X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=murk.el;h=2e89982dc1ebbba34fe39f957370bad032c18000;hb=191b189b97915566a5fee5fcde4dd3f88e67bf61;hp=1cab898aec10aa27fb62fd9c5f09869b062dfe61;hpb=64994dc2c5c36a9cdb125e6bd0ddc497e077fa25;p=lurk.git

diff --git a/murk.el b/murk.el
index 1cab898..2e89982 100644
--- a/murk.el
+++ b/murk.el
@@ -1,13 +1,13 @@
-;;; MURK --- Multiserver Unibuffer iRc Klient -*- lexical-binding:t -*-
+;;; murk.el --- Multiserver Unibuffer iRc Klient -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2024 plugd
 
 ;; Author: plugd <plugd@thelambdalab.xyz>
 ;; Created: 11 May 2024
 ;; Version: 0.0
-;; Keywords: network
 ;; Homepage: http://thelambdalab.xyz/murk
-;; Package-Requires: ((emacs "26"))
+;; Keywords: comm
+;; Package-Requires: ((emacs "26.1"))
 
 ;; This file is not part of GNU Emacs.
 
@@ -26,10 +26,14 @@
 
 ;;; Commentary:
 
+;; A very simple IRC server which uses only a single buffer.
+
 ;;; Code:
 
 (provide 'murk)
 
+(require 'cl-lib)
+
 
 ;;; Customizations
 
@@ -37,24 +41,61 @@
   "Multiserver Unibuffer iRc Klient"
   :group 'network)
 
-(defcustom murk-nick "plugd"
-  "Default nick.")
+(defcustom murk-default-nick "plugd"
+  "Default nick."
+  :type '(string))
 
 (defcustom murk-default-quit-msg "Bye"
-  "Default quit message when none supplied.")
+  "Default quit message when none supplied."
+  :type '(string))
 
 (defcustom murk-networks
-  '(("libera" "irc.libera.chat" 6697)
-    ("tilde" "tilde.chat" 6697))
-  "IRC networks.")
+  '(("debug" "localhost" 6667 :notls)
+    ("libera" "irc.libera.chat" 6697)
+    ("tilde" "tilde.chat" 6697)
+    ("freenode" "chat.freenode.net" 6697))
+  "IRC networks."
+  :type '(alist :key-type string))
+
+(defcustom murk-show-joins nil
+  "Set to non-nil to be notified of joins, parts and quits.")
 
 (defcustom murk-display-header t
-  "If non-nil, use buffer header to display information on current host and channel.")
+  "If non-nil, use buffer header to display current host and channel."
+  :type '(boolean))
 
 
 ;;; Faces
 ;;
 
+(defface murk-text
+  '((t :inherit default))
+  "Face used for murk text.")
+
+(defface murk-prompt
+  '((t :inherit font-lock-keyword-face))
+  "Face used for the prompt.")
+
+(defface murk-context
+  '((t :inherit murk-context))
+  "Face used for the context name in the prompt.")
+
+(defface murk-faded
+  '((t :inherit shadow))
+  "Face used for faded murk text.")
+
+(defface murk-timestamp
+  '((t :inherit shadow))
+  "Face used for timestamps.")
+
+(defface murk-error
+  '((t :inherit error))
+  "Face used for murk error text.")
+
+(defface murk-notice
+  '((t :inherit warning))
+  "Face used for murk notice text.")
+
 
 ;;; Global variables
 ;;
@@ -66,6 +107,10 @@
 (defvar murk-error-prefix "!!!")
 (defvar murk-prompt-string ">")
 
+(defvar murk-debug nil
+  "If non-nil, enable debug mode.")
+
+
 ;;; Utility procedures
 ;;
 
@@ -77,6 +122,7 @@
       (with-output-to-string (princ obj))
     nil))
 
+
 ;;; Network processes
 ;;
 
@@ -87,30 +133,42 @@ This includes the process and the response string.")
 (defun murk-connection-process (server)
   (elt (assoc server murk-connection-table) 1))
 
-(defun murk-connection-response (server)
+(defun murk-connection-nick (server)
   (elt (assoc server murk-connection-table) 2))
 
