;;; Buid --- The builder for FG42 -*- lexical-binding: t; -*-
;;
;; Copyright (c) 2010-2021 Sameer Rahmani & Contributors
;;
;; Author: Sameer Rahmani <lxsameer@gnu.org>
;; URL: https://gitlab.com/FG42/FG42
;; Version: 3.0.0
;;
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with thnis program.  If not, see <http://www.gnu.org/licenses/>.
;;
;;; Commentary:
;; Cubes are the building blocks of any `FG42' editor.  Each `cube' is a
;; unit which defines different abilities in a deterministic and idempotent
;; way.  Cubes are composable and a composition of cubes creates an editor.
;;
;;; Code:

(require 'seq)


(defvar project-root nil
  "Root directory of the website source code.")


(defvar debug-mode nil)


(defun from-root (path)
  "Return the full path of the given PATH in the project root."
  (concat project-root path))


(defun prod-p ()
  "Return non-nil if debug mode is turned off"
  (not debug-mode))


(defun read-args (args)
  "Parse the give ARGS list and return a list in the following
format:
(FLAGS (COMMAND ARGES))"
  (seq-reduce
   (lambda (acc arg)
     (let ((flags (car acc))
           (commands (cadr acc))
           (i (caddr acc))
           (skip (cadddr acc)))

       (if skip
           (list flags commands (1+ i) ())
         (progn
           (cond
            ((string= arg ":d") (plist-put flags :d t))
            ((string= arg ":e") (progn
                                  (plist-put flags :e (nth (1+ i) args))
                                  (setq skip (1+ i))))
            (t (push arg commands)))
           (list flags commands (1+ i) skip)))))
   args
   '((:d () :e ()) () 0 ())))


(defun replace-in-buffer (str replacement)
  "Replace the given STR with its REPLACEMENT in current buffer."
  (with-current-buffer (current-buffer)
    (goto-char (point-min))
    (while (search-forward str nil t)
      (replace-match replacement))))


(defun copy-template (src dest context)
  "Replace the placeholder in SRC with list of pairs given in CONTEXT
and write it to DEST."
  (make-directory (file-name-directory dest) t)
  (message "Copy template: '%s' -> '%s'" src dest)
  (with-temp-file dest
    (insert-file-contents src)
    (dolist (pair context)
      (replace-in-buffer (format "<<<%s>>>" (car pair)) (cdr pair)))))


(provide 'fg42/build/core)
;;; core.el ends here