X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;ds=sidebyside;f=lurk.el;h=edfb66fe7d6b79b90021d2d35b7a8c79ea85c7df;hb=HEAD;hp=8b307fe6464467844ff56de42a1ad86f6a80c234;hpb=f0cb00a4471cb0c83c6fdddf1b702365c2f33f82;p=lurk.git

diff --git a/lurk.el b/lurk.el
index 8b307fe..8114597 100644
--- a/lurk.el
+++ b/lurk.el
@@ -1,13 +1,13 @@
-;;; lurk.el --- Little Unified iRc Klient -*- lexical-binding:t -*-
+;;; lurk.el --- Little Unibuffer iRc Klient -*- lexical-binding:t -*-
 
-;; Copyright (C) 2021 Tim Vaughan
+;; Copyright (C) 2021--2024 plugd
 
-;; Author: Tim Vaughan <timv@ughan.xyz>
+;; Author: plugd <plugd@thelambdalab.xyz>
 ;; Created: 14 June 2021
-;; Version: 1.0
-;; Keywords: network
+;; Version: 2.0
 ;; Homepage: http://thelambdalab.xyz/lurk
-;; Package-Requires: ((emacs "26"))
+;; Keywords: comm
+;; Package-Requires: ((emacs "26.1"))
 
 ;; This file is not part of GNU Emacs.
 
@@ -26,104 +26,179 @@
 
 ;;; Commentary:
 
+;; A very simple IRC client which uses only a single buffer.
+
 ;;; Code:
 
 (provide 'lurk)
 
+(require 'cl-lib)
+
 
 ;;; Customizations
-;;
 
 (defgroup lurk nil
-  "Little Unified iRc Klient."
+  "Multinetwork Unibuffer iRc Klient"
   :group 'network)
 
-(defcustom lurk-nick "plugd"
-  "Default nick.")
+(defcustom lurk-default-nick "plugd"
+  "Default nick."
+  :type '(string))
 
 (defcustom lurk-default-quit-msg "Bye"
-  "Default quit message when none supplied.")
+  "Default quit message when none supplied."
+  :type '(string))
 
 (defcustom lurk-networks
   '(("libera" "irc.libera.chat" 6697)
-    ("freenode" "chat.freenode.net" 6697)
     ("tilde" "tilde.chat" 6697)
-    ("mbr" "mbrserver.com" 6667 :notls)
-    ("local" "localhost" 6697))
-  "IRC networks.")
-
-(defcustom lurk-allow-ipv6 nil
-  "Set to non-nil to allow use of IPv6.")
+    ("sdf" "irc.sdf.org" 6697))
+  "IRC networks."
+  :type '(alist :key-type string))
 
 (defcustom lurk-show-joins nil
   "Set to non-nil to be notified of joins, parts and quits.")
 
+(defcustom lurk-display-header t
+  "If non-nil, use buffer header to display current host and channel."
+  :type '(boolean))
+
+(defcustom lurk-autoreply-table nil
+  "Table of autoreply messages.
+
+Each autoreply is a list of two elements: (matcher reply)
+
+Here matcher is a list:
+
+(network src cmd params ...)
+
+and reply is another list:
+
+ (cmd params ...)
+
+Each entry in the matcher list is a regular expression tested against the
+corresponding values in the incomming message.  Entries can be nil,
+in which case they match anything."
+  :type '(list (list) (list)))
+
+
 ;;; Faces
 ;;
 
 (defface lurk-text
   '((t :inherit default))
-  "Face used for Lurk text.")
+  "Face used for lurk text.")
 
 (defface lurk-prompt
-  '((t :inherit org-priority))
+  '((t :inherit font-lock-keyword-face))
   "Face used for the prompt.")
 
 (defface lurk-context
-  '((t :inherit org-tag))
+  '((t :inherit lurk-context))
   "Face used for the context name in the prompt.")
 
 (defface lurk-faded
-  '((t :inherit org-agenda-dimmed-todo-face))
-  "Face used for faded Lurk text.")
+  '((t :inherit shadow))
+  "Face used for faded lurk text.")
+
+(defface lurk-timestamp
+  '((t :inherit shadow))
+  "Face used for timestamps.")
 
 (defface lurk-error
-  '((t :inherit font-lock-regexp-grouping-construct))
-  "Face used for Lurk error text.")
+  '((t :inherit error))
+  "Face used for lurk error text.")
+
+(defface lurk-notice
+  '((t :inherit warning))
+  "Face used for lurk notice text.")
+
 
 ;;; Global variables
 ;;
 
-(defvar lurk-version "Lurk v0.1")
+(defvar lurk-version "Lurk v0.0"
+  "Value of this string is used in response to CTCP version queries.")
 
 (defvar lurk-notice-prefix "-!-")
-
 (defvar lurk-error-prefix "!!!")
+(defvar lurk-prompt-string ">")
 
-(defvar lurk-prompt-string
-  (propertize "> " 'face 'lurk-prompt))
+(defvar lurk-debug nil
+  "If non-nil, enable debug mode.")
 
 
-;;; Network process
+;;; Utility procedures
 ;;
 
-(defvar lurk-response "")
+(defun lurk--filtered-join (&rest args)
+  (string-join (seq-filter (lambda (el) el) args) " "))
+
+(defun lurk--as-string (obj)
+  (if obj
+      (with-output-to-string (princ obj))
+    nil))
 
-(defun lurk-filter (proc string)
-  (dolist (line (split-string (concat lurk-response string) "\n"))
-    (if (string-suffix-p "\r" line)
-        (lurk-eval-msg-string (string-trim line))
-      (setq lurk-response line))))
 
-(defun lurk-sentinel (proc string)
-  (unless (equal "open" (string-trim string))
-    (lurk-display-error "Disconnected from server.")
-    (clrhash lurk-contexts)
-    (lurk-set-current-context nil)
-    (lurk-render-prompt)
-    (cancel-timer lurk-ping-timer)))
+;;; Network processes
+;;
+
+(defvar lurk-connection-table nil
+  "An alist associating networks to connection information.
+This includes the process and the response string.")
+
+(defun lurk-connection-process (network)
+  (elt (assoc network lurk-connection-table) 1))
+
+(defun lurk-connection-nick (network)
+  (elt (assoc network lurk-connection-table) 2))
+
+(defun lurk-set-connection-nick (network nick)
+  (setf (elt (assoc network lurk-connection-table) 2) nick))
+
+(defun lurk-connection-response (network)
+  (elt (assoc network lurk-connection-table) 3))
+
+(defun lurk-set-connection-response (network string)
+  (setf (elt (assoc network lurk-connection-table) 3) string))
+
+(defun lurk-connection-new (network process nick)
+  (add-to-list 'lurk-connection-table
+               (list network process nick "")))
+
+(defun lurk-connection-remove (network)
+  (setq lurk-connection-table
+        (seq-remove (lambda (row) (equal (car row) network))
+                    lurk-connection-table)))
+
+(defun lurk-make-network-filter (network)
+  (lambda (_proc string)
+    (dolist (line (split-string (concat (lurk-connection-response network) string)
+                                "\n"))
+      (if (string-suffix-p "\r" line)
+          (lurk-eval-msg-string network (string-trim line))
+        (lurk-set-connection-response network line)))))
+
+(defun lurk-make-network-sentinel (network)
+  (lambda (_proc string)
+    (unless (equal "open" (string-trim string))
+      (lurk-display-error "Disconnected from network.")
+      (lurk-connection-remove network)
+      (lurk-remove-network-contexts network)
+      (lurk-highlight-current-context)
+      (lurk-render-prompt))))
 
 (defun lurk-start-process (network)
   (let* ((row (assoc network lurk-networks))
          (host (elt row 1))
          (port (elt row 2))
          (flags (seq-drop row 3)))
-    (make-network-process :name "lurk"
+    (make-network-process :name (concat "lurk-" network)
                           :host host
                           :service port
-                          :family (if lurk-allow-ipv6 nil 'ipv4)
-                          :filter #'lurk-filter
-                          :sentinel #'lurk-sentinel
+                          :family nil
+                          :filter (lurk-make-network-filter network)
+                          :sentinel (lurk-make-network-sentinel network)
                           :nowait nil
                           :tls-parameters (if (memq :notls flags)
                                               nil
@@ -133,45 +208,35 @@
                                                    :hostname host)))
                           :buffer "*lurk*")))
 
