Modified CoAuthor Plus to filter as needed on post queries

co-authors-plus.php

<?php
/*
Plugin Name: Co-Authors Plus
Plugin URI: http://wordpress.org/extend/plugins/co-authors-plus/
Description: Allows multiple authors to be assigned to a post. This plugin is an extended version of the Co-Authors plugin developed by Weston Ruter.
Version: 2.6.1
Author: Mohammad Jangda, Daniel Bachhuber
Copyright: 2008-2011 Shared and distributed between Mohammad Jangda, Daniel Bachhuber, Weston Ruter

GNU General Public License, Free Software Foundation <http://creativecommons.org/licenses/GPL/2.0/>
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

define( 'COAUTHORS_PLUS_VERSION', '2.6.1' );

if( ! defined( 'COAUTHORS_PLUS_DEBUG' ) )
	define( 'COAUTHORS_PLUS_DEBUG', false );

if( ! defined( 'COAUTHORS_DEFAULT_BEFORE' ) )
	define( 'COAUTHORS_DEFAULT_BEFORE', '' );

if( ! defined( 'COAUTHORS_DEFAULT_BETWEEN' ) )
	define( 'COAUTHORS_DEFAULT_BETWEEN', ', ' );

if( ! defined( 'COAUTHORS_DEFAULT_BETWEEN_LAST' ) )
	define( 'COAUTHORS_DEFAULT_BETWEEN_LAST', __( ' and ', 'co-authors-plus' ) );

if( ! defined( 'COAUTHORS_DEFAULT_AFTER' ) )
	define( 'COAUTHORS_DEFAULT_AFTER', '' );

define( 'COAUTHORS_PLUS_PATH', dirname( __FILE__ ) );
define( 'COAUTHORS_PLUS_URL', plugin_dir_url( __FILE__ ) );

require_once( dirname( __FILE__ ) . '/template-tags.php' );

class coauthors_plus {
	
	// Name for the taxonomy we're using to store coauthors
	var $coauthor_taxonomy = 'author';
	
	var $coreauthors_meta_box_name = 'authordiv';
	var $coauthors_meta_box_name = 'coauthorsdiv';
	
	var $gravatar_size = 25;
	
	var $_pages_whitelist = array( 'post.php', 'post-new.php' );
		
	/**
	 * __construct()
	 */
	function __construct() {

		$plugin_dir = dirname( plugin_basename( __FILE__ ) ) . '/languages/';
		load_plugin_textdomain( 'co-authors-plus', null, $plugin_dir );

		add_action('init', array($this, 'register_author_tax'), 0 );
		// Load admin_init function
		add_action( 'admin_init', array( $this,'admin_init' ) );
		
		// Modify SQL queries to include coauthors
		add_filter( 'posts_where', array( $this, 'posts_where_filter' ), 5,2 );
		add_filter( 'posts_join', array( $this, 'posts_join_filter' ), 5, 2 );
		add_filter( 'posts_groupby', array( $this, 'posts_groupby_filter' ), 5, 2);
		
		// Action to set users when a post is saved
		add_action( 'save_post', array( $this, 'coauthors_update_post' ), 10, 2 );
		// Filter to set the post_author field when wp_insert_post is called
		add_filter( 'wp_insert_post_data', array( $this, 'coauthors_set_post_author_field' ) );
		
		// Action to reassign posts when a user is deleted
		add_action( 'delete_user',  array( $this, 'delete_user_action' ) );
		
		add_filter( 'get_usernumposts', array( $this, 'filter_count_user_posts' ), 10, 2 );
		
		// Action to set up author auto-suggest
		add_action( 'wp_ajax_coauthors_ajax_suggest', array( $this, 'ajax_suggest' ) );
		
		// Filter to allow coauthors to edit posts
		add_filter( 'user_has_cap', array( $this, 'add_coauthor_cap' ), 10, 3 );
		
		add_filter( 'comment_notification_headers', array( $this, 'notify_coauthors' ), 10, 3 );
		
