;;; csv.el --- Functions for reading/parsing csv files
;;
;;  Copyright (C) 2001 by Ulf Jasper
;;
;;  Author:     Ulf Jasper <ulf.jasper@web.de>
;;  Filename:   csv.el
;;  Created:    August 19 2001
;;  Keywords:   util
;;  Version:    $Id: csv.el,v 1.2 2001/08/30 20:09:50 ulf Exp $
;;  Time-stamp: "30. August 2001, 22:09:47 (ulf)"
;;
;;
;;  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
;;
;;; Commentary:
;; 
;;  Main routine is `csv-parse-buffer' which takes a buffer containing a
;;  csv (Comma Separated Value) file and converts its contents into a list
;;  of alists. The first line of the csv file is interpreted as the list of
;;  keys. For example:
;;
;;  Key1,Key 2,"Key3"
;;  Value1a,Value1b,"Value1c"
;;  Value2a,Value2b,"Very long Value
;;  2c"
;;
;;  gets translated into
;;
;;  ((("Key1" "Value1a") ("Key 2" "Value1b") ("Key3" "Value1c")) 
;;   (("Key1" "Value2a") ("Key 2" "Value2b") ("Key3" "Very long Value
;;    2c")))
;;
;;  The function `csv-insert-contents' demonstrates how to use
;;  `csv-parse-buffer'.
;;
;;  This package has been tested on Emacs 20.7.1 and XEmacs 21.1.12.
;;
;;; History:
;; 
;;  1.0  First version
;;  
;;  1.1  First.first version
;;       automatically add missing entries for lines that are too short
;;

;;; Code:
(defun csv-parse-buffer (&optional buffer coding-system)
  "
BUFFER = csv buffer."
  (interactive)
  (let ((result nil)
	(keylist nil)
	(go-ahead t)
	(coding-system-for-read coding-system))
    (save-window-excursion
      (if buffer
	  (switch-to-buffer buffer)
	(setq buffer (current-buffer)))
      (beginning-of-buffer)
      ;; get the header line
      (setq keylist (csv-read-line))
      (next-line 1)
      ;; get all the content lines
      (while go-ahead
	(setq result (cons (csv-read-line keylist) result))
	(next-line 1)
	(end-of-line)
	(if (eobp)
	    (setq go-ahead nil))))
    (setq result (reverse result))
    ;;(csv-force-complete-lines keylist result)
    result))

(defun csv-read-line (&optional keylist)
  "Parses a single csv line. 
If KEYLIST is not nil an alist is returned, using the keys from the keylist. 
Otherwise just the list of entries is returned."
  (let ((line-contents nil)
	(match1 "")
	(match2 "")
	(match "")
	(matchstart1 0)
	(matchstart2 0)
	(matchend1 0)
	(matchend2 0)
	(index 0)
	(go-ahead t))
    (beginning-of-line)
    (setq line-contents nil)
    (while go-ahead
      (setq matchstart1 nil
	    matchstart2 nil)
      ;; try for quoted entry
      (save-excursion
	(when (re-search-forward
	       "\\(^\\|,\\)\"\\(\\([^\"]\\|\n\\|\\\\\"\\)*\\)\"\\(,\\|,?$\\)"
	       nil t)
	  (setq matchstart1 (match-beginning 0))
	  (setq matchend1 (+ 1 (match-end 2)))
	  (setq match1 (match-string 2))))
      ;; try unquoted
      (save-excursion
	(when (re-search-forward "\\(^\\|,\\)\\([^,\n]*\\)\\(,\\|,?$\\)"
				 nil t)
	  (setq matchstart2 (match-beginning 0))
	  (setq matchend2 (match-end 2))
	  (setq match2 (match-string 2))))
      ;; check whether quoted or unquoted fits better
      (setq match nil)
      (if matchstart1
	  (if matchstart2
	      (if (<= matchstart1 matchstart2)
		  (progn
		    (setq match match1)
		    (goto-char matchend1))
		(setq match match2)
		(goto-char matchend2))
	    (setq match match1)
	    (goto-char matchend1))
	(when matchstart2
	  (setq match match2)
	  (goto-char matchend2)))
      ;; check whether we found something
      (if (not match)
	  (setq go-ahead nil)
	(if (not keylist)
	    (setq line-contents (cons match line-contents))
	  (let ((key (nth index keylist)))
	    (setq line-contents (cons (cons key match) line-contents))))
	)
      (setq index (+ 1 index))
      (if (eolp) (setq go-ahead nil)))
    ;; fill up
    (while (< index (length keylist))
      (let ((key (nth index keylist)))
	(setq line-contents (cons (cons key "") line-contents)))
      (setq index (+ 1 index)))
    ;; finally reverse result -- for readability
    (reverse line-contents)))

;; (defun csv-force-complete-lines (keylist contentlist) 
;;   (mapcar (lambda (line)
;; 	    (mapcar (lambda (key)
;; 		      (or (assoc key line)
;; 			  (cons key "not found")))
;; 		    keylist))
;; 	  contentlist))


(defun csv-insert-contents (contentlist)
  "Inserts the contents of a csv file -- sample for using `csv-parse-buffer'. 
CONTENTSLIST gives a list of alists as returned by `csv-parse-buffer'."
  (interactive)
  (message "hallo")
   (mapcar (lambda (line)
	     (insert "-----\n")
	     (mapcar (lambda (i)
		       (insert (format "\"%s\" = \"%s\"\n" (car i) (cdr i)))
		       )
		     line))
	   contentlist)
)
  
(defun csv-test ()
  "Test routine -- don't care."
  (interactive)
  (let* ((b (current-buffer))
	 (tb (get-buffer-create "*csv*")))
    (switch-to-buffer-other-window tb)
    (insert "asdf")
    (erase-buffer)
    (beginning-of-buffer)
    (csv-insert-contents (csv-parse-buffer b))
    (switch-to-buffer tb)))


(provide 'csv)

;;; csv.el ends here