;;; workgroups-session.el --- Top level structure "session"

;;; Commentary:

;; Main function are: `wg-write-session-file'

;;; Code:

(require 'workgroups-variables)

(require 'workgroups-workgroup)

;;

;; Variables

;;

(defcustom wg-session-file "~/.emacs_workgroups"

  "Default filename to be used to save workgroups."

  :type 'file

  :group 'workgroups)

(defvaralias 'wg-default-session-file 'wg-session-file)

(defvar wg-incorrectly-restored-bufs nil

  "FIXME: docstring this.")

;; TODO: check it on switching WG

(defvar wg-record-incorrectly-restored-bufs nil

  "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))

      (wg-message "(The session is unmodified)")

    (wg-write-session-file

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

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

(defun wg-reset-internal (&optional session)

  "Reset Workgroups, setting `wg-current-session' to SESSION.

Resets all frame parameters, buffer-local vars, current

Workgroups session object, etc.  SESSION nil defaults to a new,

blank session object."

  (mapc 'wg-reset-frame (frame-list))

  (mapc 'wg-reset-buffer (wg-buffer-list-emacs))

  (setq wg-wconfig-kill-ring nil)

  (setq wg-current-session (or session (wg-make-session))))

(defun wg-session-all-buf-uids (&optional session)

  "Return a new list of all unique buf uids in SESSION.

SESSION nil defaults to `wg-current-session'."

  (cl-reduce 'wg-string-list-union

             (wg-session-workgroup-list (or session (wg-current-session)))

             :key 'wg-workgroup-all-buf-uids))

(defun wg-buffer-list-all-uids (&optional buffer-list)

  "Return a list of the uids of all buffers in BUFFER-LIST in

which `wg-buffer-uid' is locally bound.

BUFFER-LIST nil defaults to `buffer-list'."

  (delq nil (mapcar 'wg-buffer-uid (or buffer-list (wg-buffer-list-emacs)))))

(defun wg-all-buf-uids (&optional session buffer-list)

  "Return the union of `wg-session-all-buf-uids' and `wg-buffer-list-all-uids'."

  (cl-union (wg-session-all-buf-uids session)

            (wg-buffer-list-all-uids buffer-list)

            :test 'string=))

(defun wg-gc-bufs ()

  "gc bufs from `wg-buf-list' that are no longer needed."

  (let ((all-buf-uids (wg-all-buf-uids)))

    (wg-asetf (wg-buf-list)

              (cl-remove-if-not (lambda (uid) (member uid all-buf-uids)) it

                                :key 'wg-buf-uid))))

;; FIXME: Duplicate buf names probably shouldn't be allowed.  An unrelated error

;; causes two *scratch* buffers to be present, triggering the "uids don't match"

;; error.  Write something to remove bufs with duplicate names.

(defun wg-perform-session-maintenance ()

  "Perform various maintenance operations on the current Workgroups session."

  (wg-update-current-workgroup-working-wconfig)

  ;; Update every workgroup's base wconfig with `wg-workgroup-update-base-wconfig'

  (dolist (workgroup (wg-workgroup-list))

    (wg-awhen (wg-workgroup-selected-frame-wconfig workgroup)

      (setf (wg-workgroup-base-wconfig workgroup) it

            (wg-workgroup-selected-frame-wconfig workgroup) nil)))

  (wg-gc-bufs)

  (wg-gc-buf-uids)

  (wg-update-buf-list))

;; session consistency testing

(defun wg-modified-p ()

  "Return t when the current session or any of its workgroups are modified."

  (or (wg-session-modified (wg-current-session))

      (cl-some 'wg-workgroup-modified (wg-workgroup-list))))

(defun wg-mark-everything-unmodified ()

  "Mark the session and all workgroups as unmodified."

  (setf (wg-session-modified (wg-current-session)) nil)

  (dolist (workgroup (wg-workgroup-list))

    (setf (wg-workgroup-modified workgroup) nil)))

(defun wg-workgroup-names (&optional noerror)

  "Return a list of workgroup names or scream unless NOERROR."

  (mapcar 'wg-workgroup-name (wg-workgroup-list-or-error noerror)))

;;; session parameters

(defun wg-session-parameter (session parameter &optional default)

  "Return SESSION's value for PARAMETER.

If PARAMETER is not found, return DEFAULT which defaults to nil.

SESSION nil defaults to the current session."

  (wg-aget (wg-session-parameters (or session (wg-current-session)))

           parameter default))

(defun wg-set-session-parameter (session parameter value)

  "Set SESSION's value of PARAMETER to VALUE.

SESSION nil means use the current session.

Return value."

  (let ((session (or session (wg-current-session))))

    (wg-set-parameter (wg-session-parameters session) parameter value)

    (setf (wg-session-modified session) t)

    value))

(defun wg-remove-session-parameter (session parameter)

  "Remove parameter PARAMETER from SESSION's parameters."

  (let ((session (or session (wg-current-session))))

    (wg-asetf (wg-session-parameters session) (wg-aremove it parameter))

    (setf (wg-session-modified session) t)))

(defun wg-session-local-value (variable &optional session)

  "Return the value of VARIABLE in SESSION.

SESSION nil defaults to the current session.  If VARIABLE does

not have a session-local binding in SESSION, the value is

resolved by Emacs."

  (let* ((undefined (cl-gensym))

         (value (wg-session-parameter session variable undefined)))

    (if (not (eq value undefined)) value

      (symbol-value variable))))

(defun wg-reset-frame (frame)

  "Reset Workgroups' frame-parameters in FRAME to nil."

