MemoServ: add IGNORE

IGNORE ADD/DEL/LIST manages a per-account memo-ignore list; a memo from
an ignored account is silently dropped, and the sender is still told it
was sent so the ignore isn't revealed. New memo_ignore account field +
events, and a check in SEND.

src/engine/db/account.rs

@@ -20,7 +20,7 @@ impl Db {
             verified,
             ajoin: Vec::new(),
             suspension: None,
-            memos: Vec::new(),
+            memos: Vec::new(), memo_ignore: Vec::new(),
             greet: String::new(),
             vhost: None,
             vhost_request: None,
@@ -59,7 +59,7 @@ impl Db {
             verified: true, // the external authority vouches for it
             ajoin: Vec::new(),
             suspension: None,
-            memos: Vec::new(),
+            memos: Vec::new(), memo_ignore: Vec::new(),
             greet: String::new(),
             vhost: None,
             vhost_request: None,

src/engine/db/channel.rs

@@ -654,6 +654,40 @@ impl Db {
         })
     }
 
+    /// Add `target` to `account`'s memo-ignore list. Returns whether it was new.
+    pub fn memo_ignore_add(&mut self, account: &str, target: &str) -> bool {
+        let k = key(account);
+        let Some(a) = self.accounts.get(&k) else { return false };
+        if a.memo_ignore.iter().any(|t| t.eq_ignore_ascii_case(target)) {
+            return false;
+        }
+        let _ = self.log.append(Event::MemoIgnoreAdd { account: account.to_string(), target: target.to_string() });
+        self.accounts.get_mut(&k).unwrap().memo_ignore.push(target.to_string());
+        true
+    }
+
+    /// Remove `target` from `account`'s memo-ignore list. Returns whether it existed.
+    pub fn memo_ignore_del(&mut self, account: &str, target: &str) -> bool {
+        let k = key(account);
+        let Some(a) = self.accounts.get(&k) else { return false };
+        if !a.memo_ignore.iter().any(|t| t.eq_ignore_ascii_case(target)) {
+            return false;
+        }
+        let _ = self.log.append(Event::MemoIgnoreDel { account: account.to_string(), target: target.to_string() });
+        self.accounts.get_mut(&k).unwrap().memo_ignore.retain(|t| !t.eq_ignore_ascii_case(target));
+        true
+    }
+
+    /// `account`'s memo-ignore list.
+    pub fn memo_ignores(&self, account: &str) -> Vec<String> {
+        self.accounts.get(&key(account)).map_or(Vec::new(), |a| a.memo_ignore.clone())
+    }
+
+    /// Whether `account` is ignoring memos from `sender`.
+    pub fn memo_is_ignored(&self, account: &str, sender: &str) -> bool {
+        self.accounts.get(&key(account)).is_some_and(|a| a.memo_ignore.iter().any(|t| t.eq_ignore_ascii_case(sender)))
+    }
+
     /// How many unread memos an account has.
     pub fn unread_memos(&self, account: &str) -> usize {
         self.accounts.get(&key(account)).map_or(0, |a| a.memos.iter().filter(|m| !m.read).count())

