;; System-type definition
(defun system-is-linux()
  (string-equal system-type "gnu/linux"))
(defun system-is-windows()
  (string-equal system-type "windows-nt"))
(defun system-is-macos()
  (string-equal system-type "darwin"))

;; Start Emacs as a server
(when (system-is-linux)
  (require 'server)
  (unless (server-running-p)
    (server-start))) ;; launch emacs as a server if OS - GNU/Linux

;; MS Windows path-variable
(when (system-is-windows)
  (setq win-sbcl-exe          "C:/sbcl/sbcl.exe")
  (setq win-init-path         "C:/.emacs.d/lisp")
  (setq win-init-ct-path      "C:/.emacs.d/plugins/color-theme")
  (setq win-init-ac-path      "C:/.emacs.d/plugins/auto-complete")
  (setq win-init-slime-path   "C:/slime")
  (setq win-init-ac-dict-path "C:/.emacs.d/plugins/auto-complete/dict"))

;; Unix path-variable
(when (system-is-linux)
  (setq unix-sbcl-bin          "/usr/bin/sbcl")
  (setq unix-init-path         "~/.emacs.d/lisp")
  (setq unix-init-ct-path      "~/.emacs.d/plugins/color-theme")
  (setq unix-init-ac-path      "~/.emacs.d/plugins/auto-complete")
  (setq unix-init-slime-path   "/usr/share/common-lisp/source/slime/")
  (setq unix-init-ac-dict-path "~/.emacs.d/plugins/auto-complete/dict"))

;; Dired
(require 'dired)
(setq dired-recursive-deletes 'top) ;; so we can delete non-empty directories

;; Imenu
(require 'imenu)
(setq imenu-auto-rescan      t) ;; automatically update the list of functions in the buffer
(setq imenu-use-popup-menu nil) ;; Imenu dialog only in the mini-buffer
(global-set-key (kbd "<f6>") 'imenu) ;; press F6 to launch Imenu

;; Display the name of the current buffer in the title bar
(setq frame-title-format "GNU Emacs: %b")

;; Load path for plugins
(if (system-is-windows)
  (add-to-list 'load-path win-init-path)
  (add-to-list 'load-path unix-init-path))

;; Inhibit startup/splash screen
(setq inhibit-splash-screen   t)
(setq ingibit-startup-message t) ;;startup screen can be open with C-h

;; Show-paren-mode settings
(show-paren-mode t) ;; turn on text highlight within {},[],()
(setq show-paren-style 'expression) ;; highlight text inside {}, [], ()

;; Electric-modes settings
(electric-pair-mode    1) ;; automatically close brackets {},[],()
(electric-indent-mode -1) ;; turn off auto indent with electric-indent-mod (default in Emacs-24.4)

;; Delete selection
(delete-selection-mode t)

;; Disable GUI components
(tooltip-mode      -1)
(menu-bar-mode     -1) ;; turn off GUI menu bar
(tool-bar-mode     -1) ;; turn off toolbar
(scroll-bar-mode   -1) ;; turn off scrollbar
(blink-cursor-mode -1) ;; turn off cursor blink
(setq use-dialog-box     nil) ;; all dialogs through mini-buffer
(setq redisplay-dont-pause t)  ;; better buffer display
(setq ring-bell-function 'ignore) ;; turn off sound notification

;; Coding-system settings
(set-language-environment 'UTF-8)
(if (system-is-linux) ;; utf-8 for GNU/Linux and macOS, windows-1251 for MS Windows
    (progn
      (setq default-buffer-file-coding-system 'utf-8)
      (setq-default coding-system-for-read    'utf-8)
      (setq file-name-coding-system           'utf-8)
      (set-selection-coding-system            'utf-8)
      (set-keyboard-coding-system        'utf-8-unix)
      (set-terminal-coding-system             'utf-8)
      (prefer-coding-system                   'utf-8))
    (progn
      (prefer-coding-system                   'windows-1251)
      (set-terminal-coding-system             'windows-1251)
      (set-keyboard-coding-system        'windows-1251-unix)
      (set-selection-coding-system            'windows-1251)
      (setq file-name-coding-system           'windows-1251)
      (setq-default coding-system-for-read    'windows-1251)
      (setq default-buffer-file-coding-system 'windows-1251)))

;; Linum plugin
(require 'linum) ;; call Linum
(line-number-mode   t) ;; show line number in mode-line
(global-linum-mode  t) ;; show line number in all buffers
(column-number-mode t) ;; show column number in mode-line
(setq linum-format " %d") ;; set up line numbering format

;; Fringe settings
(fringe-mode '(8 . 0)) ;; fringe is only on the left side
(setq-default indicate-empty-lines t) ;; empty lines are marked
(setq-default indicate-buffer-boundaries 'left) ;; indication are shown on the left side

;; Display file size/time in mode-line
(setq display-time-24hr-format t) ;; 24-hour time format in the  mode-line
(display-time-mode             t) ;; show time in mode-line
(size-indication-mode          t) ;; file size in %

;; Line wrapping
(setq word-wrap          t) ;; word wrapping
(global-visual-line-mode t)

;; Start window size
(when (window-system)
  (set-frame-size (selected-frame) 100 50))

;; IDO plugin
(require 'ido)
(ido-mode                      t)
(icomplete-mode                t)
(ido-everywhere                t)
(setq ido-vitrual-buffers      t)
(setq ido-enable-flex-matching t)

;; Buffer Selection and ibuffer settings
(require 'bs)
(require 'ibuffer)
(defalias 'list-buffers 'ibuffer) ;; separate buffer list with C-x C-b
(global-set-key (kbd "<f2>") 'bs-show) ;; start buffer selection by pressing F2

;; Syntax highlighting
(require 'font-lock)
(global-font-lock-mode             t) ;; just in case... set on since Emacs-22
(setq font-lock-maximum-decoration t)

;; Indent settings
(setq-default indent-tabs-mode nil) ;; turn off indentation via tab
(setq-default tab-width          2) ;; tab size
(setq-default c-basic-offset     2)
(setq-default standart-indent    2) ;; standard offset
(setq-default lisp-body-indent   2) ;; offset in lisp
(global-set-key (kbd "RET") 'newline-and-indent) ;; with enter, make new line and indent
(setq lisp-indent-function  'common-lisp-indent-function)

;; Scrolling settings
(setq scroll-step               1) ;; up-down scrolling speed is 1
(setq scroll-margin            10) ;; set up scrolling margin
(setq scroll-conservatively 10000)

;; Short messages
(defalias 'yes-or-no-p 'y-or-n-p)

;; Clipboard settings
(setq x-select-enable-clipboard t)

;; End of file newlines
;;(setq require-final-newline    t) ;; add additional newline while saving file
(setq next-line-add-newlines nil) ;; do not add new line with arrow keys

;; Highlight search resaults
(setq search-highlight        t)
(setq query-replace-highlight t)

;; Easy transition between buffers: M-arrow-keys
(if (equal nil (equal major-mode 'org-mode))
    (windmove-default-keybindings 'meta))

;; Delete trailing whitespaces, format buffer and untabify when save buffer
;;(defun format-current-buffer()
;;    (indent-region (point-min) (point-max)))
;;(defun untabify-current-buffer()
;;    (if (not indent-tabs-mode)
;;        (untabify (point-min) (point-max)))
;;    nil)
;;(add-to-list 'write-file-functions 'format-current-buffer)
;;(add-to-list 'write-file-functions 'untabify-current-buffer)
;;(add-to-list 'write-file-functions 'delete-trailing-whitespace)

;; Mouse support
(xterm-mouse-mode 1)