissions.
     *
     * @param string $base  A column name prefix.
     * @param array $perms  A list of permissions.
     *
     * @return string  The generated criteria string.
     */
    protected function _getPermsCriteria($base, array $perms)
    {
        $criteria = array();
        foreach ($perms as $perm) {
            $criteria[] = $base . '_' . $perm . ' = ' . $this->_db->quoteTrue();
        }
        return implode(' OR ', $criteria);
    }
}
