cookies.php

<?php

require_once dirname(__FILE__) . '/url.php';

/**
 * Cookie data holder.
 * Cookie rules are full of pretty arbitary stuff
 * I have used: http://www.cookiecentral.com/faq/
 */
class SimpleCookie
{
    private $expiry;
    private $host;
    private $is_secure;
    private $name;
    private $path;
    private $value;

    /**
     * Constructor. Sets the stored values.
     *
     * @param string $name      Cookie key.
     * @param string $value     Value of cookie.
     * @param string $path      Cookie path if not host wide.
     * @param string $expiry    Expiry date as string.
     * @param bool   $is_secure Currently ignored.
     */
    public function __construct($name, $value = false, $path = false, $expiry = false, $is_secure = false)
    {
        $this->host   = false;
        $this->name   = $name;
        $this->value  = $value;
        $this->path   = ($path ? $this->fixPath($path) : '/');
        $this->expiry = false;
        if (is_string($expiry)) {
            $this->expiry = strtotime($expiry);
        } elseif (is_integer($expiry)) {
            $this->expiry = $expiry;
        }
        $this->is_secure = $is_secure;
    }

    /**
     * Sets the host. The cookie rules determine that
     * the first two parts are taken for certain TLDs and three for others.
     * If the new host does not match these rules then the call will fail.
     *
     * @param string $host New hostname.
     *
     * @return bool True if hostname is valid.
     */
    public function setHost($host)
    {
        if ($host = $this->truncateHost($host)) {
            $this->host = $host;

            return true;
        }

        return false;
    }

    /**
     * Accessor for the truncated host to which this cookie applies.
     *
     * @return string Truncated hostname.
     */
    public function getHost()
    {
        return $this->host;
    }

    /**
     * Test for a cookie being valid for a host name.
     *
     * @param string $host Host to test against.
     *
     * @return bool True if the cookie would be valid here.
     */
    public function isValidHost($host)
    {
        return ($this->truncateHost($host) === $this->getHost());
    }

    /**
     * Extracts just the domain part that determines a cookie's host validity.
     *
     * @param string $host Host name to truncate.
     *
     * @return string Domain or false on a bad host.
     */
    protected function truncateHost($host)
    {
        $tlds = SimpleUrl::getAllTopLevelDomains();
        if (preg_match('/[a-z\-]+\.(' . $tlds . ')$/i', $host, $matches)) {
            return $matches[0];
        } elseif (preg_match('/[a-z\-]+\.[a-z\-]+\.[a-z\-]+$/i', $host, $matches)) {
            return $matches[0];
        }

        return false;
    }

    /**
     * Accessor for name.
     *
     * @return string Cookie key.
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Accessor for value. A deleted cookie will have an empty string for this.
     *
     * @return string Cookie value.
     */
    public function getValue()
    {
        return $this->value;
    }

    /**
     * Accessor for path.
     *
     * @return string Valid cookie path.
     */
    public function getPath()
    {
        return $this->path;
    }

    /**
     * Tests a path to see if the cookie applies there.
     * The test path must be longer or equal to the cookie path.
     *
     * @param string $path Path to test against.
     *
     * @return bool True if cookie valid here.
     */
    public function isValidPath($path)
    {
        return (strncmp($this->fixPath($path), $this->getPath(), strlen($this->getPath())) == 0);
    }

    /**
     * Accessor for expiry.
     *
     * @return string Expiry string.
     */
    public function getExpiry()
    {
        if (! $this->expiry) {
            return false;
        }

        return gmdate('D, d M Y H:i:s', $this->expiry) . ' GMT';
    }

    /**
     * Test to see if cookie is expired against the cookie format time or timestamp.
     * Will give true for a session cookie.
     *
     * @param integer/string $now Time to test against. Result will be false if this time
     *                            is later than the cookie expiry. Can be either a timestamp
     *                            integer or a cookie format date.
     */
    public function isExpired($now)
    {
        if (! $this->expiry) {
            return true;
        }
        if (is_string($now)) {
            $now = strtotime($now);
        }

        return ($this->expiry < $now);
    }

    /**
     * Ages the cookie by the specified number of seconds.
     *
     * @param int $interval In seconds.
     */
    public function agePrematurely($interval)
    {
        if ($this->expiry) {
            $this->expiry -= $interval;
        }
    }

    /**
     * Accessor for the secure flag.
     *
     * @return bool True if cookie needs SSL.
     */
    public function isSecure()
    {
        return $this->is_secure;
    }

