;;; Eshell

;;; Eshell gets initialized differently.  When eshell.el first gets loaded, only
;;; the core is defined and `eshell-load-hook' is called. For every Eshell
;;; session, `eshell-mode' is run: it resets `eshell-mode-map', it loads
;;; modules, runs their hooks and concludes with `eshell-first-time-mode-hook'
;;; (for the first session only) and `eshell-mode-hook'.

;; Emacs pinentry for GPG.
(require 'main)

;;; REVIEW: If history contains read-only text (e.g. accidental insertion of the prompt),
;;; `eshell-write-history' won't work.
;;; See #29153.

;;; REVIEW: ANSI coloring goes wrong sometimes.  Quite often with emerge/eix.
;;; Fixed in #27407.
(require 'patch-eshell)

;;; TODO: Sometimes transmission-daemon does not start from Eshell.

;;; REVIEW: Redirecting big output to file (e.g. /dev/null) is extremely slow.
;; > cat /usr/share/dict/british-english | wc -l
;;; The above line yields rancom results.  Plus it's much slower than
;; > wc -l /usr/share/dict/british-english
;;; while it should only cost an additional process to launch.
;;; See #29154.

;;; REVIEW: Cannot "C-c C-c" during a `sudo pacman -Syu`.  A bug was filed about that already.

;;; TODO: The buffer stutters when writing "in-place", e.g. pacman, git.
;;; It seems that it does not do it as much in `emacs -Q`.

;;; REVIEW: `eshell/sudo' should not read -u in command arguments.
;;; This fails: sudo pacman -Syu --noconfirm.
;;; http://www.gnu.org/software/emacs/manual/html_node/eshell/Built_002dins.html
;;; https://emacs.stackexchange.com/questions/5608/how-to-let-eshell-remember-sudo-password-for-two-minutes
;;; See http://debbugs.gnu.org/cgi/bugreport.cgi?bug=27411
;;; and #28323.

;;; REVIEW: Eshell/Shell completion fails when PATH has a non-readable element.
;;; See https://github.com/emacs-helm/helm/issues/1785
;;; and https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27300.

;;; REVIEW: 40M+ output: Stack overflow in regexp matcher
;;; See bug#28329.
;;; I guess the chunking is significant too.  Could you try saving
;;; the output chunks, with this:
;;
;; (defvar eshell-chunk-number 0)
;; (defconst eshell-output-chunk-dir "eshell-output")
;; (make-directory eshell-output-chunk-dir t)
;;
;; (defun catch-eshell-output-chunk ()
;;   (write-region eshell-last-output-block-begin
;;                 eshell-last-output-end
;;                 (format "%s/chunk.%d"
;;                         eshell-output-chunk-dir
;;                         eshell-chunk-number)
;;                 nil :quiet)
;;   (setq eshell-chunk-number (1+ eshell-chunk-number)))
;;
;; (add-hook 'eshell-output-filter-functions
;;           'catch-eshell-output-chunk)
;;;
;;; And then afterwards 'cat eshell-output/chunk.*' should hopefully
;;; reproduce it?


;;; REVIEW: Eshell mixes stderr and stdout it seems.
;;; Example:
;;; $ mu find --nocolor --sortfield=d --maxnum=500 flag:unread AND NOT flag:trashed >/dev/null
;;; mu: no matches for search expression (4)
;;; See #21605 "24.3; Eshell not using stderr".

;;; REVIEW: Some parsing fails
;;; > echo -n $PATH | sed 's/:[^:]*sophos[^:]*/:/g'
;;; :s/:]*sophos[/:]*/:/"/
;;; Unknown modifier character ‘/’
;;;
;;; > date +%Z
;;; See #29157.

;;; TODO: Change face of eshell/* commands in commandline to avoid confusion
;;; with system programs.

;;; TODO: Merge/re-use documentation of eshell/* commands with their docstring.

;;; TODO: Hour is printed twice. We don't need to set this?
;; (setq eshell-ls-date-format (replace-regexp-in-string "^\\+*" "" (getenv "TIME_STYLE")))

;;; TODO: ls: Sort using locale.

;;; REVIEW: `kill -#' does not work.
;;; See #29156.

