<?php
/**
 * Post functions and post utility function.
 *
 * @package WordPress
 * @subpackage Post
 * @since 1.5.0
 */

//
// Post Type Registration
//

/**
 * Creates the initial post types when 'init' action is fired.
 *
 * @since 2.9.0
 */
function create_initial_post_types() {
	register_post_type( 'post', array(
		'labels' => array(
			'name_admin_bar' => _x( 'Post', 'add new on admin bar' ),
		),
		'public'  => true,
		'_builtin' => true, /* internal use only. don't use this when registering your own post type. */
		'_edit_link' => 'post.php?post=%d', /* internal use only. don't use this when registering your own post type. */
		'capability_type' => 'post',
		'map_meta_cap' => true,
		'hierarchical' => false,
		'rewrite' => false,
		'query_var' => false,
		'delete_with_user' => true,
		'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'excerpt', 'trackbacks', 'custom-fields', 'comments', 'revisions', 'post-formats' ),
	) );

	register_post_type( 'page', array(
		'labels' => array(
			'name_admin_bar' => _x( 'Page', 'add new on admin bar' ),
		),
		'public' => true,
		'publicly_queryable' => false,
		'_builtin' => true, /* internal use only. don't use this when registering your own post type. */
		'_edit_link' => 'post.php?post=%d', /* internal use only. don't use this when registering your own post type. */
		'capability_type' => 'page',
		'map_meta_cap' => true,
		'hierarchical' => true,
		'rewrite' => false,
		'query_var' => false,
		'delete_with_user' => true,
		'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'page-attributes', 'custom-fields', 'comments', 'revisions' ),
	) );

	register_post_type( 'attachment', array(
		'labels' => array(
			'name' => __( 'Media' ),
			'edit_item' => __( 'Edit Media' ),
		),
		'public' => true,
		'show_ui' => false,
		'_builtin' => true, /* internal use only. don't use this when registering your own post type. */
		'_edit_link' => 'media.php?attachment_id=%d', /* internal use only. don't use this when registering your own post type. */
		'capability_type' => 'post',
		'map_meta_cap' => true,
		'hierarchical' => false,
		'rewrite' => false,
		'query_var' => false,
		'show_in_nav_menus' => false,
		'delete_with_user' => true,
		'supports' => array( 'comments', 'author' ),
	) );

	register_post_type( 'revision', array(
		'labels' => array(
			'name' => __( 'Revisions' ),
			'singular_name' => __( 'Revision' ),
		),
		'public' => false,
		'_builtin' => true, /* internal use only. don't use this when registering your own post type. */
		'_edit_link' => 'revision.php?revision=%d', /* internal use only. don't use this when registering your own post type. */
		'capability_type' => 'post',
		'map_meta_cap' => true,
		'hierarchical' => false,
		'rewrite' => false,
		'query_var' => false,
		'can_export' => false,
		'delete_with_user' => true,
		'supports' => array( 'author' ),
	) );

	register_post_type( 'nav_menu_item', array(
		'labels' => array(
			'name' => __( 'Navigation Menu Items' ),
			'singular_name' => __( 'Navigation Menu Item' ),
		),
		'public' => false,
		'_builtin' => true, /* internal use only. don't use this when registering your own post type. */
		'hierarchical' => false,
		'rewrite' => false,
		'delete_with_user' => false,
		'query_var' => false,
	) );

	register_post_status( 'publish', array(
		'label'       => _x( 'Published', 'post' ),
		'public'      => true,
		'_builtin'    => true, /* internal use only. */
		'label_count' => _n_noop( 'Published <span class="count">(%s)</span>', 'Published <span class="count">(%s)</span>' ),
	) );

	register_post_status( 'future', array(
		'label'       => _x( 'Scheduled', 'post' ),
		'protected'   => true,
		'_builtin'    => true, /* internal use only. */
		'label_count' => _n_noop('Scheduled <span class="count">(%s)</span>', 'Scheduled <span class="count">(%s)</span>' ),
	) );

	register_post_status( 'draft', array(
		'label'       => _x( 'Draft', 'post' ),
		'protected'   => true,
		'_builtin'    => true, /* internal use only. */
		'label_count' => _n_noop( 'Draft <span class="count">(%s)</span>', 'Drafts <span class="count">(%s)</span>' ),
	) );

	register_post_status( 'pending', array(
		'label'       => _x( 'Pending', 'post' ),
		'protected'   => true,
		'_builtin'    => true, /* internal use only. */
		'label_count' => _n_noop( 'Pending <span class="count">(%s)</span>', 'Pending <span class="count">(%s)</span>' ),
	) );

	register_post_status( 'private', array(
		'label'       => _x( 'Private', 'post' ),
		'private'     => true,
		'_builtin'    => true, /* internal use only. */
		'label_count' => _n_noop( 'Private <span class="count">(%s)</span>', 'Private <span class="count">(%s)</span>' ),
	) );

	register_post_status( 'trash', array(
		'label'       => _x( 'Trash', 'post' ),
		'internal'    => true,
		'_builtin'    => true, /* internal use only. */
		'label_count' => _n_noop( 'Trash <span class="count">(%s)</span>', 'Trash <span class="count">(%s)</span>' ),
		'show_in_admin_status_list' => true,
	) );

	register_post_status( 'auto-draft', array(
		'label'    => 'auto-draft',
		'internal' => true,
		'_builtin' => true, /* internal use only. */
	) );

	register_post_status( 'inherit', array(
		'label'    => 'inherit',
		'internal' => true,
		'_builtin' => true, /* internal use only. */
		'exclude_from_search' => false,
	) );
}
add_action( 'init', 'create_initial_post_types', 0 ); // highest priority

