;;; evil-collection-eshell.el --- Evil bindings for Eshell -*- lexical-binding: t -*-

;; Copyright (C) 2017 Pierre Neidhardt

;; Author: Pierre Neidhardt <mail@ambrevar.xyz>
;; Maintainer: James Nguyen <james@jojojames.com>
;; Pierre Neidhardt <mail@ambrevar.xyz>
;; URL: https://github.com/emacs-evil/evil-collection
;; Version: 0.0.1
;; Package-Requires: ((emacs "25.1"))
;; Keywords: evil, eshell, tools

;; This file 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, or (at your
;; option) any later version.
;;
;; This file 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.
;;
;; For a full copy of the GNU General Public License
;; see <http://www.gnu.org/licenses/>.

;;; Commentary:
;; Evil bindings for Eshell.

;;; Code:
(require 'em-prompt)
(require 'eshell)
(require 'evil-collection)

(defconst evil-collection-eshell-maps '(eshell-mode-map))

(defun evil-collection-eshell-next-prompt ()
  "`evil' wrapper around `eshell-next-prompt'."
  (when (get-text-property (point) 'read-only)
    ;; If at end of prompt, `eshell-next-prompt' will not move, so go backward.
    (beginning-of-line)
    (eshell-next-prompt 1)))

(defun evil-collection-eshell-next-prompt-on-insert ()
  "Go to next prompt on `evil' replace/insert enter."
  (dolist (hook '(evil-replace-state-entry-hook evil-insert-state-entry-hook))
    (add-hook hook 'evil-collection-eshell-next-prompt nil t)))

(defun evil-collection-eshell-interrupt-process ()
  "Interupt `eshell' process and enter insert state."
  (interactive)
  (eshell-interrupt-process)
  (evil-insert 1))

;; Taken from Doom Emacs
(evil-define-operator evil-collection-eshell-evil-change (beg end type register yank-handler delete-func)
  "Like `evil-change' but will not delete/copy the prompt."
  (interactive "<R><x><y>")
  (save-restriction
    (narrow-to-region eshell-last-output-end (point-max))
    (evil-change (max beg (point-min))
                 (if (eq type 'line) (point-max) (min (or end (point-max)) (point-max)))
                 type register yank-handler delete-func)))

;; Taken from Doom Emacs
(evil-define-operator evil-collection-eshell-evil-change-line (beg end type register yank-handler)
  "Change to end of line."
  :motion evil-end-of-line
  (interactive "<R><x><y>")
  (evil-collection-eshell-evil-change beg end type register yank-handler #'evil-delete-line))

;; Taken from Doom Emacs
(evil-define-operator evil-collection-eshell-evil-delete (beg end type register yank-handler)
  "Like `evil-delete' but will not delete/copy the prompt."
  (interactive "<R><x><y>")
  (save-restriction
    (narrow-to-region eshell-last-output-end (point-max))
    (evil-delete (if beg (max beg (point-min)) (point-min))
                 (if (eq type 'line) (point-max) (min (or end (point-max)) (point-max)))
                 type register yank-handler)))

;; Taken from Doom Emacs
(evil-define-operator evil-collection-eshell-evil-delete-line (_beg end type register yank-handler)
  "Change to end of line."
  :motion nil
  :keep-visual t
  (interactive "<R><x>")
  (evil-collection-eshell-evil-delete (point) end type register yank-handler))

;;; `eshell-mode-map' is reset when Eshell is initialized in `eshell-mode'. We
;;; need to add bindings to `eshell-first-time-mode-hook'.
(defun evil-collection-eshell-setup-keys ()
  "Set up `evil' bindings for `eshell'."
  (evil-collection-define-key 'normal 'eshell-mode-map
    ;; motion
    "[[" 'eshell-previous-prompt
    "]]" 'eshell-next-prompt
    (kbd "C-k") 'eshell-previous-prompt
    (kbd "C-j") 'eshell-next-prompt
    "gk" 'eshell-previous-prompt
    "gj" 'eshell-next-prompt
    "0" 'eshell-bol
    "^" 'eshell-bol
    (kbd "M-h") 'eshell-backward-argument
    (kbd "M-l") 'eshell-forward-argument

    (kbd "C-n") 'eshell-next-matching-input-from-input
    (kbd "C-p") 'eshell-previous-matching-input-from-input

    (kbd "RET") 'eshell-send-input
    (kbd "C-c C-c") 'evil-collection-eshell-interrupt-process
    "c" 'evil-collection-eshell-evil-change
    "C" 'evil-collection-eshell-evil-change-line
    "d" 'evil-collection-eshell-evil-delete
    "D" 'evil-collection-eshell-evil-delete-line)
  (evil-collection-define-key 'insert 'eshell-mode-map
    ;; motion
    (kbd "M-h") 'eshell-backward-argument
    (kbd "M-l") 'eshell-forward-argument)
  (evil-collection-define-key 'visual 'eshell-mode-map
    ;; motion
    ;; TODO: This does not work with `evil-visual-line'.
    "[[" 'eshell-previous-prompt
    "]]" 'eshell-next-prompt
    (kbd "C-k") 'eshell-previous-prompt
    (kbd "C-j") 'eshell-next-prompt
    "gk" 'eshell-previous-prompt
    "gj" 'eshell-next-prompt
    "0" 'eshell-bol
    "^" 'eshell-bol))

;; TODO: Compare this setup procedure with evil-ediff.
;;;###autoload
(defun evil-collection-eshell-setup ()
  "Set up `evil' bindings for `eshell'."
  (add-hook 'eshell-mode-hook 'evil-collection-eshell-next-prompt-on-insert)
  (add-hook 'eshell-first-time-mode-hook 'evil-collection-eshell-setup-keys))

(provide 'evil-collection-eshell)
;;; evil-collection-eshell.el ends here