<?php
/**
 * API wrapper module.
 *
 * This file is part of MadelineProto.
 * MadelineProto is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 * MadelineProto 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 General Public License along with MadelineProto.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 * @author    Daniil Gentili <daniil@daniil.it>
 * @copyright 2016-2020 Daniil Gentili <daniil@daniil.it>
 * @license   https://opensource.org/licenses/AGPL-3.0 AGPLv3
 *
 * @link https://docs.madelineproto.xyz MadelineProto documentation
 */

namespace danog\MadelineProto\Ipc;

use Amp\Ipc\IpcServer;
use Amp\Ipc\Sync\ChannelledSocket;
use danog\Loop\SignalLoop;
use danog\MadelineProto\Ipc\Runner\ProcessRunner;
use danog\MadelineProto\Ipc\Runner\WebRunner;
use danog\MadelineProto\Logger;
use danog\MadelineProto\Tools;

/**
 * IPC server.
 */
class Server extends SignalLoop
{
    /**
     * Session not initialized, should initialize.
     */
    const NOT_INITED = 'not inited';
    /**
     * Session uses event handler, should start from main event handler file.
     */
    const EVENT_HANDLER = 'event';
    /**
     * IPC server.
     */
    private IpcServer $server;
    /**
     * Set IPC path.
     *
     * @param string $path IPC path
     *
     * @return void
     */
    public function setIpcPath(string $path): void
    {
        $this->server = new IpcServer($path);
    }
    /**
     * Start IPC server in background.
     *
     * @param string $session Session path
     *
     * @return void
     */
    public static function startMe(string $session): void
    {
        try {
            Logger::log("Starting IPC server $session (process)");
            ProcessRunner::start($session);
            return;
        } catch (\Throwable $e) {
            Logger::log($e);
        }
        Logger::log("Starting IPC server $session (web)");
        WebRunner::start($session);
    }
    /**
     * Main loop.
     *
     * @return \Generator
     */
    public function loop(): \Generator
    {
        while ($socket = yield $this->waitSignal($this->server->accept())) {
            Tools::callFork($this->clientLoop($socket));
        }
        $this->server->close();
    }
    /**
     * Client handler loop.
     *
     * @param ChannelledSocket $socket Client
     *
     * @return \Generator
     */
    private function clientLoop(ChannelledSocket $socket): \Generator
    {
        $this->API->logger("Accepted IPC client connection!");

        $id = 0;
        try {
            while ($payload = yield $socket->receive()) {
                Tools::callFork($this->clientRequest($socket, $id++, $payload));
            }
        } catch (\Throwable $e) {
        }
    }
    /**
     * Handle client request.
     *
     * @param ChannelledSocket $socket  Socket
     * @param integer          $id      Request ID
     * @param array            $payload Payload
     *
     * @return \Generator
     */
    public function clientRequest(ChannelledSocket $socket, int $id, $payload): \Generator
    {
        try {
            $result = $this->API->{$payload[0]}(...$payload[1]);
            $result = $result instanceof \Generator ? yield from $result : yield $result;
        } catch (\Throwable $e) {
            $result = new ExitFailure($e);
        }
        try {
            yield $socket->send([$id, $result]);
        } catch (\Throwable $e) {
            $this->API->logger("Got error while trying to send result of ${payload[0]}: $e", Logger::ERROR);
            try {
                yield $socket->send([$id, new ExitFailure($e)]);
            } catch (\Throwable $e) {
                $this->API->logger("Got error while trying to send error of error of ${payload[0]}: $e", Logger::ERROR);
            }
        }
    }
    /**
     * Get the name of the loop.
     *
     * @return string
     */
    public function __toString(): string
    {
        return "IPC server";
    }
}