/**
 * Retrieve attached file path based on attachment ID.
 *
 * You can optionally send it through the 'get_attached_file' filter, but by
 * default it will just return the file path unfiltered.
 *
 * The function works by getting the single post meta name, named
 * '_wp_attached_file' and returning it. This is a convenience function to
 * prevent looking up the meta name and provide a mechanism for sending the
 * attached filename through a filter.
 *
 * @since 2.0.0
 * @uses apply_filters() Calls 'get_attached_file' on file path and attachment ID.
 *
 * @param int $attachment_id Attachment ID.
 * @param bool $unfiltered Whether to apply filters.
 * @return string|bool The file path to the attached file, or false if the attachment does not exist.
 */
function get_attached_file( $attachment_id, $unfiltered = false ) {
	$file = get_post_meta( $attachment_id, '_wp_attached_file', true );
	// If the file is relative, prepend upload dir
	if ( $file && 0 !== strpos($file, '/') && !preg_match('|^.:\\\|', $file) && ( ($uploads = wp_upload_dir()) && false === $uploads['error'] ) )
		$file = $uploads['basedir'] . "/$file";
	if ( $unfiltered )
		return $file;
	return apply_filters( 'get_attached_file', $file, $attachment_id );
}

/**
 * Update attachment file path based on attachment ID.
 *
 * Used to update the file path of the attachment, which uses post meta name
 * '_wp_attached_file' to store the path of the attachment.
 *
 * @since 2.1.0
 * @uses apply_filters() Calls 'update_attached_file' on file path and attachment ID.
 *
 * @param int $attachment_id Attachment ID
 * @param string $file File path for the attachment
 * @return bool False on failure, true on success.
 */
function update_attached_file( $attachment_id, $file ) {
	if ( !get_post( $attachment_id ) )
		return false;

	$file = apply_filters( 'update_attached_file', $file, $attachment_id );
	$file = _wp_relative_upload_path($file);

	return update_post_meta( $attachment_id, '_wp_attached_file', $file );
}

/**
 * Return relative path to an uploaded file.
 *
 * The path is relative to the current upload dir.
 *
 * @since 2.9.0
 * @uses apply_filters() Calls '_wp_relative_upload_path' on file path.
 *
 * @param string $path Full path to the file
 * @return string relative path on success, unchanged path on failure.
 */
function _wp_relative_upload_path( $path ) {
	$new_path = $path;

	if ( ($uploads = wp_upload_dir()) && false === $uploads['error'] ) {
		if ( 0 === strpos($new_path, $uploads['basedir']) ) {
				$new_path = str_replace($uploads['basedir'], '', $new_path);
				$new_path = ltrim($new_path, '/');
		}
	}

	return apply_filters( '_wp_relative_upload_path', $new_path, $path );
}

/**
 * Retrieve all children of the post parent ID.
 *
 * Normally, without any enhancements, the children would apply to pages. In the
 * context of the inner workings of WordPress, pages, posts, and attachments
 * share the same table, so therefore the functionality could apply to any one
 * of them. It is then noted that while this function does not work on posts, it
 * does not mean that it won't work on posts. It is recommended that you know
 * what context you wish to retrieve the children of.
 *
 * Attachments may also be made the child of a post, so if that is an accurate
 * statement (which needs to be verified), it would then be possible to get
 * all of the attachments for a post. Attachments have since changed since
 * version 2.5, so this is most likely unaccurate, but serves generally as an
 * example of what is possible.
 *
 * The arguments listed as defaults are for this function and also of the
 * {@link get_posts()} function. The arguments are combined with the
 * get_children defaults and are then passed to the {@link get_posts()}
 * function, which accepts additional arguments. You can replace the defaults in
 * this function, listed below and the additional arguments listed in the
 * {@link get_posts()} function.
 *
 * The 'post_parent' is the most important argument and important attention
 * needs to be paid to the $args parameter. If you pass either an object or an
 * integer (number), then just the 'post_parent' is grabbed and everything else
 * is lost. If you don't specify any arguments, then it is assumed that you are
 * in The Loop and the post parent will be grabbed for from the current post.
 *
 * The 'post_parent' argument is the ID to get the children. The 'numberposts'
 * is the amount of posts to retrieve that has a default of '-1', which is
 * used to get all of the posts. Giving a number higher than 0 will only
 * retrieve that amount of posts.
 *
 * The 'post_type' and 'post_status' arguments can be used to choose what
 * criteria of posts to retrieve. The 'post_type' can be anything, but WordPress
 * post types are 'post', 'pages', and 'attachments'. The 'post_status'
 * argument will accept any post status within the write administration panels.
 *
 * @see get_posts() Has additional arguments that can be replaced.
 * @internal Claims made in the long description might be inaccurate.
 *
 * @since 2.0.0
 *
 * @param mixed $args Optional. User defined arguments for replacing the defaults.
 * @param string $output Optional. Constant for return type, either OBJECT (default), ARRAY_A, ARRAY_N.
 * @return array|bool False on failure and the type will be determined by $output parameter.
 */
function get_children($args = '', $output = OBJECT) {
	$kids = array();
	if ( empty( $args ) ) {
		if ( isset( $GLOBALS['post'] ) ) {
			$args = array('post_parent' => (int) $GLOBALS['post']->post_parent );
		} else {
			return $kids;
		}
	} elseif ( is_object( $args ) ) {
		$args = array('post_parent' => (int) $args->post_parent );
	} elseif ( is_numeric( $args ) ) {
		$args = array('post_parent' => (int) $args);
	}

	$defaults = array(
		'numberposts' => -1, 'post_type' => 'any',
		'post_status' => 'any', 'post_parent' => 0,
	);

	$r = wp_parse_args( $args, $defaults );

	$children = get_posts( $r );

	if ( !$children )
		return $kids;

	update_post_cache($children);

	foreach ( $children as $key => $child )
		$kids[$child->ID] = $children[$key];

	if ( $output == OBJECT ) {
		return $kids;
	} elseif ( $output == ARRAY_A ) {
		foreach ( (array) $kids as $kid )
			$weeuns[$kid->ID] = get_object_vars($kids[$kid->ID]);
		return $weeuns;
	} elseif ( $output == ARRAY_N ) {
		foreach ( (array) $kids as $kid )
			$babes[$kid->ID] = array_values(get_object_vars($kids[$kid->ID]));
		return $babes;
	} else {
		return $kids;
	}
}

/**
 * Get extended entry info (<!--more-->).
 *
 * There should not be any space after the second dash and before the word
 * 'more'. There can be text or space(s) after the word 'more', but won't be
 * referenced.
 *
 * The returned array has 'main', 'extended', and 'more_text' keys. Main has the text before
 * the <code><!--more--></code>. The 'extended' key has the content after the
 * <code><!--more--></code> comment. The 'more_text' key has the custom "Read More" text.
 *
 * @since 1.0.0
 *
 * @param string $post Post content.
 * @return array Post before ('main'), after ('extended'), and custom readmore ('more_text').
 */
function get_extended($post) {
	//Match the new style more links
	if ( preg_match('/<!--more(.*?)?-->/', $post, $matches) ) {
		list($main, $extended) = explode($matches[0], $post, 2);
		$more_text = $matches[1];
	} else {
		$main = $post;
		$extended = '';
		$more_text = '';
	}

