;;; pic-a-sig
;;; Copyright 2003 by Adrian Hosey <alh@warhound.org>
;;; For updates check http://web.warhound.org/

(add-hook 'write-file-hooks 'select-sig)

(defun select-sig (&optional sigbuf)
  "Find magic sig string and replace it with a random line"
  (save-excursion
    (save-restriction
      (save-match-data
	(widen)
	(goto-char (point-min))
	(if (re-search-forward "^$$Sig$$$" nil t)
	    ; Grrr... this replace-match should work but doesn't, so
	    ; we have to use the let clause. Why doesn't it work?
	    ;(replace-match (pic-a-sig sigbuf) t t nil)))))
	    (let ((start (- (point) 7)))
	      (delete-region start (point))
	      (goto-char start)
	      (if sigbuf 
		  (insert (pic-a-sig sigbuf))
		  (insert (pic-a-sig (make-sigbuf))))
	      ))))))

(defun select-sig-at-point (&optional sigbuf)
  "Insert a random line at the point"
  (interactive)
  (if sigbuf
      (insert (pic-a-sig sigbuf))
      (insert (pic-a-sig (make-sigbuf))))
  )

(defun pic-a-sig (sigbuf)
  "Pick a sig line from the supplied buffer."
  (progn
    (switch-to-buffer sigbuf)
    (let ((max-line-count (count-lines 1 (point-max))))
      (random t)
      (goto-line (random (+ max-line-count 1)))
      (let ((sigline (thing-at-point 'line)))
	(while (string-match "\C-m" sigline)
	    (aset sigline (match-beginning 0) ?\n))
	(kill-buffer nil)
	(substring sigline 0 (- (length sigline) 1))
	))))

(defun make-sigbuf ()
  "Fill a new buffer with the contents of the .pic-a-sig file"
  (let ((sigbuf (generate-new-buffer (generate-new-buffer-name "sigtmp"))))
    (save-excursion
      (switch-to-buffer sigbuf)
      (insert-file-contents-literally "~/.pic-a-sig"))
    ; If I've got save-excursion up there why do I need switch-to-buffer here?
    (switch-to-buffer (other-buffer))
    sigbuf))

(defun sig-cheat ()
  "Insert a sigline matching the given pattern"
  (interactive)
  (let ((sigbuf (make-sigbuf))
	(pattern (read-string "Pattern? ")))
    (save-excursion
      (save-restriction
	(save-match-data
	  (switch-to-buffer sigbuf)
	  (widen)
	  (goto-char (point-min))
	  (let ((start (point)))
	    (while (re-search-forward pattern nil t)
	      (beginning-of-line)
	      (delete-region start (point))
	      (end-of-line)
	      (setq start (+ 1 (point))))
	    (goto-char (point-max))
	    (delete-region start (point))))))
    (select-sig sigbuf)))