;;; boon-arguments.el --- An Ergonomic Command Mode  -*- lexical-binding: t -*-

;;; Commentary:


;; A region list has either of the following forms:
;;  ('region (begining . end) (begining . end) ...)
 
;;; Code:

(require 'boon-core)
(require 'boon-regs)
(require 'multiple-cursors)

(defcustom boon-enclosures
      '(
        (?A . ("⟨" "⟩"))
        (?a . ("<" ">"))
        (?b . ("[" "]"))
        (?c . ("{-" "-}"))
        (?d . ("\"" "\"")) ;; double quotes
        (?D . ("``" "''")) ;; Double quotes
        (?f . ("«" "»")) ;; french quotes
        (?h . ("#" "#")) ;; hash
        (?m . ("`" "'"))
        (?p . ("(" ")"))
        (?q . ("'" "'"))
        (?r . ("{" "}"))
        (?o . ("⟦" "⟧")) ;; oxford brackets
        (?t . ("~" "~")) ;; tilda
        )
        "Enclosures to use with the boon-enclose command."
        :type '(alist :key-type character :value-type (list string))
        :group 'boon
        )

(defun boon-spec-enclosure ()
  "Specify an enclosure style.  To be used as an argument to interactive."
  (let* ((c (boon-read-char "Specify the enclosure"))
         (s (make-string 1 c))
         (choice (assoc c boon-enclosures)))
    (if choice (cdr choice) (list s s))))

(defun boon-select-thing-at-point (thing)
  "Return a region list with a single item pointing to the THING at point."
  (lambda ()(cons 'bounds (bounds-of-thing-at-point thing))))

(defun boon-select-from-region (select-fun)
  "Return a region list with a single item: the region selected after calling SELECT-FUN (interactively)."
  (interactive)
  (save-excursion
    ;; FIXME: deactivate mark
    (call-interactively select-fun)
    (lambda ()(cons 'bounds (cons (region-beginning) (region-end))))))

(defun boon-select-wim () ;; what i mean
  "Return a region list with a single item: either the symbol at point, or, if this fails, the sexp at point."
  (interactive)
  (lambda ()(let ((bounds (or (bounds-of-thing-at-point 'symbol)
                              (bounds-of-thing-at-point 'sexp))))
              (cons 'bounds bounds))))

(defun boon-jump-over-blanks-forward ()
  "Jump over blanks, forward."
  (interactive)
  (skip-chars-forward "\n\t "))

(defun boon-jump-over-blanks-backward ()
  "Jump over blanks, backward."
  (interactive)
  (skip-chars-backward "\n\t "))

(defun boon-select-org-table-cell ()
  "Return the region between pipes (|)."
  (interactive)
  (lambda ()(cons 'bounds
        (cons (save-excursion
                (skip-chars-backward "^|") (point))
              (save-excursion
                (skip-chars-forward "^|") (point))))))

(defun boon-select-justline ()
  "Return the region of the current line, without any newline."
  (interactive) (cons 'bounds (cons (line-beginning-position) (line-end-position))))

(defun boon-select-line (count)
  "Return a region of COUNT visual lines."
  (interactive "p")
  (setq temporary-goal-column 0)
  (boon-select-n count 'beginning-of-visual-line 'line-move-visual))

(defun boon-select-n (count goto-beginning forward-n)
  "Return a region of COUNT objects defined by GOTO-BEGINNING and FORWARD-N."
  (lambda()(save-excursion
    (funcall goto-beginning)
    (cons 'bounds (cons (point) (progn (funcall forward-n count) (point)))))))

(defun boon-select-paragraph (count) (interactive "p") (boon-select-n count 'start-of-paragraph-text 'forward-paragraph))
(defun boon-select-document () (interactive) (cons 'bounds (cons (point-min) (point-max))))
(defun boon-select-word () (interactive) (boon-select-thing-at-point 'word))
(defun boon-select-sentence () (interactive) (boon-select-thing-at-point 'sentence))
(defun boon-select-symbol () (interactive) (boon-select-thing-at-point 'symbol))
(defun boon-select-list () (interactive) (boon-select-thing-at-point 'list))
(defun boon-select-sexp () (interactive) (boon-select-thing-at-point 'sexp))
(defun boon-select-outside-pairs () (interactive) (boon-select-from-region 'er/mark-outside-pairs))
(defun boon-select-comment () (interactive) (boon-select-from-region 'er/mark-comment))
(defun boon-select-inside-pairs () (interactive) (boon-select-from-region 'er/mark-inside-pairs))
(defun boon-select-outside-quotes () (interactive) (boon-select-from-region 'er/mark-outside-quotes))
(defun boon-select-whitespace () (interactive) (boon-select-thing-at-point 'whitespace))
(defun boon-select-blanks ()
  (interactive)
  (cons 'bounds (cons
                 (save-excursion
                   (boon-jump-over-blanks-backward)
                   (point))
                 (save-excursion
                   (boon-jump-over-blanks-forward)
                   (point)))))

(defun boon-spec-string (prompt)
  "Read a string using the region selection functionality.
Intented to be used as an argument to interactive.
Display PROMPT in the echo area."
  (let ((head (read-event)))
    (if (equal head ? ) (read-string (concat prompt ": "))
      ; if space, read a literal string, otherwise use the region specifier.
      (setq unread-command-events
            (cons head unread-command-events))
      (let* ((regs (boon-spec-region prompt))
             (reg (car regs)))
        (buffer-substring-no-properties (boon-reg-begin reg) (boon-reg-end reg))))))