	// Strip leading and trailing whitespace
	$main = preg_replace('/^[\s]*(.*)[\s]*$/', '\\1', $main);
	$extended = preg_replace('/^[\s]*(.*)[\s]*$/', '\\1', $extended);
	$more_text = preg_replace('/^[\s]*(.*)[\s]*$/', '\\1', $more_text);

	return array( 'main' => $main, 'extended' => $extended, 'more_text' => $more_text );
}

/**
 * Retrieves post data given a post ID or post object.
 *
 * See {@link sanitize_post()} for optional $filter values. Also, the parameter
 * $post, must be given as a variable, since it is passed by reference.
 *
 * @since 1.5.1
 * @uses $wpdb
 * @link http://codex.wordpress.org/Function_Reference/get_post
 *
 * @param int|object $post Post ID or post object.
 * @param string $output Optional, default is Object. Either OBJECT, ARRAY_A, or ARRAY_N.
 * @param string $filter Optional, default is raw.
 * @return mixed Post data
 */
function &get_post(&$post, $output = OBJECT, $filter = 'raw') {
	global $wpdb;
	$null = null;

	if ( empty($post) ) {
		if ( isset($GLOBALS['post']) )
			$_post = & $GLOBALS['post'];
		else
			return $null;
	} elseif ( is_object($post) && empty($post->filter) ) {
		_get_post_ancestors($post);
		$_post = sanitize_post($post, 'raw');
		wp_cache_add($post->ID, $_post, 'posts');
	} elseif ( is_object($post) && 'raw' == $post->filter ) {
		$_post = $post;
	} else {
		if ( is_object($post) )
			$post_id = $post->ID;
		else
			$post_id = $post;

		$post_id = (int) $post_id;
		if ( ! $_post = wp_cache_get($post_id, 'posts') ) {
			$_post = $wpdb->get_row($wpdb->prepare("SELECT * FROM $wpdb->posts WHERE ID = %d LIMIT 1", $post_id));
			if ( ! $_post )
				return $null;
			_get_post_ancestors($_post);
			$_post = sanitize_post($_post, 'raw');
			wp_cache_add($_post->ID, $_post, 'posts');
		}
	}

	if ($filter != 'raw')
		$_post = sanitize_post($_post, $filter);

	if ( $output == OBJECT ) {
		return $_post;
	} elseif ( $output == ARRAY_A ) {
		$__post = get_object_vars($_post);
		return $__post;
	} elseif ( $output == ARRAY_N ) {
		$__post = array_values(get_object_vars($_post));
		return $__post;
	} else {
		return $_post;
	}
}

/**
 * Retrieve ancestors of a post.
 *
 * @since 2.5.0
 *
 * @param int|object $post Post ID or post object
 * @return array Ancestor IDs or empty array if none are found.
 */
function get_post_ancestors($post) {
	$post = get_post($post);

	if ( ! isset( $post->ancestors ) )
		_get_post_ancestors( $post );

	if ( ! empty( $post->ancestors ) )
		return $post->ancestors;

	return array();
}

/**
 * Retrieve data from a post field based on Post ID.
 *
 * Examples of the post field will be, 'post_type', 'post_status', 'post_content',
 * etc and based off of the post object property or key names.
 *
 * The context values are based off of the taxonomy filter functions and
 * supported values are found within those functions.
 *
 * @since 2.3.0
 * @uses sanitize_post_field() See for possible $context values.
 *
 * @param string $field Post field name
 * @param id $post Post ID
 * @param string $context Optional. How to filter the field. Default is display.
 * @return WP_Error|string Value in post field or WP_Error on failure
 */
function get_post_field( $field, $post, $context = 'display' ) {
	$post = (int) $post;
	$post = get_post( $post );

	if ( is_wp_error($post) )
		return $post;

	if ( !is_object($post) )
		return '';

	if ( !isset($post->$field) )
		return '';

	return sanitize_post_field($field, $post->$field, $post->ID, $context);
}

/**
 * Retrieve the mime type of an attachment based on the ID.
 *
 * This function can be used with any post type, but it makes more sense with
 * attachments.
 *
 * @since 2.0.0
 *
 * @param int $ID Optional. Post ID.
 * @return bool|string False on failure or returns the mime type
 */
function get_post_mime_type($ID = '') {
	$post = & get_post($ID);

	if ( is_object($post) )
		return $post->post_mime_type;

	return false;
}

/**
 * Retrieve the format slug for a post
 *
 * @since 3.1.0
 *
 * @param int|object $post A post
 *
 * @return mixed The format if successful. False if no format is set. WP_Error if errors.
 */
function get_post_format( $post = null ) {
	$post = get_post($post);

	if ( ! post_type_supports( $post->post_type, 'post-formats' ) )
		return false;

	$_format = get_the_terms( $post->ID, 'post_format' );

	if ( empty( $_format ) )
		return false;

	$format = array_shift( $_format );

	return ( str_replace('post-format-', '', $format->slug ) );
}

/**
 * Check if a post has a particular format
 *
 * @since 3.1.0
 * @uses has_term()
 *
 * @param string $format The format to check for
 * @param object|id $post The post to check. If not supplied, defaults to the current post if used in the loop.
 * @return bool True if the post has the format, false otherwise.
 */
function has_post_format( $format, $post = null ) {
	return has_term('post-format-' . sanitize_key($format), 'post_format', $post);
}

