From 7b9cc70e7c07d055829608033d416af4f8ce919e Mon Sep 17 00:00:00 2001
From: Alexander Rosenberg <zanderpkg@pm.me>
Date: Wed, 17 Jan 2024 04:16:49 -0800
Subject: [PATCH] Move eshell prompt to its own file

---
 elisp/eshell-starship.el | 214 +++++++++++++++++++++++++++++++++++++++
 init.el                  | 174 +------------------------------
 2 files changed, 219 insertions(+), 169 deletions(-)
 create mode 100644 elisp/eshell-starship.el

diff --git a/elisp/eshell-starship.el b/elisp/eshell-starship.el
new file mode 100644
index 0000000..7443f32
--- /dev/null
+++ b/elisp/eshell-starship.el
@@ -0,0 +1,214 @@
+;;; eshell-starship.el --- Starship-like (https://starship.rs) prompt for eshell
+;;; Commentary:
+;;; Code:
+
+(require 'vc)
+(require 'vc-git)
+(require 'eshell)
+
+(defun eshell-starship--git-process-lines (&rest flags)
+  "Run `vc-git-program' and return an array of its output lines.
+FLAGS are passed to `vc-git-program' as its arguments."
+  (with-temp-buffer
+    (apply 'vc-git-command t 0 nil flags)
+    (if (zerop (buffer-size))
+        '()
+      (string-lines (buffer-substring-no-properties 1 (buffer-size))))))
+
+(defun eshell-starship--replace-home-with-tilda (path)
+  "If PATH beings with $HOME (the environment variable), replace it with ~."
+  (let ((home (getenv "HOME")))
+    (if (equal home path)
+        "~"
+      (setq home (file-name-as-directory home))
+      (if (string-prefix-p home path)
+          (concat "~/" (seq-subseq path (length home)))
+        path))))
+
+(defun eshell-starship--prompt-cut-path (num path)
+  "Cut PATH down to NUM components.
+Example:
+/this/is/a/path 3-> is/a/path"
+  (let ((parts (string-split path "/" t nil)))
+    (concat
+     (when (and (file-name-absolute-p path)
+                (not (equal "~" (car parts)))
+                (<=  (length parts) num))
+       "/")
+     (string-join (last parts num) "/"))))
+
+(defun eshell-starship--prompt-get-dir ()
+  "Get dir for `eshell-starship--prompt-function'."
+  (eshell-starship--prompt-cut-path 3
+                              (if-let ((worktree (vc-root-dir))
+                                       (parent (file-name-parent-directory worktree)))
+                                  (file-relative-name default-directory parent)
+                                (eshell-starship--replace-home-with-tilda default-directory))))
+
+(defun eshell-starship--prompt-status-char-for-branch (branch remote)
+  "Get the status char representing the relation between BRANCH and REMOTE."
+  (let ((lines (eshell-starship--git-process-lines
+                "rev-list"
+                "--left-right"
+                (concat branch "..." remote)))
+        (to-remote nil)
+        (to-local nil))
+    (dolist (line lines)
+      (if-let (((not (string-empty-p line)))
+               (dir-char (aref line 0)))
+          (if (= dir-char ?<)
+              (setq to-remote t)
+            (setq to-local t))))
+    (cond
+     ((and to-remote to-local) ?󰹺)
+     (to-remote ?󰜷)
+     (to-local ?󰜮))))
+
+
+(defun eshell-starship--prompt-current-branch-status ()
+  "Get the status char for the current branch and its remote."
+  (let ((refs (eshell-starship--git-process-lines
+               "for-each-ref"
+               "--format=%(HEAD)%00%(refname:short)%00%(upstream:short)"
+               "refs/heads")))
+    (catch 'break
+      (dolist (ref refs)
+        (if-let ((split-ref (split-string ref "\0" nil nil))
+                 ((equal (car split-ref) "*")))
+            (throw 'break (eshell-starship--prompt-status-char-for-branch
+                           (cadr split-ref)
+                           (caddr split-ref))))))))
+
+(defun eshell-starship--prompt-git-state-chars ()
+  "Get chars, like + and ✘ for `eshell-starship--prompt-function'."
+  (let ((lines (eshell-starship--git-process-lines "status" "--porcelain=v1"))
+        (branch-status (eshell-starship--prompt-current-branch-status))
+        (status-arr))
+    (dolist (line lines)
+      (cl-loop with fields = (string-split line " " t " *")
+               with status-str = (car-safe fields)
+               for status-char across status-str
+               do
+               (cond ((or (= status-char ?M) (= status-char ?T))
+                      (add-to-list 'status-arr ?!))
+                     ((= status-char ??)
