<?php

/**

 * WordPress Link Template Functions

 *

 * @package WordPress

 * @subpackage Template

 */

/**

 * Displays the permalink for the current post.

 *

 * @since 1.2.0

 * @since 4.4.0 Added the `$post` parameter.

 *

 * @param int|WP_Post $post Optional. Post ID or post object. Default is the global `$post`.

 */

function the_permalink( $post = 0 ) {

	/**

	 * Filters the display of the permalink for the current post.

	 *

	 * @since 1.5.0

	 * @since 4.4.0 Added the `$post` parameter.

	 *

	 * @param string      $permalink The permalink for the current post.

	 * @param int|WP_Post $post      Post ID, WP_Post object, or 0. Default 0.

	 */

	echo esc_url( apply_filters( 'the_permalink', get_permalink( $post ), $post ) );

}

/**

 * Retrieves a trailing-slashed string if the site is set for adding trailing slashes.

 *

 * Conditionally adds a trailing slash if the permalink structure has a trailing

 * slash, strips the trailing slash if not. The string is passed through the

 * {@see 'user_trailingslashit'} filter. Will remove trailing slash from string, if

 * site is not set to have them.

 *

 * @since 2.2.0

 *

 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.

 *

 * @param string $string      URL with or without a trailing slash.

 * @param string $type_of_url Optional. The type of URL being considered (e.g. single, category, etc)

 *                            for use in the filter. Default empty string.

 * @return string The URL with the trailing slash appended or stripped.

 */

function user_trailingslashit( $string, $type_of_url = '' ) {

	global $wp_rewrite;

	if ( $wp_rewrite->use_trailing_slashes ) {

		$string = trailingslashit( $string );

	} else {

		$string = untrailingslashit( $string );

	}

	/**

	 * Filters the trailing-slashed string, depending on whether the site is set to use trailing slashes.

	 *

	 * @since 2.2.0

	 *

	 * @param string $string      URL with or without a trailing slash.

	 * @param string $type_of_url The type of URL being considered. Accepts 'single', 'single_trackback',

	 *                            'single_feed', 'single_paged', 'commentpaged', 'paged', 'home', 'feed',

	 *                            'category', 'page', 'year', 'month', 'day', 'post_type_archive'.

	 */

	return apply_filters( 'user_trailingslashit', $string, $type_of_url );

}

/**

 * Displays the permalink anchor for the current post.

 *

 * The permalink mode title will use the post title for the 'a' element 'id'

 * attribute. The id mode uses 'post-' with the post ID for the 'id' attribute.

 *

 * @since 0.71

 *

 * @param string $mode Optional. Permalink mode. Accepts 'title' or 'id'. Default 'id'.

 */

function permalink_anchor( $mode = 'id' ) {

	$post = get_post();

	switch ( strtolower( $mode ) ) {

		case 'title':

			$title = sanitize_title( $post->post_title ) . '-' . $post->ID;

			echo '<a id="' . $title . '"></a>';

			break;

		case 'id':

		default:

			echo '<a id="post-' . $post->ID . '"></a>';

			break;

	}

}

/**

 * Determine whether post should always use a plain permalink structure.

 *

 * @since 5.7.0

 *

 * @param WP_Post|int|null $post   Optional. Post ID or post object. Defaults to global $post.

 * @param bool|null        $sample Optional. Whether to force consideration based on sample links.

 *                                 If omitted, a sample link is generated if a post object is passed

 *                                 with the filter property set to 'sample'.

 * @return bool Whether to use a plain permalink structure.

 */

function wp_force_plain_post_permalink( $post = null, $sample = null ) {

	if (

		null === $sample &&

		is_object( $post ) &&

		isset( $post->filter ) &&

		'sample' === $post->filter

	) {

		$sample = true;

	} else {

		$post   = get_post( $post );

		$sample = null !== $sample ? $sample : false;

	}

	if ( ! $post ) {

		return true;

	}

	$post_status_obj = get_post_status_object( get_post_status( $post ) );

	$post_type_obj   = get_post_type_object( get_post_type( $post ) );

	if ( ! $post_status_obj || ! $post_type_obj ) {

		return true;

	}

	if (

		// Publicly viewable links never have plain permalinks.

		is_post_status_viewable( $post_status_obj ) ||

		(

			// Private posts don't have plain permalinks if the user can read them.

			$post_status_obj->private &&

			current_user_can( 'read_post', $post->ID )

		) ||

		// Protected posts don't have plain links if getting a sample URL.

		( $post_status_obj->protected && $sample )

	) {

		return false;

	}

	return true;

}

/**

 * Retrieves the full permalink for the current post or post ID.

 *

 * This function is an alias for get_permalink().

 *

 * @since 3.9.0

 *

 * @see get_permalink()

 *

 * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.

 * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.

 * @return string|false The permalink URL or false if post does not exist.

 */

function get_the_permalink( $post = 0, $leavename = false ) {

	return get_permalink( $post, $leavename );

}

/**

 * Retrieves the full permalink for the current post or post ID.