/**
 * Assign a format to a post
 *
 * @since 3.1.0
 *
 * @param int|object $post The post for which to assign a format
 * @param string $format  A format to assign. Use an empty string or array to remove all formats from the post.
 * @return mixed WP_Error on error. Array of affected term IDs on success.
 */
function set_post_format( $post, $format ) {
	$post = get_post($post);

	if ( empty($post) )
		return new WP_Error('invalid_post', __('Invalid post'));

	if ( !empty($format) ) {
		$format = sanitize_key($format);
		if ( 'standard' == $format || !in_array( $format, array_keys( get_post_format_slugs() ) ) )
			$format = '';
		else
			$format = 'post-format-' . $format;
	}

	return wp_set_post_terms($post->ID, $format, 'post_format');
}

/**
 * Retrieve the post status based on the Post ID.
 *
 * If the post ID is of an attachment, then the parent post status will be given
 * instead.
 *
 * @since 2.0.0
 *
 * @param int $ID Post ID
 * @return string|bool Post status or false on failure.
 */
function get_post_status($ID = '') {
	$post = get_post($ID);

	if ( !is_object($post) )
		return false;

	if ( 'attachment' == $post->post_type ) {
		if ( 'private' == $post->post_status )
			return 'private';

		// Unattached attachments are assumed to be published
		if ( ( 'inherit' == $post->post_status ) && ( 0 == $post->post_parent) )
			return 'publish';

		// Inherit status from the parent
		if ( $post->post_parent && ( $post->ID != $post->post_parent ) )
			return get_post_status($post->post_parent);
	}

	return $post->post_status;
}

/**
 * Retrieve all of the WordPress supported post statuses.
 *
 * Posts have a limited set of valid status values, this provides the
 * post_status values and descriptions.
 *
 * @since 2.5.0
 *
 * @return array List of post statuses.
 */
function get_post_statuses( ) {
	$status = array(
		'draft'			=> __('Draft'),
		'pending'		=> __('Pending Review'),
		'private'		=> __('Private'),
		'publish'		=> __('Published')
	);

	return $status;
}

/**
 * Retrieve all of the WordPress support page statuses.
 *
 * Pages have a limited set of valid status values, this provides the
 * post_status values and descriptions.
 *
 * @since 2.5.0
 *
 * @return array List of page statuses.
 */
function get_page_statuses( ) {
	$status = array(
		'draft'			=> __('Draft'),
		'private'		=> __('Private'),
		'publish'		=> __('Published')
	);

	return $status;
}

/**
 * Register a post status. Do not use before init.
 *
 * A simple function for creating or modifying a post status based on the
 * parameters given. The function will accept an array (second optional
 * parameter), along with a string for the post status name.
 *
 *
 * Optional $args contents:
 *
 * label - A descriptive name for the post status marked for translation. Defaults to $post_status.
 * public - Whether posts of this status should be shown in the front end of the site. Defaults to true.
 * exclude_from_search - Whether to exclude posts with this post status from search results. Defaults to false.
 * show_in_admin_all_list - Whether to include posts in the edit listing for their post type
 * show_in_admin_status_list - Show in the list of statuses with post counts at the top of the edit
 *                             listings, e.g. All (12) | Published (9) | My Custom Status (2) ...
 *
 * Arguments prefixed with an _underscore shouldn't be used by plugins and themes.
 *
 * @package WordPress
 * @subpackage Post
 * @since 3.0.0
 * @uses $wp_post_statuses Inserts new post status object into the list
 *
 * @param string $post_status Name of the post status.
 * @param array|string $args See above description.
 */
function register_post_status($post_status, $args = array()) {
	global $wp_post_statuses;

	if (!is_array($wp_post_statuses))
		$wp_post_statuses = array();

	// Args prefixed with an underscore are reserved for internal use.
	$defaults = array('label' => false, 'label_count' => false, 'exclude_from_search' => null, '_builtin' => false, '_edit_link' => 'post.php?post=%d', 'capability_type' => 'post', 'hierarchical' => false, 'public' => null, 'internal' => null, 'protected' => null, 'private' => null, 'show_in_admin_all' => null, 'publicly_queryable' => null, 'show_in_admin_status_list' => null, 'show_in_admin_all_list' => null, 'single_view_cap' => null);
	$args = wp_parse_args($args, $defaults);
	$args = (object) $args;

	$post_status = sanitize_key($post_status);
	$args->name = $post_status;

	if ( null === $args->public && null === $args->internal && null === $args->protected && null === $args->private )
		$args->internal = true;

	if ( null === $args->public  )
		$args->public = false;

	if ( null === $args->private  )
		$args->private = false;

	if ( null === $args->protected  )
		$args->protected = false;

	if ( null === $args->internal  )
		$args->internal = false;

	if ( null === $args->publicly_queryable )
		$args->publicly_queryable = $args->public;

	if ( null === $args->exclude_from_search )
		$args->exclude_from_search = $args->internal;

	if ( null === $args->show_in_admin_all_list )
		$args->show_in_admin_all_list = !$args->internal;

	if ( null === $args->show_in_admin_status_list )
			$args->show_in_admin_status_list = !$args->internal;

	if ( null === $args->single_view_cap )
		$args->single_view_cap = $args->public ? '' : 'edit';

	if ( false === $args->label )
		$args->label = $post_status;

	if ( false === $args->label_count )
		$args->label_count = array( $args->label, $args->label );

	$wp_post_statuses[$post_status] = $args;

	return $args;
}

/**
 * Retrieve a post status object by name
 *
 * @package WordPress
 * @subpackage Post
 * @since 3.0.0
 * @uses $wp_post_statuses
 * @see register_post_status
 * @see get_post_statuses
 *
 * @param string $post_status The name of a registered post status
 * @return object A post status object
 */
function get_post_status_object( $post_status ) {
	global $wp_post_statuses;

	if ( empty($wp_post_statuses[$post_status]) )
		return null;

	return $wp_post_statuses[$post_status];
}

/**
 * Get a list of all registered post status objects.
 *
 * @package WordPress
 * @subpackage Post
 * @since 3.0.0
 * @uses $wp_post_statuses
 * @see register_post_status
 * @see get_post_status_object
 *
 * @param array|string $args An array of key => value arguments to match against the post status objects.
 * @param string $output The type of output to return, either post status 'names' or 'objects'. 'names' is the default.
 * @param string $operator The logical operation to perform. 'or' means only one element
 *  from the array needs to match; 'and' means all elements must match. The default is 'and'.
 * @return array A list of post status names or objects
 */
function get_post_stati( $args = array(), $output = 'names', $operator = 'and' ) {
	global $wp_post_statuses;

