<?php

/*
 * This file is part of the Predis package.
 *
 * (c) 2009-2020 Daniele Alessandri
 * (c) 2021-2025 Till Krüss
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Predis\Pipeline;

use Predis\CommunicationException;
use Predis\Connection\Cluster\ClusterInterface;
use Predis\Connection\ConnectionInterface;
use Predis\Connection\NodeConnectionInterface;
use Predis\NotSupportedException;
use SplQueue;

/**
 * Command pipeline that does not throw exceptions on connection errors, but
 * returns the exception instances as the rest of the response elements.
 */
class ConnectionErrorProof extends Pipeline
{
    /**
     * {@inheritdoc}
     */
    protected function getConnection()
    {
        return $this->getClient()->getConnection();
    }

    /**
     * {@inheritdoc}
     */
    protected function executePipeline(ConnectionInterface $connection, SplQueue $commands)
    {
        if ($connection instanceof NodeConnectionInterface) {
            return $this->executeSingleNode($connection, $commands);
        } elseif ($connection instanceof ClusterInterface) {
            return $this->executeCluster($connection, $commands);
        } else {
            $class = get_class($connection);

            throw new NotSupportedException("The connection class '$class' is not supported.");
        }
    }

    /**
     * {@inheritdoc}
     */
    protected function executeSingleNode(NodeConnectionInterface $connection, SplQueue $commands)
    {
        $responses = [];
        $sizeOfPipe = count($commands);
        $buffer = '';

        foreach ($commands as $command) {
            $buffer .= $command->serializeCommand();
        }

        try {
            $connection->write($buffer);
        } catch (CommunicationException $exception) {
            return array_fill(0, $sizeOfPipe, $exception);
        }

        for ($i = 0; $i < $sizeOfPipe; ++$i) {
            $command = $commands->dequeue();

            try {
                $responses[$i] = $connection->readResponse($command);
            } catch (CommunicationException $exception) {
                $add = count($commands) - count($responses);
                $responses = array_merge($responses, array_fill(0, $add, $exception));

                break;
            }
        }

        return $responses;
    }

    /**
     * {@inheritdoc}
     */
    protected function executeCluster(ClusterInterface $connection, SplQueue $commands)
    {
        $responses = [];
        $sizeOfPipe = count($commands);
        $exceptions = [];

        foreach ($commands as $command) {
            $nodeConnection = $connection->getConnectionByCommand($command);
            $nodeConnection->write($command->serializeCommand());
        }

        for ($i = 0; $i < $sizeOfPipe; ++$i) {
            $command = $commands->dequeue();

            $cmdConnection = $connection->getConnectionByCommand($command);
            $connectionHash = spl_object_hash($cmdConnection);

            if (isset($exceptions[$connectionHash])) {
                $responses[$i] = $exceptions[$connectionHash];
                continue;
            }

            try {
                $responses[$i] = $cmdConnection->readResponse($command);
            } catch (CommunicationException $exception) {
                $responses[$i] = $exception;
                $exceptions[$connectionHash] = $exception;
            }
        }

        return $responses;
    }
}
