<?php
/*
  Plugin Name: Image Source Control
  Version: 1.1.3
  Plugin URI: http://webgilde.com/en/image-source-control/
  Description: The Image Source Control saves the source of an image, lists them and warns if it is missing.
  Author: Thomas Maier
  Author URI: http://www.webgilde.com/
  License: GPL v3

  Image Source Control Plugin for WordPress
  Copyright (C) 2012, Thomas Maier - thomas.maier@webgilde.com

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Followed the following tutorials
 * http://wpengineer.com/2076/add-custom-field-attachment-in-wordpress/
 * http://bueltge.de/eigene-felder-dateiverwaltung-wordpress/1226/ (same like above, but in German)
 *
 *
 */

//avoid direct calls to this file
if (!function_exists('add_action')) {
    header('Status: 403 Forbidden');
    header('HTTP/1.1 403 Forbidden');
    exit();
}

define('ISCVERSION', '1.1.3');
define('ISCNAME', 'Image Source Control');
define('ISCTEXTDOMAIN', 'isc');
define('ISCDIR', basename(dirname(__FILE__)));
define('ISCPATH', plugin_dir_path(__FILE__));

load_plugin_textdomain(ISCTEXTDOMAIN, false, dirname(plugin_basename(__FILE__)) . '/languages/');

if (!class_exists('ISC_CLASS')) {

    class ISC_CLASS
    {
        /**
         * define default meta fields
         */
        protected $_fields = array(
            'image_source' => array(
                'id' => 'isc_image_source',
                'default' => '',
            ),
            'image_source_own' => array(
                'id' => 'isc_image_source_own',
                'default' => '',
            )
        );

        /**
         * allowed image file types/extensions
         * @since 1.1
         */
        protected $_allowedExtensions = array(
            'jpg', 'png', 'gif'
        );

        /**
         * Setup registers filterts and actions.
         */
        public function __construct()
        {
            // insert all function for the frontend here
            
            add_shortcode('isc_list', array($this, 'list_post_attachments_with_sources_shortcode'));
            add_shortcode('isc_list_all', array($this, 'list_all_post_attachments_sources_shortcode'));
            
            // insert all backend functions below this check
            if (!current_user_can('upload_files')) {
                return false;
            }

            add_filter('attachment_fields_to_edit', array($this, 'add_isc_fields'), 10, 2);
            add_filter('attachment_fields_to_save', array($this, 'isc_fields_save'), 10, 2);

            add_action('admin_menu', array($this, 'create_menu'));

            add_action('admin_enqueue_scripts', array($this, 'add_admin_scripts'));

            // ajax function; 'add_meta_fields' is the action defined in isc.js as the action to be called via ajax
            add_action('wp_ajax_add_meta_fields', array($this, 'add_meta_values_to_attachments'));

            // save image information in meta field when a post is saved
            add_action('save_post', array($this, 'save_image_information_on_post_save'));
        }

        /**
         * create the menu pages for isc
         */
        public function create_menu()
        {
            // this page should be accessable by editors and higher
            $menuhook = add_submenu_page('upload.php', 'missing image sources by Image Source Control Plugin', __('Missing Sources', ISCTEXTDOMAIN), 'edit_others_posts', ISCPATH . '/templates/missing_sources.php', '');
        }

        /**
         * add scripts to admin pages
         * @since 1.0
         * @update 1.1.1
         */
        public function add_admin_scripts($hook)
        {
            if ($hook != 'image-source-control-isc/templates/missing_sources.php') {
                return;
            }
            wp_enqueue_script('isc_script', plugins_url('/js/isc.js', __FILE__), false, ISCVERSION);
            // this is to define ajaxurl to be able to use this in its own js script
            // wp_localize_script( 'isc_script', 'IscAjax', array( 'ajaxurl' => admin_url( 'admin-ajax.php' ) ) );
        }