-(defvar lurk-ping-timer nil)
 (defvar lurk-ping-period 60)
 
-(defun lurk-ping-function ()
-  (lurk-send-msg (lurk-msg nil nil "PING" (car (process-contact (get-process "lurk")))))
-  (setq lurk-ping-timer (run-with-timer lurk-ping-period nil #'lurk-ping-function)))
+;; IDEA: Have a single ping timer which pings all connected hosts
 
 (defun lurk-connect (network)
-  (if (get-process "lurk")
-      (lurk-display-error "Already connected.  Disconnect first.")
+  (if (assoc network lurk-connection-table)
+      (lurk-display-error "Already connected to this network")
     (if (not (assoc network lurk-networks))
         (lurk-display-error "Network '" network "' is unknown.")
-      (clrhash lurk-contexts)
-      (lurk-set-current-context nil)
-      (lurk-start-process network)
-      (lurk-send-msg (lurk-msg nil nil "USER" lurk-nick 0 "*" lurk-nick))
-      (lurk-send-msg (lurk-msg nil nil "NICK" lurk-nick))
-      (setq lurk-ping-timer (run-with-timer lurk-ping-period nil #'lurk-ping-function)))))
-
-(defun lurk-connected-p ()
-  (let ((proc (get-process "lurk")))
-    (and proc (eq (process-status proc) 'open))))
-
-(defun lurk-send-msg (msg)
-  (let ((proc (get-process "lurk")))
+      (let ((proc (lurk-start-process network)))
+        (lurk-connection-new network proc lurk-default-nick))
+      (lurk-send-msg network (lurk-msg nil nil "USER" lurk-default-nick 0 "*" lurk-default-nick))
+      (lurk-send-msg network (lurk-msg nil nil "NICK" lurk-default-nick))
+      (lurk-add-context (list network))
+      (lurk-highlight-current-context)
+      (lurk-render-prompt))))
+
+(defun lurk-send-msg (network msg)
+  (if lurk-debug
+      (lurk-display-string nil nil (lurk-msg->string msg)))
+  (let ((proc (lurk-connection-process network)))
     (if (and proc (eq (process-status proc) 'open))
         (process-send-string proc (concat (lurk-msg->string msg) "\r\n"))
-      (lurk-display-error "No server connection established.")
-      (error "No server connection established"))))
+      (lurk-display-error "No network connection established"))))
 
 
-;;; Server messages
+;;; network messages
 ;;
 
-(defun lurk--as-string (obj)
-  (if obj
-      (with-output-to-string (princ obj))
-    nil))
-
 (defun lurk-msg (tags src cmd &rest params)
   (list (lurk--as-string tags)
         (lurk--as-string src)
@@ -202,7 +267,7 @@
    (opt (group (+ not-newline))))
   "Regex used to parse IRC messages.
 Note that this regex is incomplete.  Noteably, we discard the non-nick
-portion of the source component of the message, as LURK doesn't use this.")
+portion of the source component of the message, as lurk doesn't use this.")
 
 (defun lurk-string->msg (string)
   (if (string-match lurk-msg-regex string)
@@ -212,16 +277,13 @@ portion of the source component of the message, as LURK doesn't use this.")
              (params-str (match-string 4 string))
              (params
               (if params-str
-                  (let* ((idx (cl-search ":" params-str))
+                  (let* ((idx (seq-position params-str ?:))
                          (l (split-string (string-trim (substring params-str 0 idx))))
                          (r (if idx (list (substring params-str (+ 1 idx))) nil)))
                     (append l r))
                 nil)))
         (apply #'lurk-msg (append (list tags src cmd) params)))
-    (error "Failed to parse string " string)))
-
-(defun lurk--filtered-join (&rest args)
-  (string-join (seq-filter (lambda (el) el) args) " "))
+    (error "Failed to parse string %s" string)))
 
 (defun lurk-msg->string (msg)
   (let ((tags (lurk-msg-tags msg))
@@ -243,77 +305,152 @@ portion of the source component of the message, as LURK doesn't use this.")
 ;;; Contexts
 ;;
 
-(defvar lurk-current-context nil)
-(defvar lurk-contexts (make-hash-table :test #'equal))
-
-(defun lurk-add-context (name)
-  (puthash name nil lurk-contexts))
-
-(defun lurk-del-context (name)
-  (remhash name lurk-contexts))
-
-(defun lurk-get-context-users (name)
-  (gethash name lurk-contexts))
-
-(defun lurk-add-context-users (context users)
-  (puthash context
-           (append users
-                   (gethash context lurk-contexts))
-           lurk-contexts))
-
-(defun lurk-del-context-user (context user)
-  (puthash context
-           (remove user (gethash context lurk-contexts))
-           lurk-contexts))
-
-(defun lurk-del-user (user)
-  (dolist (context (lurk-get-context-list))
-    (lurk-del-context-user context user)))
-
-(defun lurk-rename-user (old-nick new-nick)
-  (dolist (context (lurk-get-context-list))
-    (lurk-del-context-user context old-nick)
-    (lurk-add-context-users context (list new-nick))))
-
-(defun lurk-get-context-type (name)
-  (cond
-   ((string-prefix-p "#" name) 'channel)
-   ((string-match-p (rx (or "." "localhost")) name) 'host)
-   (t 'nick)))
-
-(defun lurk-get-context-list ()
-  (let ((res nil))
-    (maphash (lambda (key val)
-               (cl-pushnew key res))
-             lurk-contexts)
-    res))
-
-(defun lurk-get-next-context (&optional prev)
-  (if lurk-current-context
-      (let* ((context-list (if prev
-                               (reverse (lurk-get-context-list))
-                             (lurk-get-context-list)))
-             (context-list* (member lurk-current-context context-list)))
-        (if (> (length context-list*) 1)
-            (cadr context-list*)
-          (car context-list)))
+;; A context is a list (network channel) identifying the network
+;; and channel.  The tail of the list contains the nicks of users
+;; present in the channel.
+;;
+;; Each network has a special context (network) used for messages
+;; to/from the network itself.
+
+(defvar lurk-contexts nil
+  "List of currently-available contexts.
+The head of this list is always the current context.")
+
+(defun lurk-current-context ()
+  "Return the current context."
+  (if lurk-contexts
+      (car lurk-contexts)
     nil))
 
-(defun lurk-set-current-context (context)
-  (setq lurk-current-context context)
-  (lurk-highlight-context context))
+(defun lurk-contexts-equal (c1 c2)
+  (if (lurk-network-context-p c1)
+      (and (lurk-network-context-p c2)
+           (equal (lurk-context-network c1)
+                  (lurk-context-network c2)))
+    (and (not (lurk-network-context-p c2))
+         (equal (seq-take c1 2)
+                (seq-take c2 2)))))
+
+(defun lurk-context-network (ctx)
+  (elt ctx 0))
+
+(defun lurk-context-channel (ctx)
+  (elt ctx 1))
+
+(defun lurk-network-context-p (ctx)
+  (not (cdr ctx)))
+
+(defun lurk-add-context (ctx)
+  (add-to-list 'lurk-contexts ctx))
+
+(defun lurk-remove-context (ctx)
+  (setq lurk-contexts
+        (seq-remove
+         (lambda (this-ctx)
+           (lurk-contexts-equal this-ctx ctx))
+         lurk-contexts)))
+
+(defun lurk-remove-network-contexts (network)
+  (setq lurk-contexts
+        (seq-remove (lambda (row) (equal (car row) network))
+                    lurk-contexts)))
+
+(defun lurk-context->string (ctx)
+  (concat
+   (if (lurk-network-context-p ctx)
+       ""
+     (concat (lurk-context-channel ctx) "@"))
+   (lurk-context-network ctx)))
+
+(defun lurk-string->context (string)
+  (if (not (string-prefix-p "#" string))
+      (lurk-get-context string)
+    (let* ((parts (string-split string "@"))
+           (channel (elt parts 0))
+           (network (elt parts 1)))
+      (lurk-get-context network channel))))
+
+(defun lurk-get-context (network &optional channel)
+  (if (and channel (string-prefix-p "#" channel))
+      (let ((test-ctx (list network channel)))
+        (seq-find (lambda (ctx)
+                    (equal (seq-take ctx 2) test-ctx))
+                  lurk-contexts))
+    (car (member (list network) lurk-contexts))))
+
+(defun lurk-cycle-contexts (&optional reverse)
+  (setq lurk-contexts
+        (if reverse
+            (let ((nminus1 (- (length lurk-contexts) 1)))
+              (cons
+               (elt lurk-contexts nminus1)
+               (seq-take lurk-contexts nminus1)))
+          (append (cdr lurk-contexts) (list (car lurk-contexts))))))
+
+(defun lurk-switch-to-context (ctx)
+  (setq lurk-contexts
+        (let* ((new-head (memq ctx lurk-contexts))
+               (new-tail (take (- (length lurk-contexts)
+                                  (length new-head))
+                               lurk-contexts)))
+          (append new-head new-tail))))
+
+
+;;; Context users
+;;
 