+(defun murk-set-connection-nick (server nick)
+  (setf (elt (assoc server murk-connection-table) 2) nick))
+
+(defun murk-connection-response (server)
+  (elt (assoc server murk-connection-table) 3))
+
 (defun murk-set-connection-response (server string)
-  (setf (elt (assoc server murk-connection-table) 2) string))
+  (setf (elt (assoc server murk-connection-table) 3) string))
+
+(defun murk-connection-new (server process nick)
+  (add-to-list 'murk-connection-table
+               (list server process nick "")))
 
-(defun murk-connection-close (server)
-  (setq murk-connection-table (assoc-delete-all server murk-connection-table)))
+(defun murk-connection-remove (server)
+  (setq murk-connection-table
+        (seq-remove (lambda (row) (equal (car row) server))
+                    murk-connection-table)))
 
 (defun murk-make-server-filter (server)
-  (lambda (proc string)
+  (lambda (_proc string)
     (dolist (line (split-string (concat (murk-connection-response server) string)
                                 "\n"))
       (if (string-suffix-p "\r" line)
           (murk-eval-msg-string server (string-trim line))
-        (murk-set-connection-response line)))))
+        (murk-set-connection-response server line)))))
 
 (defun murk-make-server-sentinel (server)
-  (lambda (proc string)
+  (lambda (_proc string)
     (unless (equal "open" (string-trim string))
       (murk-display-error "Disconnected from server.")
-      (murk-remove-contexts-for-server server)
-      (murk-render-prompt)
-      (murk-connection-close server))))
+      (murk-connection-remove server)
+      (murk-remove-server-contexts server)
+      (murk-render-prompt))))
 
 (defun murk-start-process (server)
   (let* ((row (assoc server murk-networks))
@@ -138,14 +196,15 @@ This includes the process and the response string.")
 
 (defun murk-connect (server)
   (if (assoc server murk-connection-table)
-      (murk-display-error "Already connected to this network.")
+      (murk-display-error "Already connected to this network")
     (if (not (assoc server murk-networks))
         (murk-display-error "Network '" server "' is unknown.")
       (let ((proc (murk-start-process server)))
-        (add-to-list murk-connection-table
-                     (list server proc "")))
-      (murk-send-msg server (murk-msg nil nil "USER" murk-nick 0 "*" murk-nick))
-      (murk-send-msg server (murk-msg nil nil "NICK" murk-nick)))))
+        (murk-connection-new server proc murk-default-nick))
+      (murk-send-msg server (murk-msg nil nil "USER" murk-default-nick 0 "*" murk-default-nick))
+      (murk-send-msg server (murk-msg nil nil "NICK" murk-default-nick))
+      (murk-add-context (list server))
+      (murk-render-prompt))))
 
 (defun murk-send-msg (server msg)
   (if murk-debug
@@ -153,8 +212,8 @@ This includes the process and the response string.")
   (let ((proc (murk-connection-process server)))
     (if (and proc (eq (process-status proc) 'open))
         (process-send-string proc (concat (murk-msg->string msg) "\r\n"))
-      (murk-display-error "No server connection established.")
-      (error "No server connection established"))))
+      (murk-display-error "No server connection established"))))
+
 
 ;;; Server messages
 ;;
@@ -199,13 +258,13 @@ portion of the source component of the message, as mURK 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 #'murk-msg (append (list tags src cmd) params)))
-    (error "Failed to parse string " string)))
+    (error "Failed to parse string %s" string)))
 
 (defun murk-msg->string (msg)
   (let ((tags (murk-msg-tags msg))
@@ -224,12 +283,12 @@ portion of the source component of the message, as mURK doesn't use this.")
        nil))))
 
 
-;;; Contexts and Servers
+;;; Contexts
 ;;
 
-;; A context is a list (server name ...) where name is a string
-;; representing either a channel name or nick, and server is a symbol
-;; identifying the server.
+;; A context is a list (server channel users) identifying the server
+;; and channel.  The tail of the list contains the nicks of users
+;; present in the channel.
 ;;
 ;; Each server has a special context (server) used for messages
 ;; to/from the server itself.
@@ -239,17 +298,84 @@ portion of the source component of the message, as mURK doesn't use this.")
 The head of this list is always the current context.")
 