        /**
         * add custom field to attachment
         * @param arr $form_fields
         * @param object $post
         * @return arr
         * @since 1.0
         * @updated 1.1
         */
        public function add_isc_fields($form_fields, $post)
        {
            // add input field for source
            $form_fields['isc_image_source']['label'] = __('Image Source', ISCTEXTDOMAIN);
            $form_fields['isc_image_source']['value'] = get_post_meta($post->ID, 'isc_image_source', true);
            $form_fields['isc_image_source']['helps'] = __('Include the image source here.', ISCTEXTDOMAIN);

            // add checkbox to mark as your own image
            $form_fields['isc_image_source_own']['input'] = 'html';
            $form_fields['isc_image_source_own']['label'] = '';
            $form_fields['isc_image_source_own']['helps'] =
                __('Check this box if this is your own image and doesn\'t need a source.', ISCTEXTDOMAIN);
            $form_fields['isc_image_source_own']['html'] =
                "<input type='checkbox' value='1' name='attachments[{$post->ID}][isc_image_source_own]' id='attachments[{$post->ID}][isc_image_source_own]' "
                . checked(get_post_meta($post->ID, 'isc_image_source_own', true), 1, false )
                . " style=\"width:14px\"/> "
                . __('This is my image', ISCTEXTDOMAIN);

            return $form_fields;
        }

        /**
         * save image source to post_meta
         * @param object $post
         * @param $attachment
         * @return object $post
         */
        public function isc_fields_save($post, $attachment)
        {
            if (isset($attachment['isc_image_source'])) {
                update_post_meta($post['ID'], 'isc_image_source', $attachment['isc_image_source']);
            }

            update_post_meta($post['ID'], 'isc_image_source_own', $attachment['isc_image_source_own']);
            return $post;
        }

        /**
         * create image sources list for all images of this post
         * @since 1.0
         * @update 1.1
         * @param int $post_id id of the current post/page
         * @return echo output
         */
        public function list_post_attachments_with_sources($post_id = 0)
        {
            global $post;

            if (empty($post_id)) {
                if (!empty($post->ID)) {
                    $post_id = $post->ID;
                } else {
                    return;
                }
            }

            $attachments = get_post_meta($post_id, 'isc_post_images', true);
            // if attachments is an empty string, search for images in it
            if ($attachments == '') {
                $this->save_image_information_on_load ($post_id, $_content);
                $attachments = get_post_meta($post_id, 'isc_post_images', true);
            }

            $return = '';
            if (!empty($attachments)) {
                $atts = array();
                foreach ($attachments as $attachment_id => $attachment_array) {
                    $atts[$attachment_id]['title'] = get_the_title($attachment_id);
                    $own = get_post_meta($attachment_id, 'isc_image_source_own', true);
                    $source = get_post_meta($attachment_id, 'isc_image_source', true);

                    if ( $own == '' && $source == '' ) {
                        // remove if no information set
                        unset($atts[$attachment_id]);
                        continue;
                    } elseif ($own != '') {
                        $atts[$attachment_id ]['source'] = __('by the author', ISCTEXTDOMAIN);
                    } else {
                        $atts[$attachment_id ]['source'] = $source;
                    }
                }

                $return = $this->_renderAttachments($atts);
            }

            return $return;
        }

        /**
         * @param array $attachments
         */
        protected function _renderAttachments($attachments)
        {
            // don't display anything, if no image sources displayed
            if ($attachments == array()) {
                return ;
            }
            ob_start();
            // TODO this is almost trivial to replace with sprintf
            ?>
            <p class="isc_image_list_title"><?php _e('image sources:', ISCTEXTDOMAIN); ?></p>
            <ul class="isc_image_list"><?php

            foreach ($attachments as $atts_id => $atts_array) :
                if (empty($atts_array['source'])) {
                    continue;
                }
                // TODO localise
                ?><li><?php echo $atts_array['title'] . ': ' . $atts_array['source']; ?></li><?php
            endforeach;
            ?></ul><?php
            return ob_get_clean();
        }

        /**
         * shortcode function to list all image sources
         * @param arr $atts
         */
        public function list_post_attachments_with_sources_shortcode($atts = array())
        {
            global $post;
            extract(shortcode_atts(array('id' => 0), $atts));

