feat: add Slack client module with dashboard integration

Add emacs-slack config with auth-source credentials, DM/mention-only
notifications via notify script, compose buffer workflow, and dashboard
icon. Keybindings under C-; S prefix.

2 files changed, 149 insertions, 0 deletions

diff --git a/modules/dashboard-config.el b/modules/dashboard-config.el
index 3dcc6b6b..833fb7b5 100644
--- a/modules/dashboard-config.el
+++ b/modules/dashboard-config.el
@@ -160,6 +160,11 @@ Adjust this if the title doesn't appear centered under the banner image.")
             (lambda (&rest _) (cj/erc-switch-to-buffer-with-completion))
             nil " " "")
 
+           (,(nerd-icons-faicon "nf-fa-slack")
+            "Slack" "Slack Client"
+            (lambda (&rest _) (cj/slack-start))
+            nil " " "")
+
            (,(nerd-icons-mdicon "nf-md-school")
             "Flashcards" "Org-Drill"
             (lambda (&rest _) (cj/drill-start))
@@ -193,6 +198,7 @@ Adjust this if the title doesn't appear centered under the banner image.")
   (define-key dashboard-mode-map (kbd "f") (lambda () (interactive) (cj/drill-start)))
   (define-key dashboard-mode-map (kbd "r") (lambda () (interactive) (cj/elfeed-open)))
   (define-key dashboard-mode-map (kbd "i") (lambda () (interactive) (cj/erc-switch-to-buffer-with-completion)))
+  (define-key dashboard-mode-map (kbd "s") (lambda () (interactive) (cj/slack-start)))
   (define-key dashboard-mode-map (kbd "t") (lambda () (interactive) (vterm)))
   (define-key dashboard-mode-map (kbd "d") (lambda () (interactive) (dirvish user-home-dir))))
 