src/engine/db/event.rs

@@ -29,6 +29,8 @@ pub enum Event {
     MemoSent { account: String, from: String, text: String, ts: u64 },
     MemoRead { account: String, index: usize },
     MemoDeleted { account: String, index: usize },
+    MemoIgnoreAdd { account: String, target: String },
+    MemoIgnoreDel { account: String, target: String },
     NickGrouped { nick: String, account: String },
     NickUngrouped { nick: String },
     ChannelRegistered { name: String, founder: String, ts: u64 },
@@ -156,6 +158,8 @@ impl Event {
             | Event::MemoSent { .. }
             | Event::MemoRead { .. }
             | Event::MemoDeleted { .. }
+            | Event::MemoIgnoreAdd { .. }
+            | Event::MemoIgnoreDel { .. }
             | Event::NickGrouped { .. }
             | Event::NickUngrouped { .. }
             | Event::AccountSeen { .. }
@@ -338,6 +342,18 @@ pub(crate) fn apply(accounts: &mut HashMap<String, Account>, channels: &mut Hash
                 }
             }
         }
+        Event::MemoIgnoreAdd { account, target } => {
+            if let Some(a) = accounts.get_mut(&key(&account)) {
+                if !a.memo_ignore.iter().any(|t| t.eq_ignore_ascii_case(&target)) {
+                    a.memo_ignore.push(target);
+                }
+            }
+        }
+        Event::MemoIgnoreDel { account, target } => {
+            if let Some(a) = accounts.get_mut(&key(&account)) {
+                a.memo_ignore.retain(|t| !t.eq_ignore_ascii_case(&target));
+            }
+        }
         Event::NickGrouped { nick, account } => {
             grouped.insert(key(&nick), account);
         }

src/engine/db/mod.rs

@@ -79,6 +79,9 @@ pub struct Account {
     // Memos left for this account (MemoServ), oldest first.
     #[serde(default)]
     pub memos: Vec<Memo>,
+    // Accounts this user won't receive memos from (MemoServ IGNORE).
+    #[serde(default)]
+    pub memo_ignore: Vec<String>,
     // Personal greet a bot shows when this account joins a greet-enabled channel.
     #[serde(default)]
     pub greet: String,

src/engine/db/store.rs

@@ -456,6 +456,18 @@ impl Store for Db {
     fn memo_cancel(&mut self, account: &str, sender: &str) -> bool {
         Db::memo_cancel(self, account, sender)
     }
+    fn memo_ignore_add(&mut self, account: &str, target: &str) -> bool {
+        Db::memo_ignore_add(self, account, target)
+    }
+    fn memo_ignore_del(&mut self, account: &str, target: &str) -> bool {
+        Db::memo_ignore_del(self, account, target)
+    }
+    fn memo_ignores(&self, account: &str) -> Vec<String> {
+        Db::memo_ignores(self, account)
+    }
+    fn memo_is_ignored(&self, account: &str, sender: &str) -> bool {
+        Db::memo_is_ignored(self, account, sender)
+    }
     fn memo_check(&self, account: &str, sender: &str) -> Option<(bool, u64)> {
         Db::memo_check(self, account, sender)
     }

src/engine/db/tests.rs

@@ -32,7 +32,7 @@
         // which of the two competing registrations we're looking at.
         let alice = |tag: &str, ts: u64, home: &str| Account {
             name: "alice".into(), email: Some(tag.into()),
-            ts, home: home.into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], greet: String::new(), vhost: None, vhost_request: None, last_seen: ts, noexpire: false, expiry_warned: false, oper_note: None,
+            ts, home: home.into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], memo_ignore: vec![], greet: String::new(), vhost: None, vhost_request: None, last_seen: ts, noexpire: false, expiry_warned: false, oper_note: None,
         };
         let converge = |first: &Account, second: &Account| {
             let (mut acc, mut ch, mut gr, mut bo, mut hc, mut nd) = (HashMap::new(), HashMap::new(), HashMap::new(), HashMap::new(), HostConfig::default(), NetData::default());
@@ -329,7 +329,7 @@
         db.register("alice", "pw", None).unwrap();
         let bob = Account {
             name: "bob".into(), email: None,
-            ts: 0, home: "peer".into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], greet: String::new(), vhost: None, vhost_request: None, last_seen: 0, noexpire: false, expiry_warned: false, oper_note: None,
+            ts: 0, home: "peer".into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], memo_ignore: vec![], greet: String::new(), vhost: None, vhost_request: None, last_seen: 0, noexpire: false, expiry_warned: false, oper_note: None,
         };
         let entry = LogEntry { origin: "peer".into(), seq: 0, lamport: 1, event: Event::AccountRegistered(Box::new(bob)) };
         db.ingest(entry).unwrap();