(ns emptyhead.newlib.math.arithmetic
  "Airthmetic operators."
  (:require [emptyhead.thought.define :as def]
            [emptyhead.thought.crud :as thought]
            [emptyhead.newlib.message :as msg]
            [emptyhead.newlib.delegate :as del]
            [emptyhead.thought.extend :as extend]
            [emptyhead.thought.eval :as eval]
            [emptyhead.newlib.util :as util]))
;; TODO values are now consumed when used instantly, this will give issues once we have variables

;; Initial addition, e.g. =5 +=. Returns partially applied pointer.
(def/define! [:EH :PRIM [:EH :PRIM :NUM] :+]
  (fn [thought parent]
    (let [to (:to (thought/data parent))
          th (thought/register-thought! [:EH :IO :RETURN]
                                        :data to
                                        :reference (str "<" to "+_>"))]

      (del/add-delegate th [:EH :PRIM :PARTIAL :+])
      [parent th])))

;; Final addition, e.g. =(5 +) 5=.
(def/define! [:EH :PRIM :PARTIAL :+ [:EH :PRIM :NUM]]
  (fn [thought parent]
    (let [from (:from (thought/data parent))
          [_ to] (thought/pop-stack (eval/execute! (:to (thought/data parent)) parent))
          th (thought/register-thought! [:EH :IO :RETURN]
                                        :data [to from]
                                        :reference (str "<" to "+" from ">"))]
      (del/add-delegate th [:EH :LAZY [:EH :PRIM :NUM]])
      [parent th])))

(def/define! [:EH :LAZY [:EH :PRIM :NUM] :REIFY]
  (fn [thought parent]
    (let [[_ [to from]] (thought/pop-stack (eval/execute! (:to (thought/data parent)) parent))
          to (if (symbol? to) (msg/apply-msg to [:EH :REIFY]) to)
          from (if (symbol? from) (msg/apply-msg to [:EH :REIFY]) from)]
      [parent (+ to from)])))

(del/add-delegate [:EH :LAZY [:EH :PRIM :NUM]] [:EH :PRIM :NUM])

(thought/register-singleton! [:EH :PRIM :PARTIAL :+ [:EH :PRIM :NUM]])
(msg/register-single-impl [:EH :PRIM :PARTIAL :+] [:EH :PRIM :NUM] [:EH :PRIM :PARTIAL :+ [:EH :PRIM :NUM]])

(thought/register-singleton! [:EH :LAZY [:EH :PRIM :NUM] :REIFY])
(msg/register-single-impl [:EH :LAZY [:EH :PRIM :NUM]] [:EH :REIFY] [:EH :LAZY [:EH :PRIM :NUM] :REIFY])