;;; informat.el --- info support functions package for Emacs

;; Copyright (C) 1986 Free Software Foundation, Inc.

;; Maintainer: FSF
;; Keywords: help

;; 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 2, 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; see the file COPYING.  If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Code:

(require 'info)

;;;###autoload
(defun Info-tagify ()
  "Create or update Info-file tag table in current buffer."
  (interactive)
  ;; Save and restore point and restrictions.
  ;; save-restrictions would not work
  ;; because it records the old max relative to the end.
  ;; We record it relative to the beginning.
  (message "Tagifying %s ..." (file-name-nondirectory (buffer-file-name)))
  (let ((omin (point-min))
	(omax (point-max))
	(nomax (= (point-max) (1+ (buffer-size))))
	(opoint (point)))
    (unwind-protect
	(progn
	  (widen)
	  (goto-char (point-min))
	  (if (search-forward "\^_\nIndirect:\n" nil t)
	      (message "Cannot tagify split info file")
	    (let ((regexp "Node:[ \t]*\\([^,\n\t]*\\)[,\t\n]")
		  (case-fold-search t)
		  list)
	      (while (search-forward "\n\^_" nil t)
		;; We want the 0-origin character position of the ^_.
		;; That is the same as the Emacs (1-origin) position
		;; of the newline before it.
		(let ((beg (match-beginning 0)))
		  (forward-line 2)
		  (if (re-search-backward regexp beg t)
		      (setq list
			    (cons (list (buffer-substring-no-properties
					  (match-beginning 1)
					  (match-end 1))
					beg)
				  list)))))
	      (goto-char (point-max))
	      (forward-line -8)
	      (let ((buffer-read-only nil))
		(if (search-forward "\^_\nEnd tag table\n" nil t)
		    (let ((end (point)))
		      (search-backward "\nTag table:\n")
		      (beginning-of-line)
		      (delete-region (point) end)))
		(goto-char (point-max))
		(insert "\^_\f\nTag table:\n")
		(move-marker Info-tag-table-marker (point))
		(setq list (nreverse list))
		(while list
		  (insert "Node: " (car (car list)) ?\177)
		  (princ (car (cdr (car list))) (current-buffer))
		  (insert ?\n)
		  (setq list (cdr list)))
		(insert "\^_\nEnd tag table\n")))))
      (goto-char opoint)
      (narrow-to-region omin (if nomax (1+ (buffer-size))
			       (min omax (point-max))))))
  (message "Tagifying %s ... done" (file-name-nondirectory (buffer-file-name))))

;;;###autoload
(defun Info-split ()
  "Split an info file into an indirect file plus bounded-size subfiles.
Each subfile will be up to 50,000 characters plus one node.

To use this command, first visit a large Info file that has a tag
table.  The buffer is modified into a (small) indirect info file which
should be saved in place of the original visited file.

The subfiles are written in the same directory the original file is
in, with names generated by appending `-' and a number to the original
file name.  The indirect file still functions as an Info file, but it
contains just the tag table and a directory of subfiles."

  (interactive)
  (if (< (buffer-size) 70000)
      (error "This is too small to be worth splitting"))
  (goto-char (point-min))
  (search-forward "\^_")
  (forward-char -1)
  (let ((start (point))
	(chars-deleted 0)
	subfiles
	(subfile-number 1)
	(case-fold-search t)
	(filename (file-name-sans-versions buffer-file-name)))
    (goto-char (point-max))
    (forward-line -8)
    (setq buffer-read-only nil)
    (or (search-forward "\^_\nEnd tag table\n" nil t)
	(error "Tag table required; use M-x Info-tagify"))
    (search-backward "\nTag table:\n")
    (if (looking-at "\nTag table:\n\^_")
	(error "Tag table is just a skeleton; use M-x Info-tagify"))
    (beginning-of-line)
    (forward-char 1)
    (save-restriction
      (narrow-to-region (point-min) (point))
      (goto-char (point-min))
      (while (< (1+ (point)) (point-max))
	(goto-char (min (+ (point) 50000) (point-max)))
	(search-forward "\^_" nil 'move)
	(setq subfiles
	      (cons (list (+ start chars-deleted)
			  (concat (file-name-nondirectory filename)
				  (format "-%d" subfile-number)))
		    subfiles))
	;; Put a newline at end of split file, to make Unix happier.
	(insert "\n")
	(write-region (point-min) (point)
		      (concat filename (format "-%d" subfile-number)))
	(delete-region (1- (point)) (point))
	;; Back up over the final ^_.
	(forward-char -1)
	(setq chars-deleted (+ chars-deleted (- (point) start)))
	(delete-region start (point))
	(setq subfile-number (1+ subfile-number))))
    (while subfiles
      (goto-char start)
      (insert (nth 1 (car subfiles))
	      (format ": %d" (1- (car (car subfiles))))
	      "\n")
      (setq subfiles (cdr subfiles)))
    (goto-char start)
    (insert "\^_\nIndirect:\n")
    (search-forward "\nTag Table:\n")
    (insert "(Indirect)\n")))

