;; powershell-mode.el, version 0.5 
;; 
;; Author: Vivek Sharma (http://www.viveksharma.com/techlog) 
;; Provides: Major mode for editing PS (PowerShell) scripts 
;; Last Updated: 08/19/08 
;; 
;; DONE 
;; - Indentation support  (done) 
;; - support here strings (done) 
;;
;; TODO
;; - C# class support 
;; - PowerShell v2 support 
;; 
;; CHANGES 
;; 0.1 - initial version with text highlighting support and indenting 
;; 0.2 - fixed file based on feedback to handle xemacs and syntax file changes 
;; 0.3 - updated to reflect Monad --> PowerShell name change 
;; 0.4 - added manual indentation support, not totally what I'd like, but good enough 
;; 0.5 - update from Richard Bielawski (email address excluded till he grants permission to 
;;       include it :) - Many thanks Richard! Fixes: indenting fixed, elseif keyword added, 
;;       visiting file bug fixed, standard comment support added. I only tested with latest
;;       EmacsWin32, YMMV  
 

;; custom hooks 
(defvar powershell-mode-hook nil)  

;; default mode map, really simple 
(defvar powershell-mode-map   
  (let ((powershell-mode-map (make-keymap))) 
;;    (define-key powershell-mode-map "\r" 'powershell-indent-line) 
    (define-key powershell-mode-map "\t" 'powershell-indent-line) 
;;    (define-key powershell-mode-map "{" 'powershell-electric-brace) 
;;    (define-key powershell-mode-map "}" 'powershell-electric-brace) 
    powershell-mode-map) 
  "Keymap for PS major mode")  

(defvar powershell-indent-width 4) 

;; make braces indent properly 
(defun powershell-electric-brace (arg) 
  "Correct indentation for squigly brace" 
  (interactive "P") 
  (self-insert-command (prefix-numeric-value arg)) 
  (unless 
      (save-excursion 
        (beginning-of-line) 
        (or 
;;          (looking-at "$\w+") ;Don't do this in a variable 
          (looking-at "{\s*|[^}]") ;Don't do this in an open procedure block 
          (looking-at "\"[^\"]*$")) ;Don't do this in a open string 
       ) 
    (powershell-indent-line) 
    (forward-char 1) 
  ) 
)  

;(add-to-list 'auto-mode-alist '("\\.ps1\\'" . powershell-mode))  

;; Function to control indenting. 
(defun powershell-indent-line () 
  "Indent current PowerShell script line" 
  (interactive)  

  ;; Set the point to beginning of line. 
  (beginning-of-line)  
  (if (bobp) 
      (indent-line-to 0)  

    (let ((not-indented t) (lines-back 0) cur-indent)  
      (if (looking-at "^[ \t]*}") ; Check for closing brace 
          (progn 
            (save-excursion 
              (forward-line -1) 
              (setq lines-back (+ lines-back 1)) 
              (if (looking-at "^[ \t]*{") ; If now looking at opening block 
                (setq cur-indent (current-indentation)) ;; duplicate indent 
                (setq cur-indent (- (current-indentation) powershell-indent-width))) 
            )  

  ;; Safety check to make sure we don't indent negative. 
            (if (< cur-indent 0) 
                (setq cur-indent 0)))  

        (save-excursion 
          (if (looking-at "^[ \t]*{") ; Opening block 
              (progn 
                (forward-line -1) 
                (setq lines-back (+ lines-back 1)) 
                (setq cur-indent (current-indentation)) 
                (setq not-indented nil))  

            (while not-indented 
              (forward-line -1) 
              (setq lines-back (+ lines-back 1)) 
              (if (looking-at "^[ \t]*}") ; Closing block 
                  (progn 
                    (setq cur-indent (current-indentation)) 
                    (setq not-indented nil)) 

                (if (looking-at "^[ \t]*{") ; Opening block 
                    (progn 
                      (setq cur-indent (+ (current-indentation) powershell-indent-width)) 
                      (setq not-indented nil)) 

                (if (looking-at "^[ \t]*\\(if\\|for\\|foreach\\|function\\|else\\|do\\|while\\)\\>") 
                    (progn 
                      (setq cur-indent (current-indentation)) 
                      (forward-line 1) 
                      (setq lines-back (- lines-back 1)) 
                      (if (looking-at "^[ \t]*{") ; Has block 
                          (setq not-indented nil) 
                        (if (equal lines-back 0) ; No block 
                            (progn 
                              (setq cur-indent (+ cur-indent powershell-indent-width)) 
                              (setq not-indented nil)) 
                          (setq not-indented nil))) 
                      ) 

