;;; ob-tangle.el --- extract source code from org-mode files

;; Copyright (C) 2009-2012  Free Software Foundation, Inc.

;; Author: Eric Schulte
;; Keywords: literate programming, reproducible research
;; Homepage: http://orgmode.org

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Extract the code from source blocks out into raw source-code files.

;;; Code:
(require 'org-src)
(eval-when-compile
  (require 'cl))

(declare-function org-link-escape "org" (text &optional table))
(declare-function org-heading-components "org" ())
(declare-function org-back-to-heading "org" (invisible-ok))
(declare-function org-fill-template "org" (template alist))
(declare-function org-babel-update-block-body "org" (new-body))
(declare-function make-directory "files" (dir &optional parents))

(defun org-babel-find-file-noselect-refresh (file)
  "Find file ensuring that the latest changes on disk are
represented in the file."
  (find-file-noselect file)
  (with-current-buffer (get-file-buffer file)
    (revert-buffer t t t)))

(defmacro org-babel-with-temp-filebuffer (file &rest body)
  "Open FILE into a temporary buffer execute BODY there like
`progn', then kill the FILE buffer returning the result of
evaluating BODY."
  (declare (indent 1))
  (let ((temp-path (make-symbol "temp-path"))
	(temp-result (make-symbol "temp-result"))
	(temp-file (make-symbol "temp-file"))
	(visited-p (make-symbol "visited-p")))
    `(let* ((,temp-path ,file)
	    (,visited-p (get-file-buffer ,temp-path))
	    ,temp-result ,temp-file)
       (org-babel-find-file-noselect-refresh ,temp-path)
       (setf ,temp-file (get-file-buffer ,temp-path))
       (with-current-buffer ,temp-file
	 (setf ,temp-result (progn ,@body)))
       (unless ,visited-p (kill-buffer ,temp-file))
       ,temp-result)))
(def-edebug-spec org-babel-with-temp-filebuffer (form body))

;;;###autoload
(defun org-babel-load-file (file)
  "Load Emacs Lisp source code blocks in the Org-mode FILE.
This function exports the source code using
`org-babel-tangle' and then loads the resulting file using
`load-file'."
  (interactive "fFile to load: ")
  (let* ((age (lambda (file)
		(float-time
		 (time-subtract (current-time)
				(nth 5 (or (file-attributes (file-truename file))
					   (file-attributes file)))))))
	 (base-name (file-name-sans-extension file))
	 (exported-file (concat base-name ".el")))
    ;; tangle if the org-mode file is newer than the elisp file
    (unless (and (file-exists-p exported-file)
		 (> (funcall age file) (funcall age exported-file)))
      (org-babel-tangle-file file exported-file "emacs-lisp"))
    (load-file exported-file)
    (message "Loaded %s" exported-file)))

;;;###autoload
(defun org-babel-tangle-file (file &optional target-file lang)
  "Extract the bodies of source code blocks in FILE.
Source code blocks are extracted with `org-babel-tangle'.
Optional argument TARGET-FILE can be used to specify a default
export file for all source blocks.  Optional argument LANG can be
used to limit the exported source code blocks by language."
  (interactive "fFile to tangle: \nP")
  (let ((visited-p (get-file-buffer (expand-file-name file)))
	to-be-removed)
    (save-window-excursion
      (find-file file)
      (setq to-be-removed (current-buffer))
      (org-babel-tangle nil target-file lang))
    (unless visited-p
      (kill-buffer to-be-removed))))

(defun org-babel-tangle-publish (_ filename pub-dir)
  "Tangle FILENAME and place the results in PUB-DIR."
  (mapc (lambda (el) (copy-file el pub-dir t)) (org-babel-tangle-file filename)))