  (set-frame-parameter frame 'wg-workgroup-state-table nil)

  (set-frame-parameter frame 'wg-current-workgroup-uid nil)

  (set-frame-parameter frame 'wg-previous-workgroup-uid nil))

(defun wg-save-session-on-exit (behavior)

  "Perform session-saving operations based on BEHAVIOR."

  (cl-case behavior

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

    (save

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

         (wg-save-session)

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

(defun wg-save-frames ()

  "Save opened frames as a session parameter.

Exclude `selected-frame' and daemon one (if any).

http://stackoverflow.com/questions/21151992/why-emacs-as-daemon-gives-1-more-frame-than-is-opened"

  (interactive)

  (let ((fl (frame-list)))

    (mapc (lambda (frame)

;;; workgroups-variables --- Workgroups vars and consts

;;; Commentary:

;;; Code:

(defconst wg-version "1.1.1" "Current version of Workgroups.")

;;; customization

(defcustom wg-session-load-on-start (not (daemonp))

  "Load a session file on Workgroups start.

But only if Emacs is not started as daemon.  You don't want any

promts while Emacs is being started as daemon."

  :type 'boolean

  :group 'workgroups)

(defvaralias 'wg-use-default-session-file 'wg-session-load-on-start)

(defgroup workgroups nil

  "Workgroups for Emacs -- Emacs session manager"

  :group 'convenience)

(defcustom workgroups-mode nil

  "Non-nil if Workgroups mode is enabled."

  :set 'custom-set-minor-mode

  :initialize 'custom-initialize-default

  :group 'workgroups

  :type 'boolean)

(defcustom wg-first-wg-name "First workgroup"

  "Title of the first workgroup created."

  :type 'string

  :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

variable.

The `caddr' of the entry should be either nil or a function of

one argument.  If nil, the serialized value from above is

assigned to the variable as-is.  It a function, `funcall'ing it

on the serialized value from above should do whatever is

necessary to properly restore the original value of the variable.

For example, in the case of `major-mode' it should funcall the

value (a major-mode function symbol) rather than just assigning

it to `major-mode'."

  :type 'alist

  :group 'workgroups)

(defcustom wg-nowg-string "No workgroups"

  "Display this string if there are no workgroups and

`wg-display-nowg' is t."

  :type 'string

  :group 'workgroups)

(defcustom wg-display-nowg nil

  "Display something if there are no workgroups."

  :type 'boolean

  :group 'workgroups)

;; What to restore:

(defcustom wg-restore-remote-buffers t

  "Restore buffers that get \"t\" with `file-remote-p'."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-frame-position t

  "Non-nil means restore frame position on workgroup restore."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-scroll-bars t

  "Non-nil means restore scroll-bar settings on workgroup restore."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-fringes t

  "Non-nil means restore fringe settings on workgroup restore."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-margins t

  "Non-nil means restore margin settings on workgroup restore."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-point t

  "Non-nil means restore `point' on workgroup restore.

This is included mainly so point restoration can be suspended

during `wg-morph' -- you probably want this non-nil."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-point-max t

  "Controls point restoration when point is at `point-max'.

If `point' is at `point-max' when a wconfig is created, put

`point' back at `point-max' when the wconfig is restored, even if

`point-max' has increased in the meantime.  This is useful in,

say, irc buffers where `point-max' is constantly increasing."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-mark t

  "Non-nil means restore mark data on workgroup restore."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-restore-window-dedicated-p t

  "Non-nil means restore `window-dedicated-p' on workgroup restore."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-remember-frame-for-each-wg nil

  "When switching workgroups - restore frame parameters for each workgroup.

When nil - save/restore frame parameters to/from the first workgroup."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-wconfig-undo-list-max 20

  "Number of past window configs to retain for undo."

  :type 'integer

  :group 'workgroups)

(defcustom wg-wconfig-kill-ring-max 20

  "Maximum length of the `wg-wconfig-kill-ring'."

  :type 'integer

  :group 'workgroups)

;; buffer-list filtration customization

(defcustom wg-buffer-list-filtration-on t

  "Non-nil means Workgroups' buffer-list filtration feature is on.

Nil means ido and iswitchb behave normally.  See

`wg-buffer-list-filter-definitions' for more info."

  :type 'boolean

  :group 'workgroups)

(defcustom wg-buffer-list-filter-definitions

  '((all "all" wg-buffer-list-filter-all)

    (fallback "fallback" nil))

  "List of buffer list filter definitions.

Each entry should be a list containing an identifier symbol, a

prompt string, and a function form that's funcall'd to produce

the filtered buffer-list.

The prompt string is displayed as part of the minibuffer prompt

when its filter is active.

The function form should be either a function-symbol or a lambda, and

should take two arguments: a workgroup and a list of live Emacs

buffers.  The function should return a new list of live buffers,

typically by filtering its second argument in some way.

Default buffer-list-filters include:

`all'           All buffer names

`fallback'      A special case used to fallback to the

                original (non-ido/iswitchb) Emacs command.

                `fallback' isn't actually a buffer-list-filter

                itself, but can be used in

                `wg-buffer-list-filter-order-alist' just the

                same.

Becomes workgroup-local when set with `wg-set-workgroup-parameter'.

Becomes session-local when set with `wg-set-session-parameter'."

  :type 'list

  :group 'workgroups)

(defcustom wg-buffer-list-filter-order-alist

  '((default all fallback))

  "Alist defining the order in which filtered buffer-lists are presented.

The car of each entry should be the symbol of the original Emacs

command (not the ido or iswitchb remappings) -- i.e. one of