 (defun murk-current-context ()
-  "Returns the current context."
+  "Return the current context."
   (if murk-contexts
       (car murk-contexts)
     nil))
 
+(defun murk-contexts-equal (c1 c2)
+  (if (murk-server-context-p c1)
+      (and (murk-server-context-p c2)
+           (equal (murk-context-server c1)
+                  (murk-context-server c2)))
+    (and (not (murk-server-context-p c2))
+         (equal (seq-take c1 2)
+                (seq-take c2 2)))))
+
 (defun murk-context-server (ctx) (elt ctx 0))
-(defun murk-context-name (ctx) (elt ctx 1))
+(defun murk-context-channel (ctx) (elt ctx 1))
+(defun murk-context-users (ctx) (elt ctx 2))
+(defun murk-set-context-users (ctx users)
+  (setcar (cddr ctx) users))
+(defun murk-server-context-p (ctx) (not (cdr ctx)))
+
+(defun murk-add-context (ctx)
+  (add-to-list 'murk-contexts ctx))
+
+(defun murk-remove-context (ctx)
+  (setq murk-contexts
+        (seq-remove
+         (lambda (this-ctx)
+           (murk-contexts-equal this-ctx ctx))
+         murk-contexts)))
+
+(defun murk-remove-server-contexts (server)
+  (setq murk-contexts
+        (seq-remove (lambda (row) (equal (car row) server))
+                    murk-contexts)))
+
+(defun murk-context->string (ctx)
+   (if (murk-server-context-p ctx)
+       (concat "[" (murk-context-server ctx) "]")
+     (concat (murk-context-channel ctx) "@"
+             (murk-context-server ctx))))
+
+(defun murk-get-context (server &optional name)
+  (if name
+      (let ((test-ctx (list server name)))
+        (seq-find (lambda (ctx)
+                    (equal (seq-take ctx 2) test-ctx))
+                  murk-contexts))
+    (assoc server murk-contexts)))
+
+(defun murk-cycle-contexts (&optional reverse)
+  (setq murk-contexts
+        (if reverse
+            (let ((nminus1 (- (length murk-contexts) 1)))
+              (cons
+               (elt murk-contexts nminus1)
+               (seq-take murk-contexts nminus1)))
+          (append (cdr murk-contexts) (list (car murk-contexts))))))
+
+(defun murk-add-context-users (ctx users)
+  (murk-set-context-users
+   ctx
+   (cl-union users (murk-context-users ctx))))
+
+(defun murk-del-context-user (ctx user)
+  (murk-set-context-users
+   ctx
+   (delete user (murk-context-users ctx))))
 
 ;;; Buffer
 ;;
 
+(defvar murk-prompt-marker nil
+  "Marker for prompt position in murk buffer.")
+
+(defvar murk-input-marker nil
+  "Marker for prompt position in murk buffer.")
+
 (defun murk-render-prompt ()
   (with-current-buffer "*murk*"
     (let ((update-point (= murk-input-marker (point)))
@@ -266,8 +392,8 @@ The head of this list is always the current context.")
           (insert
            (propertize (let ((ctx (murk-current-context)))
                          (if ctx
-                           (concat (murk-context-name) "@" (murk-context-server ctx))
-                         ""))
+                             (murk-context->string ctx)
+                           ""))
                        'face 'murk-context
                        'read-only t)
            (propertize murk-prompt-string
@@ -283,15 +409,25 @@ The head of this list is always the current context.")
         (if (car v)
             (set-window-point (cadr v) murk-input-marker))))))
   
-(defvar murk-prompt-marker nil
-  "Marker for prompt position in murk buffer.")
-
-(defvar murk-input-marker nil
-  "Marker for prompt position in murk buffer.")
-
 (defun murk-setup-header ()
-  ;; To do
-  )
+  (with-current-buffer "*murk*"
+    (setq-local header-line-format
+                '((:eval
+                   (let* ((ctx (murk-current-context)))
+                     (if ctx
+                         (let ((server (murk-context-server ctx)))
+                           (concat
+                            "Network: " server ", "
+                            (if (murk-server-context-p ctx)
+                                "Server"
+                              (concat
+                               "Channel: "
+                               (murk-context-channel ctx)
+                               " ("
+                               (number-to-string
+                                (length (murk-context-users ctx)))
+                               ")"))))
+                       "No connection")))))))
 
