<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/

namespace phpbb\notification\method;

use Minishlink\WebPush\Subscription;
use phpbb\config\config;
use phpbb\controller\helper;
use phpbb\db\driver\driver_interface;
use phpbb\form\form_helper;
use phpbb\log\log_interface;
use phpbb\notification\type\type_interface;
use phpbb\user;
use phpbb\user_loader;

/**
* Web Push notification method class
* This class handles sending push messages for notifications
*/

class webpush extends base implements extended_method_interface
{
	/** @var config */
	protected $config;

	/** @var driver_interface */
	protected $db;

	/** @var log_interface */
	protected $log;

	/** @var user_loader */
	protected $user_loader;

	/** @var user */
	protected $user;

	/** @var string */
	protected $phpbb_root_path;

	/** @var string */
	protected $php_ext;

	/** @var string Notification Web Push table */
	protected $notification_webpush_table;

	/** @var string Notification push subscriptions table */
	protected $push_subscriptions_table;

	/** @var int Fallback size for padding if endpoint is mozilla, see https://github.com/web-push-libs/web-push-php/issues/108#issuecomment-2133477054 */
	const MOZILLA_FALLBACK_PADDING = 2820;

	/** @var array Map for storing push token between db insertion and sending of notifications */
	private array $push_token_map = [];

	/**
	 * Notification Method Web Push constructor
	 *
	 * @param config $config
	 * @param driver_interface $db
	 * @param log_interface $log
	 * @param user_loader $user_loader
	 * @param user $user
	 * @param string $phpbb_root_path
	 * @param string $php_ext
	 * @param string $notification_webpush_table
	 * @param string $push_subscriptions_table
	 */
	public function __construct(config $config, driver_interface $db, log_interface $log, user_loader $user_loader, user $user, string $phpbb_root_path,
								string $php_ext, string $notification_webpush_table, string $push_subscriptions_table)
	{
		$this->config = $config;
		$this->db = $db;
		$this->log = $log;
		$this->user_loader = $user_loader;
		$this->user = $user;
		$this->phpbb_root_path = $phpbb_root_path;
		$this->php_ext = $php_ext;
		$this->notification_webpush_table = $notification_webpush_table;
		$this->push_subscriptions_table = $push_subscriptions_table;
	}

	/**
	* {@inheritDoc}
	*/
	public function get_type(): string
	{
		return 'notification.method.webpush';
	}

	/**
	* {@inheritDoc}
	*/
	public function is_available(type_interface|null $notification_type = null): bool
	{
		return $this->config['webpush_enable']
			&& $this->config['webpush_vapid_public']
			&& $this->config['webpush_vapid_private'];
	}

	/**
	 * {@inheritDoc}
	 */
	public function is_enabled_by_default()
	{
		return (bool) $this->config['webpush_method_default_enable'];
	}

	/**
	* {@inheritdoc}
	*/
	public function get_notified_users($notification_type_id, array $options): array
	{
		$notified_users = [];

		$sql = 'SELECT user_id
			FROM ' . $this->notification_webpush_table . '
			WHERE notification_type_id = ' . (int) $notification_type_id .
			(isset($options['item_id']) ? ' AND item_id = ' . (int) $options['item_id'] : '') .
			(isset($options['item_parent_id']) ? ' AND item_parent_id = ' . (int) $options['item_parent_id'] : '') .
			(isset($options['user_id']) ? ' AND user_id = ' . (int) $options['user_id'] : '');
		$result = $this->db->sql_query($sql);
		while ($row = $this->db->sql_fetchrow($result))
		{
			$notified_users[$row['user_id']] = $row;
		}
		$this->db->sql_freeresult($result);

		return $notified_users;
	}

	/**
	* Parse the queue and notify the users
	*/
	public function notify()
	{
		$insert_buffer = new \phpbb\db\sql_insert_buffer($this->db, $this->notification_webpush_table);

		/** @var type_interface $notification */
		foreach ($this->queue as $notification)
		{
			$data = $notification->get_insert_array();
			$data += [
				'push_data'				=> json_encode(array_merge(
					$data,
					['notification_type_name' => $notification->get_type()],
				)),
				'notification_time'		=> time(),
				'push_token'			=> hash('sha256', random_bytes(32))
			];
			$data = self::clean_data($data);
			$insert_buffer->insert($data);
			$this->push_token_map[$notification->notification_type_id][$notification->item_id] = $data['push_token'];
		}

		$insert_buffer->flush();

		$this->notify_using_webpush();

		return false;
	}

	/**
	 * Notify using Web Push
	 *
	 * @return void
	 */
	protected function notify_using_webpush(): void
	{
		if (empty($this->queue))
		{
			return;
		}

		// Load all users we want to notify
		$user_ids = [];
		foreach ($this->queue as $notification)
		{
			$user_ids[] = $notification->user_id;
		}

		// Do not send push notifications to banned users
		if (!function_exists('phpbb_get_banned_user_ids'))
		{
			include($this->phpbb_root_path . 'includes/functions_user.' . $this->php_ext);
		}
		$banned_users = phpbb_get_banned_user_ids($user_ids);

