Merge pull request #57 from blowmage/user_search_refactor

Refactor UserController#search_users

app/models/user_search.rb

@@ -0,0 +1,43 @@
+class UserSearch
+
+  def self.search term, topic_id = nil
+    User.find_by_sql sql(term, topic_id)
+  end
+
+  private
+
+  def self.sql term, topic_id
+    sql = "select id, username, name, email from users u "
+    if topic_id
+      sql << "left join (select distinct p.user_id from posts p where topic_id = :topic_id) s on
+        s.user_id = u.id "
+    end
+
+    if term.present?
+      sql << "where username ilike :term_like or
+              to_tsvector('simple', name) @@
+              to_tsquery('simple',
+                regexp_replace(
+                  regexp_replace(
+                    cast(plainto_tsquery(:term) as text)
+                    ,'\''(?: |$)', ':*''', 'g'),
+                '''', '', 'g')
+              ) "
+
+    end
+
+    sql << "order by case when username_lower = :term then 0 else 1 end asc, "
+    if topic_id
+      sql << " case when s.user_id is null then 0 else 1 end desc, "
+    end
+
+    sql << " case when last_seen_at is null then 0 else 1 end desc, last_seen_at desc, username asc limit(20)"
+
+    sanitize_sql_array(sql, topic_id: topic_id, term_like: "#{term}%", term: term)
+  end
+
+  def self.sanitize_sql_array *args
+    ActiveRecord::Base.send(:sanitize_sql_array, args)
+  end
+
+end