-(defun lurk-cycle-contexts (&optional rev)
-  (if lurk-current-context
-      (progn
-        (lurk-set-current-context (lurk-get-next-context rev))
-        (lurk-render-prompt))
-    (lurk-display-error "No channels joined.")))
+(defvar lurk-context-users nil
+  "Association list between channel contexts and users.")
+
+(defun lurk-get-context-users (ctx)
+  (cdr (assoc ctx lurk-context-users)))
+
+(defun lurk-set-context-users (ctx users)
+  (setq lurk-context-users
+        (cons (cons ctx users) (assoc-delete-all ctx lurk-context-users))))
+
+(defun lurk-add-context-users (ctx users)
+  (lurk-set-context-users
+   ctx
+   (cl-union users (lurk-get-context-users ctx))))
+
+(defun lurk-del-context-user (ctx user)
+  (lurk-set-context-users
+   ctx
+   (delete user (lurk-get-context-users ctx))))
+
+(defun lurk-del-all-context-users (ctx)
+  (lurk-set-context-users ctx nil))
+
+(defun lurk-del-network-user (network user)
+  (dolist (ctx lurk-contexts)
+    (if (and (equal (lurk-context-network ctx) network)
+             (not (lurk-network-context-p ctx)))
+        (lurk-del-context-user ctx user))))
+
+(defun lurk-del-all-network-users (network)
+  (dolist (ctx lurk-contexts)
+    (if (and (equal (lurk-context-network ctx) network)
+             (not (lurk-network-context-p ctx)))
+        (lurk-del-all-context-users ctx))))
+
+(defun lurk-rename-network-user (network old-nick new-nick)
+  (dolist (ctx lurk-contexts)
+    (when (and (equal (lurk-context-network ctx) network)
+               (member old-nick (lurk-get-context-users ctx)))
+      (lurk-del-context-user ctx old-nick)
+      (lurk-add-context-users ctx (list new-nick)))))
 
 
 ;;; Buffer
 ;;
 
+(defvar lurk-prompt-marker nil
+  "Marker for prompt position in lurk buffer.")
+
+(defvar lurk-input-marker nil
+  "Marker for prompt position in lurk buffer.")
+
 (defun lurk-render-prompt ()
   (with-current-buffer "*lurk*"
     (let ((update-point (= lurk-input-marker (point)))
@@ -328,13 +465,16 @@ portion of the source component of the message, as LURK doesn't use this.")
           (delete-region lurk-prompt-marker lurk-input-marker)
           (goto-char lurk-prompt-marker)
           (insert
-           (propertize (if lurk-current-context
-                           lurk-current-context
-                         "")
+           (propertize (let ((ctx (lurk-current-context)))
+                         (if ctx
+                             (lurk-context->string ctx)
+                           ""))
                        'face 'lurk-context
                        'read-only t)
            (propertize lurk-prompt-string
                        'face 'lurk-prompt
+                       'read-only t)
+           (propertize " " ; Need this to be separate to mark it as rear-nonsticky
                        'read-only t
                        'rear-nonsticky t)))
         (set-marker-insertion-type lurk-input-marker nil))
@@ -344,15 +484,30 @@ portion of the source component of the message, as LURK doesn't use this.")
         (if (car v)
             (set-window-point (cadr v) lurk-input-marker))))))
   
-(defvar lurk-prompt-marker nil
-  "Marker for prompt position in LURK buffer.")
-
-(defvar lurk-input-marker nil
-  "Marker for prompt position in LURK buffer.")
+(defun lurk-setup-header ()
+  (with-current-buffer "*lurk*"
+    (setq-local header-line-format
+                '((:eval
+                   (let* ((ctx (lurk-current-context)))
+                     (if ctx
+                         (let ((network (lurk-context-network ctx)))
+                           (concat
+                            "Network: " network ", "
+                            (if (lurk-network-context-p ctx)
+                                "network"
+                              (concat
+                               "Channel: "
+                               (lurk-context-channel ctx)
+                               " ("
+                               (number-to-string
+                                (length (lurk-get-context-users ctx)))
+                               ")"))))
+                       "No connection")))))))
 
 (defun lurk-setup-buffer ()
   (with-current-buffer (get-buffer-create "*lurk*")
     (setq-local scroll-conservatively 1)
+    (setq-local buffer-invisibility-spec nil)
     (if (markerp lurk-prompt-marker)
         (set-marker lurk-prompt-marker (point-max))
       (setq lurk-prompt-marker (point-max-marker)))
@@ -360,94 +515,151 @@ portion of the source component of the message, as LURK doesn't use this.")
         (set-marker lurk-input-marker (point-max))
       (setq lurk-input-marker (point-max-marker)))
     (goto-char (point-max))
-    (lurk-render-prompt)))
+    (lurk-highlight-current-context)
+    (lurk-render-prompt)
+    (if lurk-display-header
+        (lurk-setup-header))))
+
+(defun lurk-clear-buffer ()
+  "Completely erase all non-prompt and non-input text from lurk buffer."
+  (with-current-buffer "*lurk*"
+    (let ((inhibit-read-only t))
+      (delete-region (point-min) lurk-prompt-marker))))
 
 
 ;;; Output formatting and highlighting
 ;;
 
-;; Partially-implemented idea: the face text property can be
-;; a list of faces, applied in order.  By assigning each context
-;; a unique list and keeping track of these in a hash table, we can
-;; easily switch the face corresponding to a particular context
-;; by modifying the elements of this list.
+;; Idea: the face text property can be a list of faces, applied in
+;; order.  By assigning each context a unique list and keeping track
+;; of these in a hash table, we can easily switch the face
+;; corresponding to a particular context by modifying the elements of
+;; this list.
 ;;
 ;; More subtly, we make only the cdrs of this list shared among
 ;; all text of a given context, allowing the cars to be different
 ;; and for different elements of the context-specific text to have
 ;; different styling.
 
-;; Additionally, we can allow selective hiding of contexts via
+;; Additionally, we allow selective hiding of contexts via
 ;; the buffer-invisibility-spec.
 
 (defvar lurk-context-facelists (make-hash-table :test 'equal)
   "List of seen contexts and associated face lists.")
 