            // if $id not set, use the current ID from the post
            if (empty($id)) {
                $id = $post->ID;
            }

            if (empty($id)) {
                return;
            }
            return $this->list_post_attachments_with_sources($id);
        }

        /**
         * get all attachments without sources
         * the downside of this function: is there is not even an empty metakey field, nothing is going to be retrieved
         * @todo fix this in WP 3.5 with compare => 'NOT EXISTS'
         */
        public function get_attachments_without_sources()
        {
            $args = array(
                'post_type' => 'attachment',
                'numberposts' => -1,
                'post_status' => null,
                'post_parent' => null,
                'meta_query' => array(
                    // image source is empty
                    array(
                        'key' => 'isc_image_source',
                        'value' => '',
                        'compare' => '=',
                    ),
                    // and image source is not set
                    array(
                        'key' => 'isc_image_source_own',
                        'value' => '1',
                        'compare' => '!=',
                    ),
                )
            );

            $attachments = get_posts($args);
            if (!empty($attachments)) {
                return $attachments;
            }
        }

        /**
         * add meta values to all attachments
         * @todo probably need to fix this when more fields are added along the way
         * @todo use compare => 'NOT EXISTS' when WP 3.5 is up to retrieve only values where it is not set
         * @todo this currently updates all empty fields; empty in this context is empty string, 0, false or not existing; add check if meta field already existed before
         */
        public function add_meta_values_to_attachments()
        {
            // retrieve all attachments
            $args = array(
                'post_type' => 'attachment',
                'numberposts' => -1,
                'post_status' => null,
                'post_parent' => null,
            );

            $attachments = get_posts($args);
            if (empty($attachments)) {
                return;
            }

            $count = 0;
            foreach ($attachments as $_attachment) {
                $set = false;
                setup_postdata($_attachment);
                foreach ($this->_fields as $_field) {
                    $meta = get_post_meta($_attachment->ID, $_field['id'], true);
                    if (empty($meta)) {
                        update_post_meta($_attachment->ID, $_field['id'], $_field['default']);
                        $set = true;
                    }
                }
                if ($set) {
                    $count++;
                }
            }
            echo sprintf(__('Added meta fields to %d images.', ISCTEXTDOMAIN), $count) .
                    '<br/><input type="button" value="' . __('reload page', ISCTEXTDOMAIN ) . '" onClick="window.location.reload()">';
            die();
        }

        /**
         * show the loading image from wp-admin/images/loading.gif
         * @param bool $display should this be displayed directly or hidden? via inline css
         */
        public function show_loading_image($display = true)
        {
            $img_path = admin_url("/images/loading.gif");
            $file_path = ABSPATH . "wp-admin/images/loading.gif";
            if (file_exists($file_path)) {
                echo '<span id="isc_loading_img" style="display: none;"><img src="' . $img_path . '" width="16" height="16" alt="loading"/></span>';
            }
        }

        /**
         * this is an entry function to save image information to a post when it is saved
         * @since 1.1
         * @param type $post_id
         */
        public function save_image_information_on_post_save($post_id)
        {
            // return, if save_post is called more than one time
            if (did_action('save_post') !== 1) {
                return;
            }

            if (isset($_POST['post_type']) && 'attachment' == $_POST['post_type']) {
                return;
            }

            // check if this is a revision and if so, use parent post id
            if ($_id = wp_is_post_revision($post_id)) {
                $post_id = $_id;
            }

            $_content = stripslashes($_REQUEST['content']);
            $this->save_image_information($post_id, $_content);
        }

        /**
         * save image information for a post when it is viewed and the image source list is enabled
         * (this is in case the plugin is new and the current post wasn't saved before)
         *
         * @since 1.1
         */
        public function save_image_information_on_load()
        {
            global $post;
            if (empty($post->ID)) {
                return;
            }

            $post_id = $post->ID;
            $_content = $post->post_content;

