feat(api): init rust rewrite

services/api/src/middleware/ignore_invalid_routes.rs

@@ -0,0 +1,61 @@
+use axum::{
+    extract::MatchedPath,
+    http::{Request, StatusCode},
+    middleware::Next,
+    response::{IntoResponse, Response},
+};
+
+use crate::util::header_or_unknown;
+
+fn is_trying_to_use_v1_path_on_v2(path: &str) -> bool {
+    path.starts_with("/v2/s/")
+        || path.starts_with("/v2/m/")
+        || path.starts_with("/v2/a/")
+        || path.starts_with("/v2/msg/")
+        || path == "/v2/s"
+        || path == "/v2/m"
+}
+
+pub async fn ignore_invalid_routes<B>(request: Request<B>, next: Next<B>) -> Response {
+    let path = request
+        .extensions()
+        .get::<MatchedPath>()
+        .cloned()
+        .map(|v| v.as_str().to_string())
+        .unwrap_or("unknown".to_string());
+    let user_agent = header_or_unknown(request.headers().get("User-Agent"));
+
+    if request.uri().path().starts_with("/v1") {
+        (
+            StatusCode::GONE,
+            r#"{"message":"Unsupported API version","code":0}"#,
+        )
+            .into_response()
+    } else if is_trying_to_use_v1_path_on_v2(request.uri().path()) {
+        (
+            StatusCode::BAD_REQUEST,
+            r#"{"message":"Invalid path for API version","code":0}"#,
+        )
+            .into_response()
+    }
+    // we ignored v1 routes earlier, now let's ignore all non-v2 routes
+    else if !request.uri().clone().path().starts_with("/v2") {
+        return (
+            StatusCode::BAD_REQUEST,
+            r#"{"message":"Unsupported API version","code":0}"#,
+        )
+            .into_response();
+    } else if path == "unknown" {
+        // current prod api responds with 404 with empty body to invalid endpoints
+        // just doing that here as well but i'm not sure if it's the correct behaviour
+        return StatusCode::NOT_FOUND.into_response();
+    }
+    // yes, technically because of how we parse headers this will break for user-agents literally set to "unknown"
+    // but "unknown" isn't really a valid user-agent
+    else if user_agent == "unknown" {
+        // please set a valid user-agent
+        return StatusCode::FORBIDDEN.into_response();
+    } else {
+        next.run(request).await
+    }
+}