;;;###autoload
(defun org-babel-tangle (&optional only-this-block target-file lang)
  "Write code blocks to source-specific files.
Extract the bodies of all source code blocks from the current
file into their own source-specific files.  Optional argument
TARGET-FILE can be used to specify a default export file for all
source blocks.  Optional argument LANG can be used to limit the
exported source code blocks by language."
  (interactive "P")
  (run-hooks 'org-babel-pre-tangle-hook)
  ;; possibly restrict the buffer to the current code block
  (save-restriction
    (when only-this-block
      (unless (org-babel-where-is-src-block-head)
	(error "Point is not currently inside of a code block"))
      (save-match-data
	(unless (or (cdr (assoc :tangle (nth 2 (org-babel-get-src-block-info))))
		    target-file)
	  (setq target-file
		(read-from-minibuffer "Tangle to: " (buffer-file-name)))))
      (narrow-to-region (match-beginning 0) (match-end 0)))
    (save-excursion
      (let ((block-counter 0)
	    (org-babel-default-header-args
	     (if target-file
		 (org-babel-merge-params org-babel-default-header-args
					 (list (cons :tangle target-file)))
	       org-babel-default-header-args))
	    path-collector)
	(mapc ;; map over all languages
	 (lambda (by-lang)
	   (let* ((lang (car by-lang))
		  (specs (cdr by-lang))
		  (ext (or (cdr (assoc lang org-babel-tangle-lang-exts)) lang))
		  (lang-f (intern
			   (concat
			    (or (and (cdr (assoc lang org-src-lang-modes))
				     (symbol-name
				      (cdr (assoc lang org-src-lang-modes))))
				lang)
			    "-mode")))
		  she-banged)
	     (mapc
	      (lambda (spec)
		(let ((get-spec (lambda (name) (cdr (assoc name (nth 4 spec))))))
		  (let* ((tangle (funcall get-spec :tangle))
			 (she-bang ((lambda (sheb) (when (> (length sheb) 0) sheb))
				    (funcall get-spec :shebang)))
			 (base-name (cond
				     ((string= "yes" tangle)
				      (file-name-sans-extension
				       (buffer-file-name)))
				     ((string= "no" tangle) nil)
				     ((> (length tangle) 0) tangle)))
			 (file-name (when base-name
				      ;; decide if we want to add ext to base-name
				      (if (and ext (string= "yes" tangle))
					  (concat base-name "." ext) base-name))))
		    (when file-name
		      ;; possibly create the parent directories for file
		      (when ((lambda (m) (and m (not (string= m "no"))))
			     (funcall get-spec :mkdirp))
			(make-directory (file-name-directory file-name) 'parents))
		      ;; delete any old versions of file
		      (when (and (file-exists-p file-name)
				 (not (member file-name path-collector)))
			(delete-file file-name))
		      ;; drop source-block to file
		      (with-temp-buffer
			(when (fboundp lang-f) (ignore-errors (funcall lang-f)))
			(when (and she-bang (not (member file-name she-banged)))
			  (insert (concat she-bang "\n"))
			  (setq she-banged (cons file-name she-banged)))
			(org-babel-spec-to-string spec)
			;; We avoid append-to-file as it does not work with tramp.
			(let ((content (buffer-string)))
			  (with-temp-buffer
			    (if (file-exists-p file-name)
				(insert-file-contents file-name))
			    (goto-char (point-max))
			    (insert content)
			    (write-region nil nil file-name))))
		      ;; if files contain she-bangs, then make the executable
		      (when she-bang (set-file-modes file-name #o755))
		      ;; update counter
		      (setq block-counter (+ 1 block-counter))
		      (add-to-list 'path-collector file-name)))))
	      specs)))
	 (org-babel-tangle-collect-blocks lang))
	(message "Tangled %d code block%s from %s" block-counter
		 (if (= block-counter 1) "" "s")
		 (file-name-nondirectory
		  (buffer-file-name (or (buffer-base-buffer) (current-buffer)))))
	;; run `org-babel-post-tangle-hook' in all tangled files
	(when org-babel-post-tangle-hook
	  (mapc
	   (lambda (file)
	     (org-babel-with-temp-filebuffer file
	       (run-hooks 'org-babel-post-tangle-hook)))
	   path-collector))
	path-collector))))

(defun org-babel-tangle-clean ()
  "Remove comments inserted by `org-babel-tangle'.
Call this function inside of a source-code file generated by
`org-babel-tangle' to remove all comments inserted automatically
by `org-babel-tangle'.  Warning, this comment removes any lines
containing constructs which resemble org-mode file links or noweb
references."
  (interactive)
  (goto-char (point-min))
  (while (or (re-search-forward "\\[\\[file:.*\\]\\[.*\\]\\]" nil t)
             (re-search-forward (org-babel-noweb-wrap) nil t))
    (delete-region (save-excursion (beginning-of-line 1) (point))
                   (save-excursion (end-of-line 1) (forward-char 1) (point)))))