            $this->save_image_information($post_id, $_content);
        }

        /**
         * retrieve images added to a post or page and save all information as a meta value
         * @since 1.1
         * @todo check for more post types that maybe should not be parsed here
         */
        public function save_image_information($post_id, $_content)
        {
            $_image_urls = $this->_filter_src_attributes($_content);
            $_imgs = array();

            foreach ($_image_urls as $_image_url) {
                // get ID of images by url
                $img_id = $this->get_image_by_url($_image_url);
                $_imgs[$img_id] = array(
                    'src' => $_image_url
                );
            }

            // add thumbnail information
            $thumb_id = get_post_thumbnail_id($post_id);
            $_imgs[$thumb_id] = array(
                'src' => wp_get_attachment_url($thumb_id),
                'thumbnail' => true
            );

            // TODO _imgs is an non-empty array by now
            if (empty($_imgs)) {
                $_imgs = false;
            }
            update_post_meta($post_id, 'isc_post_images', $_imgs);
        }

        /**
         * filter image src attribute from text
         * @since 1.1
         * @updated 1.1.3
         * @return array with image src uris
         */
        public function _filter_src_attributes($content = '')
        {
            $srcs = array();
            if (empty($content))
                return $srcs;

            // parse HTML with DOM
            $dom = new DOMDocument;
            $dom->loadHTML($content);
            foreach ($dom->getElementsByTagName('img') as $node) {
                $srcs[] = $node->getAttribute('src');
            }

            return $srcs;
        }

        /**
         * get image by url accessing the database directly
         * @since 1.1
         * @updated 1.1.3
         * @param string $url url of the image
         * @return id of the image
         */
        public function get_image_by_url($url = '')
        {
            if (empty($url)) {
                return 0;
            }
            $types = implode('|', $this->_allowedExtensions);
            // check for the format 'image-title-(e12452112-)300x200.jpg' and remove the image size and edit mark from it
            $newurl = preg_replace("/(-e\d+){0,1}-(\d+)x(\d+)\.({$types})$/i", '.${4}', $url);
            global $wpdb;
            $query = $wpdb->prepare("SELECT ID FROM {$wpdb->posts} WHERE guid = %s", $newurl);
            $id = $wpdb->get_var($query);
            return $id;
        }
        
        /**
         * create shortcode to list all image sources in the frontend
         * @param array $atts
         * @since 1.1.3
         * @todo link to the post
         */
        public function list_all_post_attachments_sources_shortcode($atts = array())
        {
        
            /**
             * @todo why not translate here with the code below?
             */
            extract(shortcode_atts(array(
                'per_page' => 99999,
                'before_links' => '',
                'after_links' => '',
                'prev_text' => '&#171; Previous',
                'next_text' => 'Next &#187;'
                ),
                $atts));
            
            /**
             * @todo why not include this into the array above?
             */
            if ('&#171; Previous' == $prev_text) 
                $prev_text = __('&#171; Previous', ISCTEXTDOMAIN);
            if ('Next &#187;' == $next_text) 
                $next_text = __('Next &#187;', ISCTEXTDOMAIN);
        
            // retrieve all attachments
            $args = array(
                'post_type' => 'attachment',
                'numberposts' => -1,
                'post_status' => null,
                'post_parent' => null,
                /** @todo maybe add offset to not retrieve the first results when not on first page */
                /** @todo maybe add limit to not retrieve more results than on the current page */
            );

            $attachments = get_posts($args);
            if (empty($attachments)) {
                return;
            }
            
            $connected_atts = array();
            
            //Keeps only those ones who have parent
            
            foreach ($attachments as $_attachment) {
                if ($_attachment->post_parent) {
                    $connected_atts[$_attachment->ID]['source'] = get_post_meta($_attachment->ID, 'isc_image_source', true);
                    $connected_atts[$_attachment->ID]['own'] = get_post_meta($_attachment->ID, 'isc_image_source_own', true);
                    $connected_atts[$_attachment->ID]['title'] = $_attachment->post_title;
                    $connected_atts[$_attachment->ID]['parent'] = get_the_title($_attachment->post_parent);
                }
            }
            