	$field = ('names' == $output) ? 'name' : false;

	return wp_filter_object_list($wp_post_statuses, $args, $operator, $field);
}

/**
 * Whether the post type is hierarchical.
 *
 * A false return value might also mean that the post type does not exist.
 *
 * @since 3.0.0
 * @see get_post_type_object
 *
 * @param string $post_type Post type name
 * @return bool Whether post type is hierarchical.
 */
function is_post_type_hierarchical( $post_type ) {
	if ( ! post_type_exists( $post_type ) )
		return false;

	$post_type = get_post_type_object( $post_type );
	return $post_type->hierarchical;
}

/**
 * Checks if a post type is registered.
 *
 * @since 3.0.0
 * @uses get_post_type_object()
 *
 * @param string $post_type Post type name
 * @return bool Whether post type is registered.
 */
function post_type_exists( $post_type ) {
	return (bool) get_post_type_object( $post_type );
}

/**
 * Retrieve the post type of the current post or of a given post.
 *
 * @since 2.1.0
 *
 * @uses $post The Loop current post global
 *
 * @param mixed $the_post Optional. Post object or post ID.
 * @return bool|string post type or false on failure.
 */
function get_post_type( $the_post = false ) {
	global $post;

	if ( false === $the_post )
		$the_post = $post;
	elseif ( is_numeric($the_post) )
		$the_post = get_post($the_post);

	if ( is_object($the_post) )
		return $the_post->post_type;

	return false;
}

/**
 * Retrieve a post type object by name
 *
 * @package WordPress
 * @subpackage Post
 * @since 3.0.0
 * @uses $wp_post_types
 * @see register_post_type
 * @see get_post_types
 *
 * @param string $post_type The name of a registered post type
 * @return object A post type object
 */
function get_post_type_object( $post_type ) {
	global $wp_post_types;

	if ( empty($wp_post_types[$post_type]) )
		return null;

	return $wp_post_types[$post_type];
}

/**
 * Get a list of all registered post type objects.
 *
 * @package WordPress
 * @subpackage Post
 * @since 2.9.0
 * @uses $wp_post_types
 * @see register_post_type
 *
 * @param array|string $args An array of key => value arguments to match against the post type objects.
 * @param string $output The type of output to return, either post type 'names' or 'objects'. 'names' is the default.
 * @param string $operator The logical operation to perform. 'or' means only one element
 *  from the array needs to match; 'and' means all elements must match. The default is 'and'.
 * @return array A list of post type names or objects
 */
function get_post_types( $args = array(), $output = 'names', $operator = 'and' ) {
	global $wp_post_types;

	$field = ('names' == $output) ? 'name' : false;

	return wp_filter_object_list($wp_post_types, $args, $operator, $field);
}

/**
 * Register a post type. Do not use before init.
 *
 * A function for creating or modifying a post type based on the
 * parameters given. The function will accept an array (second optional
 * parameter), along with a string for the post type name.
 *
 * Optional $args contents:
 *
 * - label - Name of the post type shown in the menu. Usually plural. If not set, labels['name'] will be used.
 * - labels - An array of labels for this post type.
 *     * If not set, post labels are inherited for non-hierarchical types and page labels for hierarchical ones.
 *     * You can see accepted values in {@link get_post_type_labels()}.
 * - description - A short descriptive summary of what the post type is. Defaults to blank.
 * - public - Whether a post type is intended for use publicly either via the admin interface or by front-end users.
 *     * Defaults to false.
 *     * While the default settings of exclude_from_search, publicly_queryable, show_ui, and show_in_nav_menus are
 *       inherited from public, each does not rely on this relationship and controls a very specific intention.
 * - exclude_from_search - Whether to exclude posts with this post type from front end search results.
 *     * If not set, the the opposite of public's current value is used.
 * - publicly_queryable - Whether queries can be performed on the front end for the post type as part of parse_request().
 *     * ?post_type={post_type_key}
 *     * ?{post_type_key}={single_post_slug}
 *     * ?{post_type_query_var}={single_post_slug}
 *     * If not set, the default is inherited from public.
 * - show_ui - Whether to generate a default UI for managing this post type in the admin.
 *     * If not set, the default is inherited from public.
 * - show_in_nav_menus - Makes this post type available for selection in navigation menus.
 *     * If not set, the default is inherited from public.
 * - show_in_menu - Where to show the post type in the admin menu.
 *     * If true, the post type is shown in its own top level menu.
 *     * If false, no menu is shown
 *     * If a string of an existing top level menu (eg. 'tools.php' or 'edit.php?post_type=page'), the post type will
 *       be placed as a sub menu of that.
 *     * show_ui must be true.
 *     * If not set, the default is inherited from show_ui
 * - show_in_admin_bar - Makes this post type available via the admin bar.
 *     * If not set, the default is inherited from show_in_menu
 * - menu_position - The position in the menu order the post type should appear.
 *     * show_in_menu must be true
 *     * Defaults to null, which places it at the bottom of its area.
 * - menu_icon - The url to the icon to be used for this menu. Defaults to use the posts icon.
 * - capability_type - The string to use to build the read, edit, and delete capabilities. Defaults to 'post'.
 *     * May be passed as an array to allow for alternative plurals when using this argument as a base to construct the
 *       capabilities, e.g. array('story', 'stories').
 * - capabilities - Array of capabilities for this post type.
 *     * By default the capability_type is used as a base to construct capabilities.
 *     * You can see accepted values in {@link get_post_type_capabilities()}.
 * - map_meta_cap - Whether to use the internal default meta capability handling. Defaults to false.
 * - hierarchical - Whether the post type is hierarchical (e.g. page). Defaults to false.
 * - supports - An alias for calling add_post_type_support() directly. Defaults to title and editor.
 *     * See {@link add_post_type_support()} for documentation.
 * - register_meta_box_cb - Provide a callback function that will be called when setting up the
 *     meta boxes for the edit form. Do remove_meta_box() and add_meta_box() calls in the callback.
 * - taxonomies - An array of taxonomy identifiers that will be registered for the post type.
 *     * Default is no taxonomies.
 *     * Taxonomies can be registered later with register_taxonomy() or register_taxonomy_for_object_type().
 * - has_archive - True to enable post type archives. Default is false.
 *     * Will generate the proper rewrite rules if rewrite is enabled.
 * - rewrite - Triggers the handling of rewrites for this post type. Defaults to true, using $post_type as slug.
 *     * To prevent rewrite, set to false.
 *     * To specify rewrite rules, an array can be passed with any of these keys
 *         * 'slug' => string Customize the permastruct slug. Defaults to $post_type key
 *         * 'with_front' => bool Should the permastruct be prepended with WP_Rewrite::$front. Defaults to true.
 *         * 'feeds' => bool Should a feed permastruct be built for this post type. Inherits default from has_archive.
 *         * 'pages' => bool Should the permastruct provide for pagination. Defaults to true.
 *         * 'ep_mask' => const Assign an endpoint mask.
 *             * If not specified and permalink_epmask is set, inherits from permalink_epmask.
 *             * If not specified and permalink_epmask is not set, defaults to EP_PERMALINK
 * - query_var - Sets the query_var key for this post type. Defaults to $post_type key
 *     * If false, a post type cannot be loaded at ?{query_var}={post_slug}
 *     * If specified as a string, the query ?{query_var_string}={post_slug} will be valid.
 * - can_export - Allows this post type to be exported. Defaults to true.
 * - delete_with_user - Whether to delete posts of this type when deleting a user.
 *     * If true, posts of this type belonging to the user will be moved to trash when then user is deleted.
 *     * If false, posts of this type belonging to the user will *not* be trashed or deleted.
 *     * If not set (the default), posts are trashed if post_type_supports('author'). Otherwise posts are not trashed or deleted.
 * - _builtin - true if this post type is a native or "built-in" post_type. THIS IS FOR INTERNAL USE ONLY!
 * - _edit_link - URL segement to use for edit link of this post type. THIS IS FOR INTERNAL USE ONLY!
 *
 * @since 2.9.0
 * @uses $wp_post_types Inserts new post type object into the list
 *
 * @param string $post_type Post type key, must not exceed 20 characters
 * @param array|string $args See optional args description above.
 * @return object|WP_Error the registered post type object, or an error object
 */
function register_post_type( $post_type, $args = array() ) {
	global $wp_post_types, $wp_rewrite, $wp;