		// Handle the custom author meta box
		add_action( 'add_meta_boxes', array( $this, 'add_coauthors_box' ) );
		add_action( 'add_meta_boxes', array( $this, 'remove_authors_box' ) );
		
		// Removes the author dropdown from the post quick edit 
		add_action( 'load-edit.php', array( $this, 'remove_quick_edit_authors_box' ) );

		// Restricts WordPress from blowing away term order on bulk edit
		add_filter( 'wp_get_object_terms', array( &$this, 'filter_wp_get_object_terms' ), 10, 4 );
		
		// Fix for author info not properly displaying on author pages
		add_action( 'the_post', array( $this, 'fix_author_page' ) );

	}

	function coauthors_plus() {
		$this->__construct();
	}
	
	function register_author_tax(){
		// Register new taxonomy so that we can store all our authors
		register_taxonomy( $this->coauthor_taxonomy, 'post', array(
			'hierarchical' => false, 
			'update_count_callback' => array( &$this, '_update_users_posts_count' ), 
			'label' => false, 
			'query_var' => false, 
			'rewrite' => false, 
			'sort' => true, 
			'show_ui' => false 
		) );
	}
	
	/**
	 * Initialize the plugin for the admin 
	 */
	function admin_init() {
		global $pagenow;

		// Hook into load to initialize custom columns
		if( $this->is_valid_page() ) {
			add_action( 'load-' . $pagenow, array( $this, 'admin_load_page' ) );
		}

		// Hooks to add additional coauthors to author column to Edit page
		add_filter( 'manage_posts_columns', array( $this, '_filter_manage_posts_columns' ) );
		add_filter( 'manage_pages_columns', array( $this, '_filter_manage_posts_columns' ) );
		add_action( 'manage_posts_custom_column', array( $this, '_filter_manage_posts_custom_column' ) );
		add_action( 'manage_pages_custom_column', array( $this, '_filter_manage_posts_custom_column' ) );

		// Hooks to modify the published post number count on the Users WP List Table
		add_filter( 'manage_users_columns', array( $this, '_filter_manage_users_columns' ) );
		add_filter( 'manage_users_custom_column', array( &$this, '_filter_manage_users_custom_column' ), 10, 3 );
		
	}
	
	function admin_load_page() {
		
		// Add the main JS script and CSS file
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_scripts' ) );
		
		// Add necessary JS variables
		add_action( 'admin_print_scripts', array( $this, 'js_vars' ) );

	}
	
	/** 
	 * Checks to see if the post_type supports authors
	 */
	function authors_supported( $post_type ) {
		
		if( ! function_exists( 'post_type_supports' ) && in_array( $post_type, array( 'post', 'page' ) ) )
			return true;
		
		// Hacky way to prevent issues on the Edit page
		if( isset( $this->_edit_page_post_type_supported ) && $this->_edit_page_post_type_supported )
			return true;
		
		if( post_type_supports( $post_type, 'author' ) )
			return true;
		
		return false;
	}
	
	/**
	 * Gets the current global post type if one is set
	 */
	function get_current_post_type() {
		global $post, $typenow, $current_screen;
		
		// "Cache" it!
		if( isset( $this->_current_post_type ) )
			return $this->_current_post_type;
		
		if( $post && $post->post_type )
			$post_type = $post->post_type;
		elseif( $typenow )
			$post_type = $typenow;
		elseif( $current_screen && isset( $current_screen->post_type ) )
			$post_type = $current_screen->post_type;
		elseif( isset( $_REQUEST['post_type'] ) )
			$post_type = sanitize_key( $_REQUEST['post_type'] );
		else
			$post_type = '';
		
		if( $post_type )
			$this->_current_post_type = $post_type;
		
		return $post_type;
	}
	
	/**
	 * Removes the standard WordPress Author box.
	 * We don't need it because the Co-Authors one is way cooler.
	 */
	function remove_authors_box() {
		
		$post_type = $this->get_current_post_type();
		
		if( $this->authors_supported( $post_type ) )
			remove_meta_box( $this->coreauthors_meta_box_name, $post_type, 'normal' );
	}
	
