;;;; citation.el -- show what is cited here
;;; Time-stamp: <2005-03-10 12:06:31 john>

;;  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 2 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, write to the Free Software Foundation, Inc.,
;;  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

(provide 'citation)

(defvar buffer-bibliographies nil
  "The bibliographies for the current buffer.")

(make-variable-buffer-local 'buffer-bibliographies)

(defun buffer-bibliographies ()
  "Return the bibliography filenames for the current buffer."
  (if buffer-bibliographies
      buffer-bibliographies
    (setq buffer-bibliographies
	  (save-excursion
	    (goto-char (point-min))
	    (if (re-search-forward "\\\\bibliography{\\([^}]+\\)}" (point-max) t)
		(let ((names-string (match-string-no-properties 1)))
		  (mapcar (lambda (name) (expand-file-name
					  (concat name ".bib")))
			  (split-string names-string ",")))
	      nil)))))

;;;###autoload
(defun show-citation ()
  "Show the citation at or before point.
Return whether it was found."
  ;; done: make sure it works with multiple bibliographis
  ;; done: bury the bibliography buffer if it did not contain target
  (interactive)
  (let ((window (selected-window))
	(citation (save-excursion
		    (if (and (search-backward "\\")
			     (looking-at "\\\\cite{\\([^}]+\\)}"))
			(match-string-no-properties 1)
		      nil)))
	(bibliographies (buffer-bibliographies)))
    (if citation
	(let ((result (catch 'found
			(mapcar (lambda (bibliography)
				  (if (and bibliography (file-readable-p bibliography))
				      (progn
					(find-file-other-window bibliography)
					(let ((found (save-excursion
						       (goto-char (point-min))
						       (re-search-forward
							(concat "@[a-z]+{" citation ",")
							(point-max)
							t))))
					  (if found
					      (progn
						(goto-char found)
						(throw 'found found))
					    (bury-buffer))))
				    nil))
				bibliographies)
			nil)))
	  (select-window window)
	  result)
      nil)))

;;; end of citation.el