<?php
  /**
   * ownCloud - Database backend for Contacts
   *
   * @author Thomas Tanghus

   * @copyright 2013-2014 Thomas Tanghus (thomas@tanghus.net)

   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library 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 this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  namespace OCA\Contacts\Backend;
  
  use OCA\Contacts\Contact,
  	OCA\Contacts\VObject\VCard,
  	OCA\Contacts\Utils\Properties,
  	Sabre\VObject\Reader;
  
  /**

   * Backend class for a users own contacts.

   */
  
  class Database extends AbstractBackend {

  	static private $preparedQueries = array();
  
  	/**

  	 * The name of the backend.
  	 *
  	 * @var string
  	 */
  	public $name = 'local';
  
  	/**
  	 * The cached address books.
  	 *
  	 * @var array[]
  	 */
  	public $addressBooks;
  
  	/**
  	 * The table that holds the address books.
  	 *
  	 * @var string
  	 */
  	public $addressBooksTableName;
  
  	/**
  	 * The table that holds the contact vCards.
  	 *
  	 * @var string
  	 */
  	public $cardsTableName;
  
  	/**
  	 * The table that holds the indexed vCard properties.
  	 *
  	 * @var string
  	 */
  	public $indexTableName;
  
  	/**

  	* Sets up the backend
  	*
  	* @param string $addressBooksTableName
  	* @param string $cardsTableName
  	*/
  	public function __construct(
  		$userid = null,
  		$options = array(
  			'addressBooksTableName' => '*PREFIX*contacts_addressbooks',
  			'cardsTableName' => '*PREFIX*contacts_cards',
  			'indexTableName' => '*PREFIX*contacts_cards_properties'
  		)
  	) {
  		$this->userid = $userid ? $userid : \OCP\User::getUser();
  		$this->addressBooksTableName = $options['addressBooksTableName'];
  		$this->cardsTableName = $options['cardsTableName'];
  		$this->indexTableName = $options['indexTableName'];

  		$this->addressBooks = array();

  	}
  
  	/**

  	* {@inheritdoc}
  	*/

  	public function getAddressBooksForUser(array $options = array()) {
  
  		try {

  			$result = $this->getPreparedQuery('getaddressbooksforuser')
  				->execute(array($this->userid));

  			if (\OCP\DB::isError($result)) {

  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: '
  					. \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return $this->addressBooks;

  			}

  		} catch(\Exception $e) {

  			\OCP\Util::writeLog('contacts', __METHOD__.' exception: '
  				. $e->getMessage(), \OCP\Util::ERROR);
  			return $this->addressBooks;

  		}

  		while ($row = $result->fetchRow()) {

  			$row['permissions'] = \OCP\PERMISSION_ALL;

  			$this->addressBooks[$row['id']] = $row;

  		}

  
  		return $this->addressBooks;

  	}

  	/**
  	* {@inheritdoc}
  	*/
  	public function getAddressBook($addressBookId, array $options = array()) {

  		$owner = isset($options['shared_by']) ? $options['shared_by'] : $this->userid;

  		//\OCP\Util::writeLog('contacts', __METHOD__.' id: '
  		//	. $addressBookId, \OCP\Util::DEBUG);
  		if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {
  			//print(__METHOD__ . ' ' . __LINE__ .' addressBookInfo: ' . print_r($this->addressBooks[$addressBookId], true));
  			return $this->addressBooks[$addressBookId];

  		}

  		// Hmm, not found. Lets query the db.
  		try {

  			$result = $this->getPreparedQuery('getaddressbook')->execute(array($addressBookId, $owner));

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: '
  					. \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return null;
  			}

  
  			$row = $result->fetchRow();
  
  			if (!$row) {

  				return null;
  			}

  			$row['permissions'] = \OCP\PERMISSION_ALL;
  			$row['backend'] = $this->name;

  			$this->addressBooks[$addressBookId] = $row;

  			return $row;

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.' exception: '
  				. $e->getMessage(), \OCP\Util::ERROR);
  			return null;
  		}