 (defun lurk-get-context-facelist (context)
-  (let ((facelist (gethash context lurk-context-facelists)))
+  (let* ((facelist (gethash context lurk-context-facelists)))
     (unless facelist
       (setq facelist (list 'lurk-text))
       (puthash context facelist lurk-context-facelists))
     facelist))
 
-(defun lurk-display-string (context &rest strings)
-  (with-current-buffer (get-buffer-create "*lurk*")
+(defun lurk--fill-strings (col indent &rest strings)
+  (with-temp-buffer
+    (setq buffer-invisibility-spec nil)
+    (let ((fill-column col)
+          (adaptive-fill-regexp (rx-to-string `(= ,indent anychar))))
+      (apply #'insert strings)
+      (fill-region (point-min) (point-max) nil t)
+      (buffer-string))))
+
+(defun lurk-display-string (context prefix &rest strings)
+  (with-current-buffer "*lurk*"
     (save-excursion
       (goto-char lurk-prompt-marker)
-      (let ((inhibit-read-only t)
-            (old-pos (marker-position lurk-prompt-marker))
-            (adaptive-fill-regexp (rx (= 6 anychar)))
-            (fill-column 80)
-            (context-atom (if context (intern context) nil)))
+      (let* ((inhibit-read-only t)
+             (old-pos (marker-position lurk-prompt-marker))
+             (padded-timestamp (concat (format-time-string "%H:%M ")))
+             (padded-prefix (if prefix (concat prefix " ") ""))
+             (context-atom (if context
+                               (intern (lurk-context->string context))
+                             nil))
+             (context-face (lurk-get-context-facelist context)))
         (insert-before-markers
-         (propertize (concat (format-time-string "%H:%M") " ")
-                     'face (lurk-get-context-facelist context)
-                     'read-only t
-                     'context context
-                     'invisible context-atom
-                     'help-echo (concat "Context: " (or context "none")))
-         (propertize (concat (apply #'concat strings) "\n")
-                     'face (lurk-get-context-facelist context)
-                     'read-only t
-                     'context context
-                     'invisible context-atom
-                     'help-echo (concat "Context: " (or context "none"))))
-        (fill-region old-pos lurk-prompt-marker nil t)))))
-
-(defun lurk-display-message (from to text)
-  (let ((context (if (eq 'channel (lurk-get-context-type to))
-                     to
-                   (if (equal to lurk-nick) from to))))
-    (if (string-match (rx (: "\01ACTION " (group (* (not "\01"))) "\01")) text)
-        (lurk-display-string context to " * " from " " (match-string 1 text))
-      (lurk-display-string
-       context
-       (pcase (lurk-get-context-type to)
-         ('channel (concat to " <" from "> "))
-         ('nick (concat "[" from " -> " to "] "))
-         (_
-          (error "Unsupported context type")))
-       text))))
+         (lurk--fill-strings
+          80
+          (+ (length padded-timestamp)
+             (length padded-prefix))
+          (propertize padded-timestamp
+                      'face 'lurk-timestamp
+                      'read-only t
+                      'context context
+                      'invisible context-atom)
+          (propertize padded-prefix
+                      'read-only t
+                      'context context
+                      'invisible context-atom)
+          (lurk-add-formatting
+           (propertize (concat (apply #'lurk-buttonify-urls strings) "\n")
+                       'face context-face
+                       'read-only t
+                       'context context
+                       'invisible context-atom)))))))
+  (lurk-scroll-windows-to-last-line))
+
+(defun lurk-click-context (button)
+  (lurk-switch-to-context (button-get button 'context))
+  (lurk-highlight-current-context)
+  (lurk-render-prompt)
+  (if lurk-zoomed
+      (lurk-zoom-in (lurk-current-context))))
+
+(defun lurk-make-context-button (context &optional string)
+  (with-temp-buffer
+    (let ((label (or string (lurk-context->string context))))
+      (insert-text-button label
+                          'action #'lurk-click-context
+                          'context context
+                          'follow-link t
+                          'help-echo "Switch context"))
+    (buffer-string)))
+
+(defun lurk-display-message (network from to text)
+  (let ((context (if (string-prefix-p "#" to)
+                     (lurk-get-context network to)
+                   (lurk-get-context network))))
+    (lurk-display-string
+     context
+     (propertize
+      (if (lurk-network-context-p context)
+          (concat "[" from "->" to "]")
+        (concat
+         (lurk-make-context-button context)
+         " <" from ">"))
+      'face (lurk-get-context-facelist context))
+     text)))
+
+(defun lurk-display-action (network from to action-text)
+  (let ((context (if (string-prefix-p "#" to)
+                     (lurk-get-context network to)
+                   (lurk-get-context network))))
+    (lurk-display-string
+     context
+     (propertize
+      (concat (lurk-context->string context) " *")
+      'face (lurk-get-context-facelist context))
+     from " " action-text)))
 
 (defun lurk-display-notice (context &rest notices)
   (lurk-display-string
    context
-   lurk-notice-prefix " "
+   (propertize lurk-notice-prefix 'face 'lurk-notice)
    (apply #'concat notices)))
 
 (defun lurk-display-error (&rest messages)
   (lurk-display-string
    nil
-   lurk-error-prefix " "
+   (propertize lurk-error-prefix 'face 'lurk-error)
    (apply #'concat messages)))
 
-(defun lurk-highlight-context (context)
-  (maphash
-   (lambda (this-context facelist)
-     (if (equal this-context context)
-         (setcar facelist 'lurk-text)
-       (setcar facelist 'lurk-faded)))
-   lurk-context-facelists)
+(defun lurk-highlight-current-context ()
+  (with-current-buffer "*lurk*"
+    (maphash
+     (lambda (this-context facelist)
+       (if (equal this-context (lurk-current-context))
+           (setcar facelist 'lurk-text)
+         (setcar facelist 'lurk-faded)))
+     lurk-context-facelists))
   (force-window-update "*lurk*"))
 
 (defun lurk-zoom-in (context)
@@ -455,122 +667,250 @@ portion of the source component of the message, as LURK doesn't use this.")
     (maphash
      (lambda (this-context _)
        (when this-context
-         (let ((this-context-atom (intern this-context)))
+         (let ((this-context-atom
+                (intern (lurk-context->string this-context))))
            (if (equal this-context context)
                (remove-from-invisibility-spec this-context-atom)
              (add-to-invisibility-spec this-context-atom)))))
      lurk-context-facelists)
-    (force-window-update "*lurk*")))
+    (force-window-update "*lurk*"))
+  (lurk-scroll-windows-to-last-line))
 
 (defun lurk-zoom-out ()
   (with-current-buffer "*lurk*"
     (maphash
      (lambda (this-context _)
-       (let ((this-context-atom (if this-context (intern this-context) nil)))
+       (let ((this-context-atom
+              (if this-context
+                  (intern (lurk-context->string this-context))
+                nil)))
          (remove-from-invisibility-spec this-context-atom)))
      lurk-context-facelists)
-    (force-window-update "*lurk*")))
+    (force-window-update "*lurk*"))
+  (lurk-scroll-windows-to-last-line))
+
+(defun lurk--start-of-final-line ()
+  (with-current-buffer "*lurk*"
+    (save-excursion
+      (goto-char (point-max))
+      (line-beginning-position))))
+
+(defun lurk-scroll-windows-to-last-line ()
+  (with-current-buffer "*lurk*"
+    (dolist (window (get-buffer-window-list))
+      (if (>= (window-point window) (lurk--start-of-final-line))
+          (with-selected-window window
+            (recenter -1))))))
+
+(defconst lurk-url-regex
+  (rx (:
+       (group (+ alpha))
+       "://"
+       (group (or (+ (any alnum "." "-"))
+                  (+ (any alnum ":"))))
+       (opt (group (: ":" (+ digit))))
+       (opt (group (: "/"
+                      (opt
+                       (* (any alnum "-/.,#:%=&_?~@+"))
+                       (any alnum "-/#:%=&_~@+")))))))
+  "Imperfect regex used to find URLs in plain text.")
+
+(defun lurk-click-url (button)
+  (browse-url (button-get button 'url)))
+
+(defun lurk-buttonify-urls (&rest strings)
+  "Turn substrings which look like urls in STRING into clickable buttons."
+  (with-temp-buffer
+    (apply #'insert strings)
+    (goto-char (point-min))
+    (while (re-search-forward lurk-url-regex nil t)
+      (let ((url (match-string 0)))
+        (make-text-button (match-beginning 0)
+                          (match-end 0)
+                          'action #'lurk-click-url
+                          'url url
+                          'follow-link t
+                          'face 'button
+                          'help-echo "Open URL in browser.")))
+    (buffer-string)))
+
+(defun lurk-add-formatting (string)
+  (with-temp-buffer
+    (insert string)
+    (goto-char (point-min))
+    (let ((bold nil)
+          (italics nil)
+          (underline nil)
+          (strikethrough nil)
+          (prev-point (point)))
+      (while (re-search-forward (rx (or (any "\x02\x1D\x1F\x1E\x0F")
+                                        (: "\x03" (* digit) (opt "," (* digit)))))
+                                nil t)
+        (let ((beg (+ (match-beginning 0) 1)))
+          (if bold
+              (add-face-text-property prev-point beg '(:weight bold)))
+          (if italics
+              (add-face-text-property prev-point beg '(:slant italic)))
+          (if underline
+              (add-face-text-property prev-point beg '(:underline t)))
+          (if strikethrough
+              (add-face-text-property prev-point beg '(:strike-through t)))
+          (pcase (match-string 0)
+            ("\x02" (setq bold (not bold)))
+            ("\x1D" (setq italics (not italics)))
+            ("\x1F" (setq underline (not underline)))
+            ("\x1E" (setq strikethrough (not strikethrough)))
+            ("\x0F" ; Reset
+             (setq bold nil)
+             (setq italics nil)
+             (setq underline nil)
+             (setq strikethrough nil))
+            (_))
+          (delete-region (match-beginning 0) (match-end 0))
+          (setq prev-point (point)))))
+    (buffer-string)))
+
 