(defvar org-stored-links)
(defvar org-bracket-link-regexp)
(defun org-babel-spec-to-string (spec)
  "Insert SPEC into the current file.
Insert the source-code specified by SPEC into the current
source code file.  This function uses `comment-region' which
assumes that the appropriate major-mode is set.  SPEC has the
form

  (start-line file link source-name params body comment)"
  (let* ((start-line (nth 0 spec))
	 (file (nth 1 spec))
	 (link (nth 2 spec))
	 (source-name (nth 3 spec))
	 (body (nth 5 spec))
	 (comment (nth 6 spec))
	 (comments (cdr (assoc :comments (nth 4 spec))))
	 (padline (not (string= "no" (cdr (assoc :padline (nth 4 spec))))))
	 (link-p (or (string= comments "both") (string= comments "link")
		     (string= comments "yes") (string= comments "noweb")))
	 (link-data (mapcar (lambda (el)
			      (cons (symbol-name el)
				    ((lambda (le)
				       (if (stringp le) le (format "%S" le)))
				     (eval el))))
			    '(start-line file link source-name)))
	 (insert-comment (lambda (text)
			   (when (and comments (not (string= comments "no"))
				      (> (length text) 0))
			     (when padline (insert "\n"))
			     (comment-region (point) (progn (insert text) (point)))
			     (end-of-line nil) (insert "\n")))))
    (when comment (funcall insert-comment comment))
    (when link-p
      (funcall
       insert-comment
       (org-fill-template org-babel-tangle-comment-format-beg link-data)))
    (when padline (insert "\n"))
    (insert
     (format
      "%s\n"
      (replace-regexp-in-string
       "^," ""
       (org-babel-trim body (if org-src-preserve-indentation "[\f\n\r\v]")))))
    (when link-p
      (funcall
       insert-comment
       (org-fill-template org-babel-tangle-comment-format-end link-data)))))

(defun org-babel-tangle-collect-blocks (&optional language)
  "Collect source blocks in the current Org-mode file.
Return an association list of source-code block specifications of
the form used by `org-babel-spec-to-string' grouped by language.
Optional argument LANG can be used to limit the collected source
code blocks by language."
  (let ((block-counter 1) (current-heading "") blocks)
    (org-babel-map-src-blocks (buffer-file-name)
      ((lambda (new-heading)
	 (if (not (string= new-heading current-heading))
	     (progn
	       (setq block-counter 1)
	       (setq current-heading new-heading))
	   (setq block-counter (+ 1 block-counter))))
       (replace-regexp-in-string "[ \t]" "-"
				 (condition-case nil
				     (or (nth 4 (org-heading-components))
					 "(dummy for heading without text)")
				   (error (buffer-file-name)))))
      (let* ((start-line (save-restriction (widen)
					   (+ 1 (line-number-at-pos (point)))))
	     (file (buffer-file-name))
	     (info (org-babel-get-src-block-info 'light))
	     (src-lang (nth 0 info)))
        (unless (string= (cdr (assoc :tangle (nth 2 info))) "no")
          (unless (and language (not (string= language src-lang)))
	    (let* ((info (org-babel-get-src-block-info))
		   (params (nth 2 info))
		   (link ((lambda (link)
			    (and (string-match org-bracket-link-regexp link)
				 (match-string 1 link)))
			  (org-no-properties
			   (org-store-link nil))))
		   (source-name
		    (intern (or (nth 4 info)
				(format "%s:%d"
					current-heading block-counter))))
		   (expand-cmd
		    (intern (concat "org-babel-expand-body:" src-lang)))
		   (assignments-cmd
		    (intern (concat "org-babel-variable-assignments:" src-lang)))
		   (body
		    ((lambda (body) ;; run the tangle-body-hook
		       (with-temp-buffer
			 (insert body)
			 (run-hooks 'org-babel-tangle-body-hook)
			 (buffer-string)))
		     ((lambda (body) ;; expand the body in language specific manner
			(if (assoc :no-expand params)
			    body
			  (if (fboundp expand-cmd)
			      (funcall expand-cmd body params)
			    (org-babel-expand-body:generic
			     body params
			     (and (fboundp assignments-cmd)
				  (funcall assignments-cmd params))))))
		      (if (org-babel-noweb-p params :tangle)
			  (org-babel-expand-noweb-references info)
			(nth 1 info)))))
		   (comment
		    (when (or (string= "both" (cdr (assoc :comments params)))
			      (string= "org" (cdr (assoc :comments params))))
		      ;; from the previous heading or code-block end
		      (funcall
		       org-babel-process-comment-text
		       (buffer-substring
			(max (condition-case nil
				 (save-excursion
				   (org-back-to-heading t)  ; sets match data
				   (match-end 0))
			       (error (point-min)))
			     (save-excursion
			       (if (re-search-backward
				    org-babel-src-block-regexp nil t)
				   (match-end 0)
				 (point-min))))
			(point)))))
		   by-lang)
	      ;; add the spec for this block to blocks under it's language
	      (setq by-lang (cdr (assoc src-lang blocks)))
	      (setq blocks (delq (assoc src-lang blocks) blocks))
	      (setq blocks (cons
			    (cons src-lang
				  (cons (list start-line file link
					      source-name params body comment)
					by-lang)) blocks)))))))
    ;; ensure blocks in the correct order
    (setq blocks
          (mapcar
	   (lambda (by-lang) (cons (car by-lang) (reverse (cdr by-lang))))
	   blocks))
    blocks))

