fix: add user-agent response

Author: JayDwee

api/src/interactions/mod.rs

@@ -6,7 +6,7 @@ use axum::routing::post;
 use axum::{Json, middleware};
 use ed25519_dalek::{PUBLIC_KEY_LENGTH, Verifier, VerifyingKey};
 use hex::FromHex;
-use http::{HeaderMap, StatusCode};
+use http::{HeaderMap, HeaderValue, StatusCode};
 use http_body_util::BodyExt;
 use lambda_http::tracing::error;
 use once_cell::sync::Lazy;
@@ -32,6 +32,7 @@ pub fn router() -> axum::Router<AppState> {
     axum::Router::new()
         .route("/", post(post_interactions))
         .route_layer(middleware::from_fn(pubkey_middleware))
+        .route_layer(middleware::from_fn(user_agent_response_middleware))
         .route("/register", post(register_commands))
 }
 
@@ -75,6 +76,25 @@ pub async fn pubkey_middleware(request: Request, next: Next) -> Result<Response,
     Ok(next.run(new_request).await)
 }
 
+pub async fn user_agent_response_middleware(
+    request: Request,
+    next: Next,
+) -> Result<Response, StatusCode> {
+    let mut response = next.run(request).await;
+
+    let user_agent = response
+        .headers()
+        .get("User-Agent")
+        .and_then(|v| v.to_str().ok())
+        .unwrap_or("Unknown");
+
+    if response.headers().get("User-Agent").is_none() {
+        let full_version = env!("CARGO_PKG_VERSION");
+        response.headers_mut().insert("User-Agent", format!("KoalaBot/{} (+{})",full_version, get_url()).parse().unwrap());
+    }
+
+    Ok(response)}
+
 async fn post_interactions(
     State(_app_state): State<AppState>,
     Json(interaction): Json<Interaction>,
@@ -128,7 +148,7 @@ async fn support() -> Result<Json<Value>, StatusCode> {
 }
 
 fn get_url() -> String {
-    match std::env::var("DEPLOYMENT_ENV").expect("DEPLOYMENT_ENV must be set").as_str() {
+    match std::env::var("DEPLOYMENT_ENV").unwrap_or("prod".into()).as_str() {
         "prod" => "https://koalabot.uk".to_owned(),
         env => format!("https://{env}.koalabot.uk").to_owned()
     }