	/**
	 * Adds a custom Authors box
	 */
	function add_coauthors_box() {
		
		$post_type = $this->get_current_post_type();
		
		if( $this->authors_supported( $post_type ) && $this->current_user_can_set_authors() )
			add_meta_box($this->coauthors_meta_box_name, __('Post Authors', 'co-authors-plus'), array( &$this, 'coauthors_meta_box' ), $post_type, 'normal', 'high');
	}
	
	/**
	 * Callback for adding the custom author box
	 */
	function coauthors_meta_box( $post ) {
		global $post;
		
		$post_id = $post->ID;
		
		if( !$post_id || $post_id == 0 || !$post->post_author )
			$coauthors = array( wp_get_current_user() );
		else 
			$coauthors = get_coauthors();
		
		$count = 0;
		if( !empty( $coauthors ) ) :
			?>
			<div id="coauthors-readonly" class="hide-if-js1">
				<ul>
				<?php
				foreach( $coauthors as $coauthor ) :
					$count++;
					?>
					<li>
						<?php echo get_avatar( $coauthor->user_email, $this->gravatar_size ); ?>
						<span id="coauthor-readonly-<?php echo $count; ?>" class="coauthor-tag">
							<input type="text" name="coauthorsinput[]" readonly="readonly" value="<?php echo esc_attr( $coauthor->display_name ); ?>" />
							<input type="text" name="coauthors[]" value="<?php echo esc_attr( $coauthor->user_login ); ?>" />
							<input type="text" name="coauthorsemails[]" value="<?php echo esc_attr( $coauthor->user_email ); ?>" />
						</span>
					</li>
					<?php
				endforeach;
				?>
				</ul>				
				<div class="clear"></div>
				<p><?php _e( '<strong>Note:</strong> To edit post authors, please enable javascript or use a javascript-capable browser', 'co-authors-plus' ); ?></p>
			</div>
			<?php
		endif;
		?>
		
		<div id="coauthors-edit" class="hide-if-no-js">
			<p><?php _e( 'Click on an author to change them. Drag to change their order. Click on <strong>Remove</strong> to remove them.', 'co-authors-plus' ); ?></p>
		</div>
		
		<?php wp_nonce_field( 'coauthors-edit', 'coauthors-nonce' ); ?>
		
		<?php
	}
	
	/**
	 * Removes the author dropdown from the post quick edit
	 * It's a bit hacky, but the only way I can figure out :( 
	 */
	function remove_quick_edit_authors_box() {
		$post_type = $this->get_current_post_type();
		if( post_type_supports( $post_type, 'author' )) {
			$this->_edit_page_post_type_supported = true;
			remove_post_type_support( $post_type, 'author' );
		}
	}
	
	/**
	 * Add coauthors to author column on edit pages
	 * @param array $post_columns
	 */
	function _filter_manage_posts_columns($posts_columns) {
		$new_columns = array();
		
		foreach ($posts_columns as $key => $value) {
			$new_columns[$key] = $value;
			if( $key == 'title' )
				$new_columns['coauthors'] = __( 'Authors', 'co-authors-plus' );
			
			if ( $key == 'author' )
				unset($new_columns[$key]);
		}
		return $new_columns;
	} // END: _filter_manage_posts_columns
	
	/**
	 * Insert coauthors into post rows on Edit Page
	 * @param string $column_name
	 **/
	function _filter_manage_posts_custom_column($column_name) {
		if ($column_name == 'coauthors') {
			global $post;
			$authors = get_coauthors( $post->ID );
			
			$count = 1;
			foreach( $authors as $author ) :
				?>
				<a href="<?php echo esc_url( get_admin_url( null, 'edit.php?author=' . $author->ID ) ); ?>"><?php echo esc_html( $author->display_name ); ?></a><?php echo ( $count < count( $authors ) ) ? ',' : ''; ?>
				<?php
				$count++;
			endforeach;
		}
	}