  	}

  	/**
  	* {@inheritdoc}
  	*/
  	public function hasAddressBook($addressBookId) {

  		// First check if it's already cached

  		if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {

  			return true;
  		}

  
  		return count($this->getAddressBook($addressBookId)) > 0;

  	}
  
  	/**
  	 * Updates an addressbook's properties
  	 *

  	 * @param string $addressBookId

  	 * @param array $changes
  	 * @return bool
  	 */

  	public function updateAddressBook($addressBookId, array $changes) {
  
  		if (count($changes) === 0) {

  			return false;
  		}
  
  		$query = 'UPDATE `' . $this->addressBooksTableName . '` SET ';
  
  		$updates = array();

  		if (isset($changes['displayname'])) {

  			$query .= '`displayname` = ?, ';
  			$updates[] = $changes['displayname'];

  
  			if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {
  				$this->addressBooks[$addressBookId]['displayname'] = $changes['displayname'];

  			}

  		}

  		if (isset($changes['description'])) {

  			$query .= '`description` = ?, ';
  			$updates[] = $changes['description'];

  
  			if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {
  				$this->addressBooks[$addressBookId]['description'] = $changes['description'];

  			}

  		}
  
  		$query .= '`ctag` = ? + 1 WHERE `id` = ?';

  		$now = time();
  		$updates[] = $now;
  		$updates[] = $addressBookId;
  
  		if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {
  			$this->addressBooks[$addressBookId]['lastmodified'] = $now;
  		}

  
  		try {

  			$stmt = \OCP\DB::prepare($query);
  			$result = $stmt->execute($updates);

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts',
  					__METHOD__. 'DB error: '
  					. \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return false;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts',
  				__METHOD__ . ', exception: '
  				. $e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}
  
  		return true;
  	}
  
  	/**
  	 * Creates a new address book
  	 *
  	 * Supported properties are 'displayname', 'description' and 'uri'.
  	 * 'uri' is supported to allow to add from CardDAV requests, and MUST
  	 * be used for the 'uri' database field if present.
  	 * 'displayname' MUST be present.
  	 *
  	 * @param array $properties
  	 * @param array $options - Optional (backend specific options)
  	 * @return string|false The ID if the newly created AddressBook or false on error.
  	 */

  	public function createAddressBook(array $properties) {

  		if (count($properties) === 0 || !isset($properties['displayname'])) {

  			return false;
  		}

  		$updates = array($this->userid, $properties['displayname']);
  		$updates[] = isset($properties['uri'])
  			? $properties['uri']
  			: $this->createAddressBookURI($properties['displayname']);
  		$updates[] = isset($properties['description']) ? $properties['description'] : '';
  		$ctag = time();
  		$updates[] = $ctag;
  
  		try {

  			$result = $this->getPreparedQuery('createaddressbook')->execute($updates);

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return false;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__ . ', exception: ' . $e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}
  
  		$newid = \OCP\DB::insertid($this->addressBooksTableName);

  
  		if ($this->addressBooks) {

  			$updates['id'] = $newid;
  			$updates['ctag'] = $ctag;
  			$updates['lastmodified'] = $ctag;
  			$updates['permissions'] = \OCP\PERMISSION_ALL;

  			$this->addressBooks[$newid] = $updates;

  		}

  		return $newid;
  	}
  
  	/**

  	 * Get all contact ids from the address book to run pre_deleteAddressBook hook

  	 *

  	 * @param string $addressBookId

  	 */

  	protected function preDeleteAddressBook($addressBookId) {

  		// Get all contact ids for this address book
  		$ids = array();
  		$result = null;

  		try {

  
  			$result = $this->getPreparedQuery('getcontactids')
  				->execute(array($addressBookId));

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: '
  					. \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return false;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.
  				', exception: ' . $e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}

  		if (!is_null($result)) {
  			while ($id = $result->fetchOne()) {

  				$ids[] = $id;
  			}

  
  			\OCP\Util::emitHook('OCA\Contacts', 'pre_deleteAddressBook',
  				array('addressbookid' => $addressBookId, 'contactids' => $ids)
  			);