+                      (add-to-list 'status-arr ??))
+                     ((or (= status-char ?A) (= status-char ?C))
+                      (add-to-list 'status-arr ?+))
+                     ((= status-char ?D)
+                      (add-to-list 'status-arr ?))
+                     ((= status-char ?R)
+                      (add-to-list 'status-arr ?»))
+                     ((= status-char ?U)
+                      (add-to-list 'status-arr ?=)))))
+    (sort status-arr #'<)
+    (when branch-status
+      (push branch-status status-arr))
+    (apply 'string status-arr)))
+
+(defun eshell-starship--prompt-git-get-operation ()
+  "Return the current git operation.  For example, a revert."
+  (let ((git-dir (expand-file-name ".git" (vc-git-root default-directory))))
+    (cond
+     ((file-exists-p (expand-file-name "REVERT_HEAD" git-dir))
+      "REVERTING")
+     ((file-exists-p (expand-file-name "rebase-merge" git-dir))
+      "REBASING")
+     ((file-exists-p (expand-file-name "MERGE_HEAD" git-dir))
+      "MERGING"))))
+
+(defun eshell-starship--prompt-git-status ()
+  "Get git status for `eshell-starship--prompt-function'."
+  (let ((branch (car (vc-git-branches)))
+        (state (eshell-starship--prompt-git-state-chars))
+        (operation (eshell-starship--prompt-git-get-operation)))
+    (concat
+     (propertize (concat " 󰊢 " branch) 'face '(:foreground "medium purple"))
+     (unless (string-empty-p state)
+       (propertize (concat " [" state "]") 'face '(:foreground "red")))
+     (when operation
+       (concat " (" (propertize operation 'face
+                                '(:inherit 'bold :foreground "yellow")) ")")))))
+
+(defun eshell-starship--prompt-vc-status ()
+  "Get vc status for `eshell-starship--prompt-function'."
+  (if-let (backend (vc-responsible-backend default-directory t))
+      (if (eq backend 'Git)
+          (eshell-starship--prompt-git-status)
+        (propertize
+         (concat "  " (downcase (symbol-name backend)))
+         'face '(:foreground "purple")))))
+
+(defvar-local eshell-starship--prompt-last-start-time nil
+  "Start time of last eshell command.")
+
+(defun eshell-starship--prompt-timer-pre-cmd ()
+  "Command run before each eshell program to record the time."
+  (setq eshell-starship--prompt-last-start-time (current-time)))
+
+(add-hook 'eshell-pre-command-hook #'eshell-starship--prompt-timer-pre-cmd)
+
+(defun eshell-starship--prompt-format-span (span)
+  "Format SPAN as \"XhXms\"."
+  (let* ((hours (/ span 3600))
+         (mins (% (/ span 60) 60))
+         (secs (% span 60)))
+    (concat (unless (= hours 0)
+              (format "%dh" hours))
+            (unless (= mins 0)
+              (format "%dm" mins))
+            (format "%ds" secs))))
+
+(defun eshell-starship--prompt-last-command-time (end-time)
+  "Return the prompt component for the time of the last command.
+END-TIME is the time when the command finished executing."
+  (if-let ((eshell-starship--prompt-last-start-time)
+           (len (time-subtract end-time
+                               eshell-starship--prompt-last-start-time))
+           (float-len (float-time len))
+           ((< 3 float-len))
+           (int-len (round float-len)))
+      (concat " time "
+              (propertize (eshell-starship--prompt-format-span int-len)
+                          'face '(:foreground "gold1")))))
+
+(defun eshell-starship--prompt-function ()
+  "Function for `eshell-prompt-function'."
+  (let* ((end-time (current-time))
+         (dir (eshell-starship--prompt-get-dir))
+         (prompt (concat
+                  "\n"
+                  (propertize dir 'face '(:foreground "dark turquoise"))
+                  (unless (file-writable-p dir)
+                    " ")
+                  (eshell-starship--prompt-vc-status)
+                  (eshell-starship--prompt-last-command-time end-time)
+                  (propertize "\n" 'read-only t 'rear-nonsticky t)
+                  (propertize
+                   "❯ " 'face `(:foreground
+                                ,(if (= eshell-last-command-status 0)
+                                     "lime green"
+                                   "red"))
+                   'rear-nonsticky t))))
+    (setq eshell-starship--prompt-last-start-time nil)
+    prompt))
+
+(defvar-local ehsell-starship--restore-state nil
+  "State of various variables set by `eshell-starship-prompt-mode'.")
