#|
  This file is a part of stoe project.
  Copyright (c) 2014 Renaud Casenave-Péré (renaud@casenave-pere.fr)
|#

(uiop:define-package :stoe/core/modules
  (:use :cl)
  (:export #:initialize-modules #:finalize-modules #:update-modules #:defmodule))
(in-package :stoe/core/modules)

(defparameter *modules-list* nil)

(defun initialize-modules (&optional argv)
  "Perform the engine and subsystems initialization process."
  (format t "Initialize...~%")
  (loop for module in *modules-list*
     do (funcall (intern "INITIALIZE" (cdr module)) argv)))

(defun finalize-modules ()
  "Perform the engine and subsystems initialization process."
  (format t "Initialize...~%")
  (loop for module in (reverse *modules-list*)
     do (funcall (intern "FINALIZE" (cdr module)))))

(defun update-modules (delta-time)
  "Update-the modules each loop."
  (loop for module in *modules-list*
     do (funcall (intern "UPDATE" (cdr module)) delta-time)))

(defun register-module (module priority)
  (pushnew (cons priority module) *modules-list*)
  (sort *modules-list* (lambda (prio1 prio2)
                         (< prio1 prio2)) :key #'car))

(defmacro defmodule (module priority)
  "Register a new module.
The module is expected to have at least `initialize', `update', and `finalize' functions.
`initialize' accepts an optional `argv' argument,
`update' accepts a delta-time argument."
  `(register-module ',module
                     ,(ecase priority
                        (:first (if (null *modules-list*)
                                    0
                                    (1- (caar *modules-list*))))
                        (:last (if (null *modules-list*)
                                   10
                                   (1+ (caar (reverse *modules-list*)))))
                        (:jobs 1)
                        (:resources 2)
                        (:input 3)
                        (:game 4)
                        (:render 9)
                        (t priority))))