;;; exwm-core.el --- Core definitions  -*- lexical-binding: t -*-

;; Copyright (C) 2015-2018 Free Software Foundation, Inc.

;; Author: Chris Feng <chris.w.feng@gmail.com>

;; This file is part of GNU Emacs.

;; GNU Emacs 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 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This module includes core definitions of variables, macros, functions, etc
;; shared by various other modules.

;;; Code:

(require 'kmacro)

(require 'xcb)
(require 'xcb-icccm)
(require 'xcb-ewmh)
(require 'xcb-debug)

(defvar exwm--connection nil "X connection.")

(defvar exwm--wmsn-window nil
  "An X window owning the WM_S0 selection.")

(defvar exwm--wmsn-acquire-timeout 3
  "Number of seconds to wait for other window managers to release the selection.")

(defvar exwm--wmsn-replace 'ask
  "Replace existing window manager.")

(defvar exwm--guide-window nil
  "An X window separating workspaces and X windows.")

(defvar exwm--id-buffer-alist nil "Alist of (<X window ID> . <Emacs buffer>).")

(defvar exwm--root nil "Root window.")

(defvar exwm-input--global-prefix-keys)
(defvar exwm-input--simulation-keys)
(defvar exwm-input-line-mode-passthrough)
(defvar exwm-input-prefix-keys)
(declare-function exwm-input--fake-key "exwm-input.el" (event))
(declare-function exwm-input--on-KeyPress-line-mode "exwm-input.el"
                  (key-press raw-data))
(declare-function exwm-floating-hide "exwm-floating.el")
(declare-function exwm-floating-toggle-floating "exwm-floating.el")
(declare-function exwm-input-release-keyboard "exwm-input.el")
(declare-function exwm-input-send-next-key "exwm-input.el" (times))
(declare-function exwm-layout-set-fullscreen "exwm-layout.el" (&optional id))
(declare-function exwm-layout-toggle-mode-line "exwm-layout.el")
(declare-function exwm-manage--kill-buffer-query-function "exwm-manage.el")
(declare-function exwm-workspace-move-window "exwm-workspace.el"
                  (frame-or-index &optional id))

(defvar exwm-debug-on nil "Non-nil to turn on debug for EXWM.")

(defmacro exwm--debug (&rest forms)
  (when exwm-debug-on `(progn ,@forms)))

(defmacro exwm--log (&optional format-string &rest objects)
  "Emit a message prepending the name of the function being executed.

FORMAT-STRING is a string specifying the message to output, as in
`format'.  The OBJECTS arguments specify the substitutions."
  (unless format-string (setq format-string ""))
  `(when exwm-debug-on
     (xcb-debug-message ,(concat "%s:\t" format-string "\n")
                        (xcb-debug-compile-time-function-name)
                        ,@objects)
     nil))

(defsubst exwm--id->buffer (id)
  "X window ID => Emacs buffer."
  (cdr (assoc id exwm--id-buffer-alist)))

(defsubst exwm--buffer->id (buffer)
  "Emacs buffer BUFFER => X window ID."
  (car (rassoc buffer exwm--id-buffer-alist)))

(defun exwm--lock (&rest _args)
  "Lock (disable all events)."
  (exwm--log)
  (xcb:+request exwm--connection
      (make-instance 'xcb:ChangeWindowAttributes
                     :window exwm--root
                     :value-mask xcb:CW:EventMask
                     :event-mask xcb:EventMask:NoEvent))
  (xcb:flush exwm--connection))

(defun exwm--unlock (&rest _args)
  "Unlock (enable all events)."
  (exwm--log)
  (xcb:+request exwm--connection
      (make-instance 'xcb:ChangeWindowAttributes
                     :window exwm--root
                     :value-mask xcb:CW:EventMask
                     :event-mask (eval-when-compile
                                   (logior xcb:EventMask:SubstructureRedirect
                                           xcb:EventMask:StructureNotify))))
  (xcb:flush exwm--connection))

(defun exwm--set-geometry (xwin x y width height)
  "Set the geometry of X window XWIN to WIDTHxHEIGHT+X+Y.

Nil can be passed as placeholder."
  (exwm--log "Setting #x%x to %sx%s+%s+%s" xwin width height x y)
  (xcb:+request exwm--connection
      (make-instance 'xcb:ConfigureWindow
                     :window xwin
                     :value-mask (logior (if x xcb:ConfigWindow:X 0)
                                         (if y xcb:ConfigWindow:Y 0)
                                         (if width xcb:ConfigWindow:Width 0)
                                         (if height xcb:ConfigWindow:Height 0))
                     :x x :y y :width width :height height)))

(defmacro exwm--defer (secs function &rest args)
  "Defer the execution of FUNCTION.