  		}

  	}

  	/**
  	 * Deletes an entire addressbook and all its contents
  	 *
  	 * NOTE: For efficience this method bypasses the cleanup hooks and deletes
  	 * property indexes and category/group relations by itself.
  	 *
  	 * @param string $addressBookId
  	 * @param array $options - Optional (backend specific options)
  	 * @return bool
  	 */
  	public function deleteAddressBook($addressBookId) {
  
  		$this->preDeleteAddressBook($addressBookId);

  		try {

  			$this->getPreparedQuery('deleteaddressbookcontacts')
  				->execute(array($addressBookId));

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.
  				', exception: ' . $e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}

  		try {

  			$this->getPreparedQuery('deleteaddressbook')
  				->execute(array($addressBookId));

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.
  				', exception: ' . $e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}

  		if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {
  			unset($this->addressBooks[$addressBookId]);

  		}
  
  		return true;
  	}
  
  	/**
  	 * @brief Updates ctag for addressbook
  	 * @param integer $id
  	 * @return boolean
  	 */
  	public function setModifiedAddressBook($id) {

  		$ctag = time();

  		$this->getPreparedQuery('touchaddressbook')->execute(array($ctag, $id));

  
  		return true;
  	}

  	/**
  	* {@inheritdoc}
  	*/
  	public function lastModifiedAddressBook($addressBookId) {
  
  		if ($this->addressBooks && isset($this->addressBooks[$addressBookId])) {
  			return $this->addressBooks[$addressBookId]['lastmodified'];
  		}
  
  		$addressBook = $this->getAddressBook($addressBookId);
  		if($addressBook) {
  			$this->addressBooks[$addressBookId] = $addressBook;

  		}

  		return $addressBook ? $addressBook['lastmodified'] : null;
  	}
  
  	/**
  	 * Returns the number of contacts in a specific address book.
  	 *

  	 * @param string $addressBookId

  	 * @param bool $omitdata Don't fetch the entire carddata or vcard.
  	 * @return array
  	 */

  	public function numContacts($addressBookId) {
  
  		$result = $this->getPreparedQuery('numcontacts')->execute(array($addressBookId));

  		if (\OCP\DB::isError($result)) {
  			\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  			return null;
  		}

  		return (int)$result->fetchOne();
  	}
  
  	/**

  	* {@inheritdoc}
  	*/
  	public function getContacts($addressBookId, array $options = array()) {
  		//\OCP\Util::writeLog('contacts', __METHOD__.' addressbookid: ' . $addressBookId, \OCP\Util::DEBUG);

  		$cards = array();
  		try {

  			$queryIdentifier = (isset($options['omitdata']) && $options['omitdata'] === true)
  				? 'getcontactsomitdata'
  				: 'getcontacts';
  
  			$result = $this->getPreparedQuery($queryIdentifier, $options)->execute(array($addressBookId));

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return $cards;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.', exception: '.$e->getMessage(), \OCP\Util::ERROR);
  			return $cards;
  		}

  		if (!is_null($result)) {
  
  			while ($row = $result->fetchRow()) {

  				$row['permissions'] = \OCP\PERMISSION_ALL;
  				$cards[] = $row;
  			}

  		}
  		

  		return $cards;
  	}
  
  	/**
  	 * Returns a specific contact.
  	 *

  	 * NOTE: The contact $id for Database and Shared backends can be an array containing

  	 * either 'id' or 'uri' to be able to play seamlessly with the
  	 * CardDAV backend.

  	 * NOTE: $addressbookid isn't always used in the query, so there's no access control.
  	 * 	This is because the groups backend - \OCP\Tags - doesn't no about parent collections
  	 * 	only object IDs. Hence a hack is made with an optional 'noCollection'.