	/**
	 * Unset the post count column because it's going to be inaccurate and provide our own
	 */
	function _filter_manage_users_columns( $columns ) {

		$new_columns = array();
		// Unset and add our column while retaining the order of the columns
		foreach( $columns as $column_name => $column_title ) {
			if ( 'posts' == $column_name )
				$new_columns['coauthors_post_count'] = __( 'Posts', 'co-authors-plus' );
			else
				$new_columns[$column_name] = $column_title;
		}
		return $new_columns;
	}

	/**
	 * Provide an accurate count when looking up the number of published posts for a user
	 */
	function _filter_manage_users_custom_column( $value, $column_name, $user_id ) {
		if ( 'coauthors_post_count' != $column_name )
			return $value;
		// We filter count_user_posts() so it provides an accurate number
		$numposts = count_user_posts( $user_id );
		if ( $numposts > 0 ) {
			$value .= "<a href='edit.php?author=$user_id' title='" . esc_attr__( 'View posts by this author' ) . "' class='edit'>";
			$value .= $numposts;
			$value .= '</a>';
		} else {
			$value .= 0;
		}
		return $value;
	}

	/**
	 * When we update the terms at all, we should update the published post count for each author
	 */
	function _update_users_posts_count( $terms, $taxonomy ) {
		global $wpdb;

		$object_types = (array) $taxonomy->object_type;

		foreach ( $object_types as &$object_type ) {
			list( $object_type ) = explode( ':', $object_type );
		}

		if ( $object_types )
			$object_types = esc_sql( array_filter( $object_types, 'post_type_exists' ) );

		$object_types = array_unique( $object_types );
	
		foreach( (array)$terms as $term_taxonomy_id ) {
			$count = 0;
			if ( 0 == $term_taxonomy_id )
				continue;
			// Get the post IDs for all published posts with this co-author
			$query = $wpdb->prepare( "SELECT $wpdb->posts.ID FROM $wpdb->term_relationships, $wpdb->posts WHERE $wpdb->posts.ID = $wpdb->term_relationships.object_id AND post_status = 'publish' AND post_type IN ('" . implode("', '", $object_types ) . "') AND term_taxonomy_id = %d", $term_taxonomy_id );
			$all_coauthor_posts = $wpdb->get_results( $query );

			// Find the term_id from the term_taxonomy_id, and then get the user's user_login from that
			$query = $wpdb->prepare( "SELECT $wpdb->terms.slug FROM $wpdb->term_taxonomy INNER JOIN $wpdb->terms ON $wpdb->terms.term_id = $wpdb->term_taxonomy.term_id WHERE $wpdb->term_taxonomy.term_taxonomy_id = %d", $term_taxonomy_id );
			$term_slug = $wpdb->get_var( $query );
			$author = get_user_by( 'login', $term_slug );

			// Get all of the post IDs where the user is the primary author
			$query = $wpdb->prepare( "SELECT $wpdb->posts.ID FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ('" . implode("', '", $object_types ) . "') AND post_author = %d;", $author->ID );
			$all_author_posts = $wpdb->get_results( $query );

			// Dedupe the post IDs and then provide a final count
			$all_posts = array();
			foreach( $all_coauthor_posts as $coauthor_post ) {
				$all_posts[] = $coauthor_post->ID;
			}
			foreach( $all_author_posts as $author_post ) {
				$all_posts[] = $author_post->ID;
			}
			$count = count( array_unique( $all_posts ) );

			// Save the count to the term's count column
			$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term_taxonomy_id ) );
		}
		
	}
	
	/**
	 * Modify the author query posts SQL to include posts co-authored
	 */
	function posts_join_filter( $join, $query ){
		global $wpdb;

		if( $query->is_author() && is_object_in_taxonomy($query->query_vars['post_type'], $this->coauthor_taxonomy) ){
			// Check to see that JOIN hasn't already been added. Props michaelingp and nbaxley
			$term_relationship_join = " INNER JOIN {$wpdb->term_relationships} ON ({$wpdb->posts}.ID = {$wpdb->term_relationships}.object_id)";
			$term_taxonomy_join = " INNER JOIN {$wpdb->term_taxonomy} ON ( {$wpdb->term_relationships}.term_taxonomy_id = {$wpdb->term_taxonomy}.term_taxonomy_id )";
			
			if( strpos( $join, trim( $term_relationship_join ) ) === false ) {
				$join .= $term_relationship_join;
			}
			if( strpos( $join, trim( $term_taxonomy_join ) ) === false ) {
				$join .= $term_taxonomy_join;
			}
		}
		return $join;
	}
	