The action is to call FUNCTION with arguments ARGS.  If Emacs is not idle,
defer the action until Emacs is idle.  Otherwise, defer the action until at
least SECS seconds later."
  `(run-with-idle-timer (+ (float-time (or (current-idle-time)
					   (seconds-to-time (- ,secs))))
			   ,secs)
                        nil
                        ,function
                        ,@args))

(defconst exwm--client-event-mask (logior xcb:EventMask:StructureNotify
                                          xcb:EventMask:PropertyChange
                                          (if mouse-autoselect-window
                                              xcb:EventMask:EnterWindow 0))
  "Event mask set on all managed windows.")

;; Internal variables
(defvar-local exwm--id nil)               ;window ID
(defvar-local exwm--configurations nil)   ;initial configurations.
(defvar-local exwm--frame nil)            ;workspace frame
(defvar-local exwm--floating-frame nil)   ;floating frame
(defvar-local exwm--mode-line-format nil) ;save mode-line-format
(defvar-local exwm--floating-frame-position nil) ;set when hidden.
(defvar-local exwm--fixed-size nil)              ;fixed size
(defvar-local exwm--keyboard-grabbed nil)        ;Keyboard grabbed.
(defvar-local exwm--on-KeyPress         ;KeyPress event handler
  #'exwm-input--on-KeyPress-line-mode)
;; Properties
(defvar-local exwm--desktop nil "_NET_WM_DESKTOP.")
(defvar-local exwm-window-type nil "_NET_WM_WINDOW_TYPE.")
(defvar-local exwm--geometry nil)
(defvar-local exwm-class-name nil "Class name in WM_CLASS.")
(defvar-local exwm-instance-name nil "Instance name in WM_CLASS.")
(defvar-local exwm-title nil "Window title (either _NET_WM_NAME or WM_NAME)")
(defvar-local exwm--title-is-utf8 nil)
(defvar-local exwm-transient-for nil "WM_TRANSIENT_FOR.")
(defvar-local exwm--protocols nil)
(defvar-local exwm-state xcb:icccm:WM_STATE:NormalState "WM_STATE.")
(defvar-local exwm--ewmh-state nil "_NET_WM_STATE.")
;; _NET_WM_NORMAL_HINTS
(defvar-local exwm--normal-hints-x nil)
(defvar-local exwm--normal-hints-y nil)
(defvar-local exwm--normal-hints-width nil)
(defvar-local exwm--normal-hints-height nil)
(defvar-local exwm--normal-hints-min-width nil)
(defvar-local exwm--normal-hints-min-height nil)
(defvar-local exwm--normal-hints-max-width nil)
(defvar-local exwm--normal-hints-max-height nil)
;; (defvar-local exwm--normal-hints-win-gravity nil)
;; WM_HINTS
(defvar-local exwm--hints-input nil)
(defvar-local exwm--hints-urgency nil)
;; _MOTIF_WM_HINTS
(defvar-local exwm--mwm-hints-decorations t)

(defvar exwm-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "\C-c\C-f" #'exwm-layout-set-fullscreen)
    (define-key map "\C-c\C-h" #'exwm-floating-hide)
    (define-key map "\C-c\C-k" #'exwm-input-release-keyboard)
    (define-key map "\C-c\C-m" #'exwm-workspace-move-window)
    (define-key map "\C-c\C-q" #'exwm-input-send-next-key)
    (define-key map "\C-c\C-t\C-f" #'exwm-floating-toggle-floating)
    (define-key map "\C-c\C-t\C-m" #'exwm-layout-toggle-mode-line)
    map)
  "Keymap for `exwm-mode'.")

(defvar exwm--kmacro-map
  (let ((map (make-sparse-keymap)))
    (define-key map [t]
      (lambda ()
        (interactive)
        (cond
         ((or exwm-input-line-mode-passthrough
              ;; Do not test `exwm-input--during-command'.
              (active-minibuffer-window)
              (memq last-input-event exwm-input--global-prefix-keys)
              (memq last-input-event exwm-input-prefix-keys)
              (lookup-key exwm-mode-map (vector last-input-event))
              (gethash last-input-event exwm-input--simulation-keys))
          (set-transient-map (make-composed-keymap (list exwm-mode-map
                                                         global-map)))
          (push last-input-event unread-command-events))
         (t
          (exwm-input--fake-key last-input-event)))))
    map)
  "Keymap used when executing keyboard macros.")

