;; Copyright (C) 2015-2016, 2018 Free Software Foundation, Inc

;; Author: Rocky Bernstein <rocky@gnu.org>

;; 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/>.

(require 'comint)
(require 'eshell)
(require 'load-relative)
(require-relative-list '("utils" "window") "realgud-")
(require-relative-list '("buffer/helper") "realgud-buffer-")

(declare-function realgud-get-cmdbuf        'realgud-buffer-helper)
(declare-function realgud-get-srcbuf        'realgud-buffer-helper)
(declare-function realgud-cmdbuf-info-in-debugger?= 'realgud-command)
(declare-function realgud-window-cmd-undisturb-src 'realgud-window)
(declare-function comint-goto-process-mark  'comint)
(declare-function comint-send-input         'comint)
(declare-function realgud:canonic-major-mode 'realgud-utils)

(defun realgud:send-input ()
  "Sends command buffer line either to comint or eshell"
  (interactive)
  (let ((mode (realgud:canonic-major-mode)))
    (ignore-errors
      (cond ((eq mode 'eshell)
	     (eshell-send-input))
	    ((eq mode 'comint)
	     (comint-send-input))
	    ))))

(defun realgud:send-command-common (process command-str)
  "Assume we are in a comint buffer. Insert COMMAND-STR and
send that input onto the process."
  (if (eq 'run (process-status process))
      (let ((mode (realgud:canonic-major-mode)))
	(cond ((eq mode 'eshell)
	       (goto-char eshell-last-output-end)
	       (setq eshell-last-output-start
		     (setq realgud-last-output-start (point-marker))))
	      ((eq mode 'comint)
	       (comint-check-proc (current-buffer))
	       (comint-goto-process-mark)
	       (setq comint-last-output-start
		    (setq realgud-last-output-start (point-marker)))))
	(insert command-str)
	(realgud:send-input)
	)
    ;; else
    (message "Process %s not in `run' state; not issuing %s"
	     process command-str)
    )
  )

(defalias 'comint-output-filter-orig
  (symbol-function 'comint-output-filter))

(defvar realgud-last-output-start)
(defun fake-output-filter(process string)
  "A process output filter that saves the results into a temporary buffer."
  (with-current-buffer (get-buffer-create "*realgud-process-output-temp*")
    (goto-char (point-max))
    (set (make-local-variable 'realgud-last-output-start)
	 (point-marker))
    (insert (concat "\n" string))
    (goto-char (point-max))))

(defun realgud-send-command-process (process command-str)
  "Invoke debugger COMMAND adding that command and the
results into the command buffer."
  (fset 'comint-output-filter (symbol-function 'fake-output-filter))
  (apply comint-input-sender (list process command-str))
  (sit-for 0.25) ;; FIXME with something better
  (fset 'comint-output-filter (symbol-function 'comint-output-filter-orig))
  )

;; Here are some other possibilities for functions.
;; Comint-specific: doesn't insert input into the buffer which is
;; what gud-call does.
;;   (apply comint-input-sender (list proc command))
;;
;; Works on any process-oriented buffer, not just comint.
;;   (process-send-string (get-buffer-process (current-buffer))
;;                        (concat command "\n"))


(defun realgud-send-command (command &optional opt-send-fn opt-buffer)
  "Invoke the debugger COMMAND adding that command and the
results into the command buffer."
  (let* ((cmdbuf (realgud-get-cmdbuf opt-buffer))
	 (send-command-fn (or opt-send-fn (function realgud:send-command-common)))
	 )
    (if cmdbuf
	(with-current-buffer cmdbuf
	  (let ((process (get-buffer-process cmdbuf)))
	    (unless process
	      (realgud-cmdbuf-info-in-debugger?= nil)
	      (error "Command process buffer is not running")
	      )
	    (if (realgud-sget 'cmdbuf-info 'in-debugger?)
		(funcall send-command-fn process command)
	      (error "Command buffer doesn't think a debugger is running - Use `realgud-cmdbuf-toggle-in-debugger?' to toggle")
	      )
	    ))
      (error "Can't find command process buffer")
      )))

(defun realgud-send-command-invisible (command-str)
  (realgud-send-command command-str (function realgud-send-command-process)))

(defvar realgud-expand-format-overrides nil
  "An alist of overrides for `realgud-expand-format'.
Each element should have the form (KEY . VALUE).  Key should be a
single-character escape accepted by `realgud-expand-format';
value should be a string.  Every time %KEY is encountered in te
string, it will be replaced by VALUE instead of being processed
as usual.  If VALUE is nil, the override is ignored.")

(defun realgud-expand-format (fmt-str &optional opt-str opt-buffer)
  "Expands commands format characters inside FMT-STR.
OPT-STR is an optional string (used with %p and %s).  Values are
taken from current buffer, or OPT-BUFFER if non-nil.  Some
%-escapes in the string arguments are expanded.  These are:

  %f -- Name without directory of current source file.
  %F -- Name without directory or extension of current source file.
  %x -- Name of current source file.
  %X -- Expanded name of current source file.
  %U -- Expanded name of current source file stripping file://.
  %d -- Directory of current source file.
  %l -- Number of current source line.
  %c -- Fully qualified class name derived from the expression
        surrounding point.
  %p -- Value of OPT-STR, converted to string using `int-to-string'
  %q -- Value of OPT-STR with string escapes (as ksh, bash, and zsh do).
  %s -- Value of OPT-STR.