	if ( !is_array($wp_post_types) )
		$wp_post_types = array();

	// Args prefixed with an underscore are reserved for internal use.
	$defaults = array(
		'labels' => array(), 'description' => '', 'publicly_queryable' => null, 'exclude_from_search' => null,
		'capability_type' => 'post', 'capabilities' => array(), 'map_meta_cap' => null,
		'_builtin' => false, '_edit_link' => 'post.php?post=%d', 'hierarchical' => false,
		'public' => false, 'rewrite' => true, 'has_archive' => false, 'query_var' => true,
		'supports' => array(), 'register_meta_box_cb' => null,
		'taxonomies' => array(), 'show_ui' => null, 'menu_position' => null, 'menu_icon' => null,
		'can_export' => true,
		'show_in_nav_menus' => null, 'show_in_menu' => null, 'show_in_admin_bar' => null,
		'delete_with_user' => null,
	);
	$args = wp_parse_args($args, $defaults);
	$args = (object) $args;

	$post_type = sanitize_key($post_type);
	$args->name = $post_type;

	if ( strlen( $post_type ) > 20 )
			return new WP_Error( 'post_type_too_long', __( 'Post types cannot exceed 20 characters in length' ) );

	// If not set, default to the setting for public.
	if ( null === $args->publicly_queryable )
		$args->publicly_queryable = $args->public;

	// If not set, default to the setting for public.
	if ( null === $args->show_ui )
		$args->show_ui = $args->public;

	// If not set, default to the setting for show_ui.
	if ( null === $args->show_in_menu || ! $args->show_ui )
		$args->show_in_menu = $args->show_ui;

	// If not set, default to the whether the full UI is shown.
	if ( null === $args->show_in_admin_bar )
		$args->show_in_admin_bar = true === $args->show_in_menu;

	// Whether to show this type in nav-menus.php. Defaults to the setting for public.
	if ( null === $args->show_in_nav_menus )
		$args->show_in_nav_menus = $args->public;

	// If not set, default to true if not public, false if public.
	if ( null === $args->exclude_from_search )
		$args->exclude_from_search = !$args->public;

	// Back compat with quirky handling in version 3.0. #14122
	if ( empty( $args->capabilities ) && null === $args->map_meta_cap && in_array( $args->capability_type, array( 'post', 'page' ) ) )
		$args->map_meta_cap = true;

	if ( null === $args->map_meta_cap )
		$args->map_meta_cap = false;

	$args->cap = get_post_type_capabilities( $args );
	unset($args->capabilities);

	if ( is_array( $args->capability_type ) )
		$args->capability_type = $args->capability_type[0];

	if ( ! empty($args->supports) ) {
		add_post_type_support($post_type, $args->supports);
		unset($args->supports);
	} else {
		// Add default features
		add_post_type_support($post_type, array('title', 'editor'));
	}

	if ( false !== $args->query_var && !empty($wp) ) {
		if ( true === $args->query_var )
			$args->query_var = $post_type;
		$args->query_var = sanitize_title_with_dashes($args->query_var);
		$wp->add_query_var($args->query_var);
	}

	if ( false !== $args->rewrite && ( is_admin() || '' != get_option('permalink_structure') ) ) {
		if ( ! is_array( $args->rewrite ) )
			$args->rewrite = array();
		if ( empty( $args->rewrite['slug'] ) )
			$args->rewrite['slug'] = $post_type;
		if ( ! isset( $args->rewrite['with_front'] ) )
			$args->rewrite['with_front'] = true;
		if ( ! isset( $args->rewrite['pages'] ) )
			$args->rewrite['pages'] = true;
		if ( ! isset( $args->rewrite['feeds'] ) || ! $args->has_archive )
			$args->rewrite['feeds'] = (bool) $args->has_archive;
		if ( ! isset( $args->rewrite['ep_mask'] ) ) {
			if ( isset( $args->permalink_epmask ) )
				$args->rewrite['ep_mask'] = $args->permalink_epmask;
			else
				$args->rewrite['ep_mask'] = EP_PERMALINK;
		}

		if ( $args->hierarchical )
			add_rewrite_tag("%$post_type%", '(.+?)', $args->query_var ? "{$args->query_var}=" : "post_type=$post_type&name=");
		else
			add_rewrite_tag("%$post_type%", '([^/]+)', $args->query_var ? "{$args->query_var}=" : "post_type=$post_type&name=");

