project: first attempt of reimplemantation of caesar with websockets

src/receiver/mod.rs

@@ -1 +1,82 @@
+/// This module is the entry point for the receiver command.
+/// It contains a single function, `start_receiver`, which is the
+/// entry point for the receiver program.
+///
+/// The `start_receiver` function takes a `String` which is the URL or
+/// invite code for the room that the receiver should join. If the
+/// URL is invalid or does not contain an invite code fragment,
+/// the function falls back to using the command line arguments to get
+/// the file paths to be sent.
+///
+/// The `start_receiver` function first creates a request to connect
+/// to the WebSocket server with a specific origin. This is done to
+/// prevent cross-origin requests, which are not allowed by the
+/// WebSocket protocol.
+///
+/// If creating the request succeeds, the function inserts the origin
+/// into the request headers. Then, it attempts to connect to the
+/// server using the `connect_async` function from the
+/// `tokio_tungstenite` crate.
+///
+/// If the connection attempt succeeds, the function extracts the
+/// invite code fragment from the URL and passes it to the `start`
+/// function in the `receiver::client` module. The `start` function is
+/// defined in the `receiver::client` module and is the function that
+/// interacts with the server to receive files.
+///
+/// If the connection attempt fails or the URL does not contain an
+/// invite code fragment, the function falls back to using the command
+/// line arguments to get the file paths to be sent. It then calls the
+/// `start` function in the `sender::client` module with the
+/// WebSocket stream and the file paths. The `start` function in the
+/// `sender::client` module is defined in the `sender::client`
+/// module and is the function that sends the files over the
+/// WebSocket connection.
+///
+/// The `start` function takes ownership of the WebSocket stream and
+/// the file paths, so we pass them by value.
 pub mod client;
+
+use crate::receiver::client as receiver;
+
+use tokio_tungstenite::{
+    connect_async,
+    tungstenite::{client::IntoClientRequest, http::HeaderValue},
+};
+use tracing::error;
+use url::Url;
+
+pub async fn start_receiver(relay: &str, name: &str) {
+    let argument = name;
+    let Ok(mut request) = relay.into_client_request() else {
+        println!("Error: Failed to create request.");
+        return;
+    };
+
+    // Insert the origin into the request headers to prevent
+    // cross-origin requests.
+    request
+        .headers_mut()
+        .insert("Origin", HeaderValue::from_str(relay).unwrap());
+
+    println!("Attempting to connect...");
+
+    let Ok((socket, _)) = connect_async(request).await else {
+        error!("Error: Failed to connect.");
+        return;
+    };
+
+    // If the URL is valid and contains an invite code fragment,
+    // extract it and pass it to the receiver::client::start
+    // function. The start function is defined in the
+    // receiver::client module and is the function that interacts with
+    // the server to receive files.
+    if let Ok(url) = Url::parse(argument) {
+        let Some(fragment) = url.fragment() else {
+            error!("Error: Missing invite code fragment in url.");
+            return;
+        };
+
+        receiver::start(socket, fragment).await
+    }
+}