<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <envkt@example.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Mailer\Transport\Smtp\Stream;

use Symfony\Component\Mailer\Exception\TransportException;

/**
 * A stream supporting remote sockets.
 *
 * @author Fabien Potencier <envkt@example.com>
 * @author Chris Corbyn
 *
 * @internal
 */
final class SocketStream extends AbstractStream
{
    private string $url;
    private string $host = 'localhost';
    private int $port = 465;
    private float $timeout;
    private bool $tls = true;
    private ?string $sourceIp = null;
    private array $streamContextOptions = [];

    /**
     * @return $this
     */
    public function setTimeout(float $timeout): static
    {
        $this->timeout = $timeout;

        return $this;
    }

    public function getTimeout(): float
    {
        return $this->timeout ?? (float) \ini_get('default_socket_timeout');
    }

    /**
     * Literal IPv6 addresses should be wrapped in square brackets.
     *
     * @return $this
     */
    public function setHost(string $host): static
    {
        $this->host = $host;

        return $this;
    }

    public function getHost(): string
    {
        return $this->host;
    }

    /**
     * @return $this
     */
    public function setPort(int $port): static
    {
        $this->port = $port;

        return $this;
    }

    public function getPort(): int
    {
        return $this->port;
    }

    /**
     * Sets the TLS/SSL on the socket (disables STARTTLS).
     *
     * @return $this
     */
    public function disableTls(): static
    {
        $this->tls = false;

        return $this;
    }

    public function isTLS(): bool
    {
        return $this->tls;
    }

    /**
     * @return $this
     */
    public function setStreamOptions(array $options): static
    {
        $this->streamContextOptions = $options;

        return $this;
    }

    public function getStreamOptions(): array
    {
        return $this->streamContextOptions;
    }

    /**
     * Sets the source IP.
     *
     * IPv6 addresses should be wrapped in square brackets.
     *
     * @return $this
     */
    public function setSourceIp(string $ip): static
    {
        $this->sourceIp = $ip;

        return $this;
    }

    /**
     * Returns the IP used to connect to the destination.
     */
    public function getSourceIp(): ?string
    {
        return $this->sourceIp;
    }

    public function initialize(): void
    {
        $this->url = $this->host.':'.$this->port;
        if ($this->tls) {
            $this->url = 'ssl://'.$this->url;
        }
        $options = [];
        if ($this->sourceIp) {
            $options['socket']['bindto'] = $this->sourceIp.':0';
        }
        if ($this->streamContextOptions) {
            $options = array_merge($options, $this->streamContextOptions);
        }
        // do it unconditionally as it will be used by STARTTLS as well if supported
        $options['ssl']['crypto_method'] = $options['ssl']['crypto_method'] ?? \STREAM_CRYPTO_METHOD_TLS_CLIENT | \STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT | \STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT;
        $streamContext = stream_context_create($options);

        $timeout = $this->getTimeout();
        set_error_handler(function ($type, $msg) {
            throw new TransportException(sprintf('Connection could not be established with host "%s": ', $this->url).$msg);
        });
        try {
            $this->stream = stream_socket_client($this->url, $errno, $errstr, $timeout, \STREAM_CLIENT_CONNECT, $streamContext);
        } finally {
            restore_error_handler();
        }

        stream_set_blocking($this->stream, true);
        stream_set_timeout($this->stream, $timeout);
        $this->in = &$this->stream;
        $this->out = &$this->stream;
    }

    public function startTLS(): bool
    {
        set_error_handler(function ($type, $msg) {
            throw new TransportException('Unable to connect with STARTTLS: '.$msg);
        });
        try {
            return stream_socket_enable_crypto($this->stream, true);
        } finally {
            restore_error_handler();
        }
    }

    public function terminate(): void
    {
        if (null !== $this->stream) {
            fclose($this->stream);
        }

        parent::terminate();
    }

    protected function getReadConnectionDescription(): string
    {
        return $this->url;
    }
}
