;;; prelude-rust.el --- Emacs Prelude: Rust programming support.
;;
;; Authors: Doug MacEachern, Manoel Vilela, Ben Alex
;; Version: 1.0.1
;; Keywords: convenience rust

;; This file is not part of GNU Emacs.

;;; Commentary:

;; Prelude configuration for Rust

;;; License:

;; This program 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.
;;
;; This program 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Code:

(require 'prelude-programming)

;; You may need installing the following packages on your system:
;; * rustc (Rust Compiler)
;; * cargo (Rust Package Manager)
;; * racer (Rust Completion Tool)
;; * rustfmt (Rust Tool for formatting code)
;; * rls (Rust Language Server, if the prelude-lsp feature is enabled)

(prelude-require-packages '(rust-mode
                            cargo))

(if (featurep 'prelude-lsp)
    (prelude-require-package 'lsp-rust)
  (prelude-require-packages '(racer
                              flycheck-rust)))

(setq rust-format-on-save t)
(setq lsp-rust-rls-command '("rustup" "run" "stable" "rls"))

(with-eval-after-load 'rust-mode
  (add-hook 'rust-mode-hook 'cargo-minor-mode)

  (if (featurep 'prelude-lsp)
      (progn (require 'lsp-rust)
             (add-hook 'rust-mode-hook #'lsp-rust-enable))
    (add-hook 'rust-mode-hook 'racer-mode)
    (add-hook 'racer-mode-hook 'eldoc-mode)
    (add-hook 'rust-mode-hook 'flycheck-rust-setup)
    (add-hook 'flycheck-mode-hook 'flycheck-rust-setup))

  (defun prelude-rust-mode-defaults ()
    (unless (featurep 'prelude-lsp)
      (local-set-key (kbd "C-c C-d") 'racer-describe))

    ;; Prevent #! from chmodding rust files to be executable
    (remove-hook 'after-save-hook 'executable-make-buffer-file-executable-if-script-p)
    ;; CamelCase aware editing operations
    (subword-mode +1))

  (setq prelude-rust-mode-hook 'prelude-rust-mode-defaults)

  (add-hook 'rust-mode-hook (lambda ()
                              (run-hooks 'prelude-rust-mode-hook))))

(provide 'prelude-rust)
;;; prelude-rust.el ends here