  	 *

  	 * @param string $addressBookId
  	 * @param string|array $id Contact ID

  	 * @param array $options - Optional (backend specific options)
  	 * @return array|null
  	 */

  	public function getContact($addressBookId, $id, array $options = array()) {
  		//\OCP\Util::writeLog('contacts', __METHOD__.' identifier: ' . $addressBookId . ' / ' . $id, \OCP\Util::DEBUG);

  		// When dealing with tags we have no idea if which address book it's in
  		// but since they're all in the same table they have unique IDs anyway

  		$noCollection = isset($options['noCollection']) ? $options['noCollection'] : false;

  		$queryIdentifier = 'getcontact';
  		$queries = array();
  
  		// When querying from CardDAV we don't have the ID, only the uri
  		if (is_array($id)) {
  			if (isset($id['id'])) {
  				$queries[] = $id['id'];
  				$queryIdentifier .= 'byid';
  			} elseif (isset($id['uri'])) {
  				$queries[] = $id['uri'];
  				$queryIdentifier .= 'byuri';

  			} else {
  				throw new \Exception(
  					__METHOD__ . ' If second argument is an array, either \'id\' or \'uri\' has to be set.'
  				);

  			}

  		} else {
  			if (!trim($id)) {
  				throw new \Exception(
  					__METHOD__ . ' Missing or empty second argument \'$id\'.'
  				);
  			}
  			$queries[] = $id;
  			$queryIdentifier .= 'byid';

  		}

  		if ($noCollection) {
  			$queryIdentifier .= 'nocollection';
  		} else {
  			$queries[] = $addressBookId;

  		}
  
  		try {

  			//\OCP\Util::writeLog('contacts', __METHOD__.', identifier: '. $queryIdentifier . ', queries: ' . implode(',', $queries), \OCP\Util::DEBUG);
  			$result = $this->getPreparedQuery($queryIdentifier)->execute($queries);

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return null;
  			}

  
  		} catch (\Exception $e) {

  			\OCP\Util::writeLog('contacts', __METHOD__.', exception: '.$e->getMessage(), \OCP\Util::ERROR);
  			\OCP\Util::writeLog('contacts', __METHOD__.', id: '. $id, \OCP\Util::DEBUG);
  			return null;
  		}
  
  		$row = $result->fetchRow();

  
  		if (!$row) {

  			\OCP\Util::writeLog('contacts', __METHOD__.', Not found, id: '. $id, \OCP\Util::DEBUG);
  			return null;
  		}

  		$row['permissions'] = \OCP\PERMISSION_ALL;
  		return $row;
  	}

  	public function hasContact($addressBookId, $id) {
  		try {
  			return $this->getContact($addressBookId, $id) !== null;
  		} catch (\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.', exception: '.$e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}

  	}
  
  	/**
  	 * Creates a new contact
  	 *
  	 * In the Database and Shared backends contact be either a Contact object or a string
  	 * with carddata to be able to play seamlessly with the CardDAV backend.
  	 * If this method is called by the CardDAV backend, the carddata is already validated.
  	 * NOTE: It's assumed that this method is called either from the CardDAV backend, the
  	 * import script, or from the ownCloud web UI in which case either the uri parameter is
  	 * set, or the contact has a UID. If neither is set, it will fail.
  	 *

  	 * @param string $addressBookId

  	 * @param VCard|string $contact
  	 * @param array $options - Optional (backend specific options)
  	 * @return string|bool The identifier for the new contact or false on error.
  	 */

  	public function createContact($addressBookId, $contact, array $options = array()) {
  		//\OCP\Util::writeLog('contacts', __METHOD__.' addressBookId: ' . $addressBookId, \OCP\Util::DEBUG);

  		$uri = isset($options['uri']) ? $options['uri'] : null;

  		if (!$contact instanceof VCard) {

  			try {
  				$contact = Reader::read($contact);
  			} catch(\Exception $e) {
  				\OCP\Util::writeLog('contacts', __METHOD__.', exception: '.$e->getMessage(), \OCP\Util::ERROR);
  				return false;
  			}
  		}
  
  		try {
  			$contact->validate(VCard::REPAIR|VCard::UPGRADE);
  		} catch (\Exception $e) {

  			\OCP\Util::writeLog('contacts', __METHOD__ . ' ' .

