<?php

/**

 * WordPress Bookmark Administration API

 *

 * @package WordPress

 * @subpackage Administration

 */

/**

 *

 * @since 2.0.0

 *

 * @return int|WP_Error Value 0 or WP_Error on failure. The link ID on success.

 */

function add_link() {

	return edit_link();

}

/**

 * Updates or inserts a link using values provided in $_POST.

 *

 * @since 2.0.0

 *

 * @param int $link_id Optional. ID of the link to edit. Default 0.

 * @return int|WP_Error Value 0 or WP_Error on failure. The link ID on success.

 */

function edit_link( $link_id = 0 ) {

	if ( ! current_user_can( 'manage_links' ) ) {

		wp_die(

			'<h1>' . __( 'You need a higher level of permission.' ) . '</h1>' .

			'<p>' . __( 'Sorry, you are not allowed to edit the links for this site.' ) . '</p>',

			403

		);

	}

	$_POST['link_url']   = esc_url( $_POST['link_url'] );

	$_POST['link_name']  = esc_html( $_POST['link_name'] );

	$_POST['link_image'] = esc_html( $_POST['link_image'] );

	$_POST['link_rss']   = esc_url( $_POST['link_rss'] );

	if ( ! isset( $_POST['link_visible'] ) || 'N' !== $_POST['link_visible'] ) {

		$_POST['link_visible'] = 'Y';

	}

	if ( ! empty( $link_id ) ) {

		$_POST['link_id'] = $link_id;

		return wp_update_link( $_POST );

	} else {

		return wp_insert_link( $_POST );

	}

}

/**

 * Retrieves the default link for editing.

 *

 * @since 2.0.0

 *

 * @return stdClass Default link object.

 */

function get_default_link_to_edit() {

	if ( isset( $_GET['linkurl'] ) ) {

		$link->link_url = esc_url( wp_unslash( $_GET['linkurl'] ) );

	} else {

		$link->link_url = '';

	}

	if ( isset( $_GET['name'] ) ) {

		$link->link_name = esc_attr( wp_unslash( $_GET['name'] ) );

	} else {

		$link->link_name = '';

	}

	$link->link_visible = 'Y';

	return $link;

}

/**

 * Deletes a specified link from the database.

 *

 * @since 2.0.0

 *

 * @global wpdb $wpdb WordPress database abstraction object.

 *

 * @return true Always true.

 */

function wp_delete_link( $link_id ) {

	global $wpdb;

	/**

	 * Fires before a link is deleted.

	 *

	 * @since 2.0.0

	 *

	 * @param int $link_id ID of the link to delete.

	 */

	do_action( 'delete_link', $link_id );

	wp_delete_object_term_relationships( $link_id, 'link_category' );

	$wpdb->delete( $wpdb->links, array( 'link_id' => $link_id ) );

	/**

	 * Fires after a link has been deleted.

	 *

	 * @since 2.2.0

	 *

	 * @param int $link_id ID of the deleted link.

	 */

	do_action( 'deleted_link', $link_id );

	clean_bookmark_cache( $link_id );

	return true;

}

/**

 * Retrieves the link category IDs associated with the link specified.

 *

 * @since 2.1.0

 *

 * @param int $link_id Link ID to look up.

 * @return int[] The IDs of the requested link's categories.

 */

function wp_get_link_cats( $link_id = 0 ) {

	$cats = wp_get_object_terms( $link_id, 'link_category', array( 'fields' => 'ids' ) );

	return array_unique( $cats );

}

/**

 * Retrieves link data based on its ID.

 *

 * @since 2.0.0

 *

 * @param int|stdClass $link Link ID or object to retrieve.

 * @return object Link object for editing.

 */

function get_link_to_edit( $link ) {

	return get_bookmark( $link, OBJECT, 'edit' );

}

/**

 * Inserts a link into the database, or updates an existing link.

 *

 * Runs all the necessary sanitizing, provides default values if arguments are missing,

 * and finally saves the link.

 *

 * @since 2.0.0

 *

 * @global wpdb $wpdb WordPress database abstraction object.

 *

 * @param array $linkdata {

 *     Elements that make up the link to insert.

 *

 *     @type int    $link_id          Optional. The ID of the existing link if updating.

 *     @type string $link_url         The URL the link points to.

 *     @type string $link_name        The title of the link.