	/**
	 * Modify
	 */
	function posts_where_filter( $where, $query ){
		global $wpdb;
		
		if( $query->is_author() && is_object_in_taxonomy($query->query_vars['post_type'], $this->coauthor_taxonomy)) {
			$author = get_userdata( $query->query_vars['author'] );
			$term = get_term_by( 'name', $author->user_login, $this->coauthor_taxonomy );
				
			if( $author ) {
				$where = preg_replace( '/(\b(?:' . $wpdb->posts . '\.)?post_author\s*=\s*(\d+))/', '($1 OR (' . $wpdb->term_taxonomy . '.taxonomy = \''. $this->coauthor_taxonomy.'\' AND '. $wpdb->term_taxonomy .'.term_id = \''. $term->term_id .'\'))', $where, 1 ); #' . $wpdb->postmeta . '.meta_id IS NOT NULL AND 

			}
		}

		return $where;
	}
	
	/**
	 * 
	 */
	function posts_groupby_filter( $groupby, $query ) {
		global $wpdb;
		
		if( $query->is_author() && is_object_in_taxonomy($query->query_vars['post_type'], $this->coauthor_taxonomy)) {
			$groupby = $wpdb->posts .'.ID';
		}
		return $groupby;
	}
	
	/**
	 * Filters post data before saving to db to set post_author
	 */
	function coauthors_set_post_author_field( $data ) {
		
		// Bail on autosave
		if ( defined( 'DOING_AUTOSAVE' ) && !DOING_AUTOSAVE )
			return $data;
		
		// Bail on revisions
		if( $data['post_type'] == 'revision' )
			return $data;

		// @todo this should check the nonce before changing the value
		
		if( isset( $_REQUEST['coauthors-nonce'] ) && isset( $_POST['coauthors'] ) && is_array( $_POST['coauthors'] ) ) {
			$author = sanitize_user( $_POST['coauthors'][0] );
			if( $author ) {
				$author_data = get_user_by( 'login', $author );
				$data['post_author'] = $author_data->ID;
			}
		}

		// If for some reason we don't have the coauthors fields set
		if( ! isset( $data['post_author'] ) ) {
			$user = wp_get_current_user();
			$data['post_author'] = $user->ID;
		}
		
		return $data;
	}
	
	/**
	 * Update a post's co-authors
	 * @param $post_ID
	 * @return 
	 */
	function coauthors_update_post( $post_id, $post ) {
		$post_type = $post->post_type;
		
		if ( defined( 'DOING_AUTOSAVE' ) && !DOING_AUTOSAVE )
			return;
			
		if( isset( $_POST['coauthors-nonce'] ) && isset( $_POST['coauthors'] ) ) {
			check_admin_referer( 'coauthors-edit', 'coauthors-nonce' );
			
			if( $this->current_user_can_set_authors() ){
				$coauthors = (array) $_POST['coauthors'];
				$coauthors = array_map( 'sanitize_user', $coauthors );
				return $this->add_coauthors( $post_id, $coauthors );
			}
		}
	}
	
	/**
	 * Add a user as coauthor for a post
	 */
	function add_coauthors( $post_id, $coauthors, $append = false ) {
		global $current_user;
		
		$post_id = (int) $post_id;
		$insert = false;
		
		// if an array isn't returned, create one and populate with default author
		if ( !is_array( $coauthors ) || 0 == count( $coauthors ) || empty( $coauthors ) ) {
			$coauthors = array( $current_user->user_login );
		}
		
