(defn- schema->type
  [schema]
  (let [types (concat
               (m/search schema
                 {"format" "date-time"}           :db.type/instant
                 {"format" "uri"}                 :db.type/uri
                 {"type"   "array"}               '(Array nil)
                 {"type"   "boolean"}             :db.type/boolean
                 {"type"   "integer"}             :db.type/long
                 {"type"   "string"}              :db.type/string
                 {"items"  (m/pred some? ?item)}  (list 'Array (schema->type ?item))
                 {"$ref"   (m/pred some? ?ref)}   (if (= ?ref "#uuid")
                                                    :db.type/uuid
                                                    (subs ?ref 1)))
               (map schema->type (get schema "allOf")))]
    (reduce narrower-type nil types)))