    /**
     * Adds a trailing and leading slash to the path if missing.
     *
     * @param string $path Path to fix.
     */
    protected function fixPath($path)
    {
        if (substr($path, 0, 1) != '/') {
            $path = '/' . $path;
        }
        if (substr($path, -1, 1) != '/') {
            $path .= '/';
        }

        return $path;
    }
}

/**
 * Repository for cookies. This stuff is a tiny bit browser dependent.
 */
class SimpleCookieJar
{
    private $cookies;

    /**
     * Constructor. Jar starts empty.
     */
    public function __construct()
    {
        $this->cookies = array();
    }

    /**
     * Removes expired and temporary cookies as if the browser was closed and re-opened.
     *
     * @param string/integer $date Time to test expiry against.
     */
    public function restartSession($date = false)
    {
        $surviving_cookies = array();
        for ($i = 0; $i < count($this->cookies); $i++) {
            if (! $this->cookies[$i]->getValue()) {
                continue;
            }
            if (! $this->cookies[$i]->getExpiry()) {
                continue;
            }
            if ($date && $this->cookies[$i]->isExpired($date)) {
                continue;
            }
            $surviving_cookies[] = $this->cookies[$i];
        }
        $this->cookies = $surviving_cookies;
    }

    /**
     * Ages all cookies in the cookie jar.
     *
     * @param int $interval The old session is moved into the past by this number
     *                      of seconds. Cookies now over age will be removed.
     */
    public function agePrematurely($interval)
    {
        for ($i = 0; $i < count($this->cookies); $i++) {
            $this->cookies[$i]->agePrematurely($interval);
        }
    }

    /**
     * Sets an additional cookie. If a cookie has the same name and path it is replaced.
     *
     * @param string $name   Cookie key.
     * @param string $value  Value of cookie.
     * @param string $host   Host upon which the cookie is valid.
     * @param string $path   Cookie path if not host wide.
     * @param string $expiry Expiry date.
     */
    public function setCookie($name, $value, $host = false, $path = '/', $expiry = false)
    {
        $cookie = new SimpleCookie($name, $value, $path, $expiry);
        if ($host) {
            $cookie->setHost($host);
        }
        $this->cookies[$this->findFirstMatch($cookie)] = $cookie;
    }

    /**
     * Finds a matching cookie to write over or the first empty slot if none.
     *
     * @param SimpleCookie $cookie Cookie to write into jar.
     *
     * @return int Available slot.
     */
    protected function findFirstMatch($cookie)
    {
        for ($i = 0; $i < count($this->cookies); $i++) {
            $is_match = $this->isMatch(
                    $cookie,
                    $this->cookies[$i]->getHost(),
                    $this->cookies[$i]->getPath(),
                    $this->cookies[$i]->getName());
            if ($is_match) {
                return $i;
            }
        }

        return count($this->cookies);
    }

    /**
     * Reads the most specific cookie value from the browser cookies.
     * Looks for the longest path that matches.
     *
     * @param string $host Host to search.
     * @param string $path Applicable path.
     * @param string $name Name of cookie to read.
     *
     * @return string False if not present, else the value as a string.
     */
    public function getCookieValue($host, $path, $name)
    {
        $longest_path = '';
        foreach ($this->cookies as $cookie) {
            if ($this->isMatch($cookie, $host, $path, $name)) {
                if (strlen($cookie->getPath()) > strlen($longest_path)) {
                    $value        = $cookie->getValue();
                    $longest_path = $cookie->getPath();
                }
            }
        }

        return (isset($value) ? $value : false);
    }

    /**
     * Tests cookie for matching against search criteria.
     *
     * @param SimpleTest $cookie Cookie to test.
     * @param string     $host   Host must match.
     * @param string     $path   Cookie path must be shorter than this path.
     * @param string     $name   Name must match.
     *
     * @return bool True if matched.
     */
    protected function isMatch($cookie, $host, $path, $name)
    {
        if ($cookie->getName() != $name) {
            return false;
        }
        if ($host && $cookie->getHost() && ! $cookie->isValidHost($host)) {
            return false;
        }
        if (! $cookie->isValidPath($path)) {
            return false;
        }

        return true;
    }

    /**
     * Uses a URL to sift relevant cookies by host and path.
     * Results are list of strings of form "name=value".
     *
     * @param SimpleUrl $url Url to select by.
     *
     * @return array Valid name and value pairs.
     */
    public function selectAsPairs($url)
    {
        $pairs = array();
        foreach ($this->cookies as $cookie) {
            if ($this->isMatch($cookie, $url->getHost(), $url->getPath(), $cookie->getName())) {
                $pairs[] = $cookie->getName() . '=' . $cookie->getValue();
            }
        }

        return $pairs;
    }
}