 (defun murk-setup-buffer ()
   (with-current-buffer (get-buffer-create "*murk*")
@@ -327,12 +463,6 @@ The head of this list is always the current context.")
       (fill-region (point-min) (point-max) nil t)
       (buffer-string))))
 
-(defun murk-context->string (context)
-  (if context
-      (concat (murk-context-name) "@" (murk-context-server context))
-    nil))
-
-
 (defun murk-display-string (context prefix &rest strings)
   (with-current-buffer "*murk*"
     (save-excursion
@@ -356,9 +486,36 @@ The head of this list is always the current context.")
                       'read-only t
                       'context context
                       'invisible context-atom)
-          (concat (apply #'murk-buttonify-urls strings) "\n"))))))
+          (murk-add-formatting
+           (propertize (concat (apply #'murk-buttonify-urls strings) "\n")
+                       'read-only t
+                       'context context
+                       'invisible context-atom)))))))
   (murk-scroll-windows-to-last-line))
 
+(defun murk-display-message (server from to text)
+  (let ((context (if (string-prefix-p "#" to)
+                     (murk-get-context server to)
+                   (murk-get-context server))))
+    (murk-display-string
+     context
+     (if (murk-server-context-p context)
+         (concat "[" from " -> " to "]")
+       (concat (murk-context->string context) " <" from ">"))
+     text)))
+
+(defun murk-display-notice (context &rest notices)
+  (murk-display-string
+   context
+   (propertize murk-notice-prefix 'face 'murk-notice)
+   (apply #'concat notices)))
+
+(defun murk-display-error (&rest messages)
+  (murk-display-string
+   nil
+   (propertize murk-error-prefix 'face 'murk-error)
+   (apply #'concat messages)))
+
 (defun murk--start-of-final-line ()
   (with-current-buffer "*murk*"
     (save-excursion
@@ -404,6 +561,424 @@ The head of this list is always the current context.")
                           'help-echo "Open URL in browser.")))
     (buffer-string)))
 
