<?php

/**

 * Link/Bookmark API

 *

 * @package WordPress

 * @subpackage Bookmark

 */

/**

 * Retrieve Bookmark data

 *

 * @since 2.1.0

 * @uses $wpdb Database Object

 *

 * @param mixed $bookmark

 * @param string $output Optional. Either OBJECT, ARRAY_N, or ARRAY_A constant

 * @param string $filter Optional, default is 'raw'.

 * @return array|object Type returned depends on $output value.

 */

function get_bookmark($bookmark, $output = OBJECT, $filter = 'raw') {

	global $wpdb;

	if ( empty($bookmark) ) {

		if ( isset($GLOBALS['link']) )

			$_bookmark = & $GLOBALS['link'];

		else

			$_bookmark = null;

	} elseif ( is_object($bookmark) ) {

		wp_cache_add($bookmark->link_id, $bookmark, 'bookmark');

		$_bookmark = $bookmark;

	} else {

		if ( isset($GLOBALS['link']) && ($GLOBALS['link']->link_id == $bookmark) ) {

			$_bookmark = & $GLOBALS['link'];

		} elseif ( ! $_bookmark = wp_cache_get($bookmark, 'bookmark') ) {

			$_bookmark = $wpdb->get_row($wpdb->prepare("SELECT * FROM $wpdb->links WHERE link_id = %d LIMIT 1", $bookmark));

		}

	}

	$_bookmark = sanitize_bookmark($_bookmark, $filter);

	if ( $output == OBJECT ) {

		return $_bookmark;

	} elseif ( $output == ARRAY_A ) {

		return get_object_vars($_bookmark);

	} elseif ( $output == ARRAY_N ) {

		return array_values(get_object_vars($_bookmark));

	} else {

		return $_bookmark;

	}

}

/**

 * Retrieve single bookmark data item or field.

 *

 * @since 2.3.0

 * @uses get_bookmark() Gets bookmark object using $bookmark as ID

 * @uses sanitize_bookmark_field() Sanitizes Bookmark field based on $context.

 *

 * @param string $field The name of the data field to return

 * @param int $bookmark The bookmark ID to get field

 * @param string $context Optional. The context of how the field will be used.

 * @return string

 */

function get_bookmark_field( $field, $bookmark, $context = 'display' ) {

	$bookmark = (int) $bookmark;

	$bookmark = get_bookmark( $bookmark );

	if ( is_wp_error($bookmark) )

		return $bookmark;

	if ( !is_object($bookmark) )

		return '';

	if ( !isset($bookmark->$field) )

		return '';

	return sanitize_bookmark_field($field, $bookmark->$field, $bookmark->link_id, $context);

}

/**

 * Retrieves the list of bookmarks

 *

 * Attempts to retrieve from the cache first based on MD5 hash of arguments. If

 * that fails, then the query will be built from the arguments and executed. The

 * results will be stored to the cache.

 *

 * List of default arguments are as follows:

 * 'orderby' - Default is 'name' (string). How to order the links by. String is

 *		based off of the bookmark scheme.

 * 'order' - Default is 'ASC' (string). Either 'ASC' or 'DESC'. Orders in either

 *		ascending or descending order.

 * 'limit' - Default is -1 (integer) or show all. The amount of bookmarks to

 *		display.

 * 'category' - Default is empty string (string). Include the links in what

 *		category ID(s).

 * 'category_name' - Default is empty string (string). Get links by category

 *		name.

 * 'hide_invisible' - Default is 1 (integer). Whether to show (default) or hide

 *		links marked as 'invisible'.

 * 'show_updated' - Default is 0 (integer). Will show the time of when the

 *		bookmark was last updated.

 * 'include' - Default is empty string (string). Include bookmark ID(s)

 *		separated by commas.

 * 'exclude' - Default is empty string (string). Exclude bookmark ID(s)

 *		separated by commas.