  				'Error validating vcard: ' . $e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}

  		$uri = is_null($uri) ? $this->uniqueURI($addressBookId, $contact->UID . '.vcf') : $uri;

  		$now = new \DateTime;
  		$contact->REV = $now->format(\DateTime::W3C);
  
  		$appinfo = \OCP\App::getAppInfo('contacts');
  		$appversion = \OCP\App::getAppVersion('contacts');

  		$prodid = '-//ownCloud//NONSGML ' . $appinfo['name'] . ' ' . $appversion.'//EN';

  		$contact->PRODID = $prodid;

  		try {

  			$result = $this->getPreparedQuery('createcontact')

  				->execute(
  					array(

  						$addressBookId,

  						(string)$contact->FN,
  						$contact->serialize(),
  						$uri,
  						time()
  					)
  				);

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return false;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.', exception: '.$e->getMessage(), \OCP\Util::ERROR);
  			return false;
  		}
  		$newid = \OCP\DB::insertid($this->cardsTableName);

  		$this->setModifiedAddressBook($addressBookId);

  		\OCP\Util::emitHook('OCA\Contacts', 'post_createContact',

  			array('id' => $newid, 'parent' => $addressBookId, 'backend' => $this->name, 'contact' => $contact)

  		);
  		return (string)$newid;
  	}
  
  	/**
  	 * Updates a contact
  	 *

  	 * @param string $addressBookId
  	 * @param string|array $id Contact ID

  	 * @param VCard|string $contact
  	 * @param array $options - Optional (backend specific options)
  	 * @see getContact
  	 * @return bool

  	 * @throws \Exception if $contact is a string but can't be parsed as a VCard
  	 * @throws \Exception if the Contact to update couldn't be found

  	 */

  	public function updateContact($addressBookId, $id, $contact, array $options = array()) {
  		//\OCP\Util::writeLog('contacts', __METHOD__.' identifier: ' . $addressBookId . ' / ' . $id, \OCP\Util::DEBUG);

  		$noCollection = isset($options['noCollection']) ? $options['noCollection'] : false;
  		$isBatch = isset($options['isBatch']) ? $options['isBatch'] : false;

  
  		$updateRevision = true;
  		$isCardDAV = false;

  
  		if (!$contact instanceof VCard) {

  			try {
  				$contact = Reader::read($contact);
  			} catch(\Exception $e) {
  				\OCP\Util::writeLog('contacts', __METHOD__.', exception: '.$e->getMessage(), \OCP\Util::ERROR);
  				return false;
  			}
  		}

  		if (is_array($id)) {
  
  			if (isset($id['id'])) {

  				$id = $id['id'];

  			} elseif (isset($id['uri'])) {

  				$updateRevision = false;
  				$isCardDAV = true;
  				$id = $this->getIdFromUri($id['uri']);

  
  				if (is_null($id)) {

  					\OCP\Util::writeLog('contacts', __METHOD__ . ' Couldn\'t find contact', \OCP\Util::ERROR);
  					return false;
  				}

  			} else {
  				throw new \Exception(
  					__METHOD__ . ' If second argument is an array, either \'id\' or \'uri\' has to be set.'
  				);
  			}
  		}

  		if ($updateRevision || !isset($contact->REV)) {

  			$now = new \DateTime;
  			$contact->REV = $now->format(\DateTime::W3C);
  		}
  
  		$data = $contact->serialize();

  		if ($noCollection) {

  			$me = $this->getContact(null, $id, $options);

  			$addressBookId = $me['parent'];

  		}

  		$updates = array($contact->FN, $data, time(), $id, $addressBookId);

  		try {

  
  			$result = $this->getPreparedQuery('updatecontact')->execute($updates);

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return false;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.', exception: '
  				. $e->getMessage(), \OCP\Util::ERROR);
  			\OCP\Util::writeLog('contacts', __METHOD__.', id' . $id, \OCP\Util::DEBUG);
  			return false;
  		}