(defun boon-select-occurences (what where)
  "Return the occurences of WHAT as sub-regions of WHERE."
  (interactive (list (boon-spec-string "occurences of what?") (boon-spec-region "where?")))
  (let ((result nil))
    (save-excursion
      (dolist (reg where)
        (goto-char (boon-reg-begin reg))
        (while (search-forward what (boon-reg-end reg) t)
          (setq result (cons (boon-mk-reg (match-beginning 0)
                                          (match-end 0)
                                          (boon-reg-cursor reg))
                              result))))
      (cons 'region result))))

(defun boon-select-borders (how-much regs)
  "Return the bordering (of size HOW-MUCH) of a region list REGS.
This function is meant to be called interactively."
  (interactive (list (prefix-numeric-value current-prefix-arg) (boon-spec-region-lazy "select contents")))
  (lambda ()(cons 'region (apply 'append (mapcar (lambda (reg) (boon-borders reg how-much)) (mapcar 'boon-normalize-reg (funcall regs)))))))

(defun boon-select-with-spaces (regs)
  "Return the regions REGS, including some surrounding spaces.
This function is meant to be called interactively."
  (interactive (list (boon-spec-region-lazy "select with spaces")))
  (lambda ()(cons 'region (mapcar (lambda (reg) (boon-include-surround-spaces reg)) (mapcar 'boon-normalize-reg (funcall regs))))))

(defun boon-select-content (regs)
  "Return the contents (of size HOW-MUCH) of a region list REGS.
This function is meant to be called interactively."
  (interactive (list (boon-spec-region-lazy "select borders")))
  (lambda ()(cons 'region (mapcar 'boon-content (mapcar 'boon-normalize-reg (funcall regs))))))

(defun boon-bypass-mc ()
  "Should we bypass multiple cursors when gathering regions?"
  (and (bound-and-true-p multiple-cursors-mode)
       (memq this-command mc/cmds-to-run-once)))

(defun boon-multiple-cursor-regs ()
  "Return all regions defined by multiple-cursors-mode, and outside."
  (cons (boon-mk-reg (mark) (point) nil)
        (if (boon-bypass-mc)
            ;; TODO: is marker-position really necessary here?
            (mapcar (lambda (o) (boon-mk-reg (marker-position (overlay-get o 'mark)) (marker-position (overlay-get o 'point)) o))
                    (mc/all-fake-cursors)))))

(defun boon-read-char (&optional prompt inherit-input-method seconds)
  "Read a character, bypassing multiple cursors defadvice if applicable."
  ;; do this so that mc's read-char defadvice does not kick in; so we can actually read characters here.
  ;; a hack for now: as read-event doesn't do the same thing as read char.
  (if (boon-bypass-mc)
      (read-event prompt inherit-input-method seconds)
    (read-char prompt inherit-input-method seconds)))

(defun boon-spec-region (msg)
  "Specify a region concisely using the keyboard.
The prompt (as MSG) is displayed.  This function returns a list
of regions (See boon-regs.el).  If multiple-cursors are enabled
BUT the command is executed just once (not once per cursor), you
get a region for each cursor.
"
  (let ((orig-regs (boon-multiple-cursor-regs)))
    (if (use-region-p) orig-regs
      (let ((selector (boon-spec-region-lazy msg)))
        (apply 'append
               (mapcar (lambda (in-reg)
                         (save-excursion
                           (goto-char (boon-reg-point in-reg))
                           (mapcar (lambda (r) (boon-mk-reg (boon-reg-mark r)
                                                            (boon-reg-point r)
                                                            (boon-reg-cursor in-reg)))
                                   (funcall selector))))
                       orig-regs))))))

(defun boon-spec-region-lazy (msg)
  "Specify a region selector concisely using the keyboard.
The prompt (as MSG) is displayed.  This function returns a
non-interactive function which, when run, will return bounds.
The bounds have either of the following forms: ('bounds . begin
. end) OR a list of regions (see boon-regs.el) OR something else,
in which case the region is defined by the movement of the point.
"
  (let ((my-prefix-arg 0)
        (kmv boon-moves-map)
        (kms boon-select-map)
        last-char)
    ;; We read a move or selection, in both keymaps in parallel. First command found wins.
    (while (and (or kmv kms)  (not (commandp kms)) (not (commandp kmv)))
      (let ((last-char (boon-read-char (format "%s %s" msg my-prefix-arg))))
        (if (and (>= last-char ?0) (<= last-char ?9))
            (setq my-prefix-arg (+ (- last-char ?0) (* 10 my-prefix-arg )))
          (if kms (setq kms (lookup-key kms (vector last-char))))
          (if kmv (setq kmv (lookup-key kmv (vector last-char)))))))
    (when (eq my-prefix-arg 0) (setq my-prefix-arg nil))
      ;; The command is ready; we now execute it (once per cursor if applicable).
    (if (or kms kmv)
        (if (commandp kms)
          ;; we have a 'selection'. These commands may take prefix
          ;; args, which they parse right away, and return a
          ;; continuation constructing the region.
            (let ((action (let ((current-prefix-arg my-prefix-arg))
                            (call-interactively kms)))) ;; must be called first so that the interactive arguments are read
              (lambda () ;; FIXME: massage the return value into common format.
                (let ((regs (funcall action)))
                  (cond ((eq (car regs) 'bounds)
                         (mapcar 'boon-reg-from-bounds (list (cdr regs))))
                        ((eq (car regs) 'region)
                         (message "")
                         (cdr regs))
                        (t (error "unknown regs format"))))))
          ;; we have a 'move'. These commands do not take non-universal arguments. So just run it.
            (lambda ()
              (save-excursion
                (let ((orig (point)))
                  (let ((current-prefix-arg my-prefix-arg)) ;; dynamic bindig so env remains clean
                    (call-interactively kmv))
                  (list (boon-mk-reg orig (point) nil))))))
      (error "Unknown region specifier"))))

(provide 'boon-arguments)
;;; boon-arguments.el ends here