 *

 * @since 2.1.0

 * @uses $wpdb Database Object

 * @link http://codex.wordpress.org/Template_Tags/get_bookmarks

 *

 * @param string|array $args List of arguments to overwrite the defaults

 * @return array List of bookmark row objects

 */

function get_bookmarks($args = '') {

	global $wpdb;

	$defaults = array(

		'orderby' => 'name', 'order' => 'ASC',

		'limit' => -1, 'category' => '',

		'category_name' => '', 'hide_invisible' => 1,

		'show_updated' => 0, 'include' => '',

		'exclude' => '', 'search' => ''

	);

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

	extract( $r, EXTR_SKIP );

	$cache = array();

	$key = md5( serialize( $r ) );

	if ( $cache = wp_cache_get( 'get_bookmarks', 'bookmark' ) ) {

		if ( is_array($cache) && isset( $cache[ $key ] ) )

			return apply_filters('get_bookmarks', $cache[ $key ], $r );

	}

	if ( !is_array($cache) )

		$cache = array();

	$inclusions = '';

	if ( !empty($include) ) {

		$exclude = '';  //ignore exclude, category, and category_name params if using include

		$category = '';

		$category_name = '';

		$inclinks = preg_split('/[\s,]+/',$include);

		if ( count($inclinks) ) {

			foreach ( $inclinks as $inclink ) {

				if (empty($inclusions))

					$inclusions = ' AND ( link_id = ' . intval($inclink) . ' ';

				else

					$inclusions .= ' OR link_id = ' . intval($inclink) . ' ';

			}

		}

	}

	if (!empty($inclusions))

		$inclusions .= ')';

	$exclusions = '';

	if ( !empty($exclude) ) {

		$exlinks = preg_split('/[\s,]+/',$exclude);

		if ( count($exlinks) ) {

			foreach ( $exlinks as $exlink ) {

				if (empty($exclusions))

					$exclusions = ' AND ( link_id <> ' . intval($exlink) . ' ';

				else

					$exclusions .= ' AND link_id <> ' . intval($exlink) . ' ';

			}

		}

	}

	if (!empty($exclusions))

		$exclusions .= ')';

	if ( !empty($category_name) ) {

		if ( $category = get_term_by('name', $category_name, 'link_category') ) {

			$category = $category->term_id;

		} else {

			$cache[ $key ] = array();

			wp_cache_set( 'get_bookmarks', $cache, 'bookmark' );

			return apply_filters( 'get_bookmarks', array(), $r );

		}

	}

	if ( ! empty($search) ) {

		$search = like_escape($search);

		$search = " AND ( (link_url LIKE '%$search%') OR (link_name LIKE '%$search%') OR (link_description LIKE '%$search%') ) ";

	}

	$category_query = '';

	$join = '';

	if ( !empty($category) ) {

		$incategories = preg_split('/[\s,]+/',$category);

		if ( count($incategories) ) {

			foreach ( $incategories as $incat ) {

				if (empty($category_query))

					$category_query = ' AND ( tt.term_id = ' . intval($incat) . ' ';

				else

					$category_query .= ' OR tt.term_id = ' . intval($incat) . ' ';

			}

		}

	}

	if (!empty($category_query)) {

		$category_query .= ") AND taxonomy = 'link_category'";

		$join = " INNER JOIN $wpdb->term_relationships AS tr ON ($wpdb->links.link_id = tr.object_id) INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_taxonomy_id = tr.term_taxonomy_id";

	}

	if ( $show_updated && get_option('links_recently_updated_time') ) {

		$recently_updated_test = ", IF (DATE_ADD(link_updated, INTERVAL " . get_option('links_recently_updated_time') . " MINUTE) >= NOW(), 1,0) as recently_updated ";

	} else {

		$recently_updated_test = '';

	}

	$get_updated = ( $show_updated ) ? ', UNIX_TIMESTAMP(link_updated) AS link_updated_f ' : '';

	$orderby = strtolower($orderby);

	$length = '';

	switch ( $orderby ) {

		case 'length':

			$length = ", CHAR_LENGTH(link_name) AS length";

			break;

		case 'rand':

			$orderby = 'rand()';

			break;

		case 'link_id':

			$orderby = "$wpdb->links.link_id";

			break;

		default:

			$orderparams = array();

			foreach ( explode(',', $orderby) as $ordparam ) {

				$ordparam = trim($ordparam);

				$keys = array( 'link_id', 'link_name', 'link_url', 'link_visible', 'link_rating', 'link_owner', 'link_updated', 'link_notes' );

				if ( in_array( 'link_' . $ordparam, $keys ) )

					$orderparams[] = 'link_' . $ordparam;

				elseif ( in_array( $ordparam, $keys ) )

					$orderparams[] = $ordparam;

			}

			$orderby = implode(',', $orderparams);

	}

	if ( empty( $orderby ) )

		$orderby = 'link_name';

	$order = strtoupper( $order );

	if ( '' !== $order && !in_array( $order, array( 'ASC', 'DESC' ) ) )

		$order = 'ASC';

	$visible = '';

	if ( $hide_invisible )

		$visible = "AND link_visible = 'Y'";

