(ns java-time.format

(:refer-clojure :exclude (format))

(:require [clojure.string :as string]

[java-time.core :as jt.c]

[java-time.util :as jt.u])

(:import [java.time.temporal TemporalAccessor]

[java.time.format DateTimeFormatter DateTimeFormatterBuilder ResolverStyle]))

(def predefined-formatters

(->> (jt.u/get-static-fields-of-type DateTimeFormatter DateTimeFormatter)

(jt.u/map-kv

(fn [^String n fmt]

[(string/lower-case (.replace n \_ \-)) fmt]))))

(defn- get-resolver-style [s]

(if (instance? ResolverStyle s) s

(case s

:strict ResolverStyle/STRICT

:smart ResolverStyle/SMART

:lenient ResolverStyle/LENIENT)))

(defn ^DateTimeFormatter formatter

"Constructs a DateTimeFormatter out of a

([fmt]

(formatter fmt {}))

([fmt {:keys [resolver-style]}]

(let [^DateTimeFormatter fmt

(cond (instance? DateTimeFormatter fmt) fmt

(string? fmt) (DateTimeFormatter/ofPattern fmt)

:else (get predefined-formatters (name fmt)))

fmt (if resolver-style

(.withResolverStyle fmt (get-resolver-style resolver-style))

fmt)]

fmt)))

(defn format

"Formats the given time entity as a string.

([o] (str o))

([fmt o]

(.format (formatter fmt) o)))

(defn ^TemporalAccessor parse

([fmt o] (parse fmt o {}))

([fmt o opts]

(.parse (formatter fmt opts) o)))