 *

 * @since 1.0.0

 *

 * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.

 * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.

 * @return string|false The permalink URL or false if post does not exist.

 */

function get_permalink( $post = 0, $leavename = false ) {

	$rewritecode = array(

		'%year%',

		'%monthnum%',

		'%day%',

		'%hour%',

		'%minute%',

		'%second%',

		$leavename ? '' : '%postname%',

		'%post_id%',

		'%category%',

		'%author%',

		$leavename ? '' : '%pagename%',

	);

	if ( is_object( $post ) && isset( $post->filter ) && 'sample' === $post->filter ) {

		$sample = true;

	} else {

		$post   = get_post( $post );

		$sample = false;

	}

	if ( empty( $post->ID ) ) {

		return false;

	}

	if ( 'page' === $post->post_type ) {

		return get_page_link( $post, $leavename, $sample );

	} elseif ( 'attachment' === $post->post_type ) {

		return get_attachment_link( $post, $leavename );

	} elseif ( in_array( $post->post_type, get_post_types( array( '_builtin' => false ) ), true ) ) {

		return get_post_permalink( $post, $leavename, $sample );

	}

	$permalink = get_option( 'permalink_structure' );

	/**

	 * Filters the permalink structure for a post before token replacement occurs.

	 *

	 * Only applies to posts with post_type of 'post'.

	 *

	 * @since 3.0.0

	 *

	 * @param string  $permalink The site's permalink structure.

	 * @param WP_Post $post      The post in question.

	 * @param bool    $leavename Whether to keep the post name.

	 */

	$permalink = apply_filters( 'pre_post_link', $permalink, $post, $leavename );

	if (

		$permalink &&

		! wp_force_plain_post_permalink( $post )

	) {

		$category = '';

		if ( strpos( $permalink, '%category%' ) !== false ) {

			$cats = get_the_category( $post->ID );

			if ( $cats ) {

				$cats = wp_list_sort(

					$cats,

					array(

						'term_id' => 'ASC',

					)

				);

				/**

				 * Filters the category that gets used in the %category% permalink token.

				 *

				 * @since 3.5.0

				 *

				 * @param WP_Term  $cat  The category to use in the permalink.

				 * @param array    $cats Array of all categories (WP_Term objects) associated with the post.

				 * @param WP_Post  $post The post in question.

				 */

				$category_object = apply_filters( 'post_link_category', $cats[0], $cats, $post );

				$category_object = get_term( $category_object, 'category' );

				$category        = $category_object->slug;

				if ( $category_object->parent ) {

					$category = get_category_parents( $category_object->parent, false, '/', true ) . $category;

				}

			}

			// Show default category in permalinks,

			// without having to assign it explicitly.

			if ( empty( $category ) ) {

				$default_category = get_term( get_option( 'default_category' ), 'category' );

				if ( $default_category && ! is_wp_error( $default_category ) ) {

					$category = $default_category->slug;

				}

			}

		}

		$author = '';

		if ( strpos( $permalink, '%author%' ) !== false ) {

			$authordata = get_userdata( $post->post_author );

			$author     = $authordata->user_nicename;

		}

		// This is not an API call because the permalink is based on the stored post_date value,

		// which should be parsed as local time regardless of the default PHP timezone.

		$date = explode( ' ', str_replace( array( '-', ':' ), ' ', $post->post_date ) );

		$rewritereplace = array(

			$date[0],

			$date[1],

			$date[2],

			$date[3],

			$date[4],

			$date[5],

			$post->post_name,

			$post->ID,

			$category,

			$author,

			$post->post_name,

		);

		$permalink = home_url( str_replace( $rewritecode, $rewritereplace, $permalink ) );

		$permalink = user_trailingslashit( $permalink, 'single' );

	} else { // If they're not using the fancy permalink option.

		$permalink = home_url( '?p=' . $post->ID );

	}

	/**

	 * Filters the permalink for a post.

	 *

	 * Only applies to posts with post_type of 'post'.

	 *

	 * @since 1.5.0

	 *

	 * @param string  $permalink The post's permalink.

	 * @param WP_Post $post      The post in question.

	 * @param bool    $leavename Whether to keep the post name.

	 */

	return apply_filters( 'post_link', $permalink, $post, $leavename );

}

/**

 * Retrieves the permalink for a post of a custom post type.

 *

 * @since 3.0.0

 *

 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.

 *

 * @param int|WP_Post $id        Optional. Post ID or post object. Default is the global `$post`.

 * @param bool        $leavename Optional. Whether to keep post name. Default false.

 * @param bool        $sample    Optional. Is it a sample permalink. Default false.

 * @return string|WP_Error The post permalink.

