(ns java-time.core

(:refer-clojure :exclude (zero? range max min abs))

(:import [java.time.temporal ValueRange]

[java.time.chrono Chronology]))

(defprotocol Amount

(zero? [a]

"True if the amount is zero")

(negative? [a]

"True if the amount is negative")

(negate [a]

"Negates a temporal amount:

(negate (negate x)) == x")

(abs [a]

"Returns the absolute value of a temporal amount:

(abs (negate x)) == (abs x)"))

(defprotocol Supporting

(supports? [o p]

"True if the `o` entity supports the `p` property"))

(defprotocol HasChronology

(^Chronology chronology [o]

"The `Chronology` of the entity"))

(defprotocol HasFields

(fields [o]

"Fields present in this temporal entity")

(field* [o k]

"Internal use"))

(defprotocol HasUnits

(units [o]

"Units present in this temporal entity.")

(unit* [o k]

"Internal use"))

(defprotocol HasProperties

(properties [o]

"Map of properties present in this temporal entity")

(property [o k]

"Property of this temporal entity under key `k`"))

(defprotocol As

(as* [o k]

"Value of property/unit identified by key/object `k` of the temporal

entity `o`"))

(defn as

"Values of property/unit identified by keys/objects `ks` of the temporal

([o k]

(as* o k))

([o k1 k2]

[(as* o k1) (as* o k2)])

([o k1 k2 & ks]

(concat (as o k1 k2) (mapv #(as* o %) ks))))

(defprotocol ReadableProperty

(value [p]

"Value of the property"))

(defprotocol ReadableRangeProperty

(range [p]

"Range of values for this property")

(min-value [p]

"Minimum value of this property")

(largest-min-value [p]

"Largest minimum value of this property")

(smallest-max-value [p]

"Smallest maximum value of this property, e.g. 28th of February for months")

(max-value [p]

"Maximum value of this property, e.g. 29th of February for months"))

(defprotocol WritableProperty

(with-value [p v]

"Underlying temporal entity with the value of this property set to `v`"))

(defprotocol WritableRangeProperty

(with-min-value [p]

"Underlying temporal entity with the value set to the minimum available for

this property")

(with-largest-min-value [p]

"Underlying temporal entity with the value set to the largest minimum

available for this property")

(with-smallest-max-value [p]

"Underlying temporal entity with the value set to the smallest maximum

available for this property")

(with-max-value [p]

"Underlying temporal entity with the value set to the maximum

available for this property"))

(defprotocol KnowsTimeBetween

(time-between [o e u]

"Time between temporal entities `o` and `e` in unit `u`.

=> 365"))

(defprotocol KnowsIfLeap

(leap? [o]

"True if the year of this entity is a leap year."))

(defprotocol Truncatable

(truncate-to [o u]

"Truncates this entity to the specified time unit. Only works for units that

divide into the length of standard day without remainder (up to `:days`)."))

(defprotocol HasZone

(with-zone [o z]

"Returns this temporal entity with the specified `ZoneId`"))

(defprotocol Plusable

"Internal"

(seq-plus [o os]))

(defprotocol Minusable

"Internal"

(seq-minus [o os]))

(defprotocol Multipliable

(multiply-by [o v]

"Entity `o` mutlitplied by the value `v`"))

(defprotocol Ordered

(single-before? [a b]

"Internal use")

(single-after? [a b]

"Internal use"))

(defn max

"Latest/longest of the given time entities. Entities should be of the same

[o & os]

(last (sort (cons o os))))

(defn min

"Earliest/shortest of the given time entities. Entities should be of the same

[o & os]

(first (sort (cons o os))))

(defn before?

"Returns a truthy value if time entities are ordered from the earliest to the

([x] true)

([x y] (single-before? x y))

([x y & more]

(if (before? x y)

(if (next more)

(recur y (first more) (next more))

(before? y (first more)))

false)))

(defn after?

"Returns a truthy value if time entities are ordered from the latest to the

([x] true)

([x y] (single-after? x y))

([x y & more]

(if (after? x y)

(if (next more)

(recur y (first more) (next more))

(after? y (first more)))

false)))

(def not-after?

"Similar to [[before?]], but also returns truthy if the inputs are equal."

(complement after?))

(def not-before?

"Similar to [[after?]], but also returns truthy if the inputs are equal."

(complement before?))

(defn plus

"Adds all of the `os` to the time entity `o`. `plus` is not commutative, the

[o & os]

(seq-plus o os))

(defn minus

"Subtracts all of the `os` from the time entity `o`

[o & os]

(if (seq os)

(seq-minus o os)

(negate o)))

(extend-type Number

ReadableProperty

(value [n] n)

WritableProperty

(with-value [n v] v)

Plusable

(seq-plus [n xs]

(apply + n xs))

Minusable

(seq-minus [n xs]

(apply - n xs))

Multipliable

(multiply-by [n v]

(* n (value v)))

Amount

(zero? [n] (clojure.core/zero? n))

(negative? [n] (neg? n))

(negate [n] (- n))

(abs [n] (Math/abs (long n))))

(extend-type nil

ReadableProperty

(value [_] nil)

WritableProperty

(with-value [_ v] v))

(def readable-range-property-fns

{:min-value (fn [p] (.getMinimum ^ValueRange (range p)))

:largest-min-value (fn [p] (.getLargestMinimum ^ValueRange (range p)))

:smallest-max-value (fn [p] (.getSmallestMaximum ^ValueRange (range p)))

:max-value (fn [p] (.getMaximum ^ValueRange (range p)))})