		if ( $args->has_archive ) {
			$archive_slug = $args->has_archive === true ? $args->rewrite['slug'] : $args->has_archive;
			if ( $args->rewrite['with_front'] )
				$archive_slug = substr( $wp_rewrite->front, 1 ) . $archive_slug;
			else
				$archive_slug = $wp_rewrite->root . $archive_slug;

			add_rewrite_rule( "{$archive_slug}/?$", "index.php?post_type=$post_type", 'top' );
			if ( $args->rewrite['feeds'] && $wp_rewrite->feeds ) {
				$feeds = '(' . trim( implode( '|', $wp_rewrite->feeds ) ) . ')';
				add_rewrite_rule( "{$archive_slug}/feed/$feeds/?$", "index.php?post_type=$post_type" . '&feed=$matches[1]', 'top' );
				add_rewrite_rule( "{$archive_slug}/$feeds/?$", "index.php?post_type=$post_type" . '&feed=$matches[1]', 'top' );
			}
			if ( $args->rewrite['pages'] )
				add_rewrite_rule( "{$archive_slug}/{$wp_rewrite->pagination_base}/([0-9]{1,})/?$", "index.php?post_type=$post_type" . '&paged=$matches[1]', 'top' );
		}

		add_permastruct( $post_type, "{$args->rewrite['slug']}/%$post_type%", $args->rewrite );
	}

	if ( $args->register_meta_box_cb )
		add_action('add_meta_boxes_' . $post_type, $args->register_meta_box_cb, 10, 1);

	$args->labels = get_post_type_labels( $args );
	$args->label = $args->labels->name;

	$wp_post_types[$post_type] = $args;

	add_action( 'future_' . $post_type, '_future_post_hook', 5, 2 );

	foreach ( $args->taxonomies as $taxonomy ) {
		register_taxonomy_for_object_type( $taxonomy, $post_type );
	}

	do_action( 'registered_post_type', $post_type, $args );

	return $args;
}

/**
 * Builds an object with all post type capabilities out of a post type object
 *
 * Post type capabilities use the 'capability_type' argument as a base, if the
 * capability is not set in the 'capabilities' argument array or if the
 * 'capabilities' argument is not supplied.
 *
 * The capability_type argument can optionally be registered as an array, with
 * the first value being singular and the second plural, e.g. array('story, 'stories')
 * Otherwise, an 's' will be added to the value for the plural form. After
 * registration, capability_type will always be a string of the singular value.
 *
 * By default, seven keys are accepted as part of the capabilities array:
 *
 * - edit_post, read_post, and delete_post are meta capabilities, which are then
 *   generally mapped to corresponding primitive capabilities depending on the
 *   context, which would be the post being edited/read/deleted and the user or
 *   role being checked. Thus these capabilities would generally not be granted
 *   directly to users or roles.
 *
 * - edit_posts - Controls whether objects of this post type can be edited.
 * - edit_others_posts - Controls whether objects of this type owned by other users
 *   can be edited. If the post type does not support an author, then this will
 *   behave like edit_posts.
 * - publish_posts - Controls publishing objects of this post type.
 * - read_private_posts - Controls whether private objects can be read.
 *
 * These four primitive capabilities are checked in core in various locations.
 * There are also seven other primitive capabilities which are not referenced
 * directly in core, except in map_meta_cap(), which takes the three aforementioned
 * meta capabilities and translates them into one or more primitive capabilities
 * that must then be checked against the user or role, depending on the context.
 *
 * - read - Controls whether objects of this post type can be read.
 * - delete_posts - Controls whether objects of this post type can be deleted.
 * - delete_private_posts - Controls whether private objects can be deleted.
 * - delete_published_posts - Controls whether published objects can be deleted.
 * - delete_others_posts - Controls whether objects owned by other users can be
 *   can be deleted. If the post type does not support an author, then this will
 *   behave like delete_posts.
 * - edit_private_posts - Controls whether private objects can be edited.
 * - edit_published_posts - Controls whether published objects can be edited.
 *
 * These additional capabilities are only used in map_meta_cap(). Thus, they are
 * only assigned by default if the post type is registered with the 'map_meta_cap'
 * argument set to true (default is false).
 *
 * @see map_meta_cap()
 * @since 3.0.0
 *
 * @param object $args Post type registration arguments
 * @return object object with all the capabilities as member variables
 */
function get_post_type_capabilities( $args ) {
	if ( ! is_array( $args->capability_type ) )
		$args->capability_type = array( $args->capability_type, $args->capability_type . 's' );

	// Singular base for meta capabilities, plural base for primitive capabilities.
	list( $singular_base, $plural_base ) = $args->capability_type;

	$default_capabilities = array(
		// Meta capabilities
		'edit_post'          => 'edit_'         . $singular_base,
		'read_post'          => 'read_'         . $singular_base,
		'delete_post'        => 'delete_'       . $singular_base,
		// Primitive capabilities used outside of map_meta_cap():
		'edit_posts'         => 'edit_'         . $plural_base,
		'edit_others_posts'  => 'edit_others_'  . $plural_base,
		'publish_posts'      => 'publish_'      . $plural_base,
		'read_private_posts' => 'read_private_' . $plural_base,
	);

	// Primitive capabilities used within map_meta_cap():
	if ( $args->map_meta_cap ) {
		$default_capabilities_for_mapping = array(
			'read'                   => 'read',
			'delete_posts'           => 'delete_'           . $plural_base,
			'delete_private_posts'   => 'delete_private_'   . $plural_base,
			'delete_published_posts' => 'delete_published_' . $plural_base,
			'delete_others_posts'    => 'delete_others_'    . $plural_base,
			'edit_private_posts'     => 'edit_private_'     . $plural_base,
			'edit_published_posts'   => 'edit_published_'   . $plural_base,
		);
		$default_capabilities = array_merge( $default_capabilities, $default_capabilities_for_mapping );
	}

	$capabilities = array_merge( $default_capabilities, $args->capabilities );