+(defun murk-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 murk-eval-msg-string (server string)
+  (if murk-debug
+      (murk-display-string nil nil string))
+  (let* ((msg (murk-string->msg string)))
+    (pcase (murk-msg-cmd msg)
+      ("PING"
+       (murk-send-msg server
+        (murk-msg nil nil "PONG" (murk-msg-params msg))))
+
+      ("PONG")
+
+      ("001"
+       (let* ((params (murk-msg-params msg))
+              (nick (elt params 0))
+              (text (string-join (seq-drop params 1) " ")))
+         (murk-set-connection-nick server nick)
+         (murk-display-notice nil text)))
+
+      ("353" ; NAMEREPLY
+       (let* ((params (murk-msg-params msg))
+              (channel (elt params 2))
+              (names (split-string (elt params 3)))
+              (ctx (murk-get-context server channel)))
+         (if ctx
+             (murk-add-context-users ctx names)
+           (murk-display-notice nil "Users in " channel
+                                ": " (string-join names " ")))))
+
+      ("366" ; ENDOFNAMES
+       (let* ((params (murk-msg-params msg))
+              (channel (elt params 1))
+              (ctx (murk-get-context server channel)))
+         (if ctx
+             (murk-display-notice
+              ctx
+              (murk--as-string (length (murk-context-users ctx)))
+              " users in " channel)
+           (murk-display-notice nil "End of " channel " names list."))))
+
+      ("331"
+       (let* ((params (murk-msg-params msg))
+              (channel (elt params 1))
+              (ctx (murk-get-context server channel)))
+         (murk-display-notice ctx "No topic set.")))
+
+      ("332"
+       (let* ((params (murk-msg-params msg))
+              (channel (elt params 1))
+              (topic (elt params 2))
+              (ctx (murk-get-context server channel)))
+         (murk-display-notice ctx "Topic: " topic)))
+
+      ((rx (= 3 (any digit)))
+       (murk-display-notice nil (mapconcat 'identity (cdr (murk-msg-params msg)) " ")))
+
+      ((and "JOIN"
+            (guard (equal (murk-connection-nick server)
+                          (murk-msg-src msg))))
+       (let ((channel (car (murk-msg-params msg))))
+         (murk-add-context (list server channel nil))
+         (murk-display-notice (murk-current-context)
+                              "Joining channel " channel " on " server)
+         (murk-render-prompt)))
+
+      ("JOIN"
+       (let* ((channel (car (murk-msg-params msg)))
+              (nick (murk-msg-src msg))
+              (ctx (murk-get-context server channel)))
+         (murk-add-context-users ctx (list nick))
+         (if murk-show-joins
+             (murk-display-notice ctx nick " joined channel " channel
+                                  " on " server))))
+
+      ((and "PART"
+            (guard (equal (murk-connection-nick server)
+                          (murk-msg-src msg))))
+       (let ((channel (car (murk-msg-params msg))))
+         (murk-display-notice (murk-current-context) "Left channel " channel)
+         (murk-remove-context (list server channel))
+         (murk-render-prompt)))
+
+      ("PART"
+       (let* ((channel (car (lurk-msg-params msg)))
+              (nick (lurk-msg-src msg))
+              (ctx (murk-get-context server channel)))
+         (murk-del-context-user ctx nick)
+         (if murk-show-joins
+             (murk-display-notice ctx nick " left channel " channel
+                                  " on " server))))
+
+      ("QUIT"
+       (let ((nick (murk-msg-src msg))
+             (reason (mapconcat 'identity (murk-msg-params msg) " ")))
+         (murk-del-user nick)
+         (if murk-show-joins
+             (murk-display-notice nil nick " quit: " reason))))
+
+      ("PRIVMSG"
+       (let* ((from (murk-msg-src msg))
+              (params (murk-msg-params msg))
+              (to (car params))
+              (text (cadr params)))
+         (pcase text
+           ("\01VERSION\01"
+            (let ((version-string (concat murk-version " - running on GNU Emacs " emacs-version)))
+              (murk-send-msg server
+                             (murk-msg nil nil "NOTICE"
+                                       (list from (concat "\01VERSION "
+                                                          version-string
+                                                          "\01")))))
+            (murk-display-notice nil "CTCP version request received from "
+                                 from " on " server))
+
+           ((rx (let ping (: "\01PING " (* (not "\01")) "\01")))
+            (murk-send-msg server (murk-msg nil nil "NOTICE" (list from ping)))
+            (murk-display-notice nil "CTCP ping received from " from " on " server))
+
+           ("\01USERINFO\01"
+            (murk-display-notice nil "CTCP userinfo request from " from
+                                 " on " server " (no response sent)"))
+
+           ("\01CLIENTINFO\01"
+            (murk-display-notice nil "CTCP clientinfo request from " from
+                                 " on " server " (no response sent)"))
+
