X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=murk.el;h=e89df657a7490aab9eadd6d5ce4c5a4042aef579;hb=b91c95a6e7a26c70e794ea0acd862cc43e5b8a52;hp=49adc3499985b14d138dec725391ef4d6e4741da;hpb=ff1085dfcaa29217a3d19ef27afceaed2d614cfb;p=lurk.git

diff --git a/murk.el b/murk.el
index 49adc34..e89df65 100644
--- a/murk.el
+++ b/murk.el
@@ -6,7 +6,7 @@
 ;; Created: 11 May 2024
 ;; Version: 0.0
 ;; Keywords: network
-;; Homepage: http://thelambdalab.xyz/metalurk
+;; Homepage: http://thelambdalab.xyz/murk
 ;; Package-Requires: ((emacs "26"))
 
 ;; This file is not part of GNU Emacs.
@@ -37,21 +37,53 @@
   "Multiserver Unibuffer iRc Klient"
   :group 'network)
 
-(defcustom murk-nick "plugd"
+(defcustom murk-default-nick "plugd"
   "Default nick.")
 
 (defcustom murk-default-quit-msg "Bye"
   "Default quit message when none supplied.")
 
 (defcustom murk-networks
-  '(("libera" "irc.libera.chat" 6697)
+  '(("debug" "localhost" 6667 :notls)
+    ("libera" "irc.libera.chat" 6697)
     ("tilde" "tilde.chat" 6697))
   "IRC networks.")
 
+(defcustom murk-display-header t
+  "If non-nil, use buffer header to display information on current host and channel.")
+
 
 ;;; 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
 ;;
@@ -63,6 +95,10 @@
 (defvar murk-error-prefix "!!!")
 (defvar murk-prompt-string ">")
 
+(defvar murk-debug nil
+  "If non-nil, enable debug mode.")
+
+
 ;;; Utility procedures
 ;;
 
@@ -74,6 +110,7 @@
       (with-output-to-string (princ obj))
     nil))
 
+
 ;;; Network processes
 ;;
 
@@ -84,13 +121,23 @@ 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) 3) string))
 
-(defun murk-connection-close (server)
+(defun murk-connection-new (server process nick)
+  (add-to-list 'murk-connection-table
+               (list server process nick "")))
+
+(defun murk-connection-remove (server)
   (setq murk-connection-table (assoc-delete-all server murk-connection-table)))
 
 (defun murk-make-server-filter (server)
@@ -99,22 +146,22 @@ This includes the process and the response 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)
     (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))
          (host (elt row 1))
          (port (elt row 2))
          (flags (seq-drop row 3)))
-    (make-network-process :name (concat "lurk" server)
+    (make-network-process :name (concat "murk-" server)
                           :host host
                           :service port
                           :family nil
@@ -127,7 +174,7 @@ This includes the process and the response string.")
                                                   (gnutls-boot-parameters
                                                    :type 'gnutls-x509pki
                                                    :hostname host)))
-                          :buffer "*lurk*")))
+                          :buffer "*murk*")))
 
 (defvar murk-ping-period 60)
 