 ;;; Message evaluation
 ;;
 
-(defun lurk-eval-msg-string (string)
-  ;; (lurk-display-string nil string)
+(defun lurk-eval-msg-string (network string)
+  (if lurk-debug
+      (lurk-display-string nil nil string))
   (let* ((msg (lurk-string->msg string)))
+    (lurk-process-autoreplies network msg)
     (pcase (lurk-msg-cmd msg)
       ("PING"
-       (lurk-send-msg
+       (lurk-send-msg network
         (lurk-msg nil nil "PONG" (lurk-msg-params msg))))
-       ;; (lurk-display-notice nil "ping-pong (server initiated)"))
 
       ("PONG")
-       ;; (lurk-display-notice nil "ping-pong (client initiated)"))
 
-      ("001"
+      ("001" ; RPL_WELCOME
        (let* ((params (lurk-msg-params msg))
               (nick (elt params 0))
               (text (string-join (seq-drop params 1) " ")))
-         (setq lurk-nick nick)
-         (lurk-display-notice nil text)))
+         (lurk-set-connection-nick network nick)
+         (lurk-display-notice (lurk-get-context network) text))
+       (let* ((row (assoc network lurk-networks))
+              (channels (if (memq :channels row)
+                            (cdr (memq :channels row))
+                          nil)))
+         (dolist (channel channels)
+           (lurk-command-join (list channel)))))
 
       ("353" ; NAMEREPLY
        (let* ((params (lurk-msg-params msg))
               (channel (elt params 2))
-              (names (split-string (elt params 3))))
-         (lurk-add-context-users channel names)))
+              (names (split-string (elt params 3)))
+              (ctx (lurk-get-context network channel)))
+         (if ctx
+             (lurk-add-context-users ctx names)
+           (lurk-display-notice ctx "Users in " channel
+                                ": " (string-join names " ")))))
 
       ("366" ; ENDOFNAMES
        (let* ((params (lurk-msg-params msg))
-              (channel (elt params 1)))
-         (lurk-display-notice
-          channel
-          (lurk--as-string (length (lurk-get-context-users channel)))
-          " users in " channel)))
-
-      ("331"
+              (channel (elt params 1))
+              (ctx (lurk-get-context network channel)))
+         (if ctx
+             (lurk-display-notice
+              ctx
+              (lurk--as-string (length (lurk-get-context-users ctx)))
+              " users in " channel)
+           (lurk-display-notice (lurk-get-context network)
+                                "End of " channel " names list."))))
+
+      ("331" ; RPL_NOTOPIC
        (let* ((params (lurk-msg-params msg))
-              (channel (elt params 1)))
-         (lurk-display-notice
-          channel
-          "No topic set.")))
+              (channel (elt params 1))
+              (ctx (lurk-get-context network channel)))
+         (lurk-display-notice ctx "No topic set.")))
 
-      ("332"
+      ("332" ; RPL_TOPIC
        (let* ((params (lurk-msg-params msg))
               (channel (elt params 1))
-              (topic (elt params 2)))
-         (lurk-display-notice channel "Topic: " topic)))
+              (topic (elt params 2))
+              (ctx (lurk-get-context network channel)))
+         (lurk-display-notice ctx "Topic: " topic)))
 
       ((rx (= 3 (any digit)))
-       (lurk-display-notice nil (mapconcat 'identity (cdr (lurk-msg-params msg)) " ")))
+       (lurk-display-notice (lurk-get-context network)
+                            (mapconcat 'identity (cdr (lurk-msg-params msg)) " ")))
 
       ((and "JOIN"
-            (guard (equal lurk-nick (lurk-msg-src msg))))
-       (let ((channel (car (lurk-msg-params msg))))
-         (lurk-add-context channel)
-         (lurk-set-current-context channel)
-         (lurk-display-notice channel "Joining channel " channel)
+            (guard (equal (lurk-connection-nick network)
+                          (lurk-msg-src msg))))
+       (let* ((channel (car (lurk-msg-params msg)))
+              (context (list network channel)))
+         (lurk-add-context context)
+         (lurk-del-all-context-users context)
+         (lurk-display-notice (lurk-current-context)
+                              "Joining channel " channel " on " network)
+         (lurk-highlight-current-context)
          (lurk-render-prompt)))
 
       ("JOIN"
-       (let ((channel (car (lurk-msg-params msg)))
-             (nick (lurk-msg-src msg)))
-         (lurk-add-context-users channel (list nick))
+       (let* ((channel (car (lurk-msg-params msg)))
+              (nick (lurk-msg-src msg))
+              (ctx (lurk-get-context network channel)))
+         (lurk-add-context-users ctx (list nick))
          (if lurk-show-joins
-             (lurk-display-notice channel nick " joined channel " channel))))
+             (lurk-display-notice ctx nick " joined channel " channel
+                                  " on " network))))
 
       ((and "PART"
-            (guard (equal lurk-nick (lurk-msg-src msg))))
-       (let ((channel (car (lurk-msg-params msg))))
-         (lurk-display-notice channel "Left channel " channel)
-         (lurk-del-context channel)
-         (if (equal channel lurk-current-context)
-             (lurk-set-current-context (lurk-get-next-context)))
+            (guard (equal (lurk-connection-nick network)
+                          (lurk-msg-src msg))))
+       (let* ((channel (car (lurk-msg-params msg)))
+              (context (list network channel)))
+         (lurk-display-notice context "Left channel " channel)
+         (lurk-remove-context context)
+         (lurk-del-all-context-users context)
+         (lurk-highlight-current-context)
          (lurk-render-prompt)))
 
       ("PART"
-       (let ((channel (car (lurk-msg-params msg)))
-             (nick (lurk-msg-src msg)))
-         (lurk-del-context-user channel nick)
-         (if lurk-show-joins
-             (lurk-display-notice channel nick " left channel " channel))))
-
-      ("QUIT"
-       (let ((nick (lurk-msg-src msg))
-             (reason (mapconcat 'identity (lurk-msg-params msg) " ")))
-         (lurk-del-user nick)
+       (let* ((channel (car (lurk-msg-params msg)))
+              (nick (lurk-msg-src msg))
+              (ctx (lurk-get-context network channel)))
+         (lurk-del-context-user ctx nick)
          (if lurk-show-joins
-             (lurk-display-notice nil nick " quit: " reason))))
+             (lurk-display-notice ctx nick " left channel " channel
+                                  " on " network))))
 
       ((and "NICK"
-            (guard (equal lurk-nick (lurk-msg-src msg))))
-       (setq lurk-nick (car (lurk-msg-params msg)))
-       (lurk-display-notice nil "Set nick to " lurk-nick))
+            (guard (equal (lurk-connection-nick network)
+                          (lurk-msg-src msg))))
+       (let ((new-nick (car (lurk-msg-params msg)))
+             (old-nick (lurk-connection-nick network)))
+         (lurk-set-connection-nick network new-nick)
+         (lurk-rename-network-user network old-nick new-nick)
+         (lurk-display-notice (lurk-get-context network)
+                              "Nick set to " new-nick " on " network)))
 
