Add status endpoint to V2 API.

src/api/server.rs

@@ -12,6 +12,7 @@
 use crate::api::v2;
 use crate::{
 	api::v1::{self},
+	rpc::Node,
 	types::{RuntimeConfig, State},
 };
 use anyhow::Context;
@@ -31,6 +32,7 @@ pub struct Server {
 	pub state: Arc<Mutex<State>>,
 	pub version: String,
 	pub network_version: String,
+	pub node: Node,
 }
 
 impl Server {
@@ -41,15 +43,21 @@ impl Server {
 			http_server_port: port,
 			app_id,
 			..
-		} = self.cfg;
+		} = self.cfg.clone();
 
 		let port = (port.1 > 0)
 			.then(|| thread_rng().gen_range(port.0..=port.1))
 			.unwrap_or(port.0);
 
 		let v1_api = v1::routes(self.db.clone(), app_id, self.state.clone());
 		#[cfg(feature = "api-v2")]
-		let v2_api = v2::routes(self.version.clone(), self.network_version.clone());
+		let v2_api = v2::routes(
+			self.version.clone(),
+			self.network_version.clone(),
+			self.node,
+			self.state.clone(),
+			self.cfg,
+		);
 
 		let cors = warp::cors()
 			.allow_any_origin()

src/api/v2/README.md

@@ -34,6 +34,77 @@ Content-Type: application/json
 - **version** - the Avail Light Client version
 - **network_version** - Avail network version supported by the Avail Light Client
 
+## **GET** `/v2/status`
+
+Gets current status and active modes of the light client.
+
+Response:
+
+```yaml
+HTTP/1.1 200 OK
+Content-Type: application/json
+
+{
+  "modes": [
+    "light",
+    "app",
+    "partition"
+  ],
+  "app_id": {app-id}, // Optional
+  "genesis_hash": "{genesis-hash}",
+  "network": "{network}",
+  "blocks": {
+    "latest": {latest},
+    "available": { // Optional
+      "first": {first},
+      "last": {last}
+    },
+    "app_data": { // Optional
+      "first": {first},
+      "last": {last}
+    },
+    "historcal_sync": { // Optional
+      "synced": false,
+      "available": { // Optional
+        "first": {first},
+        "last": {last}
+      },
+      "app_data": { // Optional
+        "first": {first},
+        "last": {last}
+      }
+    }
+  },
+  "partition": "{partition}" // Optional
+}
+```
+
+- **modes** - active modes
+- **app_id** - if **app** mode is active, this field contains configured application ID
+- **genesis_hash** - genesis hash of the network to which the light client is connected
+- **network** - network host, version and spec version light client is currently con
+- **blocks** - state of processed blocks
+- **partition** - if configured, displays partition which light client distributes to the peer to peer network
+
+### Modes
+
+- **light** - data availability sampling mode, the light client performs random sampling and calculates confidence
+- **app** - light client fetches, verifies, and stores application-related data
+- **partition** - light client fetches configured block partition and publishes it to the DHT
+
+### Blocks
+
+- **latest** - block number of the latest [finalized](https://docs.substrate.io/learn/consensus/) block received from the node
+- **available** - range of blocks with verified data availability (configured confidence has been achieved)
+- **app_data** - range of blocks with app data retrieved and verified
+- **historical_sync** - state for historical blocks syncing up to configured block (ommited if historical sync is not configured)
+
+### Historical sync
+
+- **synced** - `true` if there are no historical blocks left to sync
+- **available** - range of historical blocks with verified data availability (configured confidence has been achieved)
+- **app_data** - range of historical blocks with app data retrieved and verified
+
 # WebSocket API
 
 The Avail Light Client WebSocket API allows real-time communication between a client and a server over a persistent connection, enabling push notifications as an alternative to polling. Web socket API can be used on its own or in combination with HTTP API to enable different pull/push use cases.

