From d0aadfe2997e1d561aacffb6a3d1f554af439811 Mon Sep 17 00:00:00 2001
From: Tim Vaughan <plugd@thelambdalab.xyz>
Date: Mon, 5 Jul 2021 22:58:28 +0200
Subject: [PATCH] Added history cycling.

---
 lurk.el | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/lurk.el b/lurk.el
index b22ca85..0c9c31b 100644
--- a/lurk.el
+++ b/lurk.el
@@ -738,15 +738,42 @@ portion of the source component of the message, as LURK doesn't use this.")
             (lurk-display-message lurk-nick lurk-current-context string))
         (lurk-display-error "No current context.")))))
 
+(defvar lurk-history nil
+  "Commands and messages sent in current session.")
+
+
 (defun lurk-enter ()
   "Enter current contents of line after prompt."
   (interactive)
   (with-current-buffer "*lurk*"
     (let ((line (buffer-substring lurk-input-marker (point-max))))
+      (push line lurk-history)
+      (setq lurk-history-index nil)
       (let ((inhibit-read-only t))
         (delete-region lurk-input-marker (point-max)))
       (lurk-enter-string line))))
 
+(defvar lurk-history-index nil)
+
+(defun lurk-history-cycle (delta)
+  (when lurk-history
+    (with-current-buffer "*lurk*"
+      (if lurk-history-index
+          (setq lurk-history-index
+                (max 0
+                     (min (- (length lurk-history) 1)
+                          (+ delta lurk-history-index))))
+        (setq lurk-history-index 0))
+      (delete-region lurk-input-marker (point-max))
+      (insert (elt lurk-history lurk-history-index)))))
+
+(defun lurk-history-next ()
+  (interactive)
+  (lurk-history-cycle -1))
+
+(defun lurk-history-prev ()
+  (interactive)
+  (lurk-history-cycle +1))
 
 ;;; Interactive functions
 ;;
@@ -779,6 +806,7 @@ portion of the source component of the message, as LURK doesn't use this.")
       (unless (string-prefix-p "/" (buffer-substring start end))
         (completion-in-region start end (lurk-get-context-users lurk-current-context))))))
 
+
 ;;; Mode
 ;;
 
@@ -789,8 +817,16 @@ portion of the source component of the message, as LURK doesn't use this.")
     (define-key map (kbd "C-c C-z") 'lurk-toggle-zoom)
     (define-key map (kbd "<C-tab>") 'lurk-cycle-contexts-forward)
     (define-key map (kbd "<C-S-tab>") 'lurk-cycle-contexts-reverse)
+    (define-key map (kbd "<C-up>") 'lurk-history-prev)
+    (define-key map (kbd "<C-down>") 'lurk-history-next)
+    ;; (when (fboundp 'evil-define-key*)
+    ;;   (evil-define-key* 'insert map
+    ;;                     (kbd "<C-Up>") 'lurk-history-prev
+    ;;                     (kbd "<C-Down>") 'lurk-history-next))
     map))
 
+(defvar lurk-mode-map)
+
 (define-derived-mode lurk-mode text-mode "lurk"
   "Major mode for LURK.")
 
-- 
2.20.1