database: add NostrDatabaseExt::relay_list

Signed-off-by: Yuki Kishimoto <[email protected]>

crates/nostr-database/src/lib.rs

@@ -14,7 +14,10 @@ use std::sync::Arc;
 pub use async_trait::async_trait;
 pub use nostr;
 use nostr::nips::nip01::Coordinate;
-use nostr::{Event, EventId, Filter, JsonUtil, Kind, Metadata, PublicKey, Timestamp, Url};
+use nostr::nips::nip65;
+use nostr::{
+    Event, EventId, Filter, JsonUtil, Kind, Metadata, PublicKey, RelayMetadata, Timestamp, Url,
+};
 
 mod error;
 #[cfg(feature = "flatbuf")]
@@ -255,6 +258,28 @@ pub trait NostrDatabaseExt: NostrDatabase {
             None => Ok(BTreeSet::new()),
         }
     }
+
+    /// Get relays list for [PublicKey]
+    ///
+    /// <https://github.com/nostr-protocol/nips/blob/master/65.md>
+    #[tracing::instrument(skip_all, level = "trace")]
+    async fn relay_list(
+        &self,
+        public_key: PublicKey,
+    ) -> Result<Vec<(Url, Option<RelayMetadata>)>, Self::Err> {
+        // Query
+        let filter: Filter = Filter::default()
+            .author(public_key)
+            .kind(Kind::RelayList)
+            .limit(1);
+        let events: Vec<Event> = self.query(vec![filter], Order::Desc).await?;
+
+        // Extract relay list (NIP65)
+        match events.first() {
+            Some(event) => Ok(nip65::extract_relay_list(event)),
+            None => Ok(Vec::new()),
+        }
+    }
 }
 
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]

crates/nostr/src/nips/nip65.rs

@@ -8,15 +8,16 @@
 
 use alloc::vec::Vec;
 
-use crate::{Event, RelayMetadata, Tag, UncheckedUrl};
+use crate::{Event, RelayMetadata, Tag, Url};
 
 /// Extracts the relay info (url, optional read/write flag) from the event
-pub fn extract_relay_list(event: &Event) -> Vec<(UncheckedUrl, Option<RelayMetadata>)> {
+#[inline]
+pub fn extract_relay_list(event: &Event) -> Vec<(Url, Option<RelayMetadata>)> {
     event
         .iter_tags()
         .filter_map(|tag| {
             if let Tag::RelayMetadata(url, metadata) = tag {
-                Some((url.clone(), metadata.clone()))
+                Some((Url::parse(url.as_str()).ok()?, metadata.clone()))
             } else {
                 None
             }

crates/nostr/src/types/url.rs

@@ -70,6 +70,12 @@ impl UncheckedUrl {
     pub fn empty() -> Self {
         Self(String::new())
     }
+
+    /// Get unchecked url as `&str`
+    #[inline]
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
 }
 
 impl<S> From<S> for UncheckedUrl