BotServ: add BOTLIST and AUTOASSIGN default bot

src/engine/db/channel.rs

@@ -562,6 +562,22 @@ impl Db {
         self.bots.values()
     }
 
+    /// The bot auto-assigned to newly registered channels, if one is set and
+    /// still exists (its canonical nick).
+    pub fn default_bot(&self) -> Option<&str> {
+        let k = self.net.default_bot.as_ref()?;
+        self.bots.get(k).map(|b| b.nick.as_str())
+    }
+
+    /// Set (or clear) the auto-assign bot. The caller validates the bot exists;
+    /// the nick is stored casefolded.
+    pub fn set_default_bot(&mut self, bot: Option<&str>) -> Result<(), ChanError> {
+        let stored = bot.map(|b| b.to_string());
+        self.log.append(Event::DefaultBotSet { bot: stored.clone() }).map_err(|_| ChanError::Internal)?;
+        self.net.default_bot = stored.map(|b| key(&b));
+        Ok(())
+    }
+
     /// Assign a bot to a channel.
     pub fn assign_bot(&mut self, channel: &str, bot: &str) -> Result<(), ChanError> {
         let k = key(channel);

src/engine/db/event.rs

@@ -56,6 +56,8 @@ pub enum Event {
     ChannelBotUnassigned { channel: String },
     BotAdded(Bot),
     BotRemoved { nick: String },
+    // The bot auto-assigned to newly registered channels (BotServ AUTOASSIGN).
+    DefaultBotSet { bot: Option<String> },
     VhostOfferAdded { host: String },
     VhostOfferRemoved { host: String },
     VhostForbidAdded { pattern: String },
@@ -211,6 +213,7 @@ impl Event {
             | Event::ChannelBotUnassigned { .. }
             | Event::BotAdded(_)
             | Event::BotRemoved { .. }
+            | Event::DefaultBotSet { .. }
             | Event::VhostOfferAdded { .. }
             | Event::VhostOfferRemoved { .. }
             | Event::VhostForbidAdded { .. }
@@ -469,6 +472,13 @@ pub(crate) fn apply(accounts: &mut HashMap<String, Account>, channels: &mut Hash
         }
         Event::BotRemoved { nick } => {
             bots.remove(&key(&nick));
+            // A default bot that was just removed can't stay the default.
+            if net.default_bot.as_deref() == Some(key(&nick).as_str()) {
+                net.default_bot = None;
+            }
+        }
+        Event::DefaultBotSet { bot } => {
+            net.default_bot = bot.map(|b| key(&b));
         }
         Event::VhostOfferAdded { host } => {
             if !host_cfg.offers.iter().any(|o| o == &host) {

src/engine/db/mod.rs

@@ -286,6 +286,9 @@ pub struct NetData {
     pub opers: HashMap<String, OperGrant>,
     // Session-limit exceptions (OperServ SESSION): per-IP-mask allowances.
     pub sess_exceptions: Vec<SessionException>,
+    // The bot auto-assigned to newly registered channels (BotServ AUTOASSIGN),
+    // if any. Casefolded nick; None disables auto-assignment.
+    pub default_bot: Option<String>,
 }
 
 // A session-limit exception: an IP-mask glob and the session allowance for IPs
@@ -1060,6 +1063,9 @@ impl Db {
         for b in self.bots.values() {
             snapshot.push(Event::BotAdded(b.clone()));
         }
+        if self.net.default_bot.is_some() {
+            snapshot.push(Event::DefaultBotSet { bot: self.net.default_bot.clone() });
+        }
         for host in &self.host_cfg.offers {
             snapshot.push(Event::VhostOfferAdded { host: host.clone() });
         }

src/engine/db/store.rs

@@ -441,6 +441,12 @@ impl Store for Db {
     fn unassign_bot(&mut self, channel: &str) -> Result<bool, ChanError> {
         Db::unassign_bot(self, channel)
     }
+    fn default_bot(&self) -> Option<String> {
+        Db::default_bot(self).map(str::to_string)
+    }
+    fn set_default_bot(&mut self, bot: Option<&str>) -> Result<(), ChanError> {
+        Db::set_default_bot(self, bot)
+    }
     fn memo_send(&mut self, account: &str, from: &str, text: &str, receipt: bool) -> Result<(), RegError> {
         Db::memo_send(self, account, from, text, receipt)
     }