	$query = "SELECT * $length $recently_updated_test $get_updated FROM $wpdb->links $join WHERE 1=1 $visible $category_query";

	$query .= " $exclusions $inclusions $search";

	$query .= " ORDER BY $orderby $order";

	if ($limit != -1)

		$query .= " LIMIT $limit";

	$results = $wpdb->get_results($query);

	$cache[ $key ] = $results;

	wp_cache_set( 'get_bookmarks', $cache, 'bookmark' );

	return apply_filters('get_bookmarks', $results, $r);

}

/**

 * Sanitizes all bookmark fields

 *

 * @since 2.3.0

 *

 * @param object|array $bookmark Bookmark row

 * @param string $context Optional, default is 'display'. How to filter the

 *		fields

 * @return object|array Same type as $bookmark but with fields sanitized.

 */

function sanitize_bookmark($bookmark, $context = 'display') {

	$fields = array('link_id', 'link_url', 'link_name', 'link_image', 'link_target', 'link_category',

		'link_description', 'link_visible', 'link_owner', 'link_rating', 'link_updated',

		'link_rel', 'link_notes', 'link_rss', );

	if ( is_object($bookmark) ) {

		$do_object = true;

		$link_id = $bookmark->link_id;

	} else {

		$do_object = false;

		$link_id = $bookmark['link_id'];

	}

	foreach ( $fields as $field ) {

		if ( $do_object ) {

			if ( isset($bookmark->$field) )

				$bookmark->$field = sanitize_bookmark_field($field, $bookmark->$field, $link_id, $context);

		} else {

			if ( isset($bookmark[$field]) )

				$bookmark[$field] = sanitize_bookmark_field($field, $bookmark[$field], $link_id, $context);

		}

	}

	return $bookmark;

}

/**

 * Sanitizes a bookmark field

 *

 * Sanitizes the bookmark fields based on what the field name is. If the field

 * has a strict value set, then it will be tested for that, else a more generic

 * filtering is applied. After the more strict filter is applied, if the

 * $context is 'raw' then the value is immediately return.

 *

 * Hooks exist for the more generic cases. With the 'edit' context, the

 * 'edit_$field' filter will be called and passed the $value and $bookmark_id

 * respectively. With the 'db' context, the 'pre_$field' filter is called and

 * passed the value. The 'display' context is the final context and has the

 * $field has the filter name and is passed the $value, $bookmark_id, and

 * $context respectively.

 *

 * @since 2.3.0

 *

 * @param string $field The bookmark field

 * @param mixed $value The bookmark field value

 * @param int $bookmark_id Bookmark ID

 * @param string $context How to filter the field value. Either 'raw', 'edit',

 *		'attribute', 'js', 'db', or 'display'

 * @return mixed The filtered value

 */

function sanitize_bookmark_field($field, $value, $bookmark_id, $context) {

	switch ( $field ) {

	case 'link_id' : // ints

	case 'link_rating' :

		$value = (int) $value;

		break;

	case 'link_category' : // array( ints )

		$value = array_map('absint', (array) $value);

		// We return here so that the categories aren't filtered.

		// The 'link_category' filter is for the name of a link category, not an array of a link's link categories

		return $value;

		break;

	case 'link_visible' : // bool stored as Y|N

		$value = preg_replace('/[^YNyn]/', '', $value);

		break;

	case 'link_target' : // "enum"

		$targets = array('_top', '_blank');

		if ( ! in_array($value, $targets) )

			$value = '';

		break;

	}

	if ( 'raw' == $context )

		return $value;

	if ( 'edit' == $context ) {

		$value = apply_filters("edit_$field", $value, $bookmark_id);

		if ( 'link_notes' == $field ) {

			$value = esc_html( $value ); // textarea_escaped

		} else {

			$value = esc_attr($value);

		}

	} else if ( 'db' == $context ) {

		$value = apply_filters("pre_$field", $value);

	} else {

		// Use display filters by default.

		$value = apply_filters($field, $value, $bookmark_id, $context);

		if ( 'attribute' == $context )

			$value = esc_attr($value);

		else if ( 'js' == $context )

			$value = esc_js($value);

	}

	return $value;

}

/**

 * Deletes bookmark cache

 *

 * @since 2.7.0

 * @uses wp_cache_delete() Deletes the contents of 'get_bookmarks'

 */

function clean_bookmark_cache( $bookmark_id ) {

	wp_cache_delete( $bookmark_id, 'bookmark' );

	wp_cache_delete( 'get_bookmarks', 'bookmark' );

	clean_object_term_cache( $bookmark_id, 'link');

}