How do I get the "primary" (simplest and most primitive) type of a Malli schema?e.g. :string => :string [:and :string [:fn ,,,]] => :string

simplestform.clj

(let [kinds #{:map :tuple :vector}
      fn-kind {string? :string
               int? :int
               boolean? :boolean
               double? :double}
      type-kind {(type "") :string}
      simplest-form (fn [form]
                      (cond 
                        (keyword? form)
                        form

                        (fn? form)  
                        (get fn-kind form "not handled fn form")  

                        (vector? form)
                        (let [[kind-or-and kind] form]
                          (or (get kinds kind-or-and)
                              (get kinds kind)
                              (get fn-kind kind)
                              (and (= kind-or-and :enum) (type-kind (type kind)) )
                              "unhandled vector form"))

                        :else "not handled and not branched")

                      )]
  (for [schema [[:enum "s" "b" "d"]
                string?
                int?
                :string
                [:and boolean? [:fn identity]]  
                [:tuple {:title "location"} :double :double]  
                [:map [:x int?] [:y int?]]  
                ]] 
    [(simplest-form schema) " <- " schema]
    ))