Sort Users 4Clojure

sort-users.clj

(defn users-comp [x y]
  (let [xsolved (count (:solved x))
        ysolved (count (:solved y))
        xlastlogin (:last-login x)
        ylastlogin (:last-login y)]
    (cond (> xsolved ysolved) 1
          (< xsolved ysolved) -1
          (and xlastlogin (nil? ylastlogin)) 1
          (and ylastlogin (nil? xlastlogin)) -1
          (and xlastlogin ylastlogin (.after xlastlogin ylastlogin)) 1
          (and xlastlogin ylastlogin (.after ylastlogin xlastlogin)) -1
          :else 0)))

(defn users-sort [users]
  (reverse (sort users-comp users)))

(def test-users-by-solved
    [{:user "user1" :solved [1] } {:user "user2" :solved [1 2 3 4]}
     {:user "user3" :solved [2 2] } {:user "user4" :solved [3]}])
(users-sort test-users-by-solved)

(def date1 (java.util.Date.))
(def date2 (java.util.Date.))
(def test-users-by-date
  [{:user "user1" :last-login date1  } {:user "user2" :last-login date2}
   {:user "user3" } {:user "user4" :last-login date2}])
(users-sort test-users-by-date)

(def test-users-by-solved-and-date
  [{:user "carin" :solved [1 2]} {:user "sue" :solved [1 2] :last-login date1}
   {:user "beth" :solved [1 2] :last-login date2}])
(users-sort test-users-by-solved-and-date)