string to plantuml url

str-to-plantuml-url.clj

(ns foo
  (:import
   java.io.ByteArrayOutputStream
   java.util.zip.Deflater
   java.util.zip.DeflaterOutputStream))

;; https://plantuml.com/text-encoding
;; https://gist.github.com/ryardley/88001f6822975ece088d41768431f5d6
;; https://github.com/funcool/buddy-core/blob/b152bc77597975770c347f3bc23c8d5833237b25/src/buddy/util/deflate.clj#L28

(defn str->plantuml-url [raw-str]
  (let [os         (new ByteArrayOutputStream)
        deflater   (new Deflater Deflater/DEFLATED (boolean "nowrap"))
        _          (with-open [dos (new DeflaterOutputStream os deflater)]
                     (.write dos (.getBytes raw-str)))
        deflated   (.toByteArray os)
        b64-string (new String (.encode (java.util.Base64/getEncoder) deflated))
        b64->plant (zipmap
                     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
                     "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_")
        uml-string (->> b64-string (map b64->plant) (str/join))]
    (str "http://www.plantuml.com/plantuml/uml/" uml-string)))