		// Add each co-author to the post meta
		foreach( array_unique( $coauthors ) as $author ){
			
			// Name and slug of term are the username; 
			$name = $author;
			
			// Add user as a term if they don't exist
			if( !term_exists( $name, $this->coauthor_taxonomy ) ) {
				$args = array( 'slug' => sanitize_title( $name ) );
				$insert = wp_insert_term( $name, $this->coauthor_taxonomy, $args );
			}
		}
		
		// Add authors as post terms
		if( !is_wp_error( $insert ) ) {
			$set = wp_set_post_terms( $post_id, $coauthors, $this->coauthor_taxonomy, $append );
		}
	}
	
	/**
	 * Action taken when user is deleted.
	 * - User term is removed from all associated posts
	 * - Option to specify alternate user in place for each post
	 * @param delete_id
	 */
	function delete_user_action($delete_id){
		global $wpdb;
		
		$reassign_id = absint( $_POST['reassign_user'] );
		
		// If reassign posts, do that -- use coauthors_update_post
		if($reassign_id) {
			// Get posts belonging to deleted author
			$reassign_user = get_user_by( 'id', $reassign_id );
			// Set to new author
			if( is_object( $reassign_user ) ) {
				$post_ids = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE post_author = %d", $delete_id ) );

				if ( $post_ids ) {
					foreach ( $post_ids as $post_id ) {
						$this->add_coauthors( $post_id, array( $reassign_user->user_login ), true );
					}
				}
			}
		}
		
		$delete_user = get_user_by( 'id', $delete_id );
		if ( is_object( $delete_user ) ) {
			// Delete term
			wp_delete_term( $delete_user->user_login, $this->coauthor_taxonomy );
		}
	}

	/**
	 * Restrict WordPress from blowing away author order when bulk editing terms
	 *
	 * @since 2.6
	 * @props kingkool68, http://wordpress.org/support/topic/plugin-co-authors-plus-making-authors-sortable
	 */
	function filter_wp_get_object_terms( $terms, $object_ids, $taxonomies, $args ) {

		if ( !isset( $_REQUEST['bulk_edit'] ) || $taxonomies != "'author'" )
			return $terms;

		global $wpdb; 
		$orderby = 'ORDER BY tr.term_order'; 
		$order = 'ASC';
		$object_ids = (int)$object_ids;
		$query = $wpdb->prepare( "SELECT t.slug, t.term_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON tt.term_id = t.term_id INNER JOIN $wpdb->term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ($taxonomies) AND tr.object_id IN ($object_ids) $orderby $order" );
		$raw_coauthors = $wpdb->get_results( $query ); 
		$terms = array();
		foreach( $raw_coauthors as $author ) { 
			$terms[] = $author->slug; 
		}

		return $terms;
		
	}
	
	/**
	 * Filter the count_users_posts() core function
	 */
	function filter_count_user_posts( $count, $user_id ) {
		$user = get_userdata( $user_id );
		
		$term = get_term_by( 'slug', $user->user_login, $this->coauthor_taxonomy );
		
		// Only modify the count if the author already exists as a term
		if( $term && !is_wp_error( $term ) ) {
			$count = $term->count;
		}
		
		return $count;
	}
	
	/**
	 * Checks to see if the current user can set authors or not
	 */
	function current_user_can_set_authors( ) {
		global $post, $typenow;
		
		// TODO: Enable Authors to set Co-Authors
		
		$post_type = $this->get_current_post_type();
		// TODO: need to fix this; shouldn't just say no if don't have post_type
		if( ! $post_type ) return false;
		
		$post_type_object = get_post_type_object( $post_type );
		$can_set_authors = current_user_can( $post_type_object->cap->edit_others_posts );
		
		return apply_filters( 'coauthors_plus_edit_authors', $can_set_authors );
	}
	
	/**
	 * Fix for author info not properly displaying on author pages
	 *
	 * On an author archive, if the first story has coauthors and
	 * the first author is NOT the same as the author for the archive,
	 * the query_var is changed.
	 *
	 */
	function fix_author_page( &$post ) {

		if( is_author() ) {
			global $wp_query, $authordata;
	
