From 7eefdca064dc77247d76ae0d03c5e80eab779415 Mon Sep 17 00:00:00 2001
From: Yuki Kishimoto <yukikishimoto@protonmail.com>
Date: Sat, 6 Apr 2024 18:06:37 +0200
Subject: [PATCH] gossip: init `nostr-gossip`

---
 Cargo.lock                           |   7 ++
 crates/nostr-gossip/Cargo.toml       |  15 ++++
 crates/nostr-gossip/README.md        |  13 ++++
 crates/nostr-gossip/src/constants.rs |   7 ++
 crates/nostr-gossip/src/lib.rs       | 106 +++++++++++++++++++++++++++
 5 files changed, 148 insertions(+)
 create mode 100644 crates/nostr-gossip/Cargo.toml
 create mode 100644 crates/nostr-gossip/README.md
 create mode 100644 crates/nostr-gossip/src/constants.rs
 create mode 100644 crates/nostr-gossip/src/lib.rs

diff --git a/Cargo.lock b/Cargo.lock
index d9fe1c4d4..908b94ccc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1716,6 +1716,13 @@ dependencies = [
  "uniffi",
 ]
 
+[[package]]
+name = "nostr-gossip"
+version = "0.29.0"
+dependencies = [
+ "nostr-relay-pool",
+]
+
 [[package]]
 name = "nostr-indexeddb"
 version = "0.29.0"
diff --git a/crates/nostr-gossip/Cargo.toml b/crates/nostr-gossip/Cargo.toml
new file mode 100644
index 000000000..44da0eb39
--- /dev/null
+++ b/crates/nostr-gossip/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "nostr-gossip"
+version = "0.29.0"
+edition = "2021"
+description = "Implementation of gossip protocol for nostr clients."
+authors.workspace = true
+homepage.workspace = true
+repository.workspace = true
+license.workspace = true
+readme = "README.md"
+rust-version.workspace = true
+keywords = ["nostr", "gossip"]
+
+[dependencies]
+nostr-relay-pool.workspace = true
\ No newline at end of file
diff --git a/crates/nostr-gossip/README.md b/crates/nostr-gossip/README.md
new file mode 100644
index 000000000..21b0e0d87
--- /dev/null
+++ b/crates/nostr-gossip/README.md
@@ -0,0 +1,13 @@
+# Nostr Gossip
+
+## State
+
+**This library is in an ALPHA state**, things that are implemented generally work but the API will change in breaking ways.
+
+## Donations
+
+`rust-nostr` is free and open-source. This means we do not earn any revenue by selling it. Instead, we rely on your financial support. If you actively use any of the `rust-nostr` libs/software/services, then please [donate](https://rust-nostr.org/donate).
+
+## License
+
+This project is distributed under the MIT software license - see the [LICENSE](../../LICENSE) file for details
\ No newline at end of file
diff --git a/crates/nostr-gossip/src/constants.rs b/crates/nostr-gossip/src/constants.rs
new file mode 100644
index 000000000..603539642
--- /dev/null
+++ b/crates/nostr-gossip/src/constants.rs
@@ -0,0 +1,7 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Copyright (c) 2023-2024 Rust Nostr Developers
+// Distributed under the MIT software license
+
+//! Constants
+
+pub const DEFAULT_DISCOVERY_RELAYS: [&str; 1] = ["wss://purplepag.es"];
diff --git a/crates/nostr-gossip/src/lib.rs b/crates/nostr-gossip/src/lib.rs
new file mode 100644
index 000000000..1ddbe6a07
--- /dev/null
+++ b/crates/nostr-gossip/src/lib.rs
@@ -0,0 +1,106 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Copyright (c) 2023-2024 Rust Nostr Developers
+// Distributed under the MIT software license
+
+//! Gossip
+
+use std::ops::Deref;
+use std::time::Duration;
+
+use nostr_relay_pool::pool::Error;
+use nostr_relay_pool::prelude::*;
+use nostr_relay_pool::{FilterOptions, RelayOptions, RelayPool, RelayServiceFlags};
+
+pub mod constants;
+
+/// Gossip client
+#[derive(Debug, Clone)]
+pub struct NostrGossip {
+    pool: RelayPool,
+}
+
+impl Deref for NostrGossip {
+    type Target = RelayPool;
+
+    fn deref(&self) -> &Self::Target {
+        &self.pool
+    }
+}
+
+impl NostrGossip {
+    pub async fn add_discovery_relay<U>(&self, url: U) -> Result<bool, Error>
+    where
+        U: TryIntoUrl,
+        Error: From<<U as TryIntoUrl>::Err>,
+    {
+        // Compose flags
+        let mut flags: RelayServiceFlags = RelayServiceFlags::NONE;
+        flags.add(RelayServiceFlags::DISCOVERY);
+
+        // Compose options
+        let opts: RelayOptions = RelayOptions::default().flags(flags);
+
+        // Add relay
+        self.pool.add_relay(url, opts).await
+    }
+
+    pub async fn add_inbox_relay<U>(&self, url: U) -> Result<bool, Error>
+    where
+        U: TryIntoUrl,
+        Error: From<<U as TryIntoUrl>::Err>,
+    {
+        // Compose flags
+        let mut flags: RelayServiceFlags = RelayServiceFlags::NONE;
+        flags.add(RelayServiceFlags::READ);
+        flags.add(RelayServiceFlags::INBOX);
+
+        // Compose options
+        let opts: RelayOptions = RelayOptions::default().flags(flags);
+
+        // Add relay
+        self.pool.add_relay(url, opts).await
+    }
+
+    pub async fn add_outbox_relay<U>(&self, url: U) -> Result<bool, Error>
+    where
+        U: TryIntoUrl,
+        Error: From<<U as TryIntoUrl>::Err>,
+    {
+        // Compose flags
+        let mut flags: RelayServiceFlags = RelayServiceFlags::NONE;
+        flags.add(RelayServiceFlags::WRITE);
+        flags.add(RelayServiceFlags::OUTBOX);
+
+        // Compose options
+        let opts: RelayOptions = RelayOptions::default().flags(flags);
+
+        // Add relay
+        self.pool.add_relay(url, opts).await
+    }
+
+    pub async fn get_relays_for_public_key(
+        &self,
+        public_key: PublicKey,
+        timeout: Duration,
+    ) -> Result<Vec<(UncheckedUrl, Option<RelayMetadata>)>, Error> {
+        // Get discovery relays
+        let relays = self
+            .pool
+            .relays_with_flag(RelayServiceFlags::DISCOVERY)
+            .await
+            .into_keys();
+
+        // Get events
+        let filter: Filter = Filter::default()
+            .author(public_key)
+            .kind(Kind::RelayList)
+            .limit(1);
+        let events: Vec<Event> = self
+            .get_events_from(relays, vec![filter], timeout, FilterOptions::ExitOnEOSE)
+            .await?;
+
+        // Extract relay list (NIP65)
+        let event: &Event = events.first().unwrap(); // TODO: remove unwrap
+        Ok(nip65::extract_relay_list(&event))
+    }
+}