<?php
/**
 * Klein (klein.php) - A fast & flexible router for PHP
 *
 * @author      Chris O'Hara <cohara87@gmail.com>
 * @author      Trevor Suarez (Rican7) (contributor and v2 refactorer)
 * @copyright   (c) Chris O'Hara
 * @link        https://github.com/klein/klein.php
 * @license     MIT
 */

namespace Klein\DataCollection;

/**
 * ServerDataCollection
 *
 * A DataCollection for "$_SERVER" like data
 *
 * Look familiar?
 *
 * Inspired by @fabpot's Symfony 2's HttpFoundation
 * @link https://github.com/symfony/HttpFoundation/blob/master/ServerBag.php
 */
class ServerDataCollection extends DataCollection
{

    /**
     * Class properties
     */

    /**
     * The prefix of HTTP headers normally
     * stored in the Server data
     *
     * @type string
     */
    protected static $http_header_prefix = 'HTTP_';

    /**
     * The list of HTTP headers that for some
     * reason aren't prefixed in PHP...
     *
     * @type array
     */
    protected static $http_nonprefixed_headers = array(
        'CONTENT_LENGTH',
        'CONTENT_TYPE',
        'CONTENT_MD5',
    );


    /**
     * Methods
     */

    /**
     * Quickly check if a string has a passed prefix
     *
     * @param string $string    The string to check
     * @param string $prefix    The prefix to test
     * @return boolean
     */
    public static function hasPrefix($string, $prefix)
    {
        if (strpos($string, $prefix) === 0) {
            return true;
        }

        return false;
    }

    /**
     * Get our headers from our server data collection
     *
     * PHP is weird... it puts all of the HTTP request
     * headers in the $_SERVER array. This handles that
     *
     * @return array
     */
    public function getHeaders()
    {
        // Define a headers array
        $headers = array();

        foreach ($this->attributes as $key => $value) {
            // Does our server attribute have our header prefix?
            if (self::hasPrefix($key, self::$http_header_prefix)) {
                // Add our server attribute to our header array
                $headers[
                    substr($key, strlen(self::$http_header_prefix))
                ] = $value;

            } elseif (in_array($key, self::$http_nonprefixed_headers)) {
                // Add our server attribute to our header array
                $headers[$key] = $value;
            }
        }

        return $headers;
    }
}