(setq eshell-directory-name (concat emacs-cache-folder "eshell"))

;;; Use native 'sudo', system sudo asks for password every time.
(require 'em-tramp)

(with-eval-after-load 'esh-module
  ;; Don't print the banner.
  (delq 'eshell-banner eshell-modules-list)
  (push 'eshell-tramp eshell-modules-list))

(setq
 eshell-ls-use-colors t
 ;; ffap-shell-prompt-regexp changes the behaviour of `helm-find-files' when
 ;; point is on prompt. I find this disturbing.
 ffap-shell-prompt-regexp nil
 eshell-history-size 1024
 eshell-hist-ignoredups t
 eshell-destroy-buffer-when-process-dies t)

;;; Leave `eshell-highlight-prompt' to t as it sets the read-only property.
(setq eshell-prompt-function
      (lambda nil
        (let ((path (abbreviate-file-name (eshell/pwd))))
          (concat
           (when eshell-status-p
             (propertize (or (eshell-status-display) "") 'face font-lock-comment-face))
           (format
            (propertize "(%s@%s)" 'face '(:weight bold))
            (propertize (user-login-name) 'face '(:foreground "cyan"))
            (propertize (system-name) 'face '(:foreground "cyan")))
           (if (and (require 'magit nil t) (or (magit-get-current-branch) (magit-get-current-tag)))
               (let* ((root (abbreviate-file-name (magit-rev-parse "--show-toplevel")))
                      (after-root (substring-no-properties path (min (length path) (1+ (length root))))))
                 (format
                  (propertize "[%s/%s@%s]" 'face '(:weight bold))
                  (propertize root 'face `(:foreground ,(if (= (user-uid) 0) "orange" "gold")))
                  (propertize after-root 'face `(:foreground ,(if (= (user-uid) 0) "red" "green") :weight bold))
                  (or (magit-get-current-branch) (magit-get-current-tag))))
             (format
              (propertize "[%s]" 'face '(:weight bold))
              (propertize path 'face `(:foreground ,(if (= (user-uid) 0) "red" "green") :weight bold))))
           (propertize "\n>" 'face '(:weight bold))
           " "))))
;;; If the prompt spans over multiple lines, the regexp should match
;;; last line only.
(setq-default eshell-prompt-regexp "^> ")

(with-eval-after-load 'em-term
  (dolist (p '("abook" "alsamixer" "cmus" "fzf" "htop" "mpsyt" "mpv" "mutt" "ncdu" "newsbeuter" "pinentry-curses" "ranger" "watch" "wifi-menu"))
    (add-to-list 'eshell-visual-commands p))
  (setq eshell-visual-subcommands
        '(("git" "log" "diff" "show"
           "l" "lol" "d" "dc") ; aliases
          ("sudo" "wifi-menu") ; Arch Linux
          ("sudo" "vi" "visudo"))))

;;; Alias management possibilities:
;;; - Version eshell-alias and store it in user-emacs-directory. Simplest and
;;; fastest, but aliases cannot be included conditionnaly, e.g. depending on the
;;; existence of a program.
;;; - Store eshell-alias in cache and populate it dynamically on startup.
;; (setq eshell-aliases-file (concat user-emacs-directory "eshell-alias"))
;;;
;;; `eshell/alias' is too slow as it reads and write the file on each definition.
;;; Let's write manually instead.
(with-eval-after-load 'em-alias
  ;;; TODO: This conflicts with `evil-define-key' during the initialization of
  ;;; the first eshell session: the map in insert-mode will not take the changes
  ;;; into account. Going to normal mode and back to insert mode works.
  ;;; Note: Evil has fixed some issues in the meantime.  Also test with `evil-define-key*'.
  ;;;
  ;;; If we read the alias list here, it means we make commandline-defined aliases persistent.
  ;; (eshell-read-aliases-list)
  (dolist
      (alias
       '(("l" "ls -1 $*")
         ("la" "ls -lAh $*")
         ("ll" "ls -lh $*")
         ;; TODO: Aliasing eshell/{cp,mv,ln} does not work.
         ;; TODO: "sudo" does not work on aliases.
         ;; See bug #27168.
         ;; REVIEW: Eshell/TRAMP's sudo does not work with aliases.
         ;; See #28320.
         ;; ("ls" "ls -F $*") ; not supported
         ;; ("emacs" "find-file $1")
         ;; ("cp" "eshell/cp -iv $*")
         ;; ("mv" "eshell/mv -iv $*")
         ("cpv" "cp -iv $*")
         ("mvv" "mv -iv $*")
         ("rmv" "rm -v $*")
         ("md" "eshell/mkdir -p $*")
         ("mkcd" "eshell/mkdir -p $* ; cd $1"))) ; TODO: Does not work because mkdir exits with nil?
    (add-to-list 'eshell-command-aliases-list alias))
  (eshell-write-aliases-list))