  		$this->setModifiedAddressBook($addressBookId);
  
  		if (!$isBatch) {

  			\OCP\Util::emitHook('OCA\Contacts', 'post_updateContact',
  				array(
  					'backend' => $this->name,

  					'addressBookId' => $addressBookId,

  					'contactId' => $id,
  					'contact' => $contact,
  					'carddav' => $isCardDAV
  				)
  			);

  		}

  		return true;
  	}
  
  	/**
  	 * Deletes a contact
  	 *

  	 * @param string $addressBookId
  	 * @param string|array $id

  	 * @param array $options - Optional (backend specific options)
  	 * @see getContact
  	 * @return bool
  	 */

  	public function deleteContact($addressBookId, $id, array $options = array()) {

  		// TODO: pass the uri in $options instead.

  		$noCollection = isset($options['noCollection']) ? $options['noCollection'] : false;
  		$isBatch = isset($options['isBatch']) ? $options['isBatch'] : false;

  		if (is_array($id)) {
  
  			if (isset($id['id'])) {

  				$id = $id['id'];

  			} elseif (isset($id['uri'])) {

  				$id = $this->getIdFromUri($id['uri']);

  
  				if (is_null($id)) {

  					\OCP\Util::writeLog('contacts', __METHOD__ . ' Couldn\'t find contact', \OCP\Util::ERROR);
  					return false;
  				}

  			} else {

  				throw new \Exception(

  					__METHOD__ . ' If second argument is an array, either \'id\' or \'uri\' has to be set.'
  				);
  			}
  		}

  		if (!$isBatch) {

  			\OCP\Util::emitHook('OCA\Contacts', 'pre_deleteContact',
  				array('id' => $id)
  			);
  		}

  		if ($noCollection) {

  			$me = $this->getContact(null, $id, $options);

  			$addressBookId = $me['parent'];

  		}

  		try {

  
  			$result = $this->getPreparedQuery('deletecontact')
  				->execute(array($id, $addressBookId));

  			if (\OCP\DB::isError($result)) {
  				\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: '
  					. \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  				return false;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__.
  				', exception: ' . $e->getMessage(), \OCP\Util::ERROR);
  			\OCP\Util::writeLog('contacts', __METHOD__.', id: '
  				. $id, \OCP\Util::DEBUG);
  			return false;
  		}

  
  		$this->setModifiedAddressBook($addressBookId);

  		return true;
  	}
  
  	/**
  	 * @brief Get the last modification time for a contact.
  	 *
  	 * Must return a UNIX time stamp or null if the backend
  	 * doesn't support it.
  	 *

  	 * @param string $addressBookId

  	 * @param mixed $id
  	 * @returns int | null
  	 */

  	public function lastModifiedContact($addressBookId, $id) {
  
  		$contact = $this->getContact($addressBookId, $id);

  		return ($contact ? $contact['lastmodified'] : null);

  	}
  
  	/**
  	 * @brief Get the contact id from the uri.
  	 *
  	 * @param mixed $id
  	 * @returns int | null
  	 */
  	public function getIdFromUri($uri) {

  
  		$stmt = $this->getPreparedQuery('contactidfromuri');

  		$result = $stmt->execute(array($uri));

  		if (\OCP\DB::isError($result)) {
  			\OCP\Util::writeLog('contacts', __METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  			return null;
  		}

  		$one = $result->fetchOne();

  
  		if (!$one) {

  			\OCP\Util::writeLog('contacts', __METHOD__.', Not found, uri: '. $uri, \OCP\Util::DEBUG);
  			return null;
  		}

  		return $one;
  	}

  	/**
  	 * Create a unique URI based on the display name.
  	 *
  	 * @param string $displayName
  	 * @return string
  	 */
  	private function createAddressBookURI($displayName) {
  
