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.

modules/memoserv/src/ignore.rs

@@ -0,0 +1,41 @@
+use echo_api::{Sender, ServiceCtx, Store};
+
+// IGNORE ADD <nick> | DEL <nick> | LIST: manage your memo-ignore list. Memos
+// from an ignored account are silently dropped.
+pub fn handle(me: &str, from: &Sender, account: &str, args: &[&str], ctx: &mut ServiceCtx, db: &mut dyn Store) {
+    match args.get(1).map(|s| s.to_ascii_uppercase()).as_deref() {
+        Some("ADD") => {
+            let Some(&nick) = args.get(2) else {
+                ctx.notice(me, from.uid, "Syntax: IGNORE ADD <nick>");
+                return;
+            };
+            let target = db.resolve_account(nick).map(str::to_string).unwrap_or_else(|| nick.to_string());
+            if db.memo_ignore_add(account, &target) {
+                ctx.notice(me, from.uid, format!("Now ignoring memos from \x02{target}\x02."));
+            } else {
+                ctx.notice(me, from.uid, format!("You're already ignoring \x02{target}\x02."));
+            }
+        }
+        Some("DEL") | Some("REMOVE") => {
+            let Some(&nick) = args.get(2) else {
+                ctx.notice(me, from.uid, "Syntax: IGNORE DEL <nick>");
+                return;
+            };
+            let target = db.resolve_account(nick).map(str::to_string).unwrap_or_else(|| nick.to_string());
+            if db.memo_ignore_del(account, &target) {
+                ctx.notice(me, from.uid, format!("No longer ignoring \x02{target}\x02."));
+            } else {
+                ctx.notice(me, from.uid, format!("You weren't ignoring \x02{target}\x02."));
+            }
+        }
+        Some("LIST") | None => {
+            let list = db.memo_ignores(account);
+            if list.is_empty() {
+                ctx.notice(me, from.uid, "Your memo-ignore list is empty.");
+            } else {
+                ctx.notice(me, from.uid, format!("You're ignoring memos from: {}", list.join(", ")));
+            }
+        }
+        _ => ctx.notice(me, from.uid, "Syntax: IGNORE ADD <nick> | DEL <nick> | LIST"),
+    }
+}

modules/memoserv/src/lib.rs

@@ -22,6 +22,8 @@ mod check;
 mod info;
 #[path = "sendall.rs"]
 mod sendall;
+#[path = "ignore.rs"]
+mod ignore;
 
 const BLURB: &str = "MemoServ delivers messages to registered users, online or not. You must be identified to use it.";
 
@@ -37,6 +39,7 @@ const TOPICS: &[HelpEntry] = &[
     HelpEntry { cmd: "CHECK", summary: "see if a memo was read", detail: "Syntax: \x02CHECK <nick>\x02\nReports whether the last memo you sent them has been read." },
     HelpEntry { cmd: "INFO", summary: "your mailbox summary", detail: "Syntax: \x02INFO\x02\nShows how many memos you have, how many are unread, and your capacity." },
     HelpEntry { cmd: "SENDALL", summary: "memo every account (admin)", detail: "Syntax: \x02SENDALL <text>\x02\nLeaves a memo on every registered account. Requires the admin privilege." },
+    HelpEntry { cmd: "IGNORE", summary: "block memos from an account", detail: "Syntax: \x02IGNORE ADD <nick> | DEL <nick> | LIST\x02\nMemos from an ignored account are silently dropped." },
 ];
 
 pub struct MemoServ {
@@ -79,6 +82,7 @@ impl Service for MemoServ {
             Some("CHECK") => check::handle(me, from, account, args, ctx, db),
             Some("INFO") => info::handle(me, from, account, ctx, db),
             Some("SENDALL") => sendall::handle(me, from, account, args, ctx, db),
+            Some("IGNORE") => ignore::handle(me, from, account, args, ctx, db),
             Some(other) => ctx.notice(me, from.uid, format!("I don't know the command \x02{other}\x02. Try \x02HELP\x02.")),
             None => {}
         }

modules/memoserv/src/send.rs

@@ -18,6 +18,12 @@ pub fn handle(me: &str, from: &Sender, account: &str, args: &[&str], ctx: &mut S
         ctx.notice(me, from.uid, format!("\x02{target}\x02's mailbox is full — they'll need to clear some memos first."));
         return;
     }
+    // If the recipient is ignoring the sender, drop it silently — the sender is
+    // told it was sent, so the ignore isn't revealed.
+    if db.memo_is_ignored(&dest, account) {
+        ctx.notice(me, from.uid, format!("Memo sent to \x02{target}\x02."));
+        return;
+    }
     match db.memo_send(&dest, account, &text) {
         Ok(()) => ctx.notice(me, from.uid, format!("Memo sent to \x02{target}\x02.")),
         Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),