utils.clj

(ns

    ^{:doc    "Random support functions and macros."
      :author "Paweł Wilk"
      :added  "1.0.0"}

    io.randomseed.utils

  (:import [java.security SecureRandom]
           [java.time     Instant Duration ZoneRegion]
           [java.util     UUID Random Locale Date Calendar Collection Collections ArrayList]
           [java.io       Console])

  (:require    [clojure.string               :as      str]
               [clojure.set                  :as      set]
               [clojure.java.io              :as       io]
               [clojure.main                 :as    cmain]
               [crypto.equality              :as       eq]
               [buddy.core.crypto            :as   crypto]
               [buddy.core.codecs            :as   codecs]
               [buddy.core.nonce             :as    nonce]
               [buddy.core.hash              :as     hash]
               [trptr.java-wrapper.locale    :as        l]
               [clojure.spec.alpha           :as        s]
               [tick.core                    :as        t]
               [tick.protocols               :as       tp]
               [clj-http.client              :as     http]))

(s/def ::set set?)
(s/def ::map map?)
(s/def ::number number?)
(s/def ::integer int?)
(s/def ::natural nat-int?)
(s/def ::positive pos-int?)
(s/def ::bytes bytes?)
(s/def ::callable ifn?)
(s/def ::vector vector?)
(s/def ::identifier ident?)
(s/def ::not-empty-string (s/and string? not-empty))
(s/def ::simple-identifier simple-ident?)
(s/def ::not-conflicting-ns (fn [[ns id]] (or (simple-ident? id) (= ns (namespace id)))))

;; Types

(defn ^Boolean atom?      [v] (instance? clojure.lang.Atom v))
(defn ^Boolean instant?   [v] (instance? Instant   v))
(defn ^Boolean exception? [v] (instance? Exception v))
(defn ^Boolean throwable? [v] (instance? Throwable v))

;; Values handling

(defn empty-string?
  ^Boolean [^String s]
  (zero? (.length ^String s)))

(defn not-empty-string?
  ^Boolean [^String s]
  (pos? (.length ^String s)))

(defn empty-ident?
  [v]
  (and (empty-string? (name v))
       (empty-string? (namespace v))))

(defn not-empty-ident?
  [v]
  (or (not-empty-string? (name v))
      (not-empty-string? (namespace v))))

(defn not-valuable?
  [x]
  (cond (nil? x)     true
        (string?  x) (empty-string? x)
        (ident?   x) (empty-ident?  x)
        (counted? x) (zero? (count  x))
        (seqable? x) (nil?  (seq    x))
        true         false))

(defn valuable?
  [x]
  (cond (nil?     x) false
        (string?  x) (not-empty-string? x)
        (ident?   x) (not-empty-ident?  x)
        (counted? x) (pos?  (count      x))
        (seqable? x) (some? (seq        x))
        true         true))

(defmacro when-valuable
  [v & more]
  `(when (valuable? ~v)
     ~@more))

(defmacro when-not-valuable
  [v & more]
  `(when (not-valuable? ~v)
     ~@more))

(defmacro valuable
  [& more]
  (if-some [b (butlast more)]
    `(do ~@b (let [l# ~(last more)] (when (valuable? l#) l#)))
    `(let [l# ~(first more)] (when (valuable? l#) l#))))

(defmacro not-valuable
  [& more]
  (if-some [b (butlast more)]
    `(do ~@b (let [l# ~(last more)] (when (not-valuable? l#) l#)))
    `(let [l# ~(first more)] (when (not-valuable? l#) l#))))

;; Text handling

(defn some-str
  [v]
  (valuable
   (when (valuable? v)
     (str (if (ident? v) (symbol v) v)))))

(defn some-str-up
  [v]
  (valuable
   (when (valuable? v)
     (str/upper-case
      (str (if (ident? v) (symbol v) v))))))

(defn some-str-simple
  [v]
  (valuable
   (when (valuable? v)
     (if (ident? v) (name v) (str v)))))

(defn some-str-simple-up
  [v]
  (valuable
   (when (valuable? v)
     (str/upper-case
      (if (ident? v) (name v) (str v))))))

(defn some-str-simple-down
  [v]
  (valuable
   (when (valuable? v)
     (str/lower-case
      (if (ident? v) (name v) (str v))))))

(defn str-spc
  [s & more]
  (if-not more
    (str s)
    (apply str (interpose " " (cons s more)))))

(defn some-str-spc
  [s & more]
  (if-not more
    (str (some-str s))
    (apply str (interpose " " (map some-str (cons s more))))))