 *     @type string $link_image       Optional. A URL of an image.

 *     @type string $link_target      Optional. The target element for the anchor tag.

 *     @type string $link_description Optional. A short description of the link.

 *     @type string $link_visible     Optional. 'Y' means visible, anything else means not.

 *     @type int    $link_owner       Optional. A user ID.

 *     @type int    $link_rating      Optional. A rating for the link.

 *     @type string $link_rel         Optional. A relationship of the link to you.

 *     @type string $link_notes       Optional. An extended description of or notes on the link.

 *     @type string $link_rss         Optional. A URL of an associated RSS feed.

 *     @type int    $link_category    Optional. The term ID of the link category.

 *                                    If empty, uses default link category.

 * }

 * @param bool  $wp_error Optional. Whether to return a WP_Error object on failure. Default false.

 * @return int|WP_Error Value 0 or WP_Error on failure. The link ID on success.

 */

function wp_insert_link( $linkdata, $wp_error = false ) {

	global $wpdb;

	$defaults = array(

		'link_id'     => 0,

		'link_name'   => '',

		'link_url'    => '',

		'link_rating' => 0,

	);

	$parsed_args = wp_parse_args( $linkdata, $defaults );

	$parsed_args = wp_unslash( sanitize_bookmark( $parsed_args, 'db' ) );

	$link_id   = $parsed_args['link_id'];

	$link_name = $parsed_args['link_name'];

	$link_url  = $parsed_args['link_url'];

	$update = false;

	if ( ! empty( $link_id ) ) {

		$update = true;

	}

	if ( '' === trim( $link_name ) ) {

		if ( '' !== trim( $link_url ) ) {

			$link_name = $link_url;

		} else {

			return 0;

		}

	}

	if ( '' === trim( $link_url ) ) {

		return 0;

	}

	$link_rating      = ( ! empty( $parsed_args['link_rating'] ) ) ? $parsed_args['link_rating'] : 0;

	$link_image       = ( ! empty( $parsed_args['link_image'] ) ) ? $parsed_args['link_image'] : '';

	$link_target      = ( ! empty( $parsed_args['link_target'] ) ) ? $parsed_args['link_target'] : '';

	$link_visible     = ( ! empty( $parsed_args['link_visible'] ) ) ? $parsed_args['link_visible'] : 'Y';

	$link_owner       = ( ! empty( $parsed_args['link_owner'] ) ) ? $parsed_args['link_owner'] : get_current_user_id();

	$link_notes       = ( ! empty( $parsed_args['link_notes'] ) ) ? $parsed_args['link_notes'] : '';

	$link_description = ( ! empty( $parsed_args['link_description'] ) ) ? $parsed_args['link_description'] : '';

	$link_rss         = ( ! empty( $parsed_args['link_rss'] ) ) ? $parsed_args['link_rss'] : '';

	$link_rel         = ( ! empty( $parsed_args['link_rel'] ) ) ? $parsed_args['link_rel'] : '';

	$link_category    = ( ! empty( $parsed_args['link_category'] ) ) ? $parsed_args['link_category'] : array();

	// Make sure we set a valid category.

	if ( ! is_array( $link_category ) || 0 === count( $link_category ) ) {

		$link_category = array( get_option( 'default_link_category' ) );

	}

	if ( $update ) {

		if ( false === $wpdb->update( $wpdb->links, compact( 'link_url', 'link_name', 'link_image', 'link_target', 'link_description', 'link_visible', 'link_owner', 'link_rating', 'link_rel', 'link_notes', 'link_rss' ), compact( 'link_id' ) ) ) {

			if ( $wp_error ) {

				return new WP_Error( 'db_update_error', __( 'Could not update link in the database.' ), $wpdb->last_error );

			} else {

				return 0;

			}

		}

	} else {

		if ( false === $wpdb->insert( $wpdb->links, compact( 'link_url', 'link_name', 'link_image', 'link_target', 'link_description', 'link_visible', 'link_owner', 'link_rating', 'link_rel', 'link_notes', 'link_rss' ) ) ) {

			if ( $wp_error ) {

				return new WP_Error( 'db_insert_error', __( 'Could not insert link into the database.' ), $wpdb->last_error );

			} else {

				return 0;

			}

		}

		$link_id = (int) $wpdb->insert_id;

	}

	wp_set_link_cats( $link_id, $link_category );

	if ( $update ) {

		/**

		 * Fires after a link was updated in the database.