diff --git a/modules/slack-config.el b/modules/slack-config.el
new file mode 100644
index 00000000..5ff33917
--- /dev/null
+++ b/modules/slack-config.el
@@ -0,0 +1,143 @@
+;;; slack-config.el --- Slack Configuration -*- lexical-binding: t; coding: utf-8; -*-
+;; author Craig Jennings <c@cjennings.net>
+
+;;; Commentary:
+
+;; Slack client using emacs-slack (https://github.com/emacs-slack/emacs-slack).
+;;
+;; Authentication:
+;;   Credentials are stored in authinfo.gpg (never plaintext).
+;;   Add an entry like:
+;;     machine deepsatworkspace.slack.com login TOKEN password xoxc-YOUR-TOKEN
+;;     machine deepsatworkspace.slack.com login COOKIE password xoxd-YOUR-COOKIE
+;;
+;;   To get these values, run M-x slack-refresh-token and follow the
+;;   instructions to extract them from your browser's developer tools.
+;;
+;; Keybindings (C-; S prefix):
+;;   C-; S s  — connect to Slack
+;;   C-; S c  — select unread rooms
+;;   C-; S C  — select any channel/room
+;;   C-; S d  — direct message a person
+;;   C-; S w  — compose message in separate buffer
+;;   C-; S r  — reply / show thread
+;;   C-; S e  — insert emoji
+;;   C-; S !  — add reaction to message
+;;   C-; S @  — embed @mention
+;;   C-; S #  — embed #channel
+;;   C-; S q  — mark channel read and bury buffer
+;;   C-; S S  — disconnect
+;;
+;; Compose buffer:
+;;   C-<return> — send message
+
+;;; Code:
+
+(require 'auth-source)
+
+(defvar cj/slack-workspace "deepsatworkspace.slack.com"
+  "Slack workspace domain for auth-source lookup.")
+
+(defun cj/slack--get-credential (login-key)
+  "Look up LOGIN-KEY credential for the Slack workspace from auth-source."
+  (let ((entry (car (auth-source-search :host cj/slack-workspace
+                                        :user login-key
+                                        :max 1))))
+    (when entry
+      (let ((secret (plist-get entry :secret)))
+        (if (functionp secret)
+            (funcall secret)
+          secret)))))
+
+(defun cj/slack-start ()
+  "Connect to Slack, registering the team if needed."
+  (interactive)
+  (require 'slack)
+  (let ((token (cj/slack--get-credential "TOKEN"))
+        (cookie (cj/slack--get-credential "COOKIE")))
+    (unless token
+      (user-error "No Slack token found in authinfo for %s (login: TOKEN)" cj/slack-workspace))
+    (unless cookie
+      (user-error "No Slack cookie found in authinfo for %s (login: COOKIE)" cj/slack-workspace))
+    (unless (and (boundp 'slack-teams) slack-teams)
+      (slack-register-team
+       :name "DeepSat"
+       :token token
+       :cookie cookie
+       :full-and-display-names t
+       :default t))
+    (slack-start)))
+
+(defun cj/slack-stop ()
+  "Disconnect from Slack."
+  (interactive)
+  (require 'slack)
+  (slack-ws-close)
+  (message "Slack disconnected."))
+
+(use-package slack
+  :defer t
+  :commands (slack-start slack-select-rooms slack-select-unread-rooms
+             slack-im-select slack-thread-show-or-create
+             slack-insert-emoji slack-register-team)
+  :custom
+  (slack-buffer-emojify t)
+  (slack-prefer-current-team t)
+  :config
+  (setq slack-message-custom-notifier #'cj/slack-notify))
+
+;; ----------------------------- Notifications ---------------------------------
+
+(defun cj/slack-notify (message room team)
+  "Send desktop notification for DMs and @mentions only.
+MESSAGE is the incoming slack message, ROOM is the channel/DM,
+TEAM is the slack team object."
+  (when (and (not (slack-message-minep message team))
+             (or (slack-room-im-p room)
+                 (slack-message-mentioned-p message)))
+    (let ((title (format "Slack: %s" (slack-room-display-name room team)))
+          (body (slack-message-to-string message team)))
+      (start-process "slack-notify" nil
+                     "notify" "info" title body))))
+
+;; ------------------------------ Keybindings ----------------------------------
+
+(defvar cj/slack-keymap (make-sparse-keymap)
+  "Keymap for Slack commands under C-; S.")
+
+(global-set-key (kbd "C-; S") cj/slack-keymap)
+
+(define-key cj/slack-keymap (kbd "s") #'cj/slack-start)
+(define-key cj/slack-keymap (kbd "c") #'slack-select-unread-rooms)
+(define-key cj/slack-keymap (kbd "C") #'slack-select-rooms)
+(define-key cj/slack-keymap (kbd "d") #'slack-im-select)
+(define-key cj/slack-keymap (kbd "w") #'slack-message-write-another-buffer)
+(define-key cj/slack-keymap (kbd "r") #'slack-thread-show-or-create)
+(define-key cj/slack-keymap (kbd "e") #'slack-insert-emoji)
+(define-key cj/slack-keymap (kbd "!") #'slack-message-add-reaction)
+(define-key cj/slack-keymap (kbd "@") #'slack-message-embed-mention)
+(define-key cj/slack-keymap (kbd "#") #'slack-message-embed-channel)
+(define-key cj/slack-keymap (kbd "q") #'slack-buffer-mark-as-read-and-bury)
+(define-key cj/slack-keymap (kbd "S") #'cj/slack-stop)
+
+(which-key-add-keymap-based-replacements cj/slack-keymap
+  "" "slack menu"
+  "s" "start slack"
+  "c" "unread rooms"
+  "C" "select channel"
+  "d" "direct message"
+  "w" "compose message"
+  "r" "reply / thread"
+  "e" "insert emoji"
+  "!" "add reaction"
+  "@" "embed @mention"
+  "#" "embed #channel"
+  "q" "mark read & bury"
+  "S" "disconnect")
+
+;; Send from compose buffer with C-<return>
+(with-eval-after-load 'slack-message-compose-buffer
+  (define-key slack-message-compose-buffer-mode-map (kbd "C-<return>") #'slack-message-send-from-buffer))
+
+(provide 'slack-config)
+;;; slack-config.el ends here.