            $total = count($connected_atts);
            
            if (0 == $total) 
                return;
            
            $page = isset($_GET['isc-page']) ? intval($_GET['isc-page']) : 1;
            $down_limit = 1; // First page
            
            $up_limit = 1;
            
            if ($per_page < $total) {
                $rem = $total % $per_page; // The Remainder of $total/$per_page
                $up_limit = ($total - $rem) / $per_page;
                if (0 < $rem) {
                    $up_limit++; //If rem is positive, add the last page that contains less than $per_page attachment;
                }
            }
                
            ob_start();
            if ( 2 > $up_limit ) {
                $this->display_all_attachment_list($connected_atts);
            } else {
                $starting_atts = $per_page * ($page - 1); // for page 2 and 3 $per_page start display on $connected_atts[3*(2-1) = 3]
                $paged_atts = array_slice($connected_atts, $starting_atts, $per_page, true);
                $this->display_all_attachment_list($paged_atts);
                $this->pagination_links($up_limit, $before_links, $after_links, $prev_text, $next_text);
            } 
            
            $output = ob_get_clean();
            return $output;
        }
        
        
        /**
        * performs rendering of all attachments list
         * @since 1.1.3
        */
        public function display_all_attachment_list($atts)
        {
            if (! is_array($atts) || $atts == array())
                return;
            ?>
            <table>
                <thead>
                    <?php /* <th><?php _e("Attachment's ID", ISCTEXTDOMAIN); ?></th>*/ ?>
                    <th><?php _e('Title', ISCTEXTDOMAIN); ?></th>
                    <th><?php _e('Attached to', ISCTEXTDOMAIN); ?></th>
                    <th><?php _e('Source', ISCTEXTDOMAIN); ?></th>
                </thead>
                <tbody>
                <?php foreach ($atts as $id => $data) : ?>
                    <?php
                        /** @todo ment for later: this text was used above already; find a place to but it so it is defined only once and used where needed */    
                        $source = __('Not available', ISCTEXTDOMAIN);
                        if (1 == $data['own']) {
                            /** @todo ment for later: this text was used above already; find a place to but it so it is defined only once and used where needed */
                            $source = __('By the author', ISCTEXTDOMAIN);
                        } elseif (!empty($data['source'])) {
                            $source = $data['source'];
                        }
                    ?>
                    <tr>
                    <?php /* <td><?php echo $id ?></td>*/ ?>
                    <td><?php echo $data['title']; ?></td><td><?php echo $data['parent']; ?></td><td><?php echo esc_attr($source); ?></td>
                    </tr>
                <?php endforeach; ?>
                </tbody>
            </table>
            <?php
        }
        
        /**
        * Render pagination links, use $before_links and after_links to wrap pagination links inside an additional block
         * @param int $max_page total page count
         * @param string $before_links optional html to display before pagination links
         * @param string $after_links optional html to display after pagination links
         * @param string $prev_text text for the previous page link
         * @param string $next_text text for the next page link
         * @since 1.1.3
         * 
        */
        public function pagination_links($max_page, $before_links, $after_links, $prev_text, $next_text)
        {
            if ((! isset($max_page)) || (! isset($before_links)) || (! isset($after_links)) || (! isset($prev_text)) || (! isset($next_text)))
                return;
            if (! empty($before_links)) 
                echo $before_links;
                ?>
                <div class="isc-paginated-links">
                <?php
                $page = isset($_GET['isc-page']) ? intval($_GET['isc-page']) : 1;
                if ($max_page < $page) {                
                    $page = $max_page;
                }
                if ($page < 1) {
                    $page = 1;
                }
                $min_page = 1;
                $backward_distance = $page - $min_page;
                $forward_distance = $max_page - $page;
                
                $original_page_link = get_page_link();
                
                /** 
                * Remove the query_string of the page_link (?page_id=xyz for the standard permalink structure), 
                * which is already captured in $_SERVER['QUERY_STRING'].
                * @todo replace regex with other value (does WP store the url path without attributes somewhere?
                */                
                $page_link = preg_replace('#\?.*$#', '', $original_page_link);
                
