<?php

declare(strict_types=1);

namespace Laminas\Diactoros;

use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\StreamInterface;
use Psr\Http\Message\UriInterface;

use function strtolower;

/**
 * HTTP Request encapsulation
 *
 * Requests are considered immutable; all methods that might change state are
 * implemented such that they retain the internal state of the current
 * message and return a new instance that contains the changed state.
 */
class Request implements RequestInterface
{
    use RequestTrait;

    /**
     * @param null|string|UriInterface $uri URI for the request, if any.
     * @param null|string $method HTTP method for the request, if any.
     * @param string|resource|StreamInterface $body Message body, if any.
     * @param array $headers Headers for the message, if any.
     * @throws Exception\InvalidArgumentException For any invalid value.
     */
    public function __construct($uri = null, ?string $method = null, $body = 'php://temp', array $headers = [])
    {
        $this->initialize($uri, $method, $body, $headers);
    }

    /**
     * {@inheritdoc}
     */
    public function getHeaders(): array
    {
        $headers = $this->headers;
        if (
            ! $this->hasHeader('host')
            && $this->uri->getHost()
        ) {
            $headers['Host'] = [$this->getHostFromUri()];
        }

        return $headers;
    }

    /**
     * {@inheritdoc}
     */
    public function getHeader($name): array
    {
        if (empty($name) || ! $this->hasHeader($name)) {
            if (
                strtolower($name) === 'host'
                && $this->uri->getHost()
            ) {
                return [$this->getHostFromUri()];
            }

            return [];
        }

        $header = $this->headerNames[strtolower($name)];

        return $this->headers[$header];
    }
}