	// Remember meta capabilities for future reference.
	if ( $args->map_meta_cap )
		_post_type_meta_capabilities( $capabilities );

	return (object) $capabilities;
}

/**
 * Stores or returns a list of post type meta caps for map_meta_cap().
 *
 * @since 3.1.0
 * @access private
 */
function _post_type_meta_capabilities( $capabilities = null ) {
	static $meta_caps = array();
	if ( null === $capabilities )
		return $meta_caps;
	foreach ( $capabilities as $core => $custom ) {
		if ( in_array( $core, array( 'read_post', 'delete_post', 'edit_post' ) ) )
			$meta_caps[ $custom ] = $core;
	}
}

/**
 * Builds an object with all post type labels out of a post type object
 *
 * Accepted keys of the label array in the post type object:
 * - name - general name for the post type, usually plural. The same and overridden by $post_type_object->label. Default is Posts/Pages
 * - singular_name - name for one object of this post type. Default is Post/Page
 * - add_new - Default is Add New for both hierarchical and non-hierarchical types. When internationalizing this string, please use a {@link http://codex.wordpress.org/I18n_for_WordPress_Developers#Disambiguation_by_context gettext context} matching your post type. Example: <code>_x('Add New', 'product');</code>
 * - add_new_item - Default is Add New Post/Add New Page
 * - edit_item - Default is Edit Post/Edit Page
 * - new_item - Default is New Post/New Page
 * - view_item - Default is View Post/View Page
 * - search_items - Default is Search Posts/Search Pages
 * - not_found - Default is No posts found/No pages found
 * - not_found_in_trash - Default is No posts found in Trash/No pages found in Trash
 * - parent_item_colon - This string isn't used on non-hierarchical types. In hierarchical ones the default is Parent Page:
 * - all_items - String for the submenu. Default is All Posts/All Pages
 * - menu_name - Default is the same as <code>name</code>
 *
 * Above, the first default value is for non-hierarchical post types (like posts) and the second one is for hierarchical post types (like pages).
 *
 * @since 3.0.0
 * @param object $post_type_object
 * @return object object with all the labels as member variables
 */
function get_post_type_labels( $post_type_object ) {
	$nohier_vs_hier_defaults = array(
		'name' => array( _x('Posts', 'post type general name'), _x('Pages', 'post type general name') ),
		'singular_name' => array( _x('Post', 'post type singular name'), _x('Page', 'post type singular name') ),
		'add_new' => array( _x('Add New', 'post'), _x('Add New', 'page') ),
		'add_new_item' => array( __('Add New Post'), __('Add New Page') ),
		'edit_item' => array( __('Edit Post'), __('Edit Page') ),
		'new_item' => array( __('New Post'), __('New Page') ),
		'view_item' => array( __('View Post'), __('View Page') ),
		'search_items' => array( __('Search Posts'), __('Search Pages') ),
		'not_found' => array( __('No posts found.'), __('No pages found.') ),
		'not_found_in_trash' => array( __('No posts found in Trash.'), __('No pages found in Trash.') ),
		'parent_item_colon' => array( null, __('Parent Page:') ),
		'all_items' => array( __( 'All Posts' ), __( 'All Pages' ) )
	);
	$nohier_vs_hier_defaults['menu_name'] = $nohier_vs_hier_defaults['name'];
	return _get_custom_object_labels( $post_type_object, $nohier_vs_hier_defaults );
}

/**
 * Builds an object with custom-something object (post type, taxonomy) labels out of a custom-something object
 *
 * @access private
 * @since 3.0.0
 */
function _get_custom_object_labels( $object, $nohier_vs_hier_defaults ) {

	if ( isset( $object->label ) && empty( $object->labels['name'] ) )
		$object->labels['name'] = $object->label;

	if ( !isset( $object->labels['singular_name'] ) && isset( $object->labels['name'] ) )
		$object->labels['singular_name'] = $object->labels['name'];

	if ( ! isset( $object->labels['name_admin_bar'] ) )
		$object->labels['name_admin_bar'] = isset( $object->labels['singular_name'] ) ? $object->labels['singular_name'] : $object->name;

	if ( !isset( $object->labels['menu_name'] ) && isset( $object->labels['name'] ) )
		$object->labels['menu_name'] = $object->labels['name'];

	if ( !isset( $object->labels['all_items'] ) && isset( $object->labels['menu_name'] ) )
		$object->labels['all_items'] = $object->labels['menu_name'];

	foreach ( $nohier_vs_hier_defaults as $key => $value )
			$defaults[$key] = $object->hierarchical ? $value[1] : $value[0];

	$labels = array_merge( $defaults, $object->labels );
	return (object)$labels;
}

/**
 * Adds submenus for post types.
 *
 * @access private
 * @since 3.1.0
 */
function _add_post_type_submenus() {
	foreach ( get_post_types( array( 'show_ui' => true ) ) as $ptype ) {
		$ptype_obj = get_post_type_object( $ptype );
		// Submenus only.
		if ( ! $ptype_obj->show_in_menu || $ptype_obj->show_in_menu === true )
			continue;
		add_submenu_page( $ptype_obj->show_in_menu, $ptype_obj->labels->name, $ptype_obj->labels->all_items, $ptype_obj->cap->edit_posts, "edit.php?post_type=$ptype" );
	}
}
add_action( 'admin_menu', '_add_post_type_submenus' );

/**
 * Register support of certain features for a post type.
 *
 * All features are directly associated with a functional area of the edit screen, such as the
 * editor or a meta box: 'title', 'editor', 'comments', 'revisions', 'trackbacks', 'author',
 * 'excerpt', 'page-attributes', 'thumbnail', and 'custom-fields'.
 *
 * Additionally, the 'revisions' feature dictates whether the post type will store revisions,
 * and the 'comments' feature dictates whether the comments count will show on the edit screen.
 *
 * @since 3.0.0
 * @param string $post_type The post type for which to add the feature
 * @param string|array $feature the feature being added, can be an array of feature strings or a single string
 */
function add_post_type_support( $post_type, $feature ) {
	global $_wp_post_type_features;

	$features = (array) $feature;
	foreach ($features as $feature) {
		if ( func_num_args() == 2 )
			$_wp_post_type_features[$post_type][$feature] = true;
		else
			$_wp_post_type_features[$post_type][$feature] = array_slice( func_get_args(), 2 );
	}
}

/**
 * Remove support for a feature from a post type.
 *
 * @since 3.0.0
 * @param string $post_type The post type for which to remove the feature
 * @param string $feature…