"FIXME: docstring this.")

(defcustom wg-emacs-exit-save-behavior 'save

  "Determines save behavior on Emacs exit.

Possible values:

`ask'           Ask the user whether to save if there are unsaved changes

`save'          Call `wg-save-session' when there are unsaved changes

Anything else   Exit Emacs without saving changes"

  :type 'symbol

  :group 'workgroups)

(defcustom wg-workgroups-mode-exit-save-behavior 'save

  "Determines save behavior on `workgroups-mode' exit.

Possible values:

`ask'           Ask the user whether to saveif there are unsaved changes

`save'          Call `wg-save-session' when there are unsaved changes

Anything else   Exit `workgroups-mode' without saving changes"

  :type 'symbol

  :group 'workgroups)

;;

;; Function

;;

(defun wg-session-uids-consistent-p ()

  "Return t if there are no duplicate bufs or buf uids in the wrong places.

nil otherwise."

  (and (not (wg-dups-p (wg-buf-list) :key 'wg-buf-uid :test 'string=))

       (not (wg-dups-p (wg-workgroup-list) :key 'wg-workgroup-uid :test 'string=))))

(defun wg-find-session-file (filename)

  "Load a session visiting FILENAME, creating one if none already exists."

  (interactive "FFind session file: ")

  (cond ((file-exists-p filename)

         (let ((session (wg-read-sexp-from-file filename)))

           (unless (wg-session-p session)

             (error "%S is not a Workgroups session file." filename))

           (setf (wg-session-file-name session) filename)

           (wg-reset-internal (wg-unpickel-session-parameters session)))

           (if (and wg-open-this-wg

                    (member wg-open-this-wg (wg-workgroup-names)))

               (wg-switch-to-workgroup wg-open-this-wg)

             (if (and wg-load-last-workgroup

                      (member (wg-session-parameter (wg-current-session t) 'last-workgroup)

                              (wg-workgroup-names)))

                 (wg-switch-to-workgroup

                  (wg-session-parameter (wg-current-session t) 'last-workgroup))

               (wg-switch-to-workgroup (car it)))

             ))

         (wg-fontified-message (:cmd "Loaded: ") (:file filename)))

        (t

         (wg-query-and-save-if-modified)

         (wg-reset-internal (wg-make-session :file-name filename))

         (wg-fontified-message

           (:cmd "(New Workgroups session file)")))))

(defalias 'wg-open-session 'wg-find-session-file)

(defun wg-write-session-file (filename &optional confirm)

  "Write the current session into file FILENAME.

This makes the session visit that file, and marks it as not modified.

If optional second arg CONFIRM is non-nil, this function asks for

confirmation before overwriting an existing file.  Interactively,

confirmation is required unless you supply a prefix argument.

Think of it as `write-file' for Workgroups sessions."

  (interactive (list (read-file-name "Save session as: ")

                     (not current-prefix-arg)))

  (when (and confirm (file-exists-p filename))

    (unless (y-or-n-p (format "File `%s' exists; overwrite? " filename))

      (error "Cancelled")))

  (unless (file-writable-p filename)

    (error "File %s can't be written to" filename))

  (wg-perform-session-maintenance)

  (setf (wg-session-file-name (wg-current-session)) filename)

  (setf (wg-session-version (wg-current-session)) wg-version)

  (if wg-control-frames

      (wg-save-frames))

  (wg-write-sexp-to-file

   (wg-pickel-all-session-parameters (wg-current-session))

   filename)

  (wg-mark-everything-unmodified)

  (wg-fontified-message (:cmd "Wrote: ") (:file filename)))

(defalias 'wg-save-session-as 'wg-write-session-file)

(defun wg-determine-session-save-file-name ()

  "Return the filename in which to save the session."

  (or (wg-session-file-name (wg-current-session))

      (and wg-session-load-on-start wg-session-file)))

(defun wg-save-session (&optional force)

  "Save the current Workgroups session if it's been modified.

Think of it as `save-buffer' for Workgroups sessions.  Optional

argument FORCE non-nil, or interactively with a prefix arg, save

the session regardless of whether it's been modified."

  (interactive "P")

  (if (and (not (wg-modified-p)) (not force))

  :group 'workgroups)

(defcustom wg-modeline-string " wg"

  "Appears in modeline."

  :type 'string

  :group 'workgroups)

(defcustom wg-load-last-workgroup t

  "Load last active (not first) workgroup from all your workgroups if it exists."

  :group 'workgroups

  :type 'boolean)

(defcustom wg-control-frames t

  "Save/restore frames."

  :group 'workgroups

  :type 'boolean)

;; hooks

(defcustom workgroups-mode-hook nil

  "Hook run when `workgroups-mode' is turned on."

  :type 'hook

  :group 'workgroups)

(defcustom workgroups-mode-exit-hook nil

  "Hook run when `workgroups-mode' is turned off."

  :type 'hook

  :group 'workgroups)

(defcustom wg-switch-to-workgroup-hook nil

  "Hook run by `wg-switch-to-workgroup'."

  :type 'hook

  :group 'workgroups)

(defcustom wg-pre-window-configuration-change-hook nil

  "Hook run before any function that triggers

`window-configuration-change-hook'."

  :type 'hook

  :group 'workgroups)

(defcustom wg-open-this-wg nil

  "Try to open this workgroup on start.

If nil - nothing happens."

  :type 'string

  :group 'workgroups)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;

;; FIXME:

;;

;; Only set `wg-workgroup-base-wconfig' on `wg-write-session-file' or

;; `delete-frame' and only with the most recently changed working-wconfig.

;; Then, since it's not overwritten on every call to

;; `wg-workgroup-working-wconfig', its restoration can be retried after manually

;; recreating buffers that couldn't be restored.  So it takes over the

;; 'incorrect restoration' portion of the base wconfig's duty.  All that leaves

;; to base wconfigs is that they're a saved wconfig the user felt was important.

;; So why not allow more of of them?  A workgroup could stash an unlimited

;; number of wconfigs.

;;

;; TODO:

;;

;;   * Write new commands for restoring stashed wconfigs

;;

;;   * Add this message on improper restoration of `base-wconfig':

;;

;;       "Unable to restore 'buf1', 'buf2'... Hit C-whatever to retry after

;;        manually recreating these buffers."

;;

;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; workgroup restoration customization

;; TODO: possibly add `buffer-file-coding-system', `text-scale-mode-amount'

(defcustom wg-buffer-local-variables-alist

  `((major-mode nil wg-deserialize-buffer-major-mode)

    (mark-ring wg-serialize-buffer-mark-ring wg-deserialize-buffer-mark-ring)

    (left-fringe-width nil nil)

    (right-fringe-width nil nil)

    (fringes-outside-margins nil nil)

    (left-margin-width nil nil)

    (right-margin-width nil nil)

    (vertical-scroll-bar nil nil))

  "Alist mapping buffer-local variable symbols to serdes functions.

The `car' of each entry should be a buffer-local variable symbol.

The `cadr' of the entry should be either nil or a function of no

arguments.  If nil, the variable's value is used as-is, and

should have a readable printed representation.  If a function,

`funcall'ing it should yield a serialization of the value of the