<?php

/*

 * This file is part of the Symfony package.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Symfony\Component\HttpFoundation;

/**

 * HeaderBag is a container for HTTP headers.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 *

 * @api

 */

class HeaderBag

{

    protected $headers;

    protected $cacheControl;

    /**

     * Constructor.

     *

     * @param array $headers An array of HTTP headers

     *

     * @api

     */

    public function __construct(array $headers = array())

    {

        $this->cacheControl = array();

        $this->headers = array();

        foreach ($headers as $key => $values) {

            $this->set($key, $values);

        }

    }

    /**

     * Returns the headers as a string.

     *

     * @return string The headers

     */

    public function __toString()

    {

        if (!$this->headers) {

            return '';

        }

        $beautifier = function ($name) {

            return preg_replace_callback('/\-(.)/', function ($match) { return '-'.strtoupper($match[1]); }, ucfirst($name));

        };

        $max = max(array_map('strlen', array_keys($this->headers))) + 1;

        $content = '';

        ksort($this->headers);

        foreach ($this->headers as $name => $values) {

            foreach ($values as $value) {

                $content .= sprintf("%-{$max}s %s\r\n", $beautifier($name).':', $value);

            }

        }

        return $content;

    }

    /**

     * Returns the headers.

     *

     * @return array An array of headers

     *

     * @api

     */

    public function all()

    {

        return $this->headers;

    }

    /**

     * Returns the parameter keys.

     *

     * @return array An array of parameter keys

     *

     * @api

     */

    public function keys()

    {

        return array_keys($this->headers);

    }

    /**

     * Replaces the current HTTP headers by a new set.

     *

     * @param array  $headers An array of HTTP headers

     *

     * @api

     */

    public function replace(array $headers = array())

    {

        $this->headers = array();

        $this->add($headers);

    }

    /**

     * Adds new headers the current HTTP headers set.

     *

     * @param array  $headers An array of HTTP headers

     *

     * @api

     */

    public function add(array $headers)

    {

        foreach ($headers as $key => $values) {

            $this->set($key, $values);

        }

    }

    /**

     * Returns a header value by name.

     *

     * @param string  $key     The header name

     * @param mixed   $default The default value

     * @param Boolean $first   Whether to return the first value or all header values

     *

     * @return string|array The first header value if $first is true, an array of values otherwise

     *

     * @api

     */

    public function get($key, $default = null, $first = true)

    {

        $key = strtr(strtolower($key), '_', '-');

        if (!array_key_exists($key, $this->headers)) {

            if (null === $default) {

                return $first ? null : array();

            }

            return $first ? $default : array($default);

        }

        if ($first) {

            return count($this->headers[$key]) ? $this->headers[$key][0] : $default;

        }

        return $this->headers[$key];

    }

    /**

     * Sets a header by name.

     *

     * @param string       $key     The key

     * @param string|array $values  The value or an array of values

     * @param Boolean      $replace Whether to replace the actual value of not (true by default)

     *

     * @api

     */

    public function set($key, $values, $replace = true)

    {

        $key = strtr(strtolower($key), '_', '-');

        $values = (array) $values;

        if (true === $replace || !isset($this->headers[$key])) {

            $this->headers[$key] = $values;

        } else {

            $this->headers[$key] = array_merge($this->headers[$key], $values);

        }

        if ('cache-control' === $key) {

            $this->cacheControl = $this->parseCacheControl($values[0]);

        }

    }

    /**

     * Returns true if the HTTP header is defined.

     *

     * @param string $key The HTTP header

     *

     * @return Boolean true if the parameter exists, false otherwise

     *

     * @api

     */

    public function has($key)

    {

        return array_key_exists(strtr(strtolower($key), '_', '-'), $this->headers);

    }

    /**

     * Returns true if the given HTTP header contains the given value.

     *

     * @param string $key   The HTTP header name

     * @param string $value The HTTP value

     *

     * @return Boolean true if the value is contained in the header, false otherwise

     *

     * @api

     */

    public function contains($key, $value)

    {

        return in_array($value, $this->get($key, null, false));

    }

    /**

     * Removes a header.

     *

     * @param string $key The HTTP header name

     *

     * @api

     */

    public function remove($key)

    {

        $key = strtr(strtolower($key), '_', '-');

        unset($this->headers[$key]);

        if ('cache-control' === $key) {

            $this->cacheControl = array();

        }

    }

    /**

     * Returns the HTTP header value converted to a date.

     *

     * @param string    $key     The parameter key

     * @param \DateTime $default The default value

     *

     * @return \DateTime The filtered value

     *

     * @api

     */

    public function getDate($key, \DateTime $default = null)

    {

        if (null === $value = $this->get($key)) {

            return $default;

        }

        if (false === $date = \DateTime::createFromFormat(DATE_RFC2822, $value)) {

            throw new \RuntimeException(sprintf('The %s HTTP header is not parseable (%s).', $key, $value));

        }

        return $date;

    }

    public function addCacheControlDirective($key, $value = true)

    {

        $this->cacheControl[$key] = $value;

        $this->set('Cache-Control', $this->getCacheControlHeader());

    }

    public function hasCacheControlDirective($key)

    {

        return array_key_exists($key, $this->cacheControl);

    }

    public function getCacheControlDirective($key)

    {

        return array_key_exists($key, $this->cacheControl) ? $this->cacheControl[$key] : null;

    }

    public function removeCacheControlDirective($key)

    {

        unset($this->cacheControl[$key]);

        $this->set('Cache-Control', $this->getCacheControlHeader());

    }

    protected function getCacheControlHeader()

    {

        $parts = array();

        ksort($this->cacheControl);

        foreach ($this->cacheControl as $key => $value) {

            if (true === $value) {

                $parts[] = $key;

            } else {

                if (preg_match('#[^a-zA-Z0-9._-]#', $value)) {

                    $value = '"'.$value.'"';

                }

                $parts[] = "$key=$value";

            }

        }

        return implode(', ', $parts);

    }

    /**

     * Parses a Cache-Control HTTP header.

     *

     * @param string $header The value of the Cache-Control HTTP header

     *

     * @return array An array representing the attribute values

     */

    protected function parseCacheControl($header)

    {

        $cacheControl = array();

        preg_match_all('#([a-zA-Z][a-zA-Z_-]*)\s*(?:=(?:"([^"]*)"|([^ \t",;]*)))?#', $header, $matches, PREG_SET_ORDER);

        foreach ($matches as $match) {

            $cacheControl[strtolower($match[1])] = isset($match[2]) && $match[2] ? $match[2] : (isset($match[3]) ? $match[3] : true);

        }

        return $cacheControl;

    }

}