;; This menu mainly acts as an reminder for users.  Thus it should be as
;; detailed as possible, even some entries do not make much sense here.
;; Also, inactive entries should be disabled rather than hidden.
(easy-menu-define exwm-mode-menu exwm-mode-map
  "Menu for `exwm-mode'."
  '("EXWM"
    "---"
    "*General*"
    "---"
    ["Toggle floating" exwm-floating-toggle-floating]
    ["Toggle fullscreen mode" exwm-layout-toggle-fullscreen]
    ["Hide window" exwm-floating-hide exwm--floating-frame]
    ["Close window" (kill-buffer (current-buffer))]

    "---"
    "*Resizing*"
    "---"
    ["Toggle mode-line" exwm-layout-toggle-mode-line :keys "C-c C-t C-m"]
    ["Enlarge window vertically" exwm-layout-enlarge-window]
    ["Enlarge window horizontally" exwm-layout-enlarge-window-horizontally]
    ["Shrink window vertically" exwm-layout-shrink-window]
    ["Shrink window horizontally" exwm-layout-shrink-window-horizontally]

    "---"
    "*Keyboard*"
    "---"
    ["Toggle keyboard mode" exwm-input-toggle-keyboard]
    ["Send key" exwm-input-send-next-key exwm--keyboard-grabbed]
    ;; This is merely a reference.
    ("Send simulation key" :filter
     (lambda (&rest _args)
       (let (result)
         (maphash
          (lambda (key value)
            (when (sequencep key)
              (setq result (append result
                                   `([
                                      ,(key-description value)
                                      (lambda ()
                                        (interactive)
                                        (dolist (i ',value)
                                          (exwm-input--fake-key i)))
                                      :keys ,(key-description key)])))))
          exwm-input--simulation-keys)
         result)))

    ["Define global binding" exwm-input-set-key]

    "---"
    "*Workspace*"
    "---"
    ["Add workspace" exwm-workspace-add]
    ["Delete current workspace" exwm-workspace-delete]
    ["Move workspace to" exwm-workspace-move]
    ["Swap workspaces" exwm-workspace-swap]
    ["Move X window to" exwm-workspace-move-window :keys "C-c C-m"]
    ["Move X window from" exwm-workspace-switch-to-buffer]
    ["Toggle minibuffer" exwm-workspace-toggle-minibuffer]
    ["Switch workspace" exwm-workspace-switch]
    ;; Place this entry at bottom to avoid selecting others by accident.
    ("Switch to" :filter
     (lambda (&rest _args)
       (mapcar (lambda (i)
                 `[,(format "workspace %d" i)
                   (lambda ()
                     (interactive)
                     (exwm-workspace-switch ,i))
                   (/= ,i exwm-workspace-current-index)])
               (number-sequence 0 (1- (exwm-workspace--count))))))))

(exwm--debug
  (let ((map exwm-mode-map))
    (define-key map "\C-c\C-d\C-l" #'xcb-debug-clear)
    (define-key map "\C-c\C-d\C-m" #'xcb-debug-mark)))

(define-derived-mode exwm-mode nil "EXWM"
  "Major mode for managing X windows.

\\{exwm-mode-map}"
  ;;
  (setq mode-name
        '(:eval (propertize "EXWM" 'face
                            (when (cl-some (lambda (i)
                                             (frame-parameter i 'exwm-urgency))
                                           exwm-workspace--list)
                              'font-lock-warning-face))))
  ;; Change major-mode is not allowed
  (add-hook 'change-major-mode-hook #'kill-buffer nil t)
  ;; Kill buffer -> close window
  (add-hook 'kill-buffer-query-functions
            #'exwm-manage--kill-buffer-query-function nil t)
  ;; Redirect events when executing keyboard macros.
  (push `(executing-kbd-macro . ,exwm--kmacro-map)
        minor-mode-overriding-map-alist)
  (setq buffer-read-only t
        cursor-type nil
        left-margin-width nil
        right-margin-width nil
        left-fringe-width 0
        right-fringe-width 0
        vertical-scroll-bar nil))



(provide 'exwm-core)

;;; exwm-core.el ends here