  		$name = str_replace(' ', '_', strtolower($displayName));

  		try {

  			$stmt = $this->getPreparedQuery('addressbookuris');
  			$result = $stmt->execute(array($this->userid));

  			if (\OCP\DB::isError($result)) {

  				\OCP\Util::writeLog('contacts',
  					__METHOD__. 'DB error: ' . \OC_DB::getErrorMessage($result),
  					\OCP\Util::ERROR
  				);

  				return $name;
  			}

  		} catch(\Exception $e) {
  			\OCP\Util::writeLog('contacts', __METHOD__ . ' exception: ' . $e->getMessage(), \OCP\Util::ERROR);
  			return $name;
  		}
  		$uris = array();

  		while ($row = $result->fetchRow()) {

  			$uris[] = $row['uri'];
  		}
  
  		$newname = $name;

  		$i = 1
  		;
  		while (in_array($newname, $uris)) {

  			$newname = $name.$i;
  			$i = $i + 1;
  		}
  		return $newname;
  	}
  
  	/**
  	* @brief Checks if a contact with the same URI already exist in the address book.
  	* @param string $addressBookId Address book ID.
  	* @param string $uri
  	* @returns string Unique URI
  	*/
  	protected function uniqueURI($addressBookId, $uri) {

  		$stmt = $this->getPreparedQuery('counturi');

  
  		$result = $stmt->execute(array($addressBookId, $uri));

  		$result = $result->fetchRow();

  		if (is_array($result) && count($result) > 0 && $result['count'] > 0) {
  
  			while (true) {

  				$uri = Properties::generateUID() . '.vcf';
  				$result = $stmt->execute(array($addressBookId, $uri));

  
  				if (is_array($result) && count($result) > 0 && $result['count'] > 0) {

  					continue;
  				} else {
  					return $uri;
  				}

  			}

  		}

  
  		return $uri;
  	}
  
  	/**
  	* Collect (nearly) all queries in one place
  	*
  	* @param string $identifier
  	* @param array $options Can be used for e.g. offset/limit
  	* @throws \Exception If $identifier isn't known
  	* @return \OC_DB_StatementWrapper
  	*/
  	protected function getPreparedQuery($identifier, array $options = array()) {
  
  		if (isset(self::$preparedQueries[$identifier])) {
  			return self::$preparedQueries[$identifier];
  		}
  
  		$args = array();
  
