;; This file found at http://www.egroups.com/group/gnu-win32/5283.html?
;;
;;; cygwin32-mount.el --- Teach EMACS about cygwin32 mount points.
;;; Michael Cook <mcook@cognex.com>.
;;; modified Jun 18 1998 by Keisuke Mori <ksk@ntts.com> 
;;;  to make it work with ange-ftp and enable mapping a drive letter
;;; modified Oct 25 1999 by Drew Moseley (drewmoseley@mindspring.com)
;;;  to support /cygdrive style drive maps and for better coexistence
;;;  with ange-ftp.

(defun cygwin-executable-exists-in-path (exec &optional path)
  (let ((paths (if (consp path)
		   path
		 (mm-string-to-tokens (or path
					  (getenv "PATH")
					  (concat
					   "/usr/bin:/bin:/usr/local/bin:"
					   "/usr/bin/X11:"
					   (expand-file-name "~/bin"))) ?:)))
	(done nil))
    (while (and paths (not done))
      (if (file-exists-p (expand-file-name exec (car paths)))
	  (setq done t)
        (if (file-exists-p (expand-file-name (concat exec ".exe") (car paths)))
            (setq done t)))
      (setq paths (cdr paths)))
    done))

(defun cygwin32-mount-build-table ()
  ;; Determine if mount.exe exists.
  (if (cygwin-executable-exists-in-path "mount" exec-path)
      (progn
        ;; Determine the cygwin mount points.
        (let ((buf (get-buffer-create " *mount*"))
              (case-fold-search t)
              mounts)
          (save-excursion
            (set-buffer buf)
            (erase-buffer)
            (call-process "mount" nil t)
            (goto-char (point-min))
            (while (search-forward-regexp
                    "^\\([a-z]:[^ \t\n]*\\) +\\([^ \t\n]+\\)" nil t)
              (let ((device (buffer-substring (match-beginning 1)
                                              (match-end 1)))
                    (direct (buffer-substring (match-beginning 2)
                                              (match-end 2))))
                (setq mounts (cons (cons device direct)
                                   mounts)))))
          (kill-buffer buf)
          mounts))))

(defvar cygwin32-mount-table (cygwin32-mount-build-table)
  "Alist of cygwin32 mount points.")

(or (assoc "^/[^/:]+\\(\\'\\|/\\)" file-name-handler-alist)
    (setq file-name-handler-alist
          (cons '("^/[^/:]+\\(\\'\\|/\\)" . cygwin32-mount-name-hook-function)
                file-name-handler-alist)))

(or (assoc "^//[A-Za-z]/" file-name-handler-alist)
    (setq file-name-handler-alist
          (cons '("^//[A-Za-z]/" . cygwin32-mount-map-drive-hook-function)
                file-name-handler-alist)))

;;; Support cygdrive style drive maps.
(or (assoc "^/cygdrive/[A-Za-z]" file-name-handler-alist)
    (setq file-name-handler-alist
          (cons '("^/cygdrive/[A-Za-z]" . cygwin32-mount-map-drive-hook-function)
                file-name-handler-alist)))

(defun cygwin32-mount-name-hook-function (operation &rest args)
  (let ((fn (get operation 'cygwin32-mount-name)))
    (if fn (apply fn operation args)
      (cygwin32-mount-run-real-handler operation args))))

(defun cygwin32-mount-map-drive-hook-function (operation &rest args)
  (let ((fn (get operation 'cygwin32-mount-map-drive)))
    (if fn (apply fn operation args)
      (cygwin32-mount-run-real-handler operation args))))

(defun cygwin32-mount-run-real-handler (operation args)
  (let ((inhibit-file-name-handlers
         (cons 'cygwin32-mount-name-hook-function
               (cons 'cygwin32-mount-map-drive-hook-function
                     (and (eq inhibit-file-name-operation operation)
                          inhibit-file-name-handlers))))
        (inhibit-file-name-operation operation))
    (apply operation args)))

;;;
;;; Unbound the ange-ftp-run-real-handler and rebind it to ours
;;; This version also inhibits the cygwin file name expansion when
;;; we are doing ange-ftp expansion.
;;;
;;; This is a real hack.  If the real definition of this function
;;; changes, we have to modify this function
;;;
(require 'ange-ftp)
(if (fboundp 'ange-ftp-run-real-handler)
    (fmakunbound 'ange-ftp-run-real-handler))

(defun ange-ftp-run-real-handler (operation args)
  (let ((inhibit-file-name-handlers
 	 (cons 'ange-ftp-hook-function
 	       (cons 'ange-ftp-completion-hook-function
                     (cons 'cygwin32-mount-name-hook-function
                           (cons 'cygwin32-mount-map-drive-hook-function
                                 (and (eq inhibit-file-name-operation operation)
                                      inhibit-file-name-handlers))))))
 	(inhibit-file-name-operation operation))
    (apply operation args)))

(put 'substitute-in-file-name 'cygwin32-mount-name 'cygwin32-mount-name-expand)
(put 'expand-file-name 'cygwin32-mount-name 'cygwin32-mount-name-expand)

(put 'substitute-in-file-name
     'cygwin32-mount-map-drive 'cygwin32-mount-map-drive)
(put 'expand-file-name 'cygwin32-mount-map-drive 'cygwin32-mount-map-drive)

(require 'cl)

(defun cygwin32-mount-name-expand (operation name &rest args)
  ;; If NAME uses a mount directory, substitute the mount device
  ;; and return the resulting string.  Otherwise, return NAME.
  (let ((mounts cygwin32-mount-table)
        (len (length name))
        match)
    (while mounts
      (let ((mount (file-name-as-directory (cdar mounts))))
        (and (>= len (length mount))
             (string= mount (substring name 0 (length mount)))
             (or (null match)
                 (> (length (cdar mounts)) (length (cdr match))))
             (setq match (car mounts))))
      (setq mounts (cdr mounts)))
    (if match
        (concat (file-name-as-directory (car match))
                (substring name (length (file-name-as-directory (cdr match)))))
      (cygwin32-mount-run-real-handler operation (cons name args)))))

(defun cygwin32-mount-map-drive (operation name &rest args)
  ;; NAME must have the format looks like "^//[A-Za-z]/" here.
  ;; Support cygdrive style drive maps.
  (cygwin32-mount-run-real-handler
   operation
   (if (string-equal (substring name 0 2) "//")
       (cons (concat (substring name 2 3) ":" (substring name 3 nil))
             args)
     (cons (concat (substring name 10 11) ":" (substring name 11 nil))
           args)
     )
   )
)

(provide 'cygwin32-mount)