;;;###autoload
(defun Info-validate ()
  "Check current buffer for validity as an Info file.
Check that every node pointer points to an existing node."
  (interactive)
  (save-excursion
    (save-restriction
      (widen)
      (goto-char (point-min))
      (if (search-forward "\nTag table:\n(Indirect)\n" nil t)
	  (error "Don't yet know how to validate indirect info files: \"%s\""
		 (buffer-name (current-buffer))))
      (goto-char (point-min))
      (let ((allnodes '(("*")))
	    (regexp "Node:[ \t]*\\([^,\n\t]*\\)[,\t\n]")
	    (case-fold-search t)
	    (tags-losing nil)
	    (lossages ()))
	(while (search-forward "\n\^_" nil t)
	  (forward-line 1)
	  (let ((beg (point)))
	    (forward-line 1)
	    (if (re-search-backward regexp beg t)
		(let ((name (downcase
			      (buffer-substring-no-properties
			        (match-beginning 1)
				(progn
				  (goto-char (match-end 1))
				  (skip-chars-backward " \t")
				  (point))))))
		  (if (assoc name allnodes)
		      (setq lossages
			    (cons (list name "Duplicate node-name" nil)
				  lossages))
		      (setq allnodes
			    (cons (list name
					(progn
					  (end-of-line)
					  (and (re-search-backward
						"prev[ious]*:" beg t)
					       (progn
						 (goto-char (match-end 0))
						 (downcase
						   (Info-following-node-name)))))
					beg)
				  allnodes)))))))
	(goto-char (point-min))
	(while (search-forward "\n\^_" nil t)
	  (forward-line 1)
	  (let ((beg (point))
		thisnode next)
	    (forward-line 1)
	    (if (re-search-backward regexp beg t)
		(save-restriction
		  (search-forward "\n\^_" nil 'move)
		  (narrow-to-region beg (point))
		  (setq thisnode (downcase
				   (buffer-substring-no-properties
				     (match-beginning 1)
				     (progn
				       (goto-char (match-end 1))
				       (skip-chars-backward " \t")
				       (point)))))
		  (end-of-line)
		  (and (search-backward "next:" nil t)
		       (setq next (Info-validate-node-name "invalid Next"))
		       (assoc next allnodes)
		       (if (equal (car (cdr (assoc next allnodes)))
				  thisnode)
			   ;; allow multiple `next' pointers to one node
			   (let ((tem lossages))
			     (while tem
			       (if (and (equal (car (cdr (car tem)))
					       "should have Previous")
					(equal (car (car tem))
					       next))
				   (setq lossages (delq (car tem) lossages)))
			       (setq tem (cdr tem))))
			 (setq lossages
			       (cons (list next
					   "should have Previous"
					   thisnode)
				     lossages))))
		  (end-of-line)
		  (if (re-search-backward "prev[ious]*:" nil t)
		      (Info-validate-node-name "invalid Previous"))
		  (end-of-line)
		  (if (search-backward "up:" nil t)
		      (Info-validate-node-name "invalid Up"))
		  (if (re-search-forward "\n* Menu:" nil t)
		      (while (re-search-forward "\n\\* " nil t)
			(Info-validate-node-name
			  (concat "invalid menu item "
				  (buffer-substring (point)
						    (save-excursion
						      (skip-chars-forward "^:")
						      (point))))
			  (Info-extract-menu-node-name))))
		  (goto-char (point-min))
		  (while (re-search-forward "\\*note[ \n]*[^:\t]*:" nil t)
		    (goto-char (+ (match-beginning 0) 5))
		    (skip-chars-forward " \n")
		    (Info-validate-node-name
		     (concat "invalid reference "
			     (buffer-substring (point)
					       (save-excursion
						 (skip-chars-forward "^:")
						 (point))))
		     (Info-extract-menu-node-name "Bad format cross-reference")))))))
	(setq tags-losing (not (Info-validate-tags-table)))
	(if (or lossages tags-losing)
	    (with-output-to-temp-buffer " *problems in info file*"
	      (while lossages
		(princ "In node \"")
		(princ (car (car lossages)))
		(princ "\", ")
		(let ((tem (nth 1 (car lossages))))
		  (cond ((string-match "\n" tem)
			 (princ (substring tem 0 (match-beginning 0)))
			 (princ "..."))
			(t
			 (princ tem))))
		(if (nth 2 (car lossages))
		    (progn
		      (princ ": ")
		      (let ((tem (nth 2 (car lossages))))
			(cond ((string-match "\n" tem)
			       (princ (substring tem 0 (match-beginning 0)))
			       (princ "..."))
			      (t
			       (princ tem))))))
		(terpri)
		(setq lossages (cdr lossages)))
	      (if tags-losing (princ "\nTags table must be recomputed\n")))
	  ;; Here if info file is valid.
	  ;; If we already made a list of problems, clear it out.
	  (save-excursion
	    (if (get-buffer " *problems in info file*")
		(progn
		  (set-buffer " *problems in info file*")
		  (kill-buffer (current-buffer)))))
	  (message "File appears valid"))))))

