;;; geiser-debug.el -- displaying debug information and evaluation results

;; Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2020, 2021 Jose Antonio Ortega Ruiz

;; This program is free software; you can redistribute it and/or
;; modify it under the terms of the Modified BSD License. You should
;; have received a copy of the license along with this program. If
;; not, see <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5>.

;; Start date: Mon Feb 23, 2009 22:34


;;; Code:

(eval-when-compile (require 'cl-macs))

(require 'geiser-edit)
(require 'geiser-autodoc)
(require 'geiser-impl)
(require 'geiser-eval)
(require 'geiser-menu)
(require 'geiser-popup)
(require 'geiser-base)
(require 'geiser-image)

(require 'ansi-color)


;;; Customization:

(defgroup geiser-debug nil
  "Debugging and error display options."
  :group 'geiser)

(geiser-custom--defcustom geiser-debug-always-display-sexp-after-p nil
  "Whether to always display the sexp whose evaluation caused an
error after the error message in the debug pop-up. If nil,
expressions shorter than `geiser-debug-long-sexp-lines` lines are
shown before the error message."
  :type 'boolean)

(geiser-custom--defcustom geiser-debug-long-sexp-lines 6
  "Length of an expression in order to be relegated to the bottom
of the debug pop-up (after the error message). If
`geiser-debug-always-display-sexp-after-p` is t, this variable
has no effect."
  :type 'int)

(geiser-custom--defcustom geiser-debug-jump-to-debug-p t
  "When set to t (the default), jump to the debug pop-up buffer
in case of evaluation errors.

See also `geiser-debug-show-debug-p`. "
  :type 'boolean)

(geiser-custom--defcustom geiser-debug-show-debug-p t
  "When set to t (the default), show the debug pop-up buffer in
case of evaluation errors.

This option takes effect even if `geiser-debug-jump-to-debug-p`
is set."
  :type 'boolean)

(geiser-custom--defcustom geiser-debug-auto-display-images-p t
  "Whether to automatically invoke the external viewer to display
images when they're evaluated.

See also `geiser-repl-auto-display-images-p'."
  :type 'boolean)

(geiser-custom--defcustom geiser-debug-treat-ansi-colors nil
  "Colorize ANSI escape sequences produced by the scheme process.

Some schemes are able to colorize their evaluation or error
results using ANSI color sequences (e.g. when using the the
colorized module in Guile).

If set to `nil', no special treatment is applied to output.  The
symbol colors indicates colorizing the display of the Geiser dbg
buffer using any color escape, and the symbol remove to remove
all ANSI sequences."
  :type '(choice (const :tag "No special treatment" nil)
                 (const :tag "Use font lock for colors" colors)
                 (const :tag "Remove all ANSI codes" remove)))


;;; Debug buffer mode:

(defvar geiser-debug-mode-map
  (let ((map (make-sparse-keymap)))
    (suppress-keymap map)
    (set-keymap-parent map button-buffer-map)
    map)
  "Keymap for `geiser-debug-mode'.")

(define-derived-mode geiser-debug-mode nil "Geiser DBG"
  "A major mode for displaying Scheme compilation and evaluation results.
\\{geiser-debug-mode-map}"
  (buffer-disable-undo)
  (set-syntax-table scheme-mode-syntax-table)
  (setq next-error-function 'geiser-edit--open-next)
  (setq buffer-read-only t))

(defun geiser-debug--button-p (nextp)
  (let ((m (funcall (if nextp 'next-button 'previous-button) (point))))
    (and m (funcall (if nextp '< '>) (point) (marker-position m)))))

(geiser-menu--defmenu debug geiser-debug-mode-map
  ("Next error" "n" forward-button :enable (geiser-debug--button-p t))
  ("Previous error" "p" backward-button :enable (geiser-debug--button-p t))
  --
  ("Quit" nil View-quit))


;;; Buffer for displaying evaluation results:

(geiser-popup--define debug "*Geiser dbg*" geiser-debug-mode)


;;; Displaying retorts

(geiser-impl--define-caller geiser-debug--display-error
    display-error (module key message)
  "This method takes 3 parameters (a module name, the error key,
and the accompanying error message) and should display
(in the current buffer) a formatted version of the error. If the
error was successfully displayed, the call should evaluate to a
non-null value.")

(geiser-impl--define-caller geiser-debug--enter-debugger
    enter-debugger ()
  "This method is called upon entering the debugger, in the REPL
buffer.")

