<?php

declare(strict_types=1);

/**
 * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

namespace OCA\WebhookListeners\Service;

use OC\Authentication\Token\IProvider;
use OCA\WebhookListeners\Db\EphemeralTokenMapper;
use OCA\WebhookListeners\Db\WebhookListener;
use OCP\AppFramework\Utility\ITimeFactory;
use OCP\Authentication\Token\IToken;
use OCP\IURLGenerator;
use OCP\IUserManager;
use OCP\L10N\IFactory;
use OCP\Security\ISecureRandom;
use Psr\Log\LoggerInterface;

class TokenService {
	public function __construct(
		private IProvider $tokenProvider,
		private IURLGenerator $urlGenerator,
		private ISecureRandom $random,
		private EphemeralTokenMapper $tokenMapper,
		private LoggerInterface $logger,
		private ITimeFactory $time,
		private IFactory $l10nFactory,
		private IUserManager $userManager,
	) {
	}

	/**
	 * creates an array which includes two arrays of tokens: 'user_ids' and 'user_roles'
	 * The array ['user_ids' => ['jane', 'bob'], 'user_roles' => ['owner', 'trigger']]
	 * as requested tokens in the registered webhook produces a result like
	 * [
	 * 		['user_ids' => [
	 * 			['jane' => [
	 * 				'userId' => 'jane',
	 * 				'token' => 'abcdtokenabcd1'
	 * 				'baseUrl' => 'https://nextcloud.example'
	 * 			],
	 * 			['bob'=> [
	 * 				'userId' => 'bob',
	 * 				'token' => 'abcdtokenabcd2'
	 * 				'baseUrl' => 'https://nextcloud.example'
	 * 			],
	 * 		],
	 * 		'owner' => [
	 * 			'userId' => 'admin',
	 * 			'token' => 'abcdtokenabcd3'
	 * 			'baseUrl' => 'https://nextcloud.example'
	 * 		],
	 * 		'trigger' => [
	 * 			'userId' => 'user1',
	 * 			'token' => 'abcdtokenabcd4'
	 * 			'baseUrl' => 'https://nextcloud.example'
	 * 		],
	 * ]
	 * Created auth tokens are valid for 1 hour.
	 *
	 * @param WebhookListener $webhookListener
	 * @param ?string $triggerUserId the user that triggered the webhook call
	 * @return array{
	 *     user_ids?: array<string, array{baseUrl: string, token: string, userId: mixed}>,
	 *     trigger?: array{baseUrl: string, token: string, userId: string},
	 *     owner?: array{baseUrl: string, token: string, userId: string},
	 * }
	 */
	public function getTokens(WebhookListener $webhookListener, ?string $triggerUserId): array {
		$tokens = [];

		$tokenNeeded = $webhookListener->getTokenNeeded();
		if (isset($tokenNeeded['user_ids'])) {
			$tokens = [
				'user_ids' => [],
			];
			foreach ($tokenNeeded['user_ids'] as $userId) {
				try {
					$tokens['user_ids'][$userId] = [
						'userId' => $userId,
						'token' => $this->createEphemeralToken($userId),
						'baseUrl' => $this->urlGenerator->getBaseUrl()
					];
				} catch (\Exception $e) {
					$this->logger->error('Webhook token creation for user ' . $userId . ' failed: ' . $e->getMessage(), ['exception' => $e]);
				}

			}
		}
		if (isset($tokenNeeded['user_roles'])) {
			foreach ($tokenNeeded['user_roles'] as $user_role) {
				switch ($user_role) {
					case 'owner':
						// token for the person who created the flow
						$ownerId = $webhookListener->getUserId();
						if (is_null($ownerId)) { // no owner uid available
							break;
						}
						$tokens['owner'] = [
							'userId' => $ownerId,
							'token' => $this->createEphemeralToken($ownerId),
							'baseUrl' => $this->urlGenerator->getBaseUrl()
						];
						break;
					case 'trigger':
						// token for the person who triggered the webhook
						if (is_null($triggerUserId)) { // no trigger uid available
							break;
						}
						$tokens['trigger'] = [
							'userId' => $triggerUserId,
							'token' => $this->createEphemeralToken($triggerUserId),
							'baseUrl' => $this->urlGenerator->getBaseUrl()
						];
						break;
					default:
						$this->logger->error('Webhook token creation for user role ' . $user_role . ' not defined. ', ['Not defined' => $user_role]);

				}
			}
		}
		return $tokens;
	}
	private function createEphemeralToken(string $userId): string {
		$token = $this->generateRandomDeviceToken();

		// we need the user`s language to have the token name showing up in the session list in the correct language
		$user = $this->userManager->get($userId);
		$lang = $this->l10nFactory->getUserLanguage($user);
		$l = $this->l10nFactory->get('webhook_listeners', $lang);
		$name = $l->t('Ephemeral webhook authentication');
		$password = null;
		$deviceToken = $this->tokenProvider->generateToken(
			$token,
			$userId,
			$userId,
			$password,
			$name,
			IToken::PERMANENT_TOKEN);

		$this->tokenMapper->addEphemeralToken(
			$deviceToken->getId(),
			$userId,
			$this->time->getTime());
		return $token;
	}

	private function generateRandomDeviceToken(): string {
		$groups = [];
		for ($i = 0; $i < 5; $i++) {
			$groups[] = $this->random->generate(5, ISecureRandom::CHAR_HUMAN_READABLE);
		}
		return implode('-', $groups);
	}
}