dyne/FXC

;; Freecoin - digital social currency toolkit

;; part of Decentralized Citizen Engagement Technologies (D-CENT)
;; R&D funded by the European Commission (FP7/CAPS 610349)

;; Copyright (C) 2015 Dyne.org foundation
;; Copyright (C) 2015 Thoughtworks, Inc.

;; Sourcecode designed, written and maintained by
;; Denis Roio <jaromil@dyne.org>
;; Gareth Rogers <grogers@thoughtworks.com>

;; This program is free software: you can redistribute it and/or modify
;; it under the terms of the GNU Affero General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU Affero General Public License for more details.

;; You should have received a copy of the GNU Affero General Public License
;; along with this program.  If not, see <http://www.gnu.org/licenses/>.

(ns fxc.utils
  (:require [clojure.walk :refer :all])
  )

(declare log!)

;; (defn pretty [edn]
;;   {:pre (coll? edn)}

;;   (page/html5
;;    [:head [:style (-> "json.human.css" clojure.java.io/resource slurp)]]
;;    (present/edn->html edn)))

(defn trunc
  "Truncate string at length"
  [s n]
  {:pre [(> n 0)
         (seq s)]} ;; not empty
  (subs s 0 (min (count s) n)))

(defn compress
  "Compress a collection removing empty elements"
  [coll]
  (clojure.walk/postwalk #(if (coll? %) (into (empty %) (remove nil? %)) %) coll))

(defmacro bench
  "Times the execution of forms, discarding their output and returning
  a long in nanoseconds."
  ([& forms]
   `(let [start# (System/nanoTime)]
      ~@forms
      (- (System/nanoTime) start#))))

;; For working with maps
(defn select-all-or-nothing [m keys]
  (when (every? (partial contains? m) keys)
    (select-keys m keys)))

;; TODO: why?
(defn bigdecimal->long
  "Convert from BigDecimal to long for storage into mongo"
  [bd]
  (.longValue (* bd 100000)))

(defn long->bigdecimal
  "Convert from long to BigDecimal for retrievals from mongo"
  [l]
  (/ (BigDecimal. l) 100000))