+
+;;;###autoload
+(define-minor-mode eshell-starship-prompt-mode
+  "Minor mode to make eshell prompts look like starship (https://starship.rs)"
+  :global nil
+  :init-value nil
+  :interactive (eshell-mode)
+  (if eshell-starship-prompt-mode
+      (setq-local eshell-starship--restore-state
+                  (buffer-local-set-state eshell-prompt-function
+                                          'eshell-starship--prompt-function
+                                          eshell-prompt-regexp "^❯ "
+                                          eshell-highlight-prompt nil))
+    (buffer-local-restore-state eshell-starship--restore-state)))
+
+(provide 'eshell-starship)
+;;; eshell-starship.el ends here
diff --git a/init.el b/init.el
index 3eac8b0..bd87f6d 100644
--- a/init.el
+++ b/init.el
@@ -923,175 +923,7 @@ If no name is given, list all bookmarks instead."
           (eshell/cd (bookmark-get-filename name))
           (when my/eshell-bm-auto-ls
             (eshell/ls)))
-      (eshell-print (string-join (bookmark-all-names) " "))))
-  (defun my/-git-process-lines (&rest flags)
-    "Run `vc-git-program' and return an array of its output lines."
-    (with-temp-buffer
-      (apply 'vc-git-command t 0 nil flags)
-      (if (zerop (buffer-size))
-          '()
-        (string-lines (buffer-substring-no-properties 1 (buffer-size))))))
-  (defun my/-replace-home-with-tilda (path)
-    (let ((home (getenv "HOME")))
-      (if (equal home path)
-          "~"
-        (setq home (file-name-as-directory home))
-        (if (string-prefix-p home path)
-            (concat "~/" (seq-subseq path (length home)))
-          path))))
-  (defun my/-eshell-prompt-cut-path (num path)
-    "Cut PATH down to NUM components."
-    (let ((parts (string-split path "/" t nil)))
-      (concat
-       (when (and (file-name-absolute-p path)
-                  (not (equal "~" (car parts)))
-                  (<=  (length parts) num))
-         "/")
-       (string-join (last parts num) "/"))))
-  (defun my/-eshell-prompt-get-dir ()
-    "Get dir for `my/-eshell-prompt-function'"
-    (my/-eshell-prompt-cut-path 3
-                                (if-let ((worktree (vc-root-dir))
-                                         (parent (file-name-parent-directory worktree)))
-                                    (file-relative-name default-directory parent)
-                                  (my/-replace-home-with-tilda default-directory))))
-  (defun my/-eshell-prompt-status-char-for-branch (branch remote)
-    "Get the status char representing the relation between BRANCH and REMOTE."
-    (let ((lines (my/-git-process-lines
-                  "rev-list"
-                  "--left-right"
-                  (concat branch "..." remote)))
-          (to-remote nil)
-          (to-local nil))
-      (dolist (line lines)
-        (if-let (((not (string-empty-p line)))
-                 (dir-char (aref line 0)))
-            (if (= dir-char ?<)
-                (setq to-remote t)
-              (setq to-local t))))
-      (cond
-       ((and to-remote to-local) ?󰹺)
-       (to-remote ?󰜷)
-       (to-local ?󰜮))))
-    (defun my/-eshell-prompt-current-branch-status ()
-      "Get the status char for the current branch and its remote."
-      (let ((refs (my/-git-process-lines
-                   "for-each-ref"
-                   "--format=%(HEAD)%00%(refname:short)%00%(upstream:short)"
-                   "refs/heads")))
-        (catch 'break
-          (dolist (ref refs)
-            (if-let ((split-ref (split-string ref "\0" nil nil))
-                     ((equal (car split-ref) "*")))
-                (throw 'break (my/-eshell-prompt-status-char-for-branch
-                               (cadr split-ref)
-                               (caddr split-ref))))))))
-    (defun my/-eshell-prompt-git-state-chars ()
-      "Get chars, like + and ✘ for `my/-eshell-prompt-function'."
-      (let ((lines (my/-git-process-lines "status" "--porcelain=v1"))
-            (branch-status (my/-eshell-prompt-current-branch-status))
-            (status-arr))
-        (dolist (line lines)
-          (cl-loop with fields = (string-split line " " t " *")
-                   with status-str = (car-safe fields)
-                   for status-char across status-str
-                   do
-                   (cond ((or (= status-char ?M) (= status-char ?T))
-                          (add-to-list 'status-arr ?!))
-                         ((= status-char ??)
-                          (add-to-list 'status-arr ??))
-                         ((or (= status-char ?A) (= status-char ?C))
-                          (add-to-list 'status-arr ?+))
-                         ((= status-char ?D)
-                          (add-to-list 'status-arr ?))
-                         ((= status-char ?R)
-                          (add-to-list 'status-arr ?»))
