<?php

declare(strict_types=1);

/**
 * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
 * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
 * SPDX-License-Identifier: AGPL-3.0-only
 */

namespace OCA\Encryption;

use OCA\Encryption\Exceptions\PrivateKeyMissingException;
use OCP\ISession;

class Session {
	public const NOT_INITIALIZED = '0';
	public const INIT_EXECUTED = '1';
	public const INIT_SUCCESSFUL = '2';

	public function __construct(
		protected ISession $session,
	) {
	}

	/**
	 * Sets status of encryption app
	 *
	 * @param string $status INIT_SUCCESSFUL, INIT_EXECUTED, NOT_INITIALIZED
	 */
	public function setStatus(string $status): void {
		$this->session->set('encryptionInitialized', $status);
	}

	/**
	 * Gets status if we already tried to initialize the encryption app
	 *
	 * @return string init status INIT_SUCCESSFUL, INIT_EXECUTED, NOT_INITIALIZED
	 */
	public function getStatus(): string {
		$status = $this->session->get('encryptionInitialized');
		if (is_null($status)) {
			$status = self::NOT_INITIALIZED;
		}

		return $status;
	}

	/**
	 * check if encryption was initialized successfully
	 */
	public function isReady(): bool {
		$status = $this->getStatus();
		return $status === self::INIT_SUCCESSFUL;
	}

	/**
	 * Gets user or public share private key from session
	 *
	 * @return string $privateKey The user's plaintext private key
	 * @throws Exceptions\PrivateKeyMissingException
	 */
	public function getPrivateKey(): string {
		$key = $this->session->get('privateKey');
		if (is_null($key)) {
			throw new PrivateKeyMissingException('please try to log-out and log-in again');
		}
		return $key;
	}

	/**
	 * check if private key is set
	 */
	public function isPrivateKeySet(): bool {
		$key = $this->session->get('privateKey');
		if (is_null($key)) {
			return false;
		}

		return true;
	}

	/**
	 * Sets user private key to session
	 *
	 * @param string $key users private key
	 *
	 * @note this should only be set on login
	 */
	public function setPrivateKey(string $key): void {
		$this->session->set('privateKey', $key);
	}

	/**
	 * store data needed for the decrypt all operation in the session
	 */
	public function prepareDecryptAll(string $user, string $key): void {
		$this->session->set('decryptAll', true);
		$this->session->set('decryptAllKey', $key);
		$this->session->set('decryptAllUid', $user);
	}

	/**
	 * check if we are in decrypt all mode
	 */
	public function decryptAllModeActivated(): bool {
		$decryptAll = $this->session->get('decryptAll');
		return ($decryptAll === true);
	}

	/**
	 * get uid used for decrypt all operation
	 *
	 * @throws \Exception
	 */
	public function getDecryptAllUid(): string {
		$uid = $this->session->get('decryptAllUid');
		if (is_null($uid) && $this->decryptAllModeActivated()) {
			throw new \Exception('No uid found while in decrypt all mode');
		} elseif (is_null($uid)) {
			throw new \Exception('Please activate decrypt all mode first');
		}

		return $uid;
	}

	/**
	 * get private key for decrypt all operation
	 *
	 * @throws PrivateKeyMissingException
	 */
	public function getDecryptAllKey(): string {
		$privateKey = $this->session->get('decryptAllKey');
		if (is_null($privateKey) && $this->decryptAllModeActivated()) {
			throw new PrivateKeyMissingException('No private key found while in decrypt all mode');
		} elseif (is_null($privateKey)) {
			throw new PrivateKeyMissingException('Please activate decrypt all mode first');
		}

		return $privateKey;
	}

	/**
	 * remove keys from session
	 */
	public function clear(): void {
		$this->session->remove('publicSharePrivateKey');
		$this->session->remove('privateKey');
		$this->session->remove('encryptionInitialized');
		$this->session->remove('decryptAll');
		$this->session->remove('decryptAllKey');
		$this->session->remove('decryptAllUid');
	}
}