(defn some-string
  ^String [^String s]
  (if (or (not (string? s)) (empty? s)) nil s))

;; Names

(defn normalize-name
  "Takes a name expressed as a string or an identifier. If the object is an identifier
  (a symbol or a keyword) then it converts it to a string using name function. If the
  second argument is present then it uses it when the given name or a name derived
  from identifier is empty."
  ([some-name]
   (normalize-name some-name nil))
  ([some-name default-name]
   (if (ident? some-name)
     (clojure.core/name some-name)
     (if (seqable? some-name)
       (if (seq some-name) (str some-name) default-name)
       (when some-name (str some-name))))))

(defn normalize-name-with-ns
  "Takes a name expressed as a string or an identifier. If the object is an identifier
  (a symbol or a keyword) then it converts it to a string using namespace and name
  functions. If the second argument is present then it uses it when the given name or
  a name derived from identifier is empty."
  ([some-name]
   (normalize-name-with-ns some-name nil))
  ([some-name default-name]
   (if (ident? some-name)
     (if-some [ns-name (clojure.core/namespace some-name)]
       (str ns-name "/" (clojure.core/name some-name))
       (clojure.core/name some-name))
     (if (seqable? some-name)
       (if (seq some-name) (str some-name) default-name)
       (when some-name (str some-name))))))

;; Bytes

(defn b64-to-bytes
  [s]
  (codecs/b64->bytes (codecs/str->bytes (str s))))

(defn to-bytes
  [obj]
  (if (bytes? obj) obj (.getBytes (str obj) "UTF-8")))

(def bzero
  (to-bytes nil))

(defn bytes-to-string
  "Converts bytes into a string"
  ^String [b]
  (s/assert ::bytes b)
  (apply str (map #(char (bit-and % 255)) b)))

(defn bytes-concat
  ([]
   nil)
  ([bary]
   (not-empty bary))
  ([bary & byte-arys]
   (let [byte-arys (remove empty? (cons bary byte-arys))]
     (when (seq byte-arys)
       (let [sum-size (apply + (map count byte-arys))
             buff     (byte-array sum-size)
             bbuff    (java.nio.ByteBuffer/wrap buff)]
         (doseq [a byte-arys] (.put bbuff a)) buff)))))

(defn text-to-bytes
  [t]
  (if (bytes? t) t (if (nil? t) bzero (to-bytes t))))

(defn normalize-to-bytes
  [t]
  (to-bytes (normalize-name t)))

;; Identifiers handling

(defn must-have-ns
  [id ^String ns]
  (s/assert ::not-empty-string ns)
  (s/assert ::identifier id)
  (if (and (qualified-ident? id) (= (namespace id) ns))
    id
    ((if (keyword? id) keyword symbol) ns (name id))))

(defn ensure-str
  ([v] (or (when (valuable? v) (str (if (ident? v) (symbol v) v))) ""))
  ([v & more]
   (apply str (map some-str (cons v more)))))

(defn ensure-ns
  [id ^String ns]
  (s/assert ::not-empty-string ns)
  (s/assert ::identifier id)
  (if (qualified-ident? id)
    id
    ((if (keyword? id) keyword symbol) ns (name id))))

(defn ensure-keyword
  [id]
  (when id
    (if (keyword? id)
      id
      (if (ident? id)
        (if (simple-ident? id)
          (keyword id)
          (keyword (namespace id) (name id)))
        (keyword (when (valuable? id) id))))))

(defn ensure-ident-keyword
  [id]
  (if (ident? id) id (ensure-keyword id)))

(defn ensure-keyword-having-ns
  [id ^String ns]
  (must-have-ns (ensure-keyword id) ns))

(defn ensure-namespaced-keyword
  [id ^String ns]
  (ensure-ns (ensure-keyword id) ns))

(defmacro try-null
  "Evaluates body and if NullPointerException exception is caught it returns
  nil. Otherwise it returns the value of last expression in the body."
  {:added "1.0.0"}
  [& body]
  `(try ~@body
        (catch NullPointerException  e# nil)))

(defmacro when-not-empty
  "Evaluates body when the given value is a non-empty collection."
  {:added "1.0.0"}
  [val & body]
  `(when (seq ~val)
     ~@body))

(defn with-not-empty
  "Returns the collection if it's not empty. Otherwise returns `nil`."
  {:added "1.0.0"}
  [obj]
  (when (seq obj) obj))

(defmacro is
  [pred val & body]
  `(let [v# ~val]
     (if (~pred v#) ~@body v#)))

