/**

* pdo

*

* @var PDO

*/

protected $pdo;

/**

* PDO table name for 'principals'

*

* @var string

*/

protected $tableName;

/**

* PDO table name for 'group members'

*

* @var string

*/

protected $groupMembersTableName;

/**

* Sets up the backend.

*

* @param PDO $pdo

* @param string $tableName

*/

public function __construct(PDO $pdo, $tableName = 'principals', $groupMembersTableName = 'groupmembers') {

$this->pdo = $pdo;

$this->tableName = $tableName;

$this->groupMembersTableName = $groupMembersTableName;

}

/**

* Returns a list of principals based on a prefix.

*

* This prefix will often contain something like 'principals'. You are only

* expected to return principals that are in this base path.

*

* You are expected to return at least a 'uri' for every user, you can

* return any additional properties if you wish so. Common properties are:

* {DAV:}displayname

* {http://sabredav.org/ns}email-address - This is a custom SabreDAV

* field that's actualy injected in a number of other properties. If

* you have an email address, use this property.

*

* @param string $prefixPath

* @return array

*/

public function getPrincipalsByPrefix($prefixPath) {

$result = $this->pdo->query('SELECT uri, email, displayname FROM `'. $this->tableName . '`');

$principals = array();

while($row = $result->fetch(PDO::FETCH_ASSOC)) {

// Checking if the principal is in the prefix

list($rowPrefix) = Sabre_DAV_URLUtil::splitPath($row['uri']);

if ($rowPrefix !== $prefixPath) continue;

$principals[] = array(

'uri' => $row['uri'],

'{DAV:}displayname' => $row['displayname']?$row['displayname']:basename($row['uri']),

'{http://sabredav.org/ns}email-address' => $row['email'],

);

}

return $principals;

}

/**

* Returns a specific principal, specified by it's path.

* The returned structure should be the exact same as from

* getPrincipalsByPrefix.

*

* @param string $path

* @return array

*/

public function getPrincipalByPath($path) {

$stmt = $this->pdo->prepare('SELECT id, uri, email, displayname FROM `'.$this->tableName.'` WHERE uri = ?');

$stmt->execute(array($path));

$users = array();

$row = $stmt->fetch(PDO::FETCH_ASSOC);

if (!$row) return;

return array(

'id' => $row['id'],

'uri' => $row['uri'],

'{DAV:}displayname' => $row['displayname']?$row['displayname']:basename($row['uri']),

'{http://sabredav.org/ns}email-address' => $row['email'],

);

}

/**

* Returns the list of members for a group-principal

*

* @param string $principal

* @return array

*/

public function getGroupMemberSet($principal) {

$principal = $this->getPrincipalByPath($principal);

if (!$principal) throw new Sabre_DAV_Exception('Principal not found');

$stmt = $this->pdo->prepare('SELECT principals.uri as uri FROM `'.$this->groupMembersTableName.'` AS groupmembers LEFT JOIN `'.$this->tableName.'` AS principals ON groupmembers.member_id = principals.id WHERE groupmembers.principal_id = ?');

$stmt->execute(array($principal['id']));

$result = array();

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {

$result[] = $row['uri'];

}

return $result;

}

/**

* Returns the list of groups a principal is a member of

*

* @param string $principal

* @return array

*/

public function getGroupMembership($principal) {

$principal = $this->getPrincipalByPath($principal);

if (!$principal) throw new Sabre_DAV_Exception('Principal not found');

$stmt = $this->pdo->prepare('SELECT principals.uri as uri FROM `'.$this->groupMembersTableName.'` AS groupmembers LEFT JOIN `'.$this->tableName.'` AS principals ON groupmembers.principal_id = principals.id WHERE groupmembers.member_id = ?');

$stmt->execute(array($principal['id']));

$result = array();

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {

$result[] = $row['uri'];

}

return $result;

}

/**

* Updates the list of group members for a group principal.

*

* The principals should be passed as a list of uri's.

*

* @param string $principal

* @param array $members

* @return void

*/

public function setGroupMemberSet($principal, array $members) {

// Grabbing the list of principal id's.

$stmt = $this->pdo->prepare('SELECT id, uri FROM `'.$this->tableName.'` WHERE uri IN (? ' . str_repeat(', ? ', count($members)) . ');');

$stmt->execute(array_merge(array($principal), $members));

$memberIds = array();

$principalId = null;

while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {

if ($row['uri'] == $principal) {

$principalId = $row['id'];

} else {

$memberIds[] = $row['id'];

}

}

if (!$principalId) throw new Sabre_DAV_Exception('Principal not found');

// Wiping out old members

$stmt = $this->pdo->prepare('DELETE FROM `'.$this->groupMembersTableName.'` WHERE principal_id = ?;');

$stmt->execute(array($principalId));

foreach($memberIds as $memberId) {

$stmt = $this->pdo->prepare('INSERT INTO `'.$this->groupMembersTableName.'` (principal_id, member_id) VALUES (?, ?);');

$stmt->execute(array($principalId, $memberId));

}

}