-                         ((= status-char ?U)
-                          (add-to-list 'status-arr ?=)))))
-        (sort status-arr #'<)
-        (when branch-status
-          (push branch-status status-arr))
-        (apply 'string status-arr)))
-    (defun my/-eshell-prompt-git-get-operation ()
-      "Return the current git operation.  For example, a revert."
-      (let ((git-dir (expand-file-name ".git" (vc-git-root default-directory))))
-        (cond
-         ((file-exists-p (expand-file-name "REVERT_HEAD" git-dir))
-          "REVERTING")
-         ((file-exists-p (expand-file-name "rebase-merge" git-dir))
-          "REBASING")
-         ((file-exists-p (expand-file-name "MERGE_HEAD" git-dir))
-          "MERGING"))))
-    (defun my/-eshell-prompt-git-status ()
-      "Get git status for `my/-eshell-prompt-function'"
-      (let ((branch (car (vc-git-branches)))
-            (state (my/-eshell-prompt-git-state-chars))
-            (operation (my/-eshell-prompt-git-get-operation)))
-        (concat
-         (propertize (concat " 󰊢 " branch) 'face '(:foreground "medium purple"))
-         (unless (string-empty-p state)
-           (propertize (concat " [" state "]") 'face '(:foreground "red")))
-         (when operation
-           (concat " (" (propertize operation 'face
-                                    '(:inherit 'bold :foreground "yellow")) ")")))))
-    (defun my/-eshell-prompt-vc-status ()
-      "Get vc status for `my/-eshell-prompt-function'."
-      (if-let (backend (vc-responsible-backend default-directory t))
-          (if (eq backend 'Git)
-              (my/-eshell-prompt-git-status)
-            (my/-eshell-prompt-set-face-color
-             (concat "  " (downcase (symbol-name backend)))
-             "purple"))))
-    (defvar-local my/-eshell-prompt-last-start-time nil
-      "Start time of last eshell command.")
-    (defun my/-eshell-prompt-timer-pre-cmd ()
-      "Command run before each eshell program to record the time."
-      (setq my/-eshell-prompt-last-start-time (current-time)))
-    (add-hook 'eshell-pre-command-hook #'my/-eshell-prompt-timer-pre-cmd)
-    (defun my/-eshell-prompt-format-span (span)
-      "Format SPAN as \"XhXms.\""
-      (let* ((hours (/ span 3600))
-             (mins (% (/ span 60) 60))
-             (secs (% span 60)))
-        (concat (unless (= hours 0)
-                  (format "%dh" hours))
-                (unless (= mins 0)
-                  (format "%dm" mins))
-                (format "%ds" secs))))
-    (defun my/-eshell-prompt-last-command-time (end-time)
-      "Return the prompt component for the time of the last command."
-      (if-let ((my/-eshell-prompt-last-start-time)
-               (len (time-subtract end-time
-                                   my/-eshell-prompt-last-start-time))
-               (float-len (float-time len))
-               ((< 3 float-len))
-               (int-len (round float-len)))
-          (concat " time "
-                  (propertize (my/-eshell-prompt-format-span int-len)
-                              'face '(:foreground "gold1")))))
-    (defun my/-eshell-prompt-function ()
-      "Function for `eshell-prompt-function'"
-      (let* ((end-time (current-time))
-             (dir (my/-eshell-prompt-get-dir))
-             (prompt (concat
-                      "\n"
-                      (propertize dir 'face '(:foreground "dark turquoise"))
-                      (unless (file-writable-p dir)
-                        " ")
-                      (my/-eshell-prompt-vc-status)
-                      (my/-eshell-prompt-last-command-time end-time)
-                      (propertize "\n" 'read-only t 'rear-nonsticky t)
-                      (propertize
-                       "❯ " 'face `(:foreground
-                                    ,(if (= eshell-last-command-status 0)
-                                         "lime green"
-                                       "red"))
-                       'rear-nonsticky t))))
-        (setq my/-eshell-prompt-last-start-time nil)
-        prompt))
-    (setq eshell-prompt-function #'my/-eshell-prompt-function
-          eshell-prompt-regexp "^❯ "
-          eshell-highlight-prompt nil))
+      (eshell-print (string-join (bookmark-all-names) " ")))))
 (use-package esh-help
   :hook (eshell-mode . my/-setup-eshell-help-func)
   :init
@@ -1102,6 +934,10 @@ If no name is given, list all bookmarks instead."
 (use-package eshell-syntax-highlighting
   :init
   (eshell-syntax-highlighting-global-mode 1))
+(use-package eshell-starship
+  :ensure nil
+  :demand t
+  :hook (eshell-prompt-mode . eshell-starship-prompt-mode))
 
 ;; proced
 (use-package proced