 */

function get_post_permalink( $id = 0, $leavename = false, $sample = false ) {

	global $wp_rewrite;

	$post = get_post( $id );

	if ( is_wp_error( $post ) ) {

		return $post;

	}

	$post_link = $wp_rewrite->get_extra_permastruct( $post->post_type );

	$slug = $post->post_name;

	$force_plain_link = wp_force_plain_post_permalink( $post );

	$post_type = get_post_type_object( $post->post_type );

	if ( $post_type->hierarchical ) {

		$slug = get_page_uri( $post );

	}

	if ( ! empty( $post_link ) && ( ! $force_plain_link || $sample ) ) {

		if ( ! $leavename ) {

			$post_link = str_replace( "%$post->post_type%", $slug, $post_link );

		}

		$post_link = home_url( user_trailingslashit( $post_link ) );

	} else {

		if ( $post_type->query_var && ( isset( $post->post_status ) && ! $force_plain_link ) ) {

			$post_link = add_query_arg( $post_type->query_var, $slug, '' );

		} else {

			$post_link = add_query_arg(

				array(

					'post_type' => $post->post_type,

					'p'         => $post->ID,

				),

				''

			);

		}

		$post_link = home_url( $post_link );

	}

	/**

	 * Filters the permalink for a post of a custom post type.

	 *

	 * @since 3.0.0

	 *

	 * @param string  $post_link The post's permalink.

	 * @param WP_Post $post      The post in question.

	 * @param bool    $leavename Whether to keep the post name.

	 * @param bool    $sample    Is it a sample permalink.

	 */

	return apply_filters( 'post_type_link', $post_link, $post, $leavename, $sample );

}

/**

 * Retrieves the permalink for the current page or page ID.

 *

 * Respects page_on_front. Use this one.

 *

 * @since 1.5.0

 *

 * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.

 * @param bool        $leavename Optional. Whether to keep the page name. Default false.

 * @param bool        $sample    Optional. Whether it should be treated as a sample permalink.

 *                               Default false.

 * @return string The page permalink.

 */

function get_page_link( $post = false, $leavename = false, $sample = false ) {

	$post = get_post( $post );

	if ( 'page' === get_option( 'show_on_front' ) && get_option( 'page_on_front' ) == $post->ID ) {

		$link = home_url( '/' );

	} else {

		$link = _get_page_link( $post, $leavename, $sample );

	}

	/**

	 * Filters the permalink for a page.

	 *

	 * @since 1.5.0

	 *

	 * @param string $link    The page's permalink.

	 * @param int    $post_id The ID of the page.

	 * @param bool   $sample  Is it a sample permalink.

	 */

	return apply_filters( 'page_link', $link, $post->ID, $sample );

}

/**

 * Retrieves the page permalink.

 *

 * Ignores page_on_front. Internal use only.

 *

 * @since 2.1.0

 * @access private

 *

 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.

 *

 * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.

 * @param bool        $leavename Optional. Whether to keep the page name. Default false.

 * @param bool        $sample    Optional. Whether it should be treated as a sample permalink.

 *                               Default false.

 * @return string The page permalink.

 */

function _get_page_link( $post = false, $leavename = false, $sample = false ) {

	global $wp_rewrite;

	$post = get_post( $post );

	$force_plain_link = wp_force_plain_post_permalink( $post );

	$link = $wp_rewrite->get_page_permastruct();

	if ( ! empty( $link ) && ( ( isset( $post->post_status ) && ! $force_plain_link ) || $sample ) ) {

		if ( ! $leavename ) {

			$link = str_replace( '%pagename%', get_page_uri( $post ), $link );

		}

		$link = home_url( $link );

		$link = user_trailingslashit( $link, 'page' );

	} else {

		$link = home_url( '?page_id=' . $post->ID );

	}

	/**

	 * Filters the permalink for a non-page_on_front page.

	 *

	 * @since 2.1.0

	 *

	 * @param string $link    The page's permalink.

	 * @param int    $post_id The ID of the page.

	 */

	return apply_filters( '_get_page_link', $link, $post->ID );

}

/**

 * Retrieves the permalink for an attachment.

 *

 * This can be used in the WordPress Loop or outside of it.

 *

 * @since 2.0.0

 *

 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.

 *

 * @param int|object $post      Optional. Post ID or object. Default uses the global `$post`.

 * @param bool       $leavename Optional. Whether to keep the page name. Default false.

 * @return string The attachment permalink.

 */

function get_attachment_link( $post = null, $leavename = false ) {

	global $wp_rewrite;

	$link = false;

	$post             = get_post( $post );

	$force_plain_link = wp_force_plain_post_permalink( $post );

	$parent_id        = $post->post_parent;

	$parent           = $parent_id ? get_post( $parent_id ) : false;

	$parent_valid     = true; // Default for no parent.

	if (

		$parent_id &&

		(

			$post->post_parent === $post->ID ||

			! $parent ||

			! is_post_type_viewable( get_post_type( $parent ) )

		)

	) {

		// Post is either its own parent or parent post unavailable.

		$parent_valid = false;

	}

	if ( $force_plain_link || ! $parent_valid ) {

		$link = false;

	} elseif ( $wp_rewrite->using_permalinks() && $parent ) {

		if ( 'page' === $parent->post_type ) {

			$parentlink = _get_page_link( $post->post_parent ); // Ignores page_on_front.

		} else {

			$parentlink = get_permalink( $post->post_parent );