(defun Info-validate-node-name (kind &optional name)
  (if name
      nil
    (goto-char (match-end 0))
    (skip-chars-forward " \t")
    (if (= (following-char) ?\()
	nil
      (setq name
	    (buffer-substring-no-properties
	     (point)
	     (progn
	      (skip-chars-forward "^,\t\n")
	      (skip-chars-backward " ")
	      (point))))))
  (if (null name)
      nil
    (setq name (downcase name))
    (or (and (> (length name) 0) (= (aref name 0) ?\())
	(assoc name allnodes)
	(setq lossages
	      (cons (list thisnode kind name) lossages))))
  name)

(defun Info-validate-tags-table ()
  (goto-char (point-min))
  (if (not (search-forward "\^_\nEnd tag table\n" nil t))
      t
    (not (catch 'losing
	   (let* ((end (match-beginning 0))
		  (start (progn (search-backward "\nTag table:\n")
				(1- (match-end 0))))
		  tem)
	     (setq tem allnodes)
	     (while tem
	       (goto-char start)
	       (or (equal (car (car tem)) "*")
		   (search-forward (concat "Node: "
					   (car (car tem))
					   "\177")
				   end t)
		   (throw 'losing 'x))
	       (setq tem (cdr tem)))
	     (goto-char (1+ start))
	     (while (looking-at ".*Node: \\(.*\\)\177\\([0-9]+\\)$")
	       (setq tem (downcase (buffer-substring-no-properties
				     (match-beginning 1)
				     (match-end 1))))
	       (setq tem (assoc tem allnodes))
	       (if (or (not tem)
		       (< 1000 (progn
				 (goto-char (match-beginning 2))
				 (setq tem (- (car (cdr (cdr tem)))
					      (read (current-buffer))))
				 (if (> tem 0) tem (- tem)))))
		   (throw 'losing 'y))
	       (forward-line 1)))
	   (if (looking-at "\^_\n")
	       (forward-line 1))
	   (or (looking-at "End tag table\n")
	       (throw 'losing 'z))
	   nil))))

;;;###autoload
(defun batch-info-validate ()
  "Runs `Info-validate' on the files remaining on the command line.
Must be used only with -batch, and kills Emacs on completion.
Each file will be processed even if an error occurred previously.
For example, invoke \"emacs -batch -f batch-info-validate $info/ ~/*.info\""
  (if (not noninteractive)
      (error "batch-info-validate may only be used -batch."))
  (let ((version-control t)
	(auto-save-default nil)
	(find-file-run-dired nil)
	(kept-old-versions 259259)
	(kept-new-versions 259259))
    (let ((error 0)
	  file
	  (files ()))
      (while command-line-args-left
	(setq file (expand-file-name (car command-line-args-left)))
	(cond ((not (file-exists-p file))
	       (message ">> %s does not exist!" file)
	       (setq error 1
		     command-line-args-left (cdr command-line-args-left))) 
	      ((file-directory-p file)
	       (setq command-line-args-left (nconc (directory-files file)
					      (cdr command-line-args-left))))
	      (t
	       (setq files (cons file files)
		     command-line-args-left (cdr command-line-args-left)))))
      (while files
	(setq file (car files)
	      files (cdr files))
	(let ((lose nil))
	  (condition-case err
	      (progn
		(if buffer-file-name (kill-buffer (current-buffer)))
		(find-file file)
		(buffer-disable-undo (current-buffer))
		(set-buffer-modified-p nil)
		(fundamental-mode)
		(let ((case-fold-search nil))
		  (goto-char (point-max))
		  (cond ((search-backward "\n\^_\^L\nTag table:\n" nil t)
			 (message "%s already tagified" file))
			((< (point-max) 30000)
			 (message "%s too small to bother tagifying" file))
			(t
			 (Info-tagify))))
		(let ((loss-name " *problems in info file*"))
		  (message "Checking validity of info file %s..." file)
		  (if (get-buffer loss-name)
		      (kill-buffer loss-name))
		  (Info-validate)
		  (if (not (get-buffer loss-name))
		      nil ;(message "Checking validity of info file %s... OK" file)
		    (message "----------------------------------------------------------------------")
		    (message ">> PROBLEMS IN INFO FILE %s" file)
		    (save-excursion
		      (set-buffer loss-name)
		      (princ (buffer-substring-no-properties
			      (point-min) (point-max))))
		    (message "----------------------------------------------------------------------")
		    (setq error 1 lose t)))
		(if (and (buffer-modified-p)
			 (not lose))
		    (progn (message "Saving modified %s" file)
			   (save-buffer))))
	    (error (message ">> Error: %s" (prin1-to-string err))))))
      (kill-emacs error))))

;;; informat.el ends here