		 *

		 * @since 2.0.0

		 *

		 * @param int $link_id ID of the link that was updated.

		 */

		do_action( 'edit_link', $link_id );

	} else {

		/**

		 * Fires after a link was added to the database.

		 *

		 * @since 2.0.0

		 *

		 * @param int $link_id ID of the link that was added.

		 */

		do_action( 'add_link', $link_id );

	}

	clean_bookmark_cache( $link_id );

	return $link_id;

}

/**

 *

 * @since 2.1.0

 *

 * @param int   $link_id         ID of the link to update.

 * @param int[] $link_categories Array of link category IDs to add the link to.

 */

function wp_set_link_cats( $link_id = 0, $link_categories = array() ) {

	// If $link_categories isn't already an array, make it one:

	if ( ! is_array( $link_categories ) || 0 === count( $link_categories ) ) {

		$link_categories = array( get_option( 'default_link_category' ) );

	}

	$link_categories = array_map( 'intval', $link_categories );

	$link_categories = array_unique( $link_categories );

	wp_set_object_terms( $link_id, $link_categories, 'link_category' );

	clean_bookmark_cache( $link_id );

}

/**

 * Updates a link in the database.

 *

 * @since 2.0.0

 *

 * @param array $linkdata Link data to update. See wp_insert_link() for accepted arguments.

 * @return int|WP_Error Value 0 or WP_Error on failure. The updated link ID on success.

 */

function wp_update_link( $linkdata ) {

	$link_id = (int) $linkdata['link_id'];

	$link = get_bookmark( $link_id, ARRAY_A );

	// Escape data pulled from DB.

	$link = wp_slash( $link );

	// Passed link category list overwrites existing category list if not empty.

	if ( isset( $linkdata['link_category'] ) && is_array( $linkdata['link_category'] )

		&& count( $linkdata['link_category'] ) > 0

	) {

		$link_cats = $linkdata['link_category'];

	} else {

		$link_cats = $link['link_category'];

	}

	// Merge old and new fields with new fields overwriting old ones.

	$linkdata                  = array_merge( $link, $linkdata );

	$linkdata['link_category'] = $link_cats;

	return wp_insert_link( $linkdata );

}

/**

 * Outputs the 'disabled' message for the WordPress Link Manager.

 *

 * @since 3.5.0

 * @access private

 *

 * @global string $pagenow The filename of the current screen.

 */

function wp_link_manager_disabled_message() {

	global $pagenow;

	if ( ! in_array( $pagenow, array( 'link-manager.php', 'link-add.php', 'link.php' ), true ) ) {

		return;

	}

	add_filter( 'pre_option_link_manager_enabled', '__return_true', 100 );

	$really_can_manage_links = current_user_can( 'manage_links' );

	remove_filter( 'pre_option_link_manager_enabled', '__return_true', 100 );

	if ( $really_can_manage_links ) {

		$plugins = get_plugins();

		if ( empty( $plugins['link-manager/link-manager.php'] ) ) {

			if ( current_user_can( 'install_plugins' ) ) {

				$install_url = wp_nonce_url(

					self_admin_url( 'update.php?action=install-plugin&plugin=link-manager' ),

					'install-plugin_link-manager'

				);

				wp_die(

					sprintf(

						/* translators: %s: A link to install the Link Manager plugin. */

						__( 'If you are looking to use the link manager, please install the <a href="%s">Link Manager plugin</a>.' ),

						esc_url( $install_url )

					)

				);

			}

		} elseif ( is_plugin_inactive( 'link-manager/link-manager.php' ) ) {

			if ( current_user_can( 'activate_plugins' ) ) {

				$activate_url = wp_nonce_url(

					self_admin_url( 'plugins.php?action=activate&plugin=link-manager/link-manager.php' ),

					'activate-plugin_link-manager/link-manager.php'

				);

				wp_die(

					sprintf(

						/* translators: %s: A link to activate the Link Manager plugin. */

						__( 'Please activate the <a href="%s">Link Manager plugin</a> to use the link manager.' ),

						esc_url( $activate_url )

					)

				);

			}

		}

	}

	wp_die( __( 'Sorry, you are not allowed to edit the links for this site.' ) );

}