       ("NICK"
        (let ((old-nick (lurk-msg-src msg))
              (new-nick (car (lurk-msg-params msg))))
-         (lurk-display-notice nil old-nick " is now known as " new-nick)
-         (lurk-rename-user old-nick new-nick)))
+         (lurk-display-notice (lurk-get-context network)
+                              old-nick " is now known as " new-nick
+                              " on " network)
+         (lurk-rename-network-user network old-nick new-nick)))
+
+      ("TOPIC"
+       (let ((channel (car (lurk-msg-params msg)))
+             (nick (lurk-msg-src msg))
+             (topic (cadr (lurk-msg-params msg))))
+         (lurk-display-notice (lurk-get-context network channel)
+                              nick " set the topic: " topic)))
+
+      ("QUIT"
+       (let ((nick (lurk-msg-src msg))
+             (reason (mapconcat 'identity (lurk-msg-params msg) " ")))
+         (lurk-del-network-user network nick)
+         (if lurk-show-joins
+             (lurk-display-notice (lurk-get-context network)
+                                  nick " on " network " has quit: " reason))))
 
       ("NOTICE"
        (let ((nick (lurk-msg-src msg))
@@ -580,9 +920,10 @@ portion of the source component of the message, as LURK doesn't use this.")
            ((rx (: "\01VERSION "
                    (let version (* (not "\01")))
                    "\01"))
-            (lurk-display-notice nil "CTCP version reply from " nick ": " version))
+            (lurk-display-notice (lurk-get-context network)
+                                 "CTCP version reply from " nick ": " version))
            (_
-            (lurk-display-notice nil text)))))
+            (lurk-display-notice (lurk-get-context network channel) text)))))
 
       ("PRIVMSG"
        (let* ((from (lurk-msg-src msg))
@@ -592,27 +933,299 @@ portion of the source component of the message, as LURK doesn't use this.")
          (pcase text
            ("\01VERSION\01"
             (let ((version-string (concat lurk-version " - running on GNU Emacs " emacs-version)))
-              (lurk-send-msg (lurk-msg nil nil "NOTICE"
+              (lurk-send-msg network
+                             (lurk-msg nil nil "NOTICE"
                                        (list from (concat "\01VERSION "
                                                           version-string
                                                           "\01")))))
-            (lurk-display-notice nil "CTCP version request received from " from))
+            (lurk-display-notice (lurk-get-context network)
+                                 "CTCP version request received from "
+                                 from " on " network))
 
            ((rx (let ping (: "\01PING " (* (not "\01")) "\01")))
-            (lurk-send-msg (lurk-msg nil nil "NOTICE" (list from ping)))
-            (lurk-display-notice "CTCP ping received from " from))
+            (lurk-send-msg network (lurk-msg nil nil "NOTICE" (list from ping)))
+            (lurk-display-notice (lurk-get-context network)
+                                 "CTCP ping received from " from " on " network))
 
            ("\01USERINFO\01"
-            (lurk-display-notice "CTCP userinfo request from " from " (no response sent)"))
+            (lurk-display-notice (lurk-get-context network)
+                                 "CTCP userinfo request from " from
+                                 " on " network " (no response sent)"))
+
+           ("\01CLIENTINFO\01"
+            (lurk-display-notice (lurk-get-context network)
+                                 "CTCP clientinfo request from " from
+                                 " on " network " (no response sent)"))
+
+           ((rx (: "\01ACTION " (let action-text (* (not "\01"))) "\01"))
+            (lurk-display-action network from to action-text))
 