+           ((rx (: "\01ACTION " (let action-text (* (not "\01"))) "\01"))
+            (murk-display-action from to action-text))
+
+           (_
+            (murk-display-message server from to text)))))
+
+      (_
+       (murk-display-notice nil (murk-msg->string msg))))))
+
+;;; Commands
+;;
+
+(defvar murk-command-table
+  '(("DEBUG" "Toggle debug mode on/off." murk-command-debug murk-boolean-completions)
+    ("HEADER" "Toggle display of header." murk-command-header murk-boolean-completions)
+    ("SHOWJOINS" "Toggles display of joins/parts." murk-command-showjoins murk-boolean-completions)
+    ("NETWORKS" "List known IRC networks." murk-command-networks)
+    ("CONNECT" "Connect to an IRC network." murk-command-connect murk-network-completions)
+    ("QUIT" "Disconnect from current network." murk-command-quit)
+    ("JOIN" "Join one or more channels." murk-command-join)
+    ("PART" "Leave channel." murk-command-part murk-context-completions)
+    ("NICK" "Change nick." murk-command-nick)
+    ("MSG" "Send private message to user." murk-command-msg murk-nick-completions)
+    ("CLEAR" "Clear buffer text." murk-command-clear murk-context-completions)
+    ("HELP" "Display help on client commands." murk-command-help murk-help-completions))
+  "Table of commands explicitly supported by murk.")
+
+(defun murk-boolean-completions ()
+  '("on" "off"))
+
+(defun murk-network-completions ()
+  (mapcar (lambda (row) (car row)) murk-networks))
+
+(defun murk-command-help (params)
+  (if params
+      (let* ((cmd-str (upcase (car params)))
+             (row (assoc cmd-str murk-command-table #'equal)))
+        (if row
+            (progn
+              (murk-display-notice nil "Help for \x02" cmd-str "\x02:")
+              (murk-display-notice nil "  " (elt row 1)))
+          (murk-display-notice nil "No such (client-interpreted) command.")))
+    (murk-display-notice nil "Client-interpreted commands:")
+    (dolist (row murk-command-table)
+      (murk-display-notice nil "  \x02" (elt row 0) "\x02: " (elt row 1)))
+    (murk-display-notice nil "Use /HELP COMMAND to display information about a specific command.")))
+
+(defun murk-command-debug (params)
+  (setq murk-debug 
+        (if params
+            (if (equal (upcase (car params)) "ON")
+                t
+              nil)
+          (not murk-debug)))
+  (murk-display-notice nil "Debug mode now " (if murk-debug "on" "off") "."))
+
+(defun murk-command-header (params)
+  (if
+      (if params
+          (equal (upcase (car params)) "ON")
+        (not header-line-format))
+      (progn
+        (murk-setup-header)
+        (murk-display-notice nil "Header enabled."))
+    (setq-local header-line-format nil)
+    (murk-display-notice nil "Header disabled.")))
+
+(defun murk-command-showjoins (params)
+  (setq murk-show-joins 
+        (if params
+            (if (equal (upcase (car params)) "ON")
+                t
+              nil)
+          (not murk-show-joins)))
+  (murk-display-notice nil "Joins/parts will now be "
+                       (if murk-show-joins "shown" "hidden") "."))
+
+(defun murk-command-clear (params)
+  (if (not params)
+      (murk-clear-buffer)
+    (dolist (context params)
+      (murk-clear-context context))))
+
+(defun murk-command-connect (params)
+  (if params
+      (let ((network (car params)))
+        (murk-display-notice nil "Attempting to connect to " network "...")
+        (murk-connect network))
+    (murk-display-notice nil "Usage: /connect <network>")))
+
+(defun murk-command-networks (_params)
+  (murk-display-notice nil "Currently-known networks:")
+  (dolist (row murk-networks)
+    (seq-let (network server port &rest _others) row
+      (murk-display-notice nil "\t" network
+                           " [" server
+                           " " (number-to-string port) "]")))
+  (murk-display-notice nil "(Modify the `murk-networks' variable to add more.)"))
+
+(defun murk-command-quit (params)
+  (let ((ctx (murk-current-context)))
+    (if (not ctx)
+        (murk-display-error "No current context")
+      (let ((quit-msg (if params (string-join params " ") murk-default-quit-msg)))
+        (murk-send-msg
+         (murk-context-server ctx)
+         (murk-msg nil nil "QUIT" quit-msg))))))
+
+(defun murk-command-join (params)
+  (if params
+      (let ((server (murk-context-server (murk-current-context))))
+        (dolist (channel params)
+          (murk-send-msg server (murk-msg nil nil "JOIN" channel))))
+    (murk-display-notice nil "Usage: /join channel [channel2 ...]")))
+
+(defun murk-command-part (params)
+  (let* ((server (murk-context-server (murk-current-context)))
+         (channel (if params
+                      (car params)
+                    (murk-context-channel (murk-current-context)))))
+    (if channel
+        (murk-send-msg server (murk-msg nil nil "PART" channel))
+      (murk-display-error "No current channel to leave"))))
+
+(defun murk-command-msg (params)
+  (let ((server (murk-context-server (murk-current-context))))
+    (if (and params (>= (length params) 2))
+        (let ((to (car params))
+              (text (string-join (cdr params) " ")))
