Add base rest client setup.

Author: G8XSU

client/Cargo.toml

@@ -4,3 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+protos = { path = "../protos" }
+reqwest = { version = "0.11.13", default-features = false, features = ["rustls-tls"] }
+tokio = { version = "1.38.0", default-features = false }
+prost = { version = "0.11.6", default-features = false, features = ["std", "prost-derive"] }

client/src/client.rs

@@ -0,0 +1,49 @@
+use prost::Message;
+
+use crate::error::LdkNodeServerError;
+use reqwest::header::CONTENT_TYPE;
+use reqwest::Client;
+
+const APPLICATION_OCTET_STREAM: &str = "application/octet-stream";
+
+/// Client to access a hosted instance of LDK Node Server.
+#[derive(Clone)]
+pub struct LdkNodeServerClient {
+	base_url: String,
+	client: Client,
+}
+
+impl LdkNodeServerClient {
+	/// Constructs a [`LdkNodeServerClient`] using `base_url` as the server endpoint.
+	pub fn new(base_url: String) -> Self {
+		Self { base_url, client: Client::new() }
+	}
+
+	async fn post_request<Rq: Message, Rs: Message + Default>(
+		&self, request: &Rq, url: &str,
+	) -> Result<Rs, LdkNodeServerError> {
+		let request_body = request.encode_to_vec();
+		let response_raw = match self
+			.client
+			.post(url)
+			.header(CONTENT_TYPE, APPLICATION_OCTET_STREAM)
+			.body(request_body)
+			.send()
+			.await
+		{
+			Ok(response) => response,
+			Err(e) => {
+				return Err(LdkNodeServerError::InternalError(e.to_string()));
+			},
+		};
+		let status = response_raw.status();
+		let payload = response_raw.bytes().await?;
+
+		if status.is_success() {
+			Ok(Rs::decode(&payload[..])?)
+		} else {
+			//TODO: Error handling and error response parsing.
+			Err(LdkNodeServerError::InternalError("Unknown Error".to_string()))
+		}
+	}
+}

client/src/error.rs

@@ -0,0 +1,20 @@
+use prost::DecodeError;
+
+/// When there is an error in request to LDK Node Server, the response contains a relevant error code.
+#[derive(Debug)]
+pub enum LdkNodeServerError {
+	/// There is an unknown error. (Placeholder until error handling is done.)
+	InternalError(String),
+}
+
+impl From<DecodeError> for LdkNodeServerError {
+	fn from(err: DecodeError) -> Self {
+		LdkNodeServerError::InternalError(err.to_string())
+	}
+}
+
+impl From<reqwest::Error> for LdkNodeServerError {
+	fn from(err: reqwest::Error) -> Self {
+		LdkNodeServerError::InternalError(err.to_string())
+	}
+}

client/src/lib.rs

@@ -1,14 +1,14 @@
-pub fn add(left: usize, right: usize) -> usize {
-	left + right
-}
-
-#[cfg(test)]
-mod tests {
-	use super::*;
-
-	#[test]
-	fn it_works() {
-		let result = add(2, 2);
-		assert_eq!(result, 4);
-	}
-}
+//! Client-side library to interact with LDK Node Server.
+
+#![deny(rustdoc::broken_intra_doc_links)]
+#![deny(rustdoc::private_intra_doc_links)]
+#![deny(missing_docs)]
+
+/// Implements a client ([`client::LdkNodeServerClient`]) to access a hosted instance of LDK Node Server.
+pub mod client;
+
+/// Implements the error type ([`error::LdkNodeServerError`]) returned on interacting with [`client::LdkNodeServerClient`]
+pub mod error;
+
+/// Request/Response structs required for interacting with the client.
+pub use protos;