			// Get the id of the author whose page we're on
			$author_id = $wp_query->get( 'author' );
	
			// Check that the the author matches the first author of the first post
			if( $author_id != $authordata->ID ) {
				// The IDs don't match, so we need to force the $authordata to the one we want		
				$authordata = get_userdata( $author_id );
			}
		}
	}
	
	/**
	 * Main function that handles search-as-you-type for adding authors
	 */
	function ajax_suggest() {
		
		if( ! isset( $_REQUEST['_wpnonce'] ) || ! wp_verify_nonce( $_REQUEST['_wpnonce'], 'coauthors-search' ) )
			die();
		
		if( empty( $_REQUEST['q'] ) )
			die();
		
		if( ! $this->current_user_can_set_authors() )
			die();
		
		$search = sanitize_text_field( strtolower( $_REQUEST['q'] ) );
		
		$authors = $this->search_authors( $search );
				
		foreach( $authors as $author ) {
			echo $author->ID ." | ". $author->user_login ." | ". $author->display_name ." | ". $author->user_email ."\n";		
		}
		
		if( COAUTHORS_PLUS_DEBUG ) {		
			echo 'queries:' . get_num_queries() ."\n";
			echo 'timer: ' . timer_stop(1) . "sec\n";
		}
		
		die();
			
	}

	/**
	 * Get matching authors based on a search value
	 */	
	function search_authors( $search = '' ) {
		
		$args = array(
			'search' => sprintf( '*%s*',  $search ), // Enable wildcard searching
			'who' => 'authors',
			'fields' => array(
				'ID',
				'display_name',
				'user_login',
				'user_email'
			),
		);
		add_filter( 'pre_user_query', array( &$this, 'filter_pre_user_query' ) );
		$authors = get_users( $args );
		remove_filter( 'pre_user_query', array( &$this, 'filter_pre_user_query' ) );
		
		return (array) $authors;
	}

	/**
	 * Modify get_users() to search display_name instead of user_nicename
	 */
	function filter_pre_user_query( &$user_query ) {
		if ( is_object( $user_query ) )
			$user_query->query_where = str_replace( "user_nicename LIKE", "display_name LIKE", $user_query->query_where );
		return $user_query;
	}
	
	/**
	 * Functions to add scripts and css
	 */
	function enqueue_scripts($hook_suffix) {
		global $pagenow, $post;
		
		$post_type = $this->get_current_post_type();
		
		// TODO: Check if user can set authors? $this->current_user_can_set_authors()
		if( $this->is_valid_page() && $this->authors_supported( $post_type ) ) {
		
			wp_enqueue_script( 'jquery' );
			wp_enqueue_script( 'jquery-ui-sortable' );
			wp_enqueue_style( 'co-authors-plus-css', COAUTHORS_PLUS_URL . 'css/co-authors-plus.css', false, COAUTHORS_PLUS_VERSION, 'all' );
			wp_enqueue_script( 'co-authors-plus-js', COAUTHORS_PLUS_URL . 'js/co-authors-plus.js', array('jquery', 'suggest'), COAUTHORS_PLUS_VERSION, true);
			
			$js_strings = array(
				'edit_label' => __( 'Edit', 'co-authors-plus' ),
				'delete_label' => __( 'Remove', 'co-authors-plus' ), 
				'confirm_delete' => __( 'Are you sure you want to remove this author?', 'co-authors-plus' ),
				'input_box_title' => __( 'Click to change this author, or drag to change their position', 'co-authors-plus' ),
				'search_box_text' => __( 'Search for an author', 'co-authors-plus' ),
				'help_text' => __( 'Click on an author to change them. Drag to change their order. Click on <strong>Remove</strong> to remove them.', 'co-authors-plus' ),
			);
			wp_localize_script( 'co-authors-plus-js', 'coAuthorsPlusStrings', $js_strings );
			
		}
	}	
	
	/**
	 * Adds necessary javascript variables to admin pages
	 */
	function js_vars() {
		