		// Load all the users we need
		$notify_users = array_diff($user_ids, $banned_users);
		$this->user_loader->load_users($notify_users, array(USER_IGNORE));

		// Get subscriptions for users
		$user_subscription_map = $this->get_user_subscription_map($notify_users);

		$auth = [
			'VAPID' => [
				'subject' => generate_board_url(false),
				'publicKey' => $this->config['webpush_vapid_public'],
				'privateKey' => $this->config['webpush_vapid_private'],
			],
		];

		$web_push = new \Minishlink\WebPush\WebPush($auth);

		$number_of_notifications = 0;
		$remove_subscriptions = [];

		// Time to go through the queue and send notifications
		/** @var type_interface $notification */
		foreach ($this->queue as $notification)
		{
			$user = $this->user_loader->get_user($notification->user_id);

			$user_subscriptions = $user_subscription_map[$notification->user_id] ?? [];

			if ($user['user_type'] == USER_INACTIVE && $user['user_inactive_reason'] == INACTIVE_MANUAL
				|| empty($user_subscriptions))
			{
				continue;
			}

			// Add actual Web Push data
			$data = [
				'item_id'	=> $notification->item_id,
				'type_id'	=> $notification->notification_type_id,
				'user_id'	=> $notification->user_id,
				'version'	=> $this->config['assets_version'],
				'token'		=> hash('sha256', $user['user_form_salt'] . $this->push_token_map[$notification->notification_type_id][$notification->item_id]),
			];
			$json_data = json_encode($data);

			foreach ($user_subscriptions as $subscription)
			{
				try
				{
					$this->set_endpoint_padding($web_push, $subscription['endpoint']);
					$push_subscription = Subscription::create([
						'endpoint'			=> $subscription['endpoint'],
						'keys'				=> [
							'p256dh'	=> $subscription['p256dh'],
							'auth'		=> $subscription['auth'],
						],
					]);
					$web_push->queueNotification($push_subscription, $json_data);
					$number_of_notifications++;
				}
				catch (\ErrorException $exception)
				{
					$remove_subscriptions[] = $subscription['subscription_id'];
					$this->log->add('user', $user['user_id'], $user['user_ip'] ?? '', 'LOG_WEBPUSH_SUBSCRIPTION_REMOVED', false, [
						'reportee_id' => $user['user_id'],
						$user['username'],
					]);
				}
			}
		}

		// Remove any subscriptions that couldn't be queued, i.e. that have invalid data
		$this->remove_subscriptions($remove_subscriptions);

		// List to fill with expired subscriptions based on return
		$expired_endpoints = [];

		try
		{
			foreach ($web_push->flush($number_of_notifications) as $report)
			{
				if (!$report->isSuccess())
				{
					// Fill array of endpoints to remove if subscription has expired
					if ($report->isSubscriptionExpired())
					{
						$expired_endpoints[] = $report->getEndpoint();
					}
					else
					{
						$report_data = \phpbb\json\sanitizer::sanitize($report->jsonSerialize());
						$this->log->add('admin', ANONYMOUS, '', 'LOG_WEBPUSH_MESSAGE_FAIL', false, [$report_data['reason']]);
					}
				}
			}
		}
		catch (\ErrorException $exception)
		{
			$this->log->add('critical', ANONYMOUS, '', 'LOG_WEBPUSH_MESSAGE_FAIL', false, [$exception->getMessage()]);
		}

		$this->clean_expired_subscriptions($user_subscription_map, $expired_endpoints);

		// We're done, empty the queue
		$this->empty_queue();
	}

	/**
	* {@inheritdoc}
	*/
	public function mark_notifications($notification_type_id, $item_id, $user_id, $time = false, $mark_read = true)
	{
		$sql = 'DELETE FROM ' . $this->notification_webpush_table . '
			WHERE ' . ($notification_type_id !== false ? $this->db->sql_in_set('notification_type_id', is_array($notification_type_id) ? $notification_type_id : [$notification_type_id]) : '1=1') .
			($user_id !== false ? ' AND ' . $this->db->sql_in_set('user_id', $user_id) : '') .
			($item_id !== false ? ' AND ' . $this->db->sql_in_set('item_id', $item_id) : '');
		$this->db->sql_query($sql);
	}

	/**
	* {@inheritdoc}
	*/
	public function mark_notifications_by_parent($notification_type_id, $item_parent_id, $user_id, $time = false, $mark_read = true)
	{
		$sql = 'DELETE FROM ' . $this->notification_webpush_table . '
			WHERE ' . ($notification_type_id !== false ? $this->db->sql_in_set('notification_type_id', is_array($notification_type_id) ? $notification_type_id : [$notification_type_id]) : '1=1') .
			($user_id !== false ? ' AND ' . $this->db->sql_in_set('user_id', $user_id) : '') .
			($item_parent_id !== false ? ' AND ' . $this->db->sql_in_set('item_parent_id', $item_parent_id, false, true) : '');
		$this->db->sql_query($sql);
	}