(defun org-babel-tangle-comment-links ( &optional info)
  "Return a list of begin and end link comments for the code block at point."
  (let* ((start-line (org-babel-where-is-src-block-head))
	 (file (buffer-file-name))
	 (link (org-link-escape (progn (call-interactively 'org-store-link)
				       (org-no-properties
					(car (pop org-stored-links))))))
	 (source-name (nth 4 (or info (org-babel-get-src-block-info 'light))))
	 (link-data (mapcar (lambda (el)
			      (cons (symbol-name el)
				    ((lambda (le)
				       (if (stringp le) le (format "%S" le)))
				     (eval el))))
			    '(start-line file link source-name))))
    (list (org-fill-template org-babel-tangle-comment-format-beg link-data)
	  (org-fill-template org-babel-tangle-comment-format-end link-data))))

;; de-tangling functions
(defvar org-bracket-link-analytic-regexp)
(defun org-babel-detangle (&optional source-code-file)
  "Propagate changes in source file back original to Org-mode file.
This requires that code blocks were tangled with link comments
which enable the original code blocks to be found."
  (interactive)
  (save-excursion
    (when source-code-file (find-file source-code-file))
    (goto-char (point-min))
    (let ((counter 0) new-body end)
      (while (re-search-forward org-bracket-link-analytic-regexp nil t)
        (when (re-search-forward
	       (concat " " (regexp-quote (match-string 5)) " ends here"))
          (setq end (match-end 0))
          (forward-line -1)
          (save-excursion
	    (when (setq new-body (org-babel-tangle-jump-to-org))
	      (org-babel-update-block-body new-body)))
          (setq counter (+ 1 counter)))
        (goto-char end))
      (prog1 counter (message "Detangled %d code blocks" counter)))))

(defun org-babel-tangle-jump-to-org ()
  "Jump from a tangled code file to the related Org-mode file."
  (interactive)
  (let ((mid (point))
	start end done
        target-buffer target-char link path block-name body)
    (save-window-excursion
      (save-excursion
	(while (and (re-search-backward org-bracket-link-analytic-regexp nil t)
		    (not ; ever wider searches until matching block comments
		     (and (setq start (point-at-eol))
			  (setq link (match-string 0))
			  (setq path (match-string 3))
			  (setq block-name (match-string 5))
			  (save-excursion
			    (save-match-data
			      (re-search-forward
			       (concat " " (regexp-quote block-name)
				       " ends here") nil t)
			      (setq end (point-at-bol))))))))
	(unless (and start (< start mid) (< mid end))
	  (error "Not in tangled code"))
        (setq body (org-babel-trim (buffer-substring start end))))
      (when (string-match "::" path)
        (setq path (substring path 0 (match-beginning 0))))
      (find-file path) (setq target-buffer (current-buffer))
      (goto-char start) (org-open-link-from-string link)
      (if (string-match "[^ \t\n\r]:\\([[:digit:]]+\\)" block-name)
          (org-babel-next-src-block
           (string-to-number (match-string 1 block-name)))
        (org-babel-goto-named-src-block block-name))
      (setq target-char (point)))
    (pop-to-buffer target-buffer)
    (prog1 body (goto-char target-char))))

(provide 'ob-tangle)

;; Local variables:
;; generated-autoload-file: "org-loaddefs.el"
;; End:

;;; ob-tangle.el ends here