(defmacro is-not
  [pred val & body]
  `(let [v# ~val]
     (if (~pred v#) v# ~@body)))

;; Namespace inference

(defn ns-infer
  "Takes a string of namespace name and a keyword. If the given keyword is not
  namespace-qualified it returns a new keyword with the given namespace added. If the
  given keyword is already equipped with a namespace it returns it."
  {:added "1.0.0" :tag clojure.lang.Keyword}
  ([^String ns-name
    ^clojure.lang.Keyword k]
   (if (simple-keyword? k)
     (keyword ns-name (name k))
     k))
  ([^String ns-name
    ^clojure.lang.Keyword k
    ^Boolean use-infer]
   (if use-infer (ns-infer ns-name k) k)))

(defn inferred-contains?
  "Just like the contains? but if the keyword is namespace-qualified it also checks if
  the collection contains the same keyword as its key but without a namespace."
  {:added "1.0.0" :tag Boolean}
  [^clojure.lang.IPersistentMap coll
   ^clojure.lang.Keyword k]
  (or (contains? coll k)
      (if (simple-keyword? k)
        false
        (contains? coll (keyword (name k))))))

(defn inferred-get
  "Just like the get function but if the keyword is namespace-qualified it first
  attempts to look for the value associated with it. If that fails it uses the
  variant of the keyword without any namespace."
  {:added "1.0.0"}
  ([^clojure.lang.IPersistentMap coll
    ^clojure.lang.Keyword k]
   (inferred-get coll k nil))
  ([^clojure.lang.IPersistentMap coll
    ^clojure.lang.Keyword k
    default]
   (if (simple-keyword? k)
     (k coll default)
     ((if (contains? coll k) k (keyword (name k))) coll default))))

;; Threads

(defn current-thread-id   [] (.. Thread currentThread getId))
(defn current-thread-name [] (.. Thread currentThread getName))
(defn current-thread      [] (Thread/currentThread))

;; Randomness

(defn get-rand-int
  "Like rand-int but optionally uses random number generator."
  {:added "1.0.0"}                      ; was: :tag 'int
  ([^long n]
   (when (some? n)
     (rand-int n)))
  ([^long n ^Random rng]
   (when (some? n)
     (if (nil? rng)
       (get-rand-int n)
       (if (zero? n) (int n) (.nextInt rng n))))))

(defn random-digits-len
  "For 0 or 1 it returns its argument. For other positive numbers it returns a random
  natural number from 1 to this number (inclusive) in 50% cases. In other 50% cases
  it returns its argument."
  {:added "1.0.0"} ; was: :tag 'long
  ([^long x
    ^long iteration
    ^Boolean shrink-now]
   (when (some? x)
     (if (zero? x) x
         (if-not shrink-now x
                 (if (zero? iteration) 1
                     (if (or (< iteration 6) (zero? (rand-int 2)))
                       (unchecked-inc (rand-int x)) x))))))
  ([^long x
    ^long iteration
    ^Boolean shrink-now
    ^Random rng]
   (when (some? x)
     (if (nil? rng)
       (random-digits-len x iteration shrink-now)
       (if (zero? x) x
           (if-not shrink-now x
                   (if (zero? iteration) 1
                       (if (or (< iteration 6) (zero? (get-rand-int 2 rng)))
                         (unchecked-inc (get-rand-int x rng)) x))))))))

(defn gen-digits
  "Generates the given number of random digits and converts all into a single string.
  When the second argument is present it should be an instance of random number
  generator used to get the digits."
  {:added "1.0.0" :tag String}
  ([^long num]
   (apply str (repeatedly num #(rand-int 10))))
  ([^long num
    ^Random rng]
   (when (some? num)
     (if (nil? rng)
       (gen-digits num)
       (apply str (repeatedly num #(.nextInt rng 10)))))))

;; Characters and digits

(defn count-digits
  {:added "1.0.0" :tag 'long}
  [^long n]
  (if (zero? n) 1
      (unchecked-inc
       (long (Math/floor (Math/log10 n))))))

(defn char-ranges->set
  "Returns a set of characters defined as a collection of collections with start and
  stop character, e.g.: [\\A \\Z][\\0 \\9]"
  {:added "1.0.0" :tag clojure.lang.PersistentHashSet}
  [& ranges]
  (set (mapcat #(map char (range (byte (first %)) (inc (byte (second %))))) ranges)))