            (_
-            (if (and (equal from "BitBot")
-                     (equal to "##moshpit")
-                     (cl-search "\\_o< QUACK!" text))
-              (lurk-send-msg (lurk-msg nil nil "PRIVMSG" to ",bef")))
-            (lurk-display-message from to text)))))
+            (lurk-display-message network from to text)))))
+
       (_
-       (lurk-display-notice nil (lurk-msg->string msg))))))
+       (lurk-display-notice (lurk-get-context network)
+                            (lurk-msg->string msg))))))
+
+
+;;; User-defined responses
+;;
+
+(defun lurk--lists-equal (l1 l2)
+    (if (and l1 l2)
+        (if (or (not (and (car l1) (car l2)))
+                (string-match (car l1) (car l2)))
+            (lurk--lists-equal (cdr l1) (cdr l2))
+          nil)
+      t))
+
+(defun lurk-process-autoreply (network msg autoreply)
+  (let ((matcher (car autoreply))
+        (reply (cadr autoreply)))
+    (let ((target-network (car matcher)))
+      (when (and (or (not target-network)
+                     (and (equal network target-network)))
+                 (lurk--lists-equal (cdr matcher)
+                                    (append (list (lurk-msg-src msg)
+                                                  (lurk-msg-cmd msg))
+                                            (lurk-msg-params msg))))
+        (lurk-send-msg network
+         (lurk-msg nil nil (car reply) (cdr reply)))))))
+
+(defun lurk-process-autoreplies (network msg)
+  (mapc
+   (lambda (autoreply)
+     (lurk-process-autoreply network msg autoreply))
+   lurk-autoreply-table))
+
+
+;;; Commands
+;;
+
+(defvar lurk-command-table
+  '(("DEBUG" "Toggle debug mode on/off." lurk-command-debug lurk-boolean-completions)
+    ("HEADER" "Toggle display of header." lurk-command-header lurk-boolean-completions)
+    ("SHOWJOINS" "Toggles display of joins/parts." lurk-command-showjoins lurk-boolean-completions)
+    ("NETWORKS" "List known IRC networks." lurk-command-networks)
+    ("CONNECT" "Connect to an IRC network." lurk-command-connect lurk-network-completions)
+    ("QUIT" "Disconnect from current network." lurk-command-quit)
+    ("JOIN" "Join one or more channels." lurk-command-join)
+    ("PART" "Leave channel." lurk-command-part lurk-channel-completions)
+    ("SWITCHCONTEXT" "Switch current context" lurk-command-switch-context lurk-context-completions)
+    ("NICK" "Change nick." lurk-command-nick)
+    ("LIST" "Display details of one or more channels." lurk-command-list)
+    ("TOPIC" "Set/query topic for current channel." lurk-command-topic)
+    ("USERS" "List nicks of users in current channel." lurk-command-users)
+    ("MSG" "Send private message to user." lurk-command-msg lurk-nick-completions)
+    ("ME" "Display action." lurk-command-me)
+    ("VERSION" "Request version of another user's client via CTCP." lurk-command-version lurk-nick-completions)
+    ("CLEAR" "Clear buffer text." lurk-command-clear lurk-context-completions)
+    ("HELP" "Display help on client commands." lurk-command-help lurk-help-completions))
+  "Table of commands explicitly supported by lurk.")
+
+(defun lurk-boolean-completions ()
+  '("on" "off"))
+
+(defun lurk-network-completions ()
+  (mapcar (lambda (row) (car row)) lurk-networks))
+
+(defun lurk-help-completions ()
+  (mapcar (lambda (row) (car row)) lurk-command-table))
+
+(defun lurk-channel-completions ()
+  (mapcar (lambda (ctx)
+            (lurk-context->string ctx))
+          (seq-filter (lambda (ctx)
+                        (not (lurk-network-context-p ctx)))
+                      lurk-contexts)))
+
+(defun lurk-context-completions ()
+  (mapcar (lambda (ctx) (lurk-context->string ctx)) lurk-contexts))
+
+(defun lurk-command-help (params)
+  (if params
+      (let* ((cmd-str (upcase (car params)))
+             (row (assoc cmd-str lurk-command-table #'equal)))
+        (if row
+            (progn
+              (lurk-display-notice nil "Help for \x02" cmd-str "\x02:")
+              (lurk-display-notice nil "  " (elt row 1)))
+          (lurk-display-notice nil "No such (client-interpreted) command.")))
+    (lurk-display-notice nil "Client-interpreted commands:")
+    (dolist (row lurk-command-table)
+      (lurk-display-notice nil "  \x02" (elt row 0) "\x02: " (elt row 1)))
+    (lurk-display-notice nil "Use /HELP COMMAND to display information about a specific command.")))
+
+(defun lurk-command-debug (params)
+  (setq lurk-debug 
+        (if params
+            (if (equal (upcase (car params)) "ON")
+                t
+              nil)
+          (not lurk-debug)))
+  (lurk-display-notice nil "Debug mode now " (if lurk-debug "on" "off") "."))
+
+(defun lurk-command-header (params)
+  (if
+      (if params
+          (equal (upcase (car params)) "ON")
+        (not header-line-format))
+      (progn
+        (lurk-setup-header)
+        (lurk-display-notice nil "Header enabled."))
+    (setq-local header-line-format nil)
+    (lurk-display-notice nil "Header disabled.")))
+
+(defun lurk-command-showjoins (params)
+  (setq lurk-show-joins 
+        (if params
+            (if (equal (upcase (car params)) "ON")
+                t
+              nil)
+          (not lurk-show-joins)))
+  (lurk-display-notice nil "Joins/parts will now be "
+                       (if lurk-show-joins "shown" "hidden") "."))
+
+(defun lurk-command-connect (params)
+  (if params
+      (let ((network (car params)))
+        (lurk-display-notice nil "Attempting to connect to " network "...")
+        (lurk-connect network))
+    (lurk-display-notice nil "Usage: /connect <network>")))
+
+(defun lurk-command-networks (_params)
+  (lurk-display-notice nil "Currently-known networks:")
+  (dolist (row lurk-networks)
+    (seq-let (network network port &rest _others) row
+      (lurk-display-notice nil "\t" network
+                           " [" network
+                           " " (number-to-string port) "]")))
+  (lurk-display-notice nil "(Modify the `lurk-networks' variable to add more.)"))
+
+(defun lurk-command-quit (params)
+  (let ((ctx (lurk-current-context)))
+    (if (not ctx)
+        (lurk-display-error "No current network")
+      (let ((quit-msg (if params (string-join params " ") lurk-default-quit-msg)))
+        (lurk-send-msg
+         (lurk-context-network ctx)
+         (lurk-msg nil nil "QUIT" quit-msg))))))
+
+(defun lurk-command-join (params)
+  (if params
+      (let ((network (lurk-context-network (lurk-current-context))))
+        (dolist (channel params)
+          (lurk-send-msg network (lurk-msg nil nil "JOIN" channel))))
+    (lurk-display-notice nil "Usage: /join channel [channel2 ...]")))
+
+(defun lurk-command-part (params)
+  (let ((ctx (cond
+              ((not params) (lurk-current-context))
+              ((seq-contains (car params) "@") (lurk-string->context (car params)))
+              (t (list (lurk-context-network (lurk-current-context))  (car params))))))
+    (let ((network (lurk-context-network ctx))
+          (channel (lurk-context-channel ctx)))
+      (if channel
+          (lurk-send-msg network (lurk-msg nil nil "PART" channel))
+        (lurk-display-error "Specify which channel to leave")))))
+
+(defun lurk-command-switch-context (params)
+  (if (not params)
+      (lurk-display-notice nil "Usage: /switchcontext #channel@network")
+    (let ((ctx (lurk-string->context (car params))))
+      (lurk-switch-to-context ctx)
+      (lurk-highlight-current-context)
+      (lurk-render-prompt)
+      (if lurk-zoomed
+          (lurk-zoom-in (lurk-current-context))))))
+
+(defun lurk-command-nick (params)
+  (if params
+      (let ((new-nick (string-join params " "))
+            (ctx (lurk-current-context)))
+        (if ctx
+            (lurk-send-msg (lurk-context-network ctx)
+                           (lurk-msg nil nil "NICK" new-nick))
+          (lurk-display-error "No current connection")))
+    (lurk-display-notice nil "Usage: /nick <new-nick>")))
+
+(defun lurk-command-list (params)
+  (let ((ctx (lurk-current-context)))
+    (if ctx
+        (if (not params)
+            (lurk-display-notice nil "This command can generate lots of output."
+                                 " Use `/LIST -yes' if you really want this,"
+                                 " or `/LIST <channel_regexp>' to reduce the output.")
+          (let ((network (lurk-context-network ctx)))
+            (if (equal (upcase (car params)) "-YES")
+                (lurk-send-msg network (lurk-msg nil nil "LIST"))
+              (lurk-send-msg network (lurk-msg nil nil "LIST"
+                                              (car params))))))
+      (lurk-display-error "No current connection"))))
+
+(defun lurk-command-topic (params)
+  (let ((ctx (lurk-current-context)))
+    (if (and ctx (not (lurk-network-context-p ctx)))
+        (let ((network (lurk-context-network ctx))
+              (channel (lurk-context-channel ctx)))
+          (if params
+              (lurk-send-msg network
+                             (lurk-msg nil nil "TOPIC" channel
+                                       (string-join params " ")))
+            (lurk-send-msg network
+                           (lurk-msg nil nil "TOPIC" channel))))
+      (lurk-display-notice nil "No current channel."))))
+
+(defun lurk-command-msg (params)
+  (let ((network (lurk-context-network (lurk-current-context))))
+    (if (and params (>= (length params) 2))
+        (let ((to (car params))
+              (text (string-join (cdr params) " ")))
+          (lurk-send-msg network (lurk-msg nil nil "PRIVMSG" to text))
+          (lurk-display-message network
+                                (lurk-connection-nick network)
+                                to text))
+      (lurk-display-notice nil "Usage: /msg <nick> <message>"))))
+
+(defun lurk-command-me (params)
+  (let* ((ctx (lurk-current-context))
+         (network (lurk-context-network ctx)))
+    (if (and ctx (not (lurk-network-context-p ctx)))
+        (if params
+            (let* ((channel (lurk-context-channel ctx))
+                   (my-nick (lurk-connection-nick network))
+                   (action (string-join params " "))
+                   (ctcp-text (concat "\01ACTION " action "\01")))
+              (lurk-send-msg network
+                             (lurk-msg nil nil "PRIVMSG"
+                                       (list channel ctcp-text)))
+              (lurk-display-action network my-nick channel action))
+          (lurk-display-notice nil "Usage: /me <action>"))
+      (lurk-display-notice nil "No current channel."))))
+
+(defun lurk-command-version (params)
+  (let ((ctx (lurk-current-context)))
+    (if ctx
+        (if params
+            (let ((network (lurk-context-network ctx))
+                  (nick (car params)))
+              (lurk-send-msg network
+                             (lurk-msg nil nil "PRIVMSG"
+                                       (list nick "\01VERSION\01")))
+              (lurk-display-notice ctx "CTCP version request sent to "
+                                   nick " on " network))
+          (lurk-display-notice ctx "Usage: /version <nick>"))
+      (lurk-display-notice nil "No current channel."))))
+
+(defun lurk-command-users (_params)
+  (let ((ctx (lurk-current-context)))
+    (if (and ctx (not (lurk-network-context-p ctx)))
+        (let ((channel (lurk-context-channel ctx))
+              (network (lurk-context-network ctx))
+              (users (lurk-get-context-users ctx)))
+          (lurk-display-notice ctx "Users in " channel " on " network ":")
+          (lurk-display-notice ctx (string-join users " ")))
+      (lurk-display-notice nil "No current channel."))))
 
 
 ;;; Command entering
@@ -620,91 +1233,95 @@ portion of the source component of the message, as LURK doesn't use this.")
 