                /**
                * Unset the actual "$_GET['isc-page']" variable (if is set). Pagination variable will be appended to the new query string with a different value for each 
                * pagination link.
                */
                
                if (isset($_GET['isc-page'])) {
                    unset($_GET['isc-page']);
                }
                
                $query_string = http_build_query($_GET);
				
                $isc_query_tag = '';
                if (empty($query_string)) {
                    $isc_query_tag = '?isc-page=';
                } else {
                    $query_string = '?' . $query_string;
                    $isc_query_tag = '&isc-page=';
                }
                
                if ($min_page != $page) {
                    ?>
                    <a href="<?php echo $page_link . $query_string . $isc_query_tag . ($page-1); ?>" class="prev page-numbers"><?php echo $prev_text; ?></a>
                    <?php
                }
                
                if (5 < $max_page) {
                    
                    if (3 < $backward_distance) {
                        ?>
                        <a href="<?php echo $page_link . $query_string . $isc_query_tag; ?>1" class="page-numbers">1</a>
                        <span class="page-numbers dots">...</span>
                        <a href="<?php echo $page_link . $query_string . $isc_query_tag . ($page-2);?>" class="page-numbers"><?php echo $page-2; ?></a>
                        <a href="<?php echo $page_link . $query_string . $isc_query_tag . ($page-1);?>" class="page-numbers"><?php echo $page-1; ?></a>
                        <span class="page-numbers current"><?php echo $page; ?></span>
                        <?php
                    } else {
                        for ($i = 1; $i <= $page; $i++) {
                            if ($i == $page) { 
                            ?>
                                <span class="page-numbers current"><?php echo $i; ?></span>
                            <?php
                            } else { 
                            ?>
                                <a href="<?php echo $page_link . $query_string . $isc_query_tag . $i;?>" class="page-numbers"><?php echo $i; ?></a>
                            <?php
                            }
                        }
                    }
                    
                    if (3 < $forward_distance) {
                    ?>
                        <a href="<?php echo $page_link . $query_string . $isc_query_tag . ($page+1);?>" class="page-numbers"><?php echo $page+1; ?></a>
                        <a href="<?php echo $page_link . $query_string . $isc_query_tag . ($page+2);?>" class="page-numbers"><?php echo $page+2; ?></a>
                        <span class="page-numbers dots">...</span>
                        <a href="<?php echo $page_link . $query_string . $isc_query_tag . $max_page;?>" class="page-numbers"><?php echo $max_page; ?></a>
                    <?php
                    } else {
                        for ($i = $page+1; $i <= $max_page; $i++) {
                            ?>
                            <a href="<?php echo $page_link . $query_string . $isc_query_tag . $i;?>" class="page-numbers"><?php echo $i; ?></a>
                            <?php
                        }
                    }                    
                } else {
                    for ($i = 1; $i <= $max_page; $i++) {
                        if ($i == $page) { 
                        ?>
                            <span class="page-numbers current"><?php echo $i; ?></span>
                        <?php
                        } else { 
                        ?>
                            <a href="<?php echo $page_link . $query_string . $isc_query_tag . $i;?>" class="page-numbers"><?php echo $i; ?></a>
                        <?php
                        }
                    }
                }                
                if ($page != $max_page) {
                    ?>
                    <a href="<?php echo $page_link . $query_string . $isc_query_tag . ($page+1);?>" class="next page-numbers"><?php echo $next_text; ?></a>
                    <?php
                }
                ?>
                </div>
                <?php
                echo $after_links;
        }
        
    }// end of class

    /**
     *
     */
    function add_image_source_fields_start() {
        $isc = new ISC_CLASS();
    }

    add_action('plugins_loaded', 'add_image_source_fields_start');

    /**
     * the next functions are just to have an easier access from outside the class
     */
    function isc_list($post_id = 0) {
        $isc = new ISC_CLASS();
        echo $isc->list_post_attachments_with_sources($post_id);
    }
}