<?php
/**
 * @author Clark Tomlinson  <fallen013@gmail.com>
 * @since 3/6/15, 2:28 PM
 * @link http:/www.clarkt.com
 * @copyright Clark Tomlinson © 2015
 *
 */

namespace OCA\Encryption\Crypto;


use OCP\Encryption\IEncryptionModule;

class Encryption implements IEncryptionModule {

	/**
	 * @var Crypt
	 */
	private $crypt;

	public function __construct(Crypt $crypt) {
		$this->crypt = $crypt;
	}

	/**
	 * @return string defining the technical unique id
	 */
	public function getId() {
		// we need to hard code this value
		return md5($this->getDisplayName());
	}

	/**
	 * In comparison to getKey() this function returns a human readable (maybe translated) name
	 *
	 * @return string
	 */
	public function getDisplayName() {
		return 'ownCloud Default Encryption';
	}

	/**
	 * start receiving chunks from a file. This is the place where you can
	 * perform some initial step before starting encrypting/decrypting the
	 * chunks
	 *
	 * @param string $path to the file
	 * @param array $header contains the header data read from the file
	 * @param array $accessList who has access to the file contains the key 'users' and 'public'
	 *
	 * $return array $header contain data as key-value pairs which should be
	 *                       written to the header, in case of a write operation
	 *                       or if no additional data is needed return a empty array
	 */
	public function begin($path, $header, $accessList) {

		$cipher = $header[''];
	}

	/**
	 * last chunk received. This is the place where you can perform some final
	 * operation and return some remaining data if something is left in your
	 * buffer.
	 *
	 * @param string $path to the file
	 * @return string remained data which should be written to the file in case
	 *                of a write operation
	 */
	public function end($path) {
		// TODO: Implement end() method.
	}

	/**
	 * encrypt data
	 *
	 * @param string $data you want to encrypt
	 * @return mixed encrypted data
	 */
	public function encrypt($data) {
		// Todo: xxx Update Signature and usages
		// passphrase is file key decrypted with user private/share key
		$this->symmetricEncryptFileContent($data);
	}

	/**
	 * decrypt data
	 *
	 * @param string $data you want to decrypt
	 * @param string $user decrypt as user (null for public access)
	 * @return mixed decrypted data
	 */
	public function decrypt($data, $user) {
		// Todo: xxx Update Usages?
		$this->symmetricDecryptFileContent($data, $user);
	}

	/**
	 * update encrypted file, e.g. give additional users access to the file
	 *
	 * @param string $path path to the file which should be updated
	 * @param array $accessList who has access to the file contains the key 'users' and 'public'
	 * @return boolean
	 */
	public function update($path, $accessList) {
		// TODO: Implement update() method.
	}

	/**
	 * should the file be encrypted or not
	 *
	 * @param string $path
	 * @return boolean
	 */
	public function shouldEncrypt($path) {
		// TODO: Implement shouldEncrypt() method.
	}

	/**
	 * calculate unencrypted size
	 *
	 * @param string $path to file
	 * @return integer unencrypted size
	 */
	public function calculateUnencryptedSize($path) {
		// TODO: Implement calculateUnencryptedSize() method.
	}

	/**
	 * get size of the unencrypted payload per block.
	 * ownCloud read/write files with a block size of 8192 byte
	 *
	 * @return integer
	 */
	public function getUnencryptedBlockSize() {
		// TODO: Implement getUnencryptedBlockSize() method.
	}
}