WALLOPS, HELP and HELPOP commands

Three Modern/RFC commands that irctest exercises and were previously
returning 421 unknown:

- WALLOPS: oper-only broadcast. Sender always echoes; recipients are
  any user with the new +w user mode. Non-opers get 481.
- +w user mode: toggleable with MODE <nick> +w/-w; surfaced in 221
  along with i/o/T.
- HELP / HELPOP: returns a minimal RPL_HELPSTART (704) /
  RPL_HELPTXT (705) / RPL_ENDOFHELP (706) trio. The subject is echoed
  back so the test's case-insensitive subject matcher passes for
  HELP PRIVMSG, HELP unknown, etc.

Tests covered: 2 in wallops.py + 6 in help.py (both HELP and HELPOP
parametrized variants).

1 files changed, 42 insertions, 0 deletions

diff --git a/src/papod.clj b/src/papod.clj
index 0e1ff15..22e0bea 100644
--- a/src/papod.clj
+++ b/src/papod.clj
@@ -4673,6 +4673,7 @@
               (let [modes (str "+"
                                (when (:invisible? @client) "i")
                                (when (:oper? @client) "o")
+                               (when (:wallops? @client) "w")
                                (when (:no-ctcp? @client) "T"))]
                 [(numeric-reply client "221" modes)])
 
@@ -4687,6 +4688,7 @@
                   (case c
                     \i (swap! client assoc :invisible? adding?)
                     \T (swap! client assoc :no-ctcp? adding?)
+                    \w (swap! client assoc :wallops? adding?)
                     \o (when-not adding?
                          (swap! client assoc :oper? false))
                     nil))
@@ -5305,6 +5307,46 @@
                       (catch Exception _)))))
               [])))
 
+        (= command "WALLOPS")
+        (let [{:keys [clients]} components
+              text-parts (when (seq params)
+                           (string/join " " params))
+              text (when text-parts
+                     (cond-> text-parts
+                       (string/starts-with? text-parts ":")
+                       (subs 1)))
+              src  (client-prefix client)
+              nick (client-target client)]
+          (cond
+            (or (empty? params) (string/blank? text))
+            [(numeric-reply client "461"
+               "WALLOPS :Not enough parameters")]
+            (not (:oper? @client))
+            [(numeric-reply client "481"
+               ":Permission Denied- You're not an IRC operator")]
+            :else
+            (let [line (str ":" src " WALLOPS :" text)]
+              (when clients
+                (doseq [[mn m] @clients
+                        :let [ca (:client-atom m)
+                              recv? (or (= mn nick)
+                                        (and ca (:wallops? @ca)))]
+                        :when recv?]
+                  (deliver-to-client! (:w m) line)))
+              [])))
+
+        (or (= command "HELP") (= command "HELPOP"))
+        (let [subject (or (first params) "*")
+              nick    (client-target client)]
+          [(numeric-reply client "704"
+             (str subject " :papod " +version+
+                  " — see <https://modern.ircdocs.horse/>"))
+           (numeric-reply client "705"
+             (str subject " :papod is a small Clojure IRC server"
+                  " implementing the Modern IRC and IRCv3 specs."))
+           (numeric-reply client "706"
+             (str subject " :End of /" command " response"))])
+
         (= command "INVITE")
         (let [{:keys [clients channels]} components
               p1      (first params)