@@ -138,9 +185,89 @@ This includes the process and the response string.")
       (murk-display-error "Already connected to this network.")
     (if (not (assoc server murk-networks))
         (murk-display-error "Network '" server "' is unknown.")
-      (murk-start-process server)
-      (murk-send-msg (murk-msg nil nil "USER" murk-nick 0 "*" murk-nick))
-      (murk-send-msg (murk-msg nil nil "NICK" murk-nick)))))
+      (let ((proc (murk-start-process server)))
+        (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
+      (murk-display-string nil nil (murk-msg->string msg)))
+  (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."))))
+
+
+;;; Server messages
+;;
+
+(defun murk-msg (tags src cmd &rest params)
+  (list (murk--as-string tags)
+        (murk--as-string src)
+        (upcase (murk--as-string cmd))
+        (mapcar #'murk--as-string
+                (if (and params (listp (elt params 0)))
+                    (elt params 0)
+                  params))))
+
+(defun murk-msg-tags (msg) (elt msg 0))
+(defun murk-msg-src (msg) (elt msg 1))
+(defun murk-msg-cmd (msg) (elt msg 2))
+(defun murk-msg-params (msg) (elt msg 3))
+(defun murk-msg-trail (msg)
+  (let ((params (murk-msg-params msg)))
+    (if params
+        (elt params (- (length params) 1)))))
+
+(defvar murk-msg-regex
+  (rx
+   (opt (: "@" (group (* (not (or "\n" "\r" ";" " ")))))
+        (* whitespace))
+   (opt (: ":" (: (group (* (not (any space "!" "@"))))
+                  (* (not (any space)))))
+        (* whitespace))
+   (group (: (* (not whitespace))))
+   (* whitespace)
+   (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 mURK doesn't use this.")
+
+(defun murk-string->msg (string)
+  (if (string-match murk-msg-regex string)
+      (let* ((tags (match-string 1 string))
+             (src (match-string 2 string))
+             (cmd (upcase (match-string 3 string)))
+             (params-str (match-string 4 string))
+             (params
+              (if params-str
+                  (let* ((idx (cl-search ":" 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)))
+
+(defun murk-msg->string (msg)
+  (let ((tags (murk-msg-tags msg))
+        (src (murk-msg-src msg))
+        (cmd (murk-msg-cmd msg))
+        (params (murk-msg-params msg)))
+    (murk--filtered-join
+     (if tags (concat "@" tags) nil)
+     (if src (concat ":" src) nil)
+     cmd
+     (if (> (length params) 1)
+         (string-join (seq-take params (- (length params) 1)) " ")
+       nil)
+     (if (> (length params) 0)
+         (concat ":" (elt params (- (length params) 1)))
+       nil))))
+
 
 ;;; Contexts and Servers
 ;;
@@ -149,15 +276,634 @@ This includes the process and the response string.")
 ;; representing either a channel name or nick, and server is a symbol
 ;; identifying the server.
 ;;
-;; Each server has a special context (server) used for messages
+;; Each server has a special context (server nil) used for messages
 ;; to/from the server itself.
 