src/api/v2/handlers.rs

@@ -1,8 +1,21 @@
 use super::{
-	types::{Client, Clients, Subscription, SubscriptionId, Version},
+	types::{
+		BlockRange, Blocks, Client, Clients, HistoricalSync, Status, Subscription, SubscriptionId,
+		Version,
+	},
 	ws,
 };
-use std::convert::Infallible;
+use crate::{
+	api::v2::types::InternalServerError,
+	rpc::Node,
+	types::{RuntimeConfig, State},
+};
+use hyper::StatusCode;
+use std::{
+	convert::Infallible,
+	sync::{Arc, Mutex},
+};
+use tracing::info;
 use uuid::Uuid;
 use warp::{ws::Ws, Rejection, Reply};
 
@@ -28,3 +41,47 @@ pub async fn ws(
 	// Multiple connections to the same client are currently allowed
 	Ok(ws.on_upgrade(move |web_socket| ws::connect(subscription_id, web_socket, clients, version)))
 }
+
+pub async fn status(
+	config: RuntimeConfig,
+	node: Node,
+	state: Arc<Mutex<State>>,
+) -> Result<impl Reply, impl Reply> {
+	let state = match state.lock() {
+		Ok(state) => state,
+		Err(error) => {
+			info!("Cannot acquire lock for last_block: {error}");
+			return Err(StatusCode::INTERNAL_SERVER_ERROR);
+		},
+	};
+
+	let historical_sync = state.synced.map(|synced| HistoricalSync {
+		synced,
+		available: state.sync_confidence_achieved.as_ref().map(From::from),
+		app_data: state.sync_data_verified.as_ref().map(From::from),
+	});
+
+	let blocks = Blocks {
+		latest: state.latest,
+		available: state.confidence_achieved.as_ref().map(From::from),
+		app_data: state.data_verified.as_ref().map(From::from),
+		historical_sync,
+	};
+
+	let status = Status {
+		modes: (&config).into(),
+		app_id: config.app_id,
+		genesis_hash: format!("{:?}", node.genesis_hash),
+		network: node.network(),
+		blocks,
+		partition: config.block_matrix_partition,
+	};
+	Ok(status)
+}
+
+pub async fn handle_rejection(error: Rejection) -> Result<impl Reply, Rejection> {
+	if error.find::<InternalServerError>().is_some() {
+		return Ok(StatusCode::INTERNAL_SERVER_ERROR.into_response());
+	}
+	Err(error)
+}

src/api/v2/mod.rs

@@ -1,5 +1,17 @@
-use self::types::{Clients, Version};
-use std::{collections::HashMap, convert::Infallible, sync::Arc};
+use crate::{
+	rpc::Node,
+	types::{RuntimeConfig, State},
+};
+
+use self::{
+	handlers::handle_rejection,
+	types::{Clients, Version},
+};
+use std::{
+	collections::HashMap,
+	convert::Infallible,
+	sync::{Arc, Mutex},
+};
 use tokio::sync::RwLock;
 use warp::{Filter, Rejection, Reply};
 
@@ -19,6 +31,20 @@ fn version_route(
 		.map(move || version.clone())
 }
 
+fn status_route(
+	config: RuntimeConfig,
+	node: Node,
+	state: Arc<Mutex<State>>,
+) -> impl Filter<Extract = (impl Reply,), Error = Rejection> + Clone {
+	warp::path!("v2" / "status")
+		.and(warp::get())
+		.and(warp::any().map(move || config.clone()))
+		.and(warp::any().map(move || node.clone()))
+		.and(warp::any().map(move || state.clone()))
+		.then(handlers::status)
+		.map(types::handle_result)
+}
+
 fn subscriptions_route(
 	clients: Clients,
 ) -> impl Filter<Extract = (impl Reply,), Error = Rejection> + Clone {
@@ -43,39 +69,50 @@ fn ws_route(
 pub fn routes(
 	version: String,
 	network_version: String,
+	node: Node,
+	state: Arc<Mutex<State>>,
+	config: RuntimeConfig,
 ) -> impl Filter<Extract = (impl Reply,), Error = Rejection> + Clone {
 	let clients: Clients = Arc::new(RwLock::new(HashMap::new()));
 	let version = Version {
 		version,
 		network_version,
 	};
 	version_route(version.clone())
+		.or(status_route(config, node, state))
 		.or(subscriptions_route(clients.clone()))
 		.or(ws_route(clients, version))
+		.recover(handle_rejection)
 }
 
