<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_View

 * @subpackage Helper

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

/** Zend_View_Helper_HtmlElement */

require_once 'Zend/View/Helper/HtmlElement.php';

/**

 * Helper for generating urls and/or image tags for use with tinysrc.net

 *

 * tinysrc.net provides an API for generating scaled, browser device-specific 

 * images. In essence, you pass the API the URL to an image on your own server,

 * and tinysrc.net then provides the appropriate image based on the device that

 * accesses it.

 *

 * Additionally, tinysrc.net allows you to specify additional configuration via 

 * the API:

 *

 * - image size. You may define this as:

 *   - explicit size

 *   - subtractive size (size of screen minus specified number of pixels)

 *   - percentage size (percentage of screen size))

 * - image format. This will convert the image to the given format; allowed 

 *   values are "png" or "jpeg". By default, gif images are converted to png.

 *

 * This helper allows you to specify all configuration options, as well as:

 *

 * - whether or not to generate the full image tag (or just the URL)

 * - base url to images (which should include the protocol, server, and 

 *   optionally port and base path)

 *

 * @see        http://tinysrc.net/

 * @package    Zend_View

 * @subpackage Helper

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_View_Helper_TinySrc extends Zend_View_Helper_HtmlElement

{

    const TINYSRC_BASE = 'http://i.tinysrc.mobi';

    /**

     * @var string Base URL for images

     */

    protected $_baseUrl;

    /**

     * @var bool Whether or not to create an image tag

     */

    protected $_createTagFlag = true;

    /**

     * @var string Default width and height

     */

    protected $_dimensions = '';

    /**

     * Default options

     *

     * Used when determining what options were passed, and needing to merge 

     * them with default options.

     * 

     * @var array

     */

    protected $_defaultOptions = array(

        'base_url'   => null,

        'format'     => null,

        'width'      => false,

        'height'     => false,

        'create_tag' => true,

    );

    /**

     * @var string Default image format to use

     */

    protected $_format = '';

    /**

     * Generate a link or image tag pointing to tinysrc.net

     * 

     * @param mixed $image 

     * @param array $options 

     * @return void

     */

    public function tinySrc($image = null, array $options = array())

    {

        if (null === $image) {

            return $this;

        }

        $defaultOptions = $this->_defaultOptions;

        $defaultOptions['create_tag'] = $this->createTag();

        $options = array_merge($defaultOptions, $options);

        $url = '/' . $this->_mergeBaseUrl($options) . ltrim($image, '/');

        $src = self::TINYSRC_BASE 

             . $this->_mergeFormat($options) 

             . $this->_mergeDimensions($options)

             . $url;

        if (!$options['create_tag']) {

            return $src;

        }

        foreach (array_keys($this->_defaultOptions) as $key) {

            switch ($key) {

                case 'width':

                case 'height':

                    if (!is_int($options[$key]) || !is_numeric($options[$key]) || $options[$key] < 0) {

                        unset($options[$key]);

                    }

                    break;

                default:

                    unset($options[$key]);

                    break;

            }

        }

        $options['src'] = $src;

        $tag = '<img' . $this->_htmlAttribs($options) . $this->getClosingBracket();

        return $tag;

    }

    /**

     * Set base URL for images

     * 

     * @param  string $url 

     * @return Zend_View_Helper_TinySrc

     */

    public function setBaseUrl($url)

    {

        $this->_baseUrl = rtrim($url, '/') . '/';

        return $this;

    }

    /**

     * Get base URL for images

     *

     * If none already set, uses the ServerUrl and BaseUrl view helpers to

     * determine the base URL to images.

     * 

     * @return string

     */

    public function getBaseUrl()

    {

        if (null === $this->_baseUrl) {

            $this->setBaseUrl($this->view->serverUrl($this->view->baseUrl()));

        }

        return $this->_baseUrl;

    }

    /**

     * Set default image format

     *

     * If set, this will set the default format to use on all images.

     * 

     * @param  null|string $format 

     * @return Zend_View_Helper_TinySrc

     * @throws Zend_View_Exception

     */

    public function setDefaultFormat($format = null)

    {

        if (null === $format) {

            $this->_format = '';

            return $this;

        }

        $format = strtolower($format);

        if (!in_array($format, array('png', 'jpeg'))) {

            require_once 'Zend/View/Exception.php';

            throw new Zend_View_Exception('Invalid format; must be one of "jpeg" or "png"');

        }

        $this->_format = "/$format";

        return $this;

    }

    /**

     * Set default dimensions

     *

     * If null is specified for width, default dimensions will be cleared. If 

     * only width is specified, only width will be used. If either dimension

     * fails validation, an exception is raised.

     * 

     * @param  null|int|string $width 

     * @param  null|int|string $height 

     * @return Zend_View_Helper_TinySrc

     * @throws Zend_View_Exception

     */

    public function setDefaultDimensions($width = null, $height = null)

    {

        if (null === $width) {

            $this->_dimensions = '';

            return $this;

        }

        if (!$this->_validateDimension($width)) {

            require_once 'Zend/View/Exception.php';

            throw new Zend_View_Exception('Invalid dimension; must be an integer, optionally preceded by "-" or "x"');

        }

        $this->_dimensions = "/$width";

        if (null === $height) {

            return $this;

        }

        if (!$this->_validateDimension($height)) {

            require_once 'Zend/View/Exception.php';

            throw new Zend_View_Exception('Invalid dimension; must be an integer, optionally preceded by "-" or "x"');

        }

        $this->_dimensions .= "/$height";

        return $this;

    }

    /**

     * Set state of "create tag" flag

     * 

     * @param  bool $flag 

     * @return Zend_View_Helper_TinySrc

     */

    public function setCreateTag($flag)

    {

        $this->_createTagFlag = (bool) $flag;

        return $this;

    }

    /**

     * Should the helper create an image tag?

     * 

     * @return bool

     */

    public function createTag()

    {

        return $this->_createTagFlag;

    }

    /**

     * Validate a dimension

     *

     * Dimensions may be integers, optionally preceded by '-' or 'x'.

     * 

     * @param  string $dim 

     * @return bool

     */

    protected function _validateDimension($dim)

    {

        if (!is_scalar($dim) || is_bool($dim)) {

            return false;

        }

        return preg_match('/^(-|x)?\d+$/', (string) $dim);

    }

    /**

     * Determine whether to use default base URL, or base URL from options

     * 

     * @param  array $options 

     * @return string

     */

    protected function _mergeBaseUrl(array $options)

    {

        if (null === $options['base_url']) {

            return $this->getBaseUrl();

        }

        return rtrim($options['base_url'], '/') . '/';

    }

    /**

     * Determine whether to use default format or format provided in options.

     * 

     * @param  array $options 

     * @return string

     */

    protected function _mergeFormat(array $options) 

    {

        if (in_array($options['format'], array('png', 'jpeg'))) {

            return '/' . $options['format'];

        }

        return $this->_format;

    }

    /**

     * Determine whether to use default dimensions, or those passed in options.

     * 

     * @param  array $options 

     * @return string

     */

    protected function _mergeDimensions(array $options)

    {

        if (!$this->_validateDimension($options['width'])) {

            return $this->_dimensions;

        }

        $dimensions = '/' . $options['width'];

        if (!$this->_validateDimension($options['height'])) {

            return $dimensions;

        }

        $dimensions .= '/' . $options['height'];

        return $dimensions;

    }

}