;; tinmop module to expand abbreviations on the command window
;; Copyright © 2021 cage

;; 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 this program.  If not, see <http://www.gnu.org/licenses/>.

;; This   module  will   expand  an   abbreviation  as   described  in
;; *expand-abbrev-rewriting-rules* when typing on the command line the
;; command line  is that  thin window  on the  bottom of  the terminal
;; where  user  can  input  data   when  requested  from  the  program
;; (e.g.     asking    for     a    password).      an    entry     in
;; *expand-abbrev-rewriting-rules*  is  composed  by  a  list  of  two
;; elements the first is a regular expression the second the expansion,
;; for example

;; ("^\\^g" "gemini://")

;; means:  if a  string that  starts ("^")  with "^g"  is expanded  to
;; gemini:// if  the input string  starts with a backslash  ("\") this
;; escape the second  character so if you want to  enter "^g" you need
;; to start typing "\^g".

(in-package :modules)

(defparameter *expand-abbrev-rewriting-rules* '(("^!ge" "gemini://")
                                                ("^!go" "gopher://")
                                                ("^!n" "np://"))
  "Before  displaying  messages that  module  will  rewrites the  first
  element of each item (a regular expression) of this list with the second

Example

   (\"foo\" \"bar\")
      ^^^
      first
              ^^^
              second

will replace 'foo' with 'bar'.

So the whole list is like: '((\"foo\" \"bar\") (\"old\" \"new\") ...)")


(defun expand-abbrev-abbrev-re (abbrev)
  (first abbrev))

(defun expand-abbrev-abbrev-replace (abbrev)
  (second abbrev))

(defparameter *expand-abbrev-actual-rewriting-rules*
  (mapcar (lambda (a) (list (create-scanner (expand-abbrev-abbrev-re a))
                            (expand-abbrev-abbrev-replace a)))
          *expand-abbrev-rewriting-rules*))

(defparameter *expand-abbrev-stop-rewrite* nil)

(defun expand-abbrev-command-hook-fn (command-window)
  (let ((expanded              (command-window:command-line command-window)))
    (when (null *expand-abbrev-stop-rewrite*)
      (if (scan "^\\\\." expanded)
          (progn
            (setf *expand-abbrev-stop-rewrite* t)
            (setf expanded (subseq expanded 1)))
          (loop for expansion in *expand-abbrev-actual-rewriting-rules* do
            (let ((start (scan (expand-abbrev-abbrev-re expansion) expanded)))
              (when start
                (setf expanded (regex-replace (expand-abbrev-abbrev-re expansion)
                                              expanded
                                              (expand-abbrev-abbrev-replace expansion)))
                (point-tracker:move-point command-window
                                          start
                                          (length expanded))
                (point-tracker:move-point-right command-window
                                                 (length expanded)
                                                 :offset
                                                 (length (expand-abbrev-abbrev-replace expansion)))))))
      (setf (command-window:command-line command-window) expanded)))
  command-window)

(defun expand-abbrev-command-fire-hook (x)
  (declare (ignore x))
  (setf *expand-abbrev-stop-rewrite* nil))

(defun expand-abbrev-command-delete-hook (x)
  (expand-abbrev-command-fire-hook x))

(hooks:add-hook 'hooks:*after-char-to-command-window*
                #'expand-abbrev-command-hook-fn)

(hooks:add-hook 'hooks:*before-fire-string-event-command-window*
                #'expand-abbrev-command-fire-hook)

(hooks:add-hook 'hooks:*after-delete-char-from-command-window*
                #'expand-abbrev-command-delete-hook)