-(defvar murk-current-context nil)
-(defvar murk-context-members nil)
+(defvar murk-contexts nil
+  "List of currently-available contexts.
+The head of this list is always the current context.")
+
+(defun murk-current-context ()
+  "Returns 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-users (ctx) (seq-drop ctx 2))
+(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
+        (assoc-delete-all server murk-contexts)))
+
+(defun murk-context->string (ctx)
+   (if (murk-server-context-p ctx)
+       (concat "[" (murk-context-server ctx) "]")
+     (concat (murk-context-name ctx) "@"
+             (murk-context-server ctx))))
+
+(defun murk-get-context (server &optional name)
+  (if name
+      (assoc server murk-contexts)
+    (let ((test-ctx (list server name)))
+      (seq-find (lambda (ctx)
+                  (equal (seq-take ctx 2) test-ctx))
+                murk-contexts))))
+
+;;; Buffer
+;;
+
+(defun murk-render-prompt ()
+  (with-current-buffer "*murk*"
+    (let ((update-point (= murk-input-marker (point)))
+          (update-window-points (mapcar (lambda (w)
+                                          (list (= (window-point w) murk-input-marker)
+                                                w))
+                                        (get-buffer-window-list nil nil t))))
+      (save-excursion
+        (set-marker-insertion-type murk-prompt-marker nil)
+        (set-marker-insertion-type murk-input-marker t)
+        (let ((inhibit-read-only t))
+          (delete-region murk-prompt-marker murk-input-marker)
+          (goto-char murk-prompt-marker)
+          (insert
+           (propertize (let ((ctx (murk-current-context)))
+                         (if ctx
+                             (murk-context->string ctx)
+                           ""))
+                       'face 'murk-context
+                       'read-only t)
+           (propertize murk-prompt-string
+                       'face 'murk-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 murk-input-marker nil))
+      (if update-point
+          (goto-char murk-input-marker))
+      (dolist (v update-window-points)
+        (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 ()
+  (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-name ctx)
+                               " ("
+                               (number-to-string
+                                (length (murk-context-users ctx)))
+                               ")"))))
+                       "No connection")))))))
+
+(defun murk-setup-buffer ()
+  (with-current-buffer (get-buffer-create "*murk*")
+    (setq-local scroll-conservatively 1)
+    (setq-local buffer-invisibility-spec nil)
+    (if (markerp murk-prompt-marker)
+        (set-marker murk-prompt-marker (point-max))
+      (setq murk-prompt-marker (point-max-marker)))
+    (if (markerp murk-input-marker)
+        (set-marker murk-input-marker (point-max))
+      (setq murk-input-marker (point-max-marker)))
+    (goto-char (point-max))
+    (murk-render-prompt)
+    (if murk-display-header
+        (murk-setup-header))))
+
+(defun murk-clear-buffer ()
+  "Completely erase all non-prompt and non-input text from murk buffer."
+  (with-current-buffer "*murk*"
+    (let ((inhibit-read-only t))
+      (delete-region (point-min) murk-prompt-marker))))
+
+
+;;; Output formatting and highlighting
+;;
+
+(defun murk--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 murk-display-string (context prefix &rest strings)
+  (with-current-buffer "*murk*"
+    (save-excursion
+      (goto-char murk-prompt-marker)
+      (let* ((inhibit-read-only t)
+             (old-pos (marker-position murk-prompt-marker))
+             (padded-timestamp (concat (format-time-string "%H:%M ")))
+             (padded-prefix (if prefix (concat prefix " ") ""))
+             (context-atom (if context (intern (murk-context->string context)) nil)))
+        (insert-before-markers
+         (murk--fill-strings
+          80
+          (+ (length padded-timestamp)
+             (length padded-prefix))
+          (propertize padded-timestamp
+                      'face 'murk-timestamp
+                      'read-only t
+                      'context context
+                      'invisible context-atom)
+          (propertize padded-prefix
+                      'read-only t
+                      'context context
+                      'invisible context-atom)
+          (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
+      (goto-char (point-max))
+      (line-beginning-position))))
+
+(defun murk-scroll-windows-to-last-line ()
+  (with-current-buffer "*murk*"
+    (dolist (window (get-buffer-window-list))
+      (if (>= (window-point window) (murk--start-of-final-line))
+          (with-selected-window window
+            (recenter -1))))))
+
+
+
+(defconst murk-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 murk-click-url (button)
+  (browse-url (button-get button 'url)))
+
+(defun murk-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 murk-url-regex nil t)
+      (let ((url (match-string 0)))
+        (make-text-button (match-beginning 0)
+                          (match-end 0)
+                          'action #'murk-click-url
+                          'url url
+                          'follow-link t
+                          'face 'button
+                          '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)))
+
+      ((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))
+         (murk-display-notice (murk-current-context)
+                              "Joining channel " channel " on " server)
+         (murk-render-prompt)))
+
+      ((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)))
+
+      ("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 (lurk-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)
+    ("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-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-name (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 (lurk-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)
+      (if (murk-current-context)
+          (let ((server (murk-context-server (murk-current-context))))
+            (murk-send-msg server
+                           (murk-msg nil nil "PRIVMSG"
+                                     (murk-context-name (murk-current-context))
+                                     string))
+            (murk-display-message server
+                                  murk-nick
+                                  (murk-context->string (murk-current-context))
+                                  string))
+        (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-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-get-context-users murk-current-context))
+                    (users-no@ (mapcar
+                                (lambda (u) (car (split-string u "@" t)))
+                                users)))
+               (completion-in-region start end users-no@)))))))))
+
+;;; Mode
+;;
+
+(defvar murk-mode-map
+  (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)
+    (when (fboundp 'evil-define-key*)
+      (evil-define-key* 'motion map
+        (kbd "TAB") 'murk-complete-input))
+    map))
+
+(define-derived-mode murk-mode text-mode "murk"
+  "Major mode for murk.")
+
+(when (fboundp 'evil-set-initial-state)
+  (evil-set-initial-state 'murk-mode 'insert))
 
 ;;; Main start procedure
 ;;
 
-(defun metalurk)
+(defun murk ()
+  "Start murk or just switch to the murk buffer if one already exists."
+  (interactive)
+  (if (get-buffer "*murk*")
+      (switch-to-buffer "*murk*")
+    (switch-to-buffer "*murk*")
+    (murk-mode)
+    (murk-setup-buffer))
+  "Started murk.")
+
 
-;;; metalurk.el ends here
+;;; murk.el ends here