		$post_type = $this->get_current_post_type();
		
		if( $this->is_valid_page() && $this->authors_supported( $post_type ) && $this->current_user_can_set_authors() ) {
			?>
			<script type="text/javascript">
				// AJAX link used for the autosuggest
				var coAuthorsPlus_ajax_suggest_link = '<?php echo add_query_arg(
					array(
						'action' => 'coauthors_ajax_suggest',
						'post_type' => $post_type,
					),
					wp_nonce_url( 'admin-ajax.php', 'coauthors-search' )
				); ?>';
			</script>
			<?php
		}
	} // END: js_vars()
	
	/**
	 * Helper to only add javascript to necessary pages. Avoids bloat in admin.
	 */
	function is_valid_page() {
		global $pagenow;
		
		return in_array( $pagenow, $this->_pages_whitelist );
	} 
	
	function get_post_id() {
		global $post;
		$post_id = 0;
		
		if ( is_object( $post ) ) {
			$post_id = $post->ID;
		}
		
		if( ! $post_id ) {
			if ( isset( $_GET['post'] ) )
				$post_id = (int) $_GET['post'];
			elseif ( isset( $_POST['post_ID'] ) )
				$post_id = (int) $_POST['post_ID'];
		}
		
		return $post_id;
	}
	
	/**
	 * Allows coauthors to edit the post they're coauthors of
	 * Pieces of code borrowed from http://pastebin.ca/1909968
	 * 
	 */
	function add_coauthor_cap( $allcaps, $caps, $args ) {
		
		// Load the post data:
		$user_id = isset( $args[1] ) ? $args[1] : 0;
		$post_id = isset( $args[2] ) ? $args[2] : 0;
		
		if( ! $post_id )
			$post_id = $this->get_post_id();
		
		if( ! $post_id )
			return $allcaps;
		
		$post = get_post( $post_id );
		
		if( ! $post )
			return $allcaps;
		
		$post_type_object = get_post_type_object( $post->post_type );
		
		// Bail out if we're not asking about a post
		if ( ! in_array( $args[0], array( $post_type_object->cap->edit_post, $post_type_object->cap->edit_others_posts ) ) )
			return $allcaps;
		
		// Bail out for users who can already edit others posts
		if ( isset( $allcaps[$post_type_object->cap->edit_others_posts] ) && $allcaps[$post_type_object->cap->edit_others_posts] )
			return $allcaps;
		
		// Bail out for users who can't publish posts if the post is already published
		if ( 'publish' == $post->post_status && ( ! isset( $allcaps[$post_type_object->cap->publish_posts] ) || ! $allcaps[$post_type_object->cap->publish_posts] ) )
			return $allcaps;
		
		// Finally, double check that the user is a coauthor of the post
		if( is_coauthor_for_post( $user_id, $post_id ) ) {
			foreach($caps as $cap) {
				$allcaps[$cap] = true;
			}
		}
		
		return $allcaps;
	}
	
	/**
	 * Emails all coauthors when comment added instead of the main author
	 * 
	 */
	function notify_coauthors( $message_headers, $comment_id ) {
		// TODO: this is broken!
		$comment = get_comment($comment_id);
		$post = get_post($comment->comment_post_ID);
		$coauthors = get_coauthors($comment->comment_post_ID);
	
		$message_headers .= 'cc: ';
		$count = 0;
		foreach($coauthors as $author) {
			$count++;
			if($author->ID != $post->post_author){
				$message_headers .= $author->user_email;
				if($count < count($coauthors)) $message_headers .= ',';
			}
		}
		$message_headers .= "\n";
		return $message_headers;
	}
	
	function debug($msg, $object) {
		if( COAUTHORS_PLUS_DEBUG ) {
			echo '<hr />';
			echo sprintf('<p>%s</p>', $msg);
			echo '<pre>';
			var_dump($object);
			echo '</pre>';
		}
	}
}

global $coauthors_plus;
$coauthors_plus = new coauthors_plus();