;;;; cl-scopes/csys - concurrent cybernetic communication systems

(defpackage :scopes/csys
  (:use :common-lisp)
  (:local-nicknames (:actor :scopes/core/actor)
                    (:config :scopes/config)
                    (:message :scopes/core/message)
                    (:shape :scopes/shape)
                    (:util :scopes/util)
                    (:alx :alexandria))
  (:export #:scope #:environ
           #:neuron #:synapse #:std-proc #:update #:create
           #:handle-action))

(in-package :scopes/csys)

;;;; scope: information a neuron has access to

(defclass scope ()
  ((value :accessor value :initarg :value :initform 0)
   (params :accessor params :initarg :params :initform nil)
   (categ :accessor categ :initarg :categ :initform '(:csys :c00))
   (stage :accessor stage :initform :initial)
   (proc :accessor proc :initarg :proc :initform #'std-proc)
   (program :reader program :initarg :program :initform nil)
   (actions :accessor actions :initarg :actions :initform nil)
   (syns :accessor syns :initform nil)
   (environ :reader environ :initarg :environ)))

(defun scope (&optional (program #'std-proc) &rest args)
  (apply #'make-instance 'scope :program program args))

(defun reset-scope (scope &rest args)
  (apply #'scope (or (getf args :program) (program scope)) 
         :categ (or (getf args :categ) (categ scope))
         :environ (or (getf args :environ) (environ scope)) 
         args))

;;;; neurons (= async tasks) and synapses (= connections)

(defun neuron (scope)
  (actor:create (process scope)))

(defun synapse (rcvr &optional (op #'identity))
  (lambda (msg)
    (actor:send rcvr (funcall op msg))))

(defun update (scope)
  (actor:become (process scope)))

;;;; message handlers, proc steps

(defun process (scope)
  (lambda (msg) (funcall (proc scope) msg scope)))

(defun std-proc (msg scope)
  ;(util:lgi msg state syns env)
  (destructuring-bind (nmsg nscope) 
        (handle-action msg scope :default #'remember)
    (forward nmsg (syns nscope))
    (update nscope)))

(defun create (msg scope)
  (let ((new (neuron (apply #'reset scope (shape:data msg)))))
    (notify-created msg new scope)))

(defun do-log (msg scope)
  (util:lgi msg))

(defun notify (msg scope)
  (actor:send (environ scope) msg))

(defun forward (msg syns)
  (dolist (s syns) 
    (funcall s msg)))

(defun handle-action (msg scope &key (default #'no-op))
  (let* ((key (message:action msg))
         ;(act (select-action msg state default))
         (act (gethash key (actions scope) default)))
    (funcall act msg scope)))

(defun notify-created (msg new scope)
  (let* ((head (list (message:domain msg) :created))
         (data (util:plist-merge (shape:data scope) '(:new new :parent actor:*self*)))
         (msg1 (message:create head :data data))) 
    (notify msg1 scope))
  )

;;;; predefined neuron actions

(defun no-op (msg scope)
  (list msg scope))

(defun remember (msg scope)
  (setf (value scope) (shape:data-value msg :value))
  ;(list msg (make-neuron-state (shape:data msg) syns))
  (list msg scope))