 #[cfg(test)]
 mod tests {
-	use crate::api::v2::types::{
-		Clients, DataFields, Subscription, SubscriptionId, Topics, Version,
+	use super::types::Client;
+	use crate::{
+		api::v2::types::{Clients, DataFields, Subscription, SubscriptionId, Topics, Version},
+		rpc::Node,
+		types::{RuntimeConfig, State},
 	};
+	use kate_recovery::matrix::Partition;
+	use sp_core::H256;
 	use std::{
 		collections::{HashMap, HashSet},
 		str::FromStr,
-		sync::Arc,
+		sync::{Arc, Mutex},
 	};
 	use tokio::sync::RwLock;
 	use uuid::Uuid;
 
-	use super::types::Client;
-
 	fn v1() -> Version {
 		Version {
 			version: "v1.0.0".to_string(),
 			network_version: "nv1.0.0".to_string(),
 		}
 	}
 
+	const GENESIS_HASH: &str = "0xc590b3c924c35c2f241746522284e4709df490d73a38aaa7d6de4ed1eac2f500";
+	const NETWORK: &str = "{host}/{system_version}/data-avail/0";
+
 	#[tokio::test]
 	async fn version_route() {
 		let route = super::version_route(v1());
@@ -91,6 +128,72 @@ mod tests {
 		);
 	}
 
+	impl Default for Node {
+		fn default() -> Self {
+			Self {
+				host: "{host}".to_string(),
+				system_version: "{system_version}".to_string(),
+				spec_version: 0,
+				genesis_hash: H256::from_str(GENESIS_HASH).unwrap(),
+			}
+		}
+	}
+
+	#[tokio::test]
+	async fn status_route_defaults() {
+		let state = Arc::new(Mutex::new(State::default()));
+		let route = super::status_route(RuntimeConfig::default(), Node::default(), state);
+		let response = warp::test::request()
+			.method("GET")
+			.path("/v2/status")
+			.reply(&route)
+			.await;
+
+		let expected = format!(
+			r#"{{"modes":["light"],"genesis_hash":"{GENESIS_HASH}","network":"{NETWORK}","blocks":{{"latest":0}}}}"#
+		);
+		assert_eq!(response.body(), &expected);
+	}
+
+	#[tokio::test]
+	async fn status_route() {
+		let runtime_config = RuntimeConfig {
+			app_id: Some(1),
+			sync_start_block: Some(10),
+			block_matrix_partition: Some(Partition {
+				number: 1,
+				fraction: 10,
+			}),
+			..Default::default()
+		};
+		let state = Arc::new(Mutex::new(State::default()));
+		{
+			let mut state = state.lock().unwrap();
+			state.latest = 30;
+			state.set_confidence_achieved(20);
+			state.set_confidence_achieved(29);
+			state.set_data_verified(20);
+			state.set_data_verified(29);
+			state.set_synced(false);
+			state.set_sync_confidence_achieved(10);
+			state.set_sync_confidence_achieved(19);
+			state.set_sync_data_verified(10);
+			state.set_sync_data_verified(18);
+		}
+
+		let route = super::status_route(runtime_config, Node::default(), state);
+		let response = warp::test::request()
+			.method("GET")
+			.path("/v2/status")
+			.reply(&route)
+			.await;
+
+		let expected = format!(
+			r#"{{"modes":["light","app","partition"],"app_id":1,"genesis_hash":"{GENESIS_HASH}","network":"{NETWORK}","blocks":{{"latest":30,"available":{{"first":20,"last":29}},"app_data":{{"first":20,"last":29}},"historical_sync":{{"synced":false,"available":{{"first":10,"last":19}},"app_data":{{"first":10,"last":18}}}}}},"partition":"1/10"}}"#
+		);
+		assert_eq!(response.body(), &expected);
+	}
+
 	fn all_topics() -> HashSet<Topics> {
 		vec![
 			Topics::HeaderVerified,