Automattic/php-push

<?php
declare( strict_types = 1 );

class HTTPMessageParser {

    /** @var string */
    private $http_version = '2.0';

    /** @var int */
    private $status_code = 0;

    /** @var string[] */
    private $headers = [];

    /** @var string */
    private $body = '';

    public function __construct( string $text ) {

        if ( empty( $text ) ) {
            // If we can't make heads or tails of the response, it's probably because of a crashed request – set the defaults and move on
            return;
        }

        $lines = explode( PHP_EOL, $text );
        $line  = trim( array_shift( $lines ) );

        if ( ! strstr( $line, 'HTTP' ) ) {
            throw new InvalidArgumentException( 'Invalid Response: HTTP Header Missing in ' . $text );
        }

        list( $http_version, $status_code ) = explode( ' ', $line, 2 );
        $this->http_version                 = $http_version;
        $this->status_code                  = intval( $status_code );

        while ( true ) {
            $line = trim( array_shift( $lines ) );

            if ( empty( $line ) ) {
                break;
            }

            list( $key, $value )   = explode( ':', $line, 2 );
            $this->headers[ $key ] = trim( $value );
        }

        $this->body = trim( implode( PHP_EOL, $lines ) );
    }

    public function get_http_version(): string {
        return $this->http_version;
    }

    public function get_status_code(): int {
        return $this->status_code;
    }

    public function get_header( string $key ): ?string {
        if ( ! isset( $this->headers[ $key ] ) ) {
            return null;
        }

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

    public function get_body(): string {
        return $this->body;
    }
}