;; Sequences

(defn lazy-iterator-seq
  "Returns a lazy sequence as an interface to the given iterable Java object."
  {:added "1.0.0" :tag clojure.lang.LazySeq}
  ([^Iterable coll]
   (lazy-iterator-seq coll (.iterator coll)))
  ([^Iterable coll ^java.util.Iterator iter]
   (lazy-seq
    (when (.hasNext ^java.util.Iterator iter)
      (cons (.next ^java.util.Iterator iter)
            (lazy-iterator-seq ^Iterable coll ^java.util.Iterator iter))))))

(defn juxt-seq
  ^clojure.lang.LazySeq [& functions]
  (fn [& args]
    (map #(apply %1 %2) functions (repeat args))))

(defn insert-at
  [index coll element]
  (let [[l r] (split-at index coll)]
    (concat l (cons element r))))

(defn find-first
  "Returns the first item from coll for which (f item) returns true or nil if no such
  item is present. If the given not-found value is supplied, it will return it
  instead of nil."
  ([f coll]
   (find-first f coll nil))
  ([f coll not-found]
   (reduce (fn [_ x] (if (f x) (reduced x) not-found))
           not-found coll)))

;; Indexed collections

(defn contains-some?
  "Takes two indexed collections and returns true if at least one element is shared in
  both. Otherwise it returns false."
  [s1 s2]
  (or (if (> (count s1) (count s2))
        (some #(contains? s1 %) s2)
        (some #(contains? s2 %) s1))
      false))

;; UUID

(defn to-uuid
  ([] (random-uuid))
  ([s] (when (valuable? s) (if (uuid? s) s (UUID/fromString (str s))))))

;; URL

(defn sanitize-base-url
  [^String url]
  (when-some [url (str/trim (str url))]
    (when (some? (seq url))
      (let [url (if (str/starts-with? url "http") url (str "https://" url))
            url (if (str/ends-with?   url    "/") url (str url "/"))]
        url))))

(defn parse-url
  "Parses URL into a map."
  [u]
  (when (and u (string? u) (> (count u) 0))
    (http/parse-url u)))

;; Numbers

(defn pos-val
  [x]
  (when (and x (number? x) (pos? x))
    x))

(defn parse-num
  ([n default]
   (or (parse-num n) default))
  ([n]
   (when (valuable? n)
     (let [s (str n)]
       (if (or (> (count s) 15) (str/index-of s \.))
         (bigdec s)
         (Long/parseLong s))))))

(defn some-long
  ([s default]
   (or (some-long s) default))
  ([s]
   (when (valuable? s)
     (if (number? s) (long s)
         (parse-long (str s))))))

(defn safe-parse-num
  ([v default]
   (or (safe-parse-num v) default))
  ([v]
   (try (parse-num v)
        (catch Throwable e nil))))

(defn safe-parse-long
  ([v default]
   (or (safe-parse-long v) default))
  ([v]
   (try (some-long v)
        (catch Throwable e nil))))

(defn to-long
  [s default]
  (s/assert ::integer default)
  (safe-parse-long s default))

(defn parse-percent
  ([n default]
   (or (parse-percent n) default))
  ([n]
   (when-some [n (parse-num n)]
     (/ n 100))))

(def percent parse-percent)

(defn safe-parse-percent
  ([v default]
   (or (safe-parse-percent v) default))
  ([v]
   (try (parse-percent v)
        (catch Throwable e nil))))

(defn parse-re
  [v]
  (when (and (valuable? v) (string? v))
    (re-pattern v)))

(defn some-keyword
  [v]
  (when (valuable? v)
    (if (keyword? v) v
        (keyword (if (symbol? v) v (str v))))))

(defn some-keyword-up
  [v]
  (when (valuable? v)
    (keyword
     (str/upper-case
      (str (if (keyword? v) (symbol v) v))))))

(defn some-keyword-simple
  [v]
  (when-some [v (some-keyword v)]
    (if (simple-keyword? v) v (keyword (name v)))))

(defn simple-keyword-up
  [v]
  (when-some [v (some-keyword-up v)]
    (if (simple-keyword? v) v (keyword (name v)))))

;; Namespaces and global identifiers

(defn try-require
  [n]
  (when n
    (when-some [n (if (ident? n) n (some-str n))]
      (when-some [n (symbol n)]
        (try (do (require n) n)
             (catch java.io.FileNotFoundException _))))))

(defn fn-name
  [f]
  (let [{mna :name mns :ns} (meta f)]
    (if (and mna mns)
      (symbol (str mns) (str mna))
      (as-> (str f) $
        (cmain/demunge $)
        (or (re-find #"(.+)--\d+@" $) (re-find #"(.+)@" $))
        (last $)
        (symbol $)))))