;;; Hooks
;;; `nobreak-char-display' makes some output look weird, e.g. with 'tree'.
(add-hook 'eshell-mode-hook 'turn-off-nobreak-char-display)

;;; History
;;; Filter out space-beginning commands from history.
;;; TODO: history/command hook: trim surrounding space.  Check `eshell-rewrite-command-hook'.
;;; TODO: history: do not save failed commands to file.
;;; TODO: history: do not store duplicates.  Push unique command to front of the list.
(setq eshell-input-filter
      (lambda (str)
        (not (or (string= "" str)
                 (string-prefix-p " " str)))))

;;; Shared history.
(defvar eshell-history-global-ring nil
  "The history ring shared across Eshell sessions.")

(defun eshell-hist-use-global-history ()
  "Make Eshell history shared across different sessions."
  (unless eshell-history-global-ring
    (let (eshell-history-ring)
      (when eshell-history-file-name
        (eshell-read-history nil t))
      (setq eshell-history-global-ring eshell-history-ring))
    (unless eshell-history-ring (setq eshell-history-global-ring (make-ring eshell-history-size))))
  (setq eshell-history-ring eshell-history-global-ring))
(add-hook 'eshell-mode-hook 'eshell-hist-use-global-history)

;;; Spawning
(defun eshell-or-new-session (&optional arg)
  "Create an interactive Eshell buffer.
Switch to last Eshell session if any.
Otherwise create a new one and switch to it.
See `eshell' for the numeric prefix ARG."
  (interactive "P")
  (if (or arg (eq major-mode 'eshell-mode))
      (eshell (or arg t))
    (let ((last (buffer-list)))
      (while (and last
                  (not (with-current-buffer (car last)
                         (eq major-mode 'eshell-mode))))
        (setq last (cdr last)))
      (if last
          (switch-to-buffer (car last))
        (eshell (or arg t))))))

;;; Auto-suggestion
(when (require 'company-eshell-autosuggest nil t)
  (defun eshell-setup-autosuggest ()
    (setq-local company-idle-delay 0.5)
    (setq-local company-backends '(company-eshell-autosuggest))
    (setq-local company-frontends '(company-preview-frontend)))
  ;; TODO: Fix https://github.com/jojojames/evil-collection/issues/41.
  ;; (define-key company-active-map (kbd "<tab>") 'company-select-next-if-tooltip-visible-or-complete-selection)
  ;; (add-to-list 'company-frontends 'company-tng-frontend)
  (add-hook 'eshell-mode-hook 'company-mode)
  (when (require 'helm-config nil t)
    (define-key company-active-map (kbd "M-p") 'helm-eshell-history))
  (add-hook 'eshell-mode-hook 'eshell-setup-autosuggest))

;;; Extra execution information
(defvar eshell-status-p t
  "If non-nil, display status before prompt.")
(defvar eshell-status--last-command-time nil)
(make-variable-buffer-local 'eshell-status--last-command-time)
(defvar eshell-status-min-duration-before-display 1
  "If a command takes more time than this, display its duration.")

(defun eshell-status-display ()
  (when eshell-status--last-command-time
    (let ((duration (time-subtract (current-time) eshell-status--last-command-time)))
      (setq eshell-status--last-command-time nil)
      (when (> (time-to-seconds duration) eshell-status-min-duration-before-display)
        (format "#[STATUS] End time %s, duration %.3fs\n"
                (format-time-string "%F %T" (current-time))
                (time-to-seconds duration))))))

(defun eshell-status-record ()
  (setq eshell-status--last-command-time (current-time)))

(add-hook 'eshell-pre-command-hook 'eshell-status-record)

;;; Detach
(when (require 'package-eshell-detach nil t)
  (defun eshell-detach-set-keys ()
    (define-key eshell-mode-map (kbd "C-c C-z") 'eshell-detach-stop)
    (define-key eshell-mode-map (kbd "S-<return>") 'eshell-detach-send-input)
    (define-key eshell-mode-map (kbd "C-<return>") 'eshell-detach-attach))
  (add-hook 'eshell-mode-hook 'eshell-detach-set-keys))

(provide 'init-eshell)