%p and %s are replaced by an empty string if OPT-STR is nil."
  (let* ((buffer (or opt-buffer (current-buffer)))
	 (srcbuf (realgud-get-srcbuf buffer))
	 (src-file-name (and srcbuf (buffer-file-name srcbuf)))
	 result)
    (while (and fmt-str
		(let ((case-fold-search nil))
		  (string-match "\\([^%]*\\)%\\([dfFlpqxUXs]\\)" fmt-str)))
      (let* ((key-str (match-string 2 fmt-str))
	     (key (string-to-char key-str)))
	(setq result
	      (concat
	       result (match-string 1 fmt-str)
	       (cond
		((cdr (assq key realgud-expand-format-overrides)))
		((eq key ?d)
		 (or (and src-file-name
			  (file-name-directory src-file-name))
		     "*source-file-not-found-for-%d"))
		((eq key ?f)
		 (or (and src-file-name
			  (file-name-nondirectory src-file-name))
		     "*source-file-not-found-for-%f*"))
		((eq key ?F)
		 (or (and src-file-name
			  (file-name-sans-extension
			   (file-name-nondirectory src-file-name)))
		     "*source-file-not-found-for-%F"))
		((eq key ?l)
		 (if srcbuf
		     (with-current-buffer srcbuf
		       (int-to-string
			(save-restriction
			  (widen)
			  (+ (count-lines (point-min) (point))
			     (if (bolp) 1 0)))))
		   "source-buffer-not-found-for-%l"))

                ((eq key ?p) (if opt-str (int-to-string opt-str) ""))

		;; String with escapes. %q follows shell (ksh, bash, zsh)
		;; The other possibility was Python's %r, !r or "repr".
		;; That isn't as perfect a fit though.
                ((eq key ?q) (if opt-str
				 (let ((print-escape-newlines t))
				   (prin1-to-string opt-str))
				 ""))

		;; String
                ((eq key ?s) (or opt-str ""))

		((eq key ?x)
		 (or (and src-file-name src-file-name)
		     "*source-file-not-found-for-%x"))

		((eq key ?X)
		 (or (and src-file-name (expand-file-name src-file-name))
		     "*source-file-not-found-for-%X"))

		((eq key ?U)
		 (if (string-match src-file-name "^file://")
		     (setq src-file-name (substring src-file-name 7)))
		 (or (and src-file-name (expand-file-name src-file-name))
		     "*source-file-not-found-for-%X"))

		;; ((eq key ?e)
		;;  (gud-find-expr))
		;; ((eq key ?a)
		;;  (gud-read-address))
		;; ((eq key ?c)
		;;   (gud-find-class srcbuf))

                (t key)))))
      (setq fmt-str (substring fmt-str (match-end 2))))
    ;; There might be text left in FMT-STR when the loop ends.
    (concat result fmt-str)))

(defun realgud-command (fmt &optional arg no-record? frame-switch? realgud-prompts?)
  "Sends a command to the process associated with the command
buffer of the current buffer. A bit of checking is done before
sending the command to make sure that we can find a command
buffer, and that it has a running process associated with it.

FMT is a string which may contain format characters that are
expanded. See `realgud-expand-format' for a list of the format
characters and their meanings.

If NO-RECORD? is set, the command won't be recorded in the
position history. This is often done in status and information
gathering or frame setting commands and is generally *not* done
in commands that continue execution.

If FRAME-SWITCH? is set, the fringe overlay array icon is set to
indicate the depth of the frame.

If REALGUD-PROMPTS? is set, then then issuing the command will cause a
debugger prompt.
"
  (interactive "sCommand (may contain format chars): ")
  (let* ((command-str (realgud-expand-format fmt arg))
	 (cmd-buff (realgud-get-cmdbuf))
	 )
    (unless cmd-buff
      (error "Can't find command buffer for buffer %s" (current-buffer)))

    ;; Display the expanded command in the message area unless the
    ;; current buffer is the command buffer.
    (unless (realgud-cmdbuf?)
      (message "Command: %s" command-str))

    (with-current-buffer cmd-buff
      (let* ((process (get-buffer-process cmd-buff))
	     (last-output-end (point-marker))
	     (in-srcbuf? (realgud-sget 'cmdbuf-info 'in-srcbuf?))
	     )
	(unless process
	  (error "Can't find process for command buffer %s" cmd-buff))
	(unless (eq 'run (process-status process))
	  (error "Process %s isn't running; status %s" process
		 (process-status process)))

	(realgud-cmdbuf-info-no-record?= no-record?)
	(realgud-cmdbuf-info-frame-switch?= frame-switch?)

	;; Down the line we may handle prompting in a more
	;; sophisticated way. But for now, we handle this by forcing
	;; display of the command buffer.
	(if realgud-prompts? (realgud-window-cmd-undisturb-src nil 't))

	(realgud-send-command command-str (function realgud:send-command-common))

	;; Wait for the process-mark to change before changing variables
	;; that effect the hook processing.
	(while (and (eq 'run (process-status process))
		    (equal last-output-end (process-mark process)))
	  (sit-for 0))

	;; Reset temporary hook-processing variables to their default state.
	(realgud-cmdbuf-info-no-record?= nil)
	(realgud-cmdbuf-info-frame-switch?=  nil)
	))))

(provide-me "realgud-")