uuid.clj

(ns tupelo.uuid
  (:use tupelo.core)
  (:refer-clojure :exclude [rand])
  (:require
    [clj-uuid :as uuid]
    [clojure.core :exclude [rand]]
    [schema.core :as s]
    [tupelo.schema :as tsk]
    [tupelo.string :as str]
    [tupelo.core.impl :as impl])
  (:import
    [java.util UUID]))

(def const-null-str
  "A null UUID string '00000000-0000-0000-0000-000000000000' "
  "00000000-0000-0000-0000-000000000000")
(def const-null-obj
  "A null UUID object '00000000-0000-0000-0000-000000000000' "
  (UUID/fromString const-null-str))

(def const-dummy-str
  "A dummy UUID string '00000000-0000-0000-0000-000000000000' "
  "cafebabe-1953-0510-0970-0123456789ff")
(def const-dummy-obj
  "A dummy UUID object '00000000-0000-0000-0000-000000000000' "
  (UUID/fromString const-dummy-str))

(def null-str
  "Returns a null UUID string '00000000-0000-0000-0000-000000000000' "
  (const->fn const-null-str))
(def null
  "Returns a null UUID object '00000000-0000-0000-0000-000000000000' "
  (const->fn const-null-obj))

(def dummy-str
  "Returns a dummy UUID string 'cafebabe-1953-0510-0970-0123456789ff' "
  (const->fn const-dummy-str))
(def dummy
  "Returns a dummy UUID object 'cafebabe-1953-0510-0970-0123456789ff'"
  (const->fn const-dummy-obj))

(def ^:no-doc uuid-regex-pattern impl/uuid-regex-pattern)
(def uuid-str?
  "Returns true iff the string shows a valid UUID-like pattern of hex digits. Does not
  distinguish between UUID subtypes."
  impl/uuid-str?)

;-----------------------------------------------------------------------------
(s/defn rand :- UUID
  "Returns a random uuid as a UUID object"
  [] (uuid/v4))

(s/defn rand-str :- s/Str
  "Returns a random uuid as a String"
  [] (str (tupelo.uuid/rand)))

;-----------------------------------------------------------------------------
(def ^:no-doc uuid-counter (atom nil)) ; uninitialized
(defn counted-reset! [] (reset! uuid-counter 0))
(counted-reset!) ; initialize upon load

(defn counted-str []
  (let [cnt      (swap-out! uuid-counter inc)
        uuid-str (format "%08x-aaaa-bbbb-cccc-ddddeeeeffff" cnt)]
    uuid-str))

(defn counted []
  (UUID/fromString (counted-str)))

;-----------------------------------------------------------------------------
(defmacro with-null
  "For testing, replace all calls to uuid/rand with uuid/null"
  [& forms]
  `(with-redefs [rand null]
     ~@forms))

(defmacro with-counted
  "For testing, replace all calls to uuid/rand with uuid/counted"
  [& forms]
  `(with-redefs [rand counted]
     (counted-reset!)
     ~@forms))