(defun geiser-debug--display-after (what)
  (or geiser-debug-always-display-sexp-after-p
      (>= (with-temp-buffer
            (insert what)
            (count-lines (point-min) (point-max)))
          geiser-debug-long-sexp-lines)))

(defun geiser-debug--insert-res (res)
  (let ((begin (point)))
    (insert res)
    (let ((end (point)))
      (goto-char begin)
      (let ((no (geiser-image--replace-images
                 t geiser-debug-auto-display-images-p)))
        (goto-char end)
        (newline 2)
        (and no (> no 0))))))

(declare-function switch-to-geiser "geiser-repl")

(defun geiser-debug--display-retort (what ret &optional res auto-p)
  (let* ((err (geiser-eval--retort-error ret))
         (key (geiser-eval--error-key err))
         (output (geiser-eval--retort-output ret))
         (output (and (stringp output) (not (string= output "")) output))
         (impl geiser-impl--implementation)
         (module (geiser-eval--get-module))
         (img nil)
         (dir default-directory)
         (buffer (current-buffer))
         (debug (eq key 'geiser-debugger))
         (debug-entered (when debug
                          (switch-to-geiser nil nil buffer)
                          (geiser-debug--enter-debugger impl)))
         (after (geiser-debug--display-after what)))
    (unless debug-entered
      (geiser-debug--with-buffer
        (erase-buffer)
        (when dir (setq default-directory dir))
        (unless after (insert what "\n\n"))
        (setq img (when (and res (not err)) (geiser-debug--insert-res res)))
        (when (or err key output)
          (or (geiser-debug--display-error impl module key output)
              (insert "\n" (if key (format "%s\n" key) "") output "\n")))
        (when after
          (goto-char (point-max))
          (insert "\nExpression evaluated was:\n\n")
          (insert what "\n"))
        (cl-case geiser-debug-treat-ansi-colors
          (colors (ansi-color-apply-on-region (point-min) (point-max)))
          (remove (ansi-color-filter-region (point-min) (point-max))))
        (goto-char (point-min)))
      (when (or img err output)
        (when (or geiser-debug-jump-to-debug-p geiser-debug-show-debug-p)
          (if geiser-debug-jump-to-debug-p
              (geiser-debug--pop-to-buffer)
            (display-buffer (geiser-debug--buffer))))
        (when err
          (ignore-errors (next-error))
          (message "=> %s" output))))))

(defsubst geiser-debug--wrap-region (str)
  (format "(begin %s\n)" str))

(defun geiser-debug--unwrap (str)
  (if (string-match "(begin[ \t\n\v\r]+\\(.+\\)*)" str)
      (match-string 1 str)
    str))

(defun geiser-debug--send-region (compile start end and-go wrap &optional nomsg)
  (let* ((str (buffer-substring-no-properties start end))
         (wrapped (if wrap (geiser-debug--wrap-region str) str))
         (code `(,(if compile :comp :eval) (:scm ,wrapped)))
         (ret (geiser-eval--send/wait code))
         (res (geiser-eval--retort-result-str ret nil))
         (err (geiser-eval--retort-error ret)))
    (when and-go (funcall and-go))
    (when (not err)
      (save-excursion
        (goto-char (/ (+ end start) 2))
        (geiser-autodoc--clean-cache))
      (unless nomsg
        (save-match-data
          (when (string-match "\\(?:[ \t\n\r]+\\)\\'" res)
            (setq res (replace-match "" t t res))))
        (message "%s" res)))
    (geiser-debug--display-retort (geiser-syntax--scheme-str str) ret res)
    ret))

(defun geiser-debug--expand-region (start end all wrap)
  (let* ((str (buffer-substring-no-properties start end))
         (wrapped (if wrap (geiser-debug--wrap-region str) str))
         (code `(:eval (:ge macroexpand (quote (:scm ,wrapped))
                            ,(if all :t :f))))
         (ret (geiser-eval--send/wait code))
         (err (geiser-eval--retort-error ret))
         (result (geiser-eval--retort-result ret)))
    (if err
        (geiser-debug--display-retort str ret)
      (geiser-debug--with-buffer
        (erase-buffer)
        (insert (format "%s" (if wrap (geiser-debug--unwrap result) result)))
        (goto-char (point-min)))
      (geiser-debug--pop-to-buffer))))


(provide 'geiser-debug)