filter: add kind blacklist filter

Signed-off-by: William Casarin <jb55@jb55.com>

src/filters/kinds.rs

@@ -0,0 +1,29 @@
+use crate::{Action, InputMessage, NoteFilter, OutputMessage};
+use serde::Deserialize;
+use std::collections::HashMap;
+
+#[derive(Deserialize, Default)]
+pub struct Kinds {
+    kinds: Vec<i64>,
+    messages: Option<HashMap<String, String>>,
+}
+
+impl NoteFilter for Kinds {
+    fn filter_note(&mut self, input: &InputMessage) -> OutputMessage {
+        let kind = input.event.kind;
+        if self.kinds.contains(&kind) {
+            let msg = self
+                .messages
+                .as_ref()
+                .and_then(|msgs| msgs.get(&kind.to_string()).cloned())
+                .unwrap_or_else(|| "blocked: note kind is not allowed here".to_string());
+            OutputMessage::new(input.event.id.clone(), Action::Reject, Some(msg))
+        } else {
+            OutputMessage::new(input.event.id.clone(), Action::Accept, None)
+        }
+    }
+
+    fn name(&self) -> &'static str {
+        "kinds"
+    }
+}

src/filters/mod.rs

@@ -1,7 +1,9 @@
+mod kinds;
 mod protected_events;
 mod ratelimit;
 mod whitelist;
 
+pub use kinds::Kinds;
 pub use protected_events::ProtectedEvents;
 pub use ratelimit::RateLimit;
 pub use whitelist::Whitelist;