	/**
	 * {@inheritDoc}
	 */
	public function prune_notifications($timestamp, $only_read = true): void
	{
		$sql = 'DELETE FROM ' . $this->notification_webpush_table . '
			WHERE notification_time < ' . (int) $timestamp;
		$this->db->sql_query($sql);

		$this->config->set('read_notification_last_gc', (string) time(), false);
	}

	/**
	 * Clean data to contain only what we need for webpush notifications table
	 *
	 * @param array $data Notification data
	 * @return array Cleaned notification data
	 */
	public static function clean_data(array $data): array
	{
		$row = [
			'notification_type_id'	=> null,
			'item_id'				=> null,
			'item_parent_id'		=> null,
			'user_id'				=> null,
			'push_data'				=> null,
			'push_token'			=> null,
			'notification_time'		=> null,
		];

		return array_intersect_key($data, $row);
	}

	/**
	 * Get template data for the UCP
	 *
	 * @param helper $controller_helper
	 * @param form_helper $form_helper
	 *
	 * @return array
	 */
	public function get_ucp_template_data(helper $controller_helper, form_helper $form_helper): array
	{
		$subscription_map = $this->get_user_subscription_map([$this->user->id()]);
		$subscriptions = [];

		if (isset($subscription_map[$this->user->id()]))
		{
			foreach ($subscription_map[$this->user->id()] as $subscription)
			{
				$subscriptions[] = [
					'endpoint'			=> $subscription['endpoint'],
					'expirationTime'	=> $subscription['expiration_time'],
				];
			}
		}

		return [
			'NOTIFICATIONS_WEBPUSH_ENABLE'	=> $this->config['webpush_dropdown_subscribe'] || stripos($this->user->page['page'], 'notification_options'),
			'U_WEBPUSH_SUBSCRIBE'			=> $controller_helper->route('phpbb_ucp_push_subscribe_controller'),
			'U_WEBPUSH_UNSUBSCRIBE'			=> $controller_helper->route('phpbb_ucp_push_unsubscribe_controller'),
			'VAPID_PUBLIC_KEY'				=> $this->config['webpush_vapid_public'],
			'U_WEBPUSH_WORKER_URL'			=> $controller_helper->route('phpbb_ucp_push_worker_controller'),
			'SUBSCRIPTIONS'					=> $subscriptions,
			'WEBPUSH_FORM_TOKENS'			=> $form_helper->get_form_tokens(\phpbb\ucp\controller\webpush::FORM_TOKEN_UCP),
		];
	}

	/**
	 * Get subscriptions for notify users
	 *
	 * @param array $notify_users Users to notify
	 *
	 * @return array Subscription map
	 */
	protected function get_user_subscription_map(array $notify_users): array
	{
		// Get subscriptions for users
		$user_subscription_map = [];

		$sql = 'SELECT subscription_id, user_id, endpoint, p256dh, auth, expiration_time
			FROM ' . $this->push_subscriptions_table . '
			WHERE ' . $this->db->sql_in_set('user_id', $notify_users);
		$result = $this->db->sql_query($sql);
		while ($row = $this->db->sql_fetchrow($result))
		{
			$user_subscription_map[$row['user_id']][] = $row;
		}
		$this->db->sql_freeresult($result);

		return $user_subscription_map;
	}

	/**
	 * Remove subscriptions
	 *
	 * @param array $subscription_ids Subscription ids to remove
	 * @return void
	 */
	public function remove_subscriptions(array $subscription_ids): void
	{
		if (count($subscription_ids))
		{
			$sql = 'DELETE FROM ' . $this->push_subscriptions_table . '
					WHERE ' . $this->db->sql_in_set('subscription_id', $subscription_ids);
			$this->db->sql_query($sql);
		}
	}

	/**
	 * Clean expired subscriptions from the database
	 *
	 * @param array $user_subscription_map User subscription map
	 * @param array $expired_endpoints Expired endpoints
	 * @return void
	 */
	protected function clean_expired_subscriptions(array $user_subscription_map, array $expired_endpoints): void
	{
		if (!count($expired_endpoints))
		{
			return;
		}

		$remove_subscriptions = [];
		foreach ($expired_endpoints as $endpoint)
		{
			foreach ($user_subscription_map as $subscriptions)
			{
				foreach ($subscriptions as $subscription)
				{
					if (isset($subscription['endpoint']) && $subscription['endpoint'] == $endpoint)
					{
						$remove_subscriptions[] = $subscription['subscription_id'];
					}
				}
			}
		}

		$this->remove_subscriptions($remove_subscriptions);
	}

	/**
	 * Set web push padding for endpoint
	 *
	 * @param \Minishlink\WebPush\WebPush $web_push
	 * @param string $endpoint
	 *
	 * @return void
	 */
	protected function set_endpoint_padding(\Minishlink\WebPush\WebPush $web_push, string $endpoint): void
	{
		if (str_contains($endpoint, 'mozilla.com') || str_contains($endpoint, 'mozaws.net'))
		{
			try
			{
				$web_push->setAutomaticPadding(self::MOZILLA_FALLBACK_PADDING);
			}
			catch (\Exception)
			{
				// This shouldn't happen since we won't pass padding length outside limits
			}
		}
	}
}