+          (murk-send-msg server (murk-msg nil nil "PRIVMSG" to text))
+          (murk-display-message server
+                                (murk-connection-nick server)
+                                to text))
+      (murk-display-notice nil "Usage: /msg <nick> <message>"))))
+
+;;; Command entering
+;;
+
+(defun murk-enter-string (string)
+  (if (string-prefix-p "/" string)
+      (pcase string
+        ((rx (: "/" (let cmd-str (+ (not whitespace)))
+                (opt (+ whitespace)
+                     (let params-str (+ anychar))
+                     string-end)))
+         (let ((command-row (assoc (upcase  cmd-str) murk-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)
+             (murk-send-msg
+              (murk-context-server (murk-current-context))
+              (murk-msg nil nil (upcase cmd-str) params)))))
+        (_
+         (murk-display-error "Badly formed command")))
+    (unless (string-empty-p string)
+      (let ((ctx (murk-current-context)))
+        (if ctx
+            (if (not (murk-server-context-p ctx))
+                (let ((server (murk-context-server ctx))
+                      (channel (murk-context-channel ctx)))
+                  (murk-send-msg server
+                                 (murk-msg nil nil "PRIVMSG" channel string))
+                  (murk-display-message server
+                                        (murk-connection-nick server)
+                                        channel string))
+              (murk-display-error "No current channel"))
+          (murk-display-error "No current context"))))))
+
+
+;;; Command history
+;;
+
+(defvar murk-history nil
+  "Commands and messages sent in current session.")
+
+(defvar murk-history-index nil)
+
+(defun murk-history-cycle (delta)
+  (when murk-history
+    (with-current-buffer "*murk*"
+      (if murk-history-index
+          (setq murk-history-index
+                (max 0
+                     (min (- (length murk-history) 1)
+                          (+ delta murk-history-index))))
+        (setq murk-history-index 0))
+      (delete-region murk-input-marker (point-max))
+      (insert (elt murk-history murk-history-index)))))
+
+
+;;; Interactive commands
+;;
+
+(defun murk-enter ()
+  "Enter current contents of line after prompt."
+  (interactive)
+  (with-current-buffer "*murk*"
+    (let ((line (buffer-substring murk-input-marker (point-max))))
+      (push line murk-history)
+      (setq murk-history-index nil)
+      (let ((inhibit-read-only t))
+        (delete-region murk-input-marker (point-max)))
+      (murk-enter-string line))))
+
+(defun murk-history-next ()
+  (interactive)
+  (murk-history-cycle -1))
+
+(defun murk-history-prev ()
+  (interactive)
+  (murk-history-cycle +1))
+
+(defun murk-cycle-contexts-forward ()
+  (interactive)
+  (murk-cycle-contexts)
+  (murk-render-prompt))
+
+(defun murk-cycle-contexts-reverse ()
+  (interactive)
+  (murk-cycle-contexts t)
+  (murk-render-prompt))
+
+(defun murk-complete-input ()
+  (interactive)
+  (let ((completion-ignore-case t))
+    (when (>= (point) murk-input-marker)
+      (pcase (buffer-substring murk-input-marker (point))
+        ((rx (: "/" (let cmd-str (+ (not whitespace))) (+ " ") (* (not whitespace)) string-end))
+         (let ((space-idx (save-excursion
+                            (re-search-backward " " murk-input-marker t)))
+               (table-row (assoc (upcase cmd-str) murk-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 murk-input-marker (point)))
+         (completion-in-region murk-input-marker (point)
+                               (mapcar (lambda (row) (concat "/" (car row) " "))
+                                       murk-command-table)))
+        (_
+         (let* ((end (max murk-input-marker (point)))
+                (space-idx (save-excursion
+                             (re-search-backward " " murk-input-marker t)))
+                (start (if space-idx (+ 1 space-idx) murk-input-marker)))
+           (unless (string-prefix-p "/" (buffer-substring start end))
+             (let* ((users (murk-context-users (murk-current-context)))
+                    (users-no@ (mapcar
+                                (lambda (u) (car (split-string u "@" t)))
+                                users)))
+               (completion-in-region start end users-no@)))))))))
 
 ;;; Mode
 ;;
@@ -412,6 +987,11 @@ The head of this list is always the current context.")
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "RET") 'murk-enter)
     (define-key map (kbd "TAB") 'murk-complete-input)
+    (define-key map (kbd "<C-up>") 'murk-history-prev)
+    (define-key map (kbd "<C-down>") 'murk-history-next)
+    (define-key map (kbd "<C-tab>") 'murk-cycle-contexts-forward)
+    (define-key map (kbd "<C-S-iso-lefttab>") 'murk-cycle-contexts-reverse)
+    (define-key map (kbd "<C-S-tab>") 'murk-cycle-contexts-reverse)
     (when (fboundp 'evil-define-key*)
       (evil-define-key* 'motion map
         (kbd "TAB") 'murk-complete-input))
@@ -436,5 +1016,4 @@ The head of this list is always the current context.")
     (murk-setup-buffer))
   "Started murk.")
 
-
 ;;; murk.el ends here