  		switch ($identifier) {
  
  			case 'getaddressbooksforuser':
  				$args[] = 'SELECT `id`, `displayname`, `description`, `ctag`'
  					. ' AS `lastmodified`, `userid` AS `owner`, `uri` FROM `'
  					. $this->addressBooksTableName
  					. '` WHERE `userid` = ? ORDER BY `displayname`';
  				break;
  			case 'getaddressbook':
  				$args[] = 'SELECT `id`, `displayname`, `description`, '
  						. '`userid` AS `owner`, `ctag` AS `lastmodified`, `uri` FROM `'
  						. $this->addressBooksTableName
  						. '` WHERE `id` = ? AND `userid` = ?';
  				break;
  			case 'createaddressbook':
  				$args[] = 'INSERT INTO `'
  						. $this->addressBooksTableName . '` '
  						. '(`userid`,`displayname`,`uri`,`description`,`ctag`) '
  						. 'VALUES(?,?,?,?,?)';
  				break;
  			case 'deleteaddressbookcontacts':
  				$args[] = 'DELETE FROM `' . $this->cardsTableName
  						. '` WHERE `addressbookid` = ?';
  				break;
  			case 'deleteaddressbook':
  				$args[] = 'DELETE FROM `'
  						. $this->addressBooksTableName . '` WHERE `id` = ?';
  				break;
  			case 'touchaddressbook':
  				$args[] = 'UPDATE `' . $this->addressBooksTableName
  						. '` SET `ctag` = ? + 1 WHERE `id` = ?';
  				break;
  			case 'counturi':
  				$args[] = 'SELECT COUNT(*) AS `count` FROM `'
  						. $this->cardsTableName
  						. '` WHERE `addressbookid` = ? AND `uri` = ?';
  				break;
  			case 'addressbookuris':
  				$args[] = 'SELECT `uri` FROM `'
  						. $this->addressBooksTableName . '` WHERE `userid` = ? ';
  				break;
  			case 'contactidfromuri':
  				$args[] = 'SELECT `id` FROM `'
  						. $this->cardsTableName
  						. '` WHERE `uri` = ?';
  				break;
  			case 'deletecontact':
  				$args[] = 'DELETE FROM `'
  					. $this->cardsTableName
  					. '` WHERE `id` = ? AND `addressbookid` = ?';
  				break;
  			case 'updatecontact':
  				$args[] = 'UPDATE `' . $this->cardsTableName
  						. '` SET `fullname` = ?,`carddata` = ?, `lastmodified` = ?'
  						. ' WHERE `id` = ? AND `addressbookid` = ?';
  				break;
  			case 'createcontact':
  				$args[] = 'INSERT INTO `'
  					. $this->cardsTableName
  					. '` (`addressbookid`,`fullname`,`carddata`,`uri`,`lastmodified`) '
  					. ' VALUES(?,?,?,?,?)';
  				break;
  			case 'getcontactbyid':
  				$args[] = 'SELECT `id`, `uri`, `carddata`, `lastmodified`, '
  						. '`addressbookid` AS `parent`, `fullname` AS `displayname` FROM `'
  						. $this->cardsTableName
  						. '` WHERE `id` = ? AND `addressbookid` = ?';
  				break;
  			case 'getcontactbyuri':
  				$args[] = 'SELECT `id`, `uri`, `carddata`, `lastmodified`, '
  						. '`addressbookid` AS `parent`, `fullname` AS `displayname` FROM `'
  						. $this->cardsTableName
  						. '` WHERE `uri` = ? AND `addressbookid` = ?';
  				break;
  			case 'getcontactbyidnocollection':
  				$args[] = 'SELECT `id`, `uri`, `carddata`, `lastmodified`, '
  						. '`addressbookid` AS `parent`, `fullname` AS `displayname` FROM `'
  						. $this->cardsTableName . '` WHERE `id` = ?';
  				break;
  			case 'getcontactbyurinocollection':
  				$args[] = 'SELECT `id`, `uri`, `carddata`, `lastmodified`, '
  						. '`addressbookid` AS `parent`, `fullname` AS `displayname` FROM `'
  						. $this->cardsTableName . '` WHERE `uri` = ?';
  				break;
  			case 'getcontactids':
  				$args[] = 'SELECT `id` FROM `'
  						. $this->cardsTableName . '` WHERE `addressbookid` = ?';
  				break;
  			case 'getcontacts':
  				$args[] = 'SELECT `id`, `uri`, `carddata`, `lastmodified`, '
  						. '`addressbookid` AS `parent`, `fullname` AS `displayname` FROM `'
  						. $this->cardsTableName . '` WHERE `addressbookid` = ?';
  				$args[] = isset($options['limit']) ? $options['limit'] : null;
  				$args[] = isset($options['offset']) ? $options['offset'] : null;
  				break;
  			case 'getcontactsomitdata':
  				$args[] = 'SELECT `id`, `uri`, `lastmodified`, '
  						. '`addressbookid` AS `parent`, `fullname` AS `displayname` FROM `'
  						. $this->cardsTableName . '` WHERE `addressbookid` = ?';
  				$args[] = isset($options['limit']) ? $options['limit'] : null;
  				$args[] = isset($options['offset']) ? $options['offset'] : null;
  				break;
  			case 'numcontacts':
  				$args[] = 'SELECT COUNT(*) AS `count` FROM `'
  						. $this->cardsTableName . '` WHERE `addressbookid` = ?';
  				break;
  			default:
  				throw new \Exception('Unknown query identifier: ' . $identifier);
  
  		}
  
  		self::$preparedQueries[$identifier] = call_user_func_array('\OCP\DB::prepare', $args);
  
  		return self::$preparedQueries[$identifier];
  	}
  
  	public function getSearchProvider($addressbook) {
  		return new \OCA\Contacts\AddressbookProvider($addressbook);

  	}

  }