;;==============================================================================
;; Shell
;;==============================================================================

(defvaralias 'sh-indentation 'sh-basic-offset)

(setq sh-indent-comment t)

(set (make-local-variable 'sh-shell-file) "/bin/sh") ; Useful for the first time this hook is loaded.
(setq-default sh-shell-file sh-shell-file)
;; (setq-default sh-shell 'sh)

(defun sh-set-interpreter ()
  "Set shell interpreter.
Set `sh-shell', `sh-shell-file' and `compile-command' according to the following rules:
- Look at shabang.
- If file has no name, use default value of sh-shell-file.
- Check extension or file name.
- If none of the above yields a result, use default value of
  sh-shell-file.
The advantages of this function over the vanilla code are:
- You can change default value of sh-shell-file in sh-mode-hook
  and it will be used subsequently.
- Zsh is supported
- compile-command is set.
- Once sh-shell is set, sh-shell-file is changed accordingly. In
  default Emacs, sh-shell-file is always the same."
  (interactive)
  (sh-set-shell
   (cond ((save-excursion
            (goto-char (point-min))
            (looking-at "#![ \t]?\\([^ \t\n]*/bin/env[ \t]\\)?\\([^ \t\n]+\\)"))
          (match-string 2))
         ((not buffer-file-name) sh-shell-file)
         ;; Checks that use `buffer-file-name' follow.
         ((string-match "\\.m?spec\\'" buffer-file-name) "rpm")
         ((string-match "[.]bash\\>"   buffer-file-name) "bash")
         ((string-match "[.]csh\\>"    buffer-file-name) "csh")
         ((string-match "[.]ksh\\>"    buffer-file-name) "ksh")
         ((string-match "[.]sh\\>"     buffer-file-name) "sh")
         ((string-match "[.]zsh\\>"    buffer-file-name) "zsh")
         ((equal (file-name-nondirectory buffer-file-name) ".profile") "sh")
         (t sh-shell-file))
   nil nil)
  ;; Universal version.
  ; (setq sh-shell-file (executable-find (symbol-name sh-shell)))
  ;; Convenient version.
  (setq sh-shell-file (concat "/bin/" (symbol-name sh-shell)))
  (set (make-local-variable 'compile-command) (concat sh-shell-file " " buffer-file-name)))

;; sh-set-shell partly resets some of the font-lock config. We use this
;; workaround to restore it.
(add-hook-and-eval
 'sh-set-shell-hook
 (lambda ()
   (font-lock-add-keywords
    'sh-mode
    '(("\\<\\(FIXME\\):" 1 font-lock-warning-face prepend)
      ("\\<\\(TODO\\):" 1 font-lock-warning-face prepend)
      ("\\<\\(WARNING\\):" 1 font-lock-warning-face prepend)))))

(add-hook-and-eval
 'sh-mode-hook
 (lambda ()
   (setq sh-indent-for-case-label 0)
   (setq sh-indent-for-case-alt '+)
   (set (make-local-variable 'defun-prompt-regexp)
        (concat "^\\(function[ \t]\\|[[:alnum:]_]+[ \t]+()[ \t]+\\)"))
   (sh-set-interpreter)))

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

(define-skeleton sh-check
  "Insert a function checking for presence in PATH."
  nil
  "check() {" \n
  "for i ; do" \n
  "if ! command -v $i >/dev/null 2>&1; then" \n
  "echo \"'$i' not found in PATH. Exiting.\" >&2" \n
  "exit 1" \n
  "fi" \n
  "done" \n
  "}" > \n)

(define-skeleton sh-command
  "Insert a line that executes if command is found in path."
  "Command name: "
  > "command -v " @ str " >/dev/null 2>&1 && " @ _)

(define-skeleton sh-command-or-die
  "Insert a line that quits if command is not found in path."
  "Command name: "
  > "if ! command -v " @ str " >/dev/null 2>&1; then" \n
  > "echo '" str " not found in PATH. Exiting.' >&2" \n
  > "exit 1" \n
  "fi" > \n)

(define-skeleton sh-for
  "Insert a for loop.  See `sh-feature'. This overrides vanilla function."
  "Index variable: "
  > "for " str | "i"
  '(setq v1 (skeleton-read "Index values: " ""))
  (unless (string= v1 "")
    (concat " in " v1))
  "; do" \n
  > _ \n
  "done" > \n)

(define-skeleton sh-ifcommand
  "Insert a test to check if command is found in path."
  "Command name: "
  > "if command -v " @ str " >/dev/null 2>&1; then" \n
  > @ _ \n
  "fi" > \n)

(define-skeleton sh-redirect-to-null
  "Insert a null redirection."
  nil
  ">/dev/null 2>&1")

(define-skeleton sh-while-getopts
  "Insert a getops prototype."
  "optstring: "
  > "usage() {" \n
  "cat<<EOF" > \n ; TODO: Why is '>' necessary here?
  "Usage: ${1##*/} [OPTIONS] FILES

Options:

  -h:  Show this help.

EOF
}" \n
\n
> "while getopts :" str " OPT; do" \n
> "case $OPT in" \n
'(setq v1 (append (vconcat str) nil))
( (prog1 (if v1 (char-to-string (car v1)))
    (if (eq (nth 1 v1) ?:)
        (setq v1 (nthcdr 2 v1)
              v2 "\"$OPTARG\"")
      (setq v1 (cdr v1)
            v2 nil)))
  > str ")" \n
  > _ v2 " ;;" \n)
> "\\?)" \n
> "usage \"$0\"" \n
"exit 1 ;;"  > \n
"esac" > \n
"done" > \n \n
"shift $(($OPTIND - 1))" \n
"if [ $# -eq 0 ]; then" \n
"usage \"$0\"" > \n ; TODO: Why is '>' necessary here?
"exit 1" \n
"fi" > \n)

(define-skeleton sh-while-read
  "Insert a while read loop."
  nil
  > "while IFS= read -r i; do" \n
  > @ _ \n
  > "done <<EOF" \n
  > "EOF" \n)

(provide 'mode-sh)