 (defun lurk-enter-string (string)
   (if (string-prefix-p "/" string)
-      (pcase (substring string 1)
-        ((rx (: "CONNECT " (let network (* not-newline))))
-         (lurk-display-notice nil "Attempting to connect to " network "...")
-         (lurk-connect network))
-
-        ((rx (: "TOPIC " (let new-topic (* not-newline))))
-         (lurk-send-msg (lurk-msg nil nil "TOPIC" lurk-current-context new-topic)))
-
-        ((rx (: "ME " (let action (* not-newline))))
-         (let ((ctcp-text (concat "\01ACTION " action "\01")))
-           (lurk-send-msg (lurk-msg nil nil "PRIVMSG"
-                                    (list lurk-current-context ctcp-text)))
-           (lurk-display-message lurk-nick lurk-current-context ctcp-text)))
-
-        ((rx (: "VERSION" " " (let nick (+ (not whitespace)))))
-         (lurk-send-msg (lurk-msg nil nil "PRIVMSG"
-                                  (list nick "\01VERSION\01")))
-         (lurk-display-notice nil "CTCP version request sent to " nick))
-
-        ((rx "PART" (opt (: " " (let channel (* not-newline)))))
-         (if (or lurk-current-context channel)
-             (lurk-send-msg (lurk-msg nil nil "PART" (if channel
-                                                         channel
-                                                       lurk-current-context)))
-           (lurk-display-error "No current channel to leave.")))
-
-        ((rx "QUIT" (opt (: " " (let quit-msg (* not-newline)))))
-         (lurk-send-msg (lurk-msg nil nil "QUIT"
-                                  (or quit-msg lurk-default-quit-msg))))
-
-        ((rx (: "NICK" (* whitespace) string-end))
-         (lurk-display-notice nil "Current nick: " lurk-nick))
-
-        ((rx (: "NICK" (+ whitespace) (let nick (+ (not whitespace)))))
-         (if (lurk-connected-p)
-             (lurk-send-msg (lurk-msg nil nil "NICK" nick))
-           (setq lurk-nick nick)
-           (lurk-display-notice nil "Set default nick to '" nick "'")))
-
-        ((rx "MSG "
-             (let to (* (not whitespace)))
-             " "
-             (let text (* not-newline)))
-         (lurk-send-msg (lurk-msg nil nil "PRIVMSG" to text))
-         (lurk-display-message lurk-nick to text))
-
-        ((rx (: (let cmd-str (+ (not whitespace)))
-                (opt (: " " (let params-str (* not-newline))))))
-         (lurk-send-msg (lurk-msg nil nil (upcase cmd-str)
-                                  (if params-str
-                                      (split-string params-str)
-                                    nil)))))
-
+      (pcase string
+        ((rx (: "/" (let cmd-str (+ (not whitespace)))
+                (opt (+ whitespace)
+                     (let params-str (+ anychar))
+                     string-end)))
+         (let ((command-row (assoc (upcase  cmd-str) lurk-command-table #'equal))
+               (params (if params-str
+                           (split-string params-str nil t)
+                         nil)))
+           (if (and command-row (elt command-row 2))
+               (funcall (elt command-row 2) params)
+             (lurk-send-msg
+              (lurk-context-network (lurk-current-context))
+              (lurk-msg nil nil (upcase cmd-str) params)))))
+        (_
+         (lurk-display-error "Badly formed command")))
     (unless (string-empty-p string)
-      (if lurk-current-context
-          (progn
-            (lurk-send-msg (lurk-msg nil nil "PRIVMSG"
-                                     lurk-current-context
-                                     string))
-            (lurk-display-message lurk-nick lurk-current-context string))
-        (lurk-display-error "No current context.")))))
+      (let ((ctx (lurk-current-context)))
+        (if ctx
+            (if (not (lurk-network-context-p ctx))
+                (let ((network (lurk-context-network ctx))
+                      (channel (lurk-context-channel ctx)))
+                  (lurk-send-msg network
+                                 (lurk-msg nil nil "PRIVMSG" channel string))
+                  (lurk-display-message network
+                                        (lurk-connection-nick network)
+                                        channel string))
+              (lurk-display-error "No current channel"))
+          (lurk-display-error "No current context"))))))
+
+
+;;; Command history
+;;
+
+(defvar lurk-history nil
+  "Commands and messages sent in current session.")
+
+(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)))))
+
+
+;;; Interactive commands
+;;
 
 (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))))
 
+(defun lurk-history-next ()
+  (interactive)
+  (lurk-history-cycle -1))
 
-;;; Command completion
-;;
-
-;;; Interactive functions
-;;
+(defun lurk-history-prev ()
+  (interactive)
+  (lurk-history-cycle +1))
 
 (defun lurk-cycle-contexts-forward ()
   (interactive)
-  (lurk-cycle-contexts))
+  (lurk-cycle-contexts)
+  (lurk-highlight-current-context)
+  (lurk-render-prompt)
+  (if lurk-zoomed
+      (lurk-zoom-in (lurk-current-context))))
 
 (defun lurk-cycle-contexts-reverse ()
   (interactive)
-  (lurk-cycle-contexts t))
+  (lurk-cycle-contexts t)
+  (lurk-highlight-current-context)
+  (lurk-render-prompt)
+  (if lurk-zoomed
+      (lurk-zoom-in (lurk-current-context))))
 
 (defvar lurk-zoomed nil
   "Keeps track of zoom status.")
@@ -713,23 +1330,60 @@ portion of the source component of the message, as LURK doesn't use this.")
   (interactive)
   (if lurk-zoomed
       (lurk-zoom-out)
-    (lurk-zoom-in lurk-current-context))
+    (lurk-zoom-in (lurk-current-context)))
   (setq lurk-zoomed (not lurk-zoomed)))
 
+
+(defun lurk-complete-input ()
+  (interactive)
+  (let ((completion-ignore-case t))
+    (when (>= (point) lurk-input-marker)
+      (pcase (buffer-substring lurk-input-marker (point))
+        ((rx (: "/" (let cmd-str (+ (not whitespace))) (+ " ") (* (not whitespace)) string-end))
+         (let ((space-idx (save-excursion
+                            (re-search-backward " " lurk-input-marker t)))
+               (table-row (assoc (upcase cmd-str) lurk-command-table #'equal)))
+           (if (and table-row (elt table-row 3))
+               (let* ((completions-nospace (funcall (elt table-row 3)))
+                      (completions (mapcar (lambda (el) (concat el " ")) completions-nospace)))
+                 (completion-in-region (+ 1 space-idx) (point) completions)))))
+        ((rx (: "/" (* (not whitespace)) string-end))
+         (message (buffer-substring lurk-input-marker (point)))
+         (completion-in-region lurk-input-marker (point)
+                               (mapcar (lambda (row) (concat "/" (car row) " "))
+                                       lurk-command-table)))
+        (_
+         (let* ((end (max lurk-input-marker (point)))
+                (space-idx (save-excursion
+                             (re-search-backward " " lurk-input-marker t)))
+                (start (if space-idx (+ 1 space-idx) lurk-input-marker)))
+           (unless (string-prefix-p "/" (buffer-substring start end))
+             (let* ((users (lurk-get-context-users (lurk-current-context)))
+                    (users-no@ (mapcar
+                                (lambda (u) (car (split-string u "@" t)))
+                                users)))
+               (completion-in-region start end users-no@)))))))))
+
 ;;; Mode
 ;;
 
 (defvar lurk-mode-map
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "RET") 'lurk-enter)
-    (define-key map (kbd "<tab>") 'lurk-complete)
+    (define-key map (kbd "TAB") 'lurk-complete-input)
     (define-key map (kbd "C-c C-z") 'lurk-toggle-zoom)
+    (define-key map (kbd "<C-up>") 'lurk-history-prev)
+    (define-key map (kbd "<C-down>") 'lurk-history-next)
     (define-key map (kbd "<C-tab>") 'lurk-cycle-contexts-forward)
+    (define-key map (kbd "<C-S-iso-lefttab>") 'lurk-cycle-contexts-reverse)
     (define-key map (kbd "<C-S-tab>") 'lurk-cycle-contexts-reverse)
+    (when (fboundp 'evil-define-key*)
+      (evil-define-key* 'motion map
+        (kbd "TAB") 'lurk-complete-input))
     map))
 
 (define-derived-mode lurk-mode text-mode "lurk"
-  "Major mode for LURK.")
+  "Major mode for lurk.")
 
 (when (fboundp 'evil-set-initial-state)
   (evil-set-initial-state 'lurk-mode 'insert))
@@ -737,15 +1391,15 @@ portion of the source component of the message, as LURK doesn't use this.")
 ;;; Main start procedure
 ;;
 
+;;;###autoload
 (defun lurk ()
-  "Switch to *lurk* buffer."
+  "Start lurk or just switch to the lurk buffer if one already exists."
   (interactive)
   (if (get-buffer "*lurk*")
       (switch-to-buffer "*lurk*")
-    (switch-to-buffer "*lurk*"))
-  (lurk-mode)
-  (lurk-setup-buffer)
-  "Started LURK.")
-
+    (switch-to-buffer "*lurk*")
+    (lurk-mode)
+    (lurk-setup-buffer))
+  "Started lurk.")
 
 ;;; lurk.el ends here