first try common friends for visitors

include/contact_widgets.php

@@ -133,3 +133,42 @@ function categories_widget($baseurl,$selected = '') {
 	));
 }
 
+function common_friends_visitor_widget($profile_uid) {
+
+	$a = get_app();
+
+	if(local_user() == $profile_uid)
+		return;
+
+	$cid = $zcid = 0;
+
+	if(can_write_wall($a,$profile_uid))
+		$cid = local_user();
+	else {
+		if(get_my_url()) {
+			$r = q("select id from gcontact where nurl = '%s' limit 1",
+				dbesc(normalise_link(get_my_url()))
+			);
+			if(count($r))
+				$zcid = $r[0]['id'];
+		}
+	}
+
+	if($cid == 0 && $zcid == 0)
+		return; 
+
+	require_once('include/socgraph.php');
+
+
+	$t = count_common_friends_remote($profile_uid,$cid,$zcid);
+	if(! $t)
+		return;
+
+	$r = common_friends_remote($profile_uid,$cid,$zcid);
+
+	return replace_macros(get_markup_template('remote_friends_common.tpl'), array(
+		'$desc' =>  sprintf( tt("%d friend in common", "%d friends in common", $t), $t),
+		'$items = $r
+	)); 
+
+};

include/socgraph.php

@@ -199,6 +199,48 @@ function common_friends($uid,$cid) {
 
 }
 
+
+function count_common_friends_remote($uid,$cid,$zid) {
+
+	$r = q("SELECT count(*) as `total` 
+		FROM `glink` left join `gcontact` on `glink`.`gcid` = `gcontact`.`id`
+		where ((`glink`.cid != 0 and `glink`.`cid` = %d) or ( `glink`.`zcid` != 0 and `glink`.`zcid` = %d ))
+		and `glink`.`uid` = %d
+		and `gcontact`.`nurl` in (select nurl from contact where uid = %d and self = 0 and id != %d ) ",
+		intval($cid),
+		intval($zid),
+		intval($uid),
+		intval($uid),
+		intval($cid)
+	);
+
+	if(count($r))
+		return $r[0]['total'];
+	return 0;
+
+}
+
+function common_friends_remote($uid,$cid,$zid,$limit = 6) {
+
+	$r = q("SELECT `gcontact`.* 
+		FROM `glink` left join `gcontact` on `glink`.`gcid` = `gcontact`.`id`
+		where ((`glink`.cid != 0 and `glink`.`cid` = %d) or ( `glink`.`zcid` != 0 and `glink`.`zcid` = %d ))
+		and `glink`.`uid` = %d
+		and `gcontact`.`nurl` in (select nurl from contact where uid = %d and self = 0 and id != %d ) 
+		order by `gcontact`.`name` asc limit 0, %d",
+		intval($cid),
+		intval($zid),
+		intval($uid),
+		intval($uid),
+		intval($cid),
+		intval($limit)
+	);
+
+	return $r;
+
+}
+
+
 function count_all_friends($uid,$cid) {
 
 	$r = q("SELECT count(*) as `total`

mod/profile.php

@@ -143,6 +143,10 @@ function profile_content(&$a, $update = 0) {
 			return $o;
 		}
 
+
+		$o .= common_friends_vistor_widget($a->profile['profile_uid']);
+
+
 		if(x($_SESSION,'new_member') && $_SESSION['new_member'] && $is_owner)
 			$o .= '<a href="newmember" id="newmember-tips" style="font-size: 1.2em;"><b>' . t('Tips for New Members') . '</b></a>' . EOL;