                  (if (bobp) 
                      (setq not-indented nil)))))))))  
      (if cur-indent 
          (indent-line-to cur-indent) 
        (indent-line-to 0)))))  
 
;; only defined one keyword list right now 

(defconst powershell-font-lock-keywords-3 
  (list 
   '("\\<\\(d\\(?:o\\|efault\\)\\|else\\(if\\)?\\|f\\(?:oreach\\|unction\\)\\|if\\|switch\\|t\\(?:hrow\\|rap\\)\\|w\\(?:here\\|hile\\)\\)\\>" . font-lock-keyword-face) 
   '("$[a-zA-Z0-9_\\.:{}]+\\>" . font-lock-variable-name-face) 
   '("\\<\\w+-\\w+\\>" . font-lock-function-name-face) 
   '("\\<-\\w+\\>" . font-lock-builtin-face) 
   '("@'[A-z0-9\n\t ]+'@" . font-lock-string-face) 
   '("@\"[A-z0-9\n\t ]+\"@" . font-lock-string-face) 
   '("\\(-\\)\\([a-z][a-zA-Z0-9]+\\)" . font-lock-type-face)) 
  "Maximum highlighting for PowerShell major mode")  


(defvar powershell-font-lock-keywords powershell-font-lock-keywords-3 
  "Maximum highlighting for PowerShell major mode")  


;; is adding punctuation to word syntax appropriate?? 

(defvar powershell-mode-syntax-table 
  (let ((powershell-mode-syntax-table (make-syntax-table))) 
   (modify-syntax-entry ?.  "_" powershell-mode-syntax-table) 
   (modify-syntax-entry ?:  "_" powershell-mode-syntax-table) 
   (modify-syntax-entry ?\\ "_" powershell-mode-syntax-table) 
   (modify-syntax-entry ?{ "(}" powershell-mode-syntax-table) 
   (modify-syntax-entry ?} "){" powershell-mode-syntax-table) 
   (modify-syntax-entry ?[ "(]" powershell-mode-syntax-table) 
   (modify-syntax-entry ?] ")[" powershell-mode-syntax-table) 
   (modify-syntax-entry ?( "()" powershell-mode-syntax-table) 
   (modify-syntax-entry ?) ")(" powershell-mode-syntax-table) 
   (modify-syntax-entry ?` "\\" powershell-mode-syntax-table) 
   (modify-syntax-entry ?_  "w" powershell-mode-syntax-table) 
   (modify-syntax-entry ?#  "<" powershell-mode-syntax-table) 
   (modify-syntax-entry ?\n ">" powershell-mode-syntax-table) 
   (modify-syntax-entry ?' "\"" powershell-mode-syntax-table) 
    powershell-mode-syntax-table) 
  "Syntax for PowerShell major mode")


(defvar powershell-imenu-expressions 
  '((nil "^\\(?:function\\|Add-Class\\)\\s-+\\([-a-z0-9A-Z_^:.]+\\)[^-a-z0-9A-Z_^:.]" 1)) 
  "alist of regexp identifying the start of powershell definitions" 
) 

(defun powershell-setup-imenu () 
  "Installs powershell-imenu-expression." 
  (require 'imenu t) 

  ;; imenu doc says these 3 are buffer-local by default 
  (setq imenu-generic-expression powershell-imenu-expressions) 
  (imenu-add-menubar-index) 
  (require 'which-func t) 
  (which-function-mode t)
)  


(defun powershell-mode () 
  "Major mode for editing PowerShell files" 
  (interactive) 
  (kill-all-local-variables) 
  (setq major-mode 'powershell-mode) 
  (setq mode-name "PS") 
  (set-syntax-table powershell-mode-syntax-table) 
  (use-local-map powershell-mode-map) 
  (set (make-local-variable 'font-lock-defaults) 
       '(powershell-font-lock-keywords))  

  (make-local-variable 'compile-command) 
  (if buffer-file-name 
      (setq compile-command (format "PowerShell -noprofile -nologo -command %s" 
                                    (expand-file-name buffer-file-name))))  

   ; Here we register our line indentation function with Emacs. Now Emacs will 
   ; call our function every time line indentation is required (like when the 
   ; user calls indent-region). 
;;  (make-local-variable 'indent-line-function) 
;;  (setq indent-line-function 'powershell-indent-line)  
   ; Set indentation defaults. 
  (make-local-variable 'powershell-indent-width) 
  (set (make-local-variable 'comment-start) "#") 
  (powershell-setup-imenu) 
  (run-hooks 'powershell-mode-hook))  

(provide 'powershell-mode)