Proper http error response codes

src/main.rs

@@ -3,6 +3,7 @@ use axum::{
         State,
         Path,
     },
+    http::StatusCode,
     response::Html,
     routing::get,
     Router,
@@ -142,9 +143,9 @@ async fn route_index(
 async fn route_station_overview(
     State(state): State<AppState>,
     Path(station): Path<String>
-) -> Result<Html<String>, String> {
+) -> Result<Html<String>, (StatusCode, String)> {
     if !state.stations.contains_key(&station) {
-        return Err(String::from(""));
+        return Err((StatusCode::NOT_FOUND, String::from("Unknown departing station")));
     }
 
     let mut out = String::new();
@@ -163,40 +164,40 @@ async fn route_station_overview(
 async fn route_station_to_dest_station(
     State(state): State<AppState>,
     Path((station_id, dest_station_id)): Path<(String, String)>
-) -> Result<String, String> {
+) -> Result<String, (StatusCode, String)> {
     if !state.stations.contains_key(&station_id) {
-        return Err(String::from(""));
+        return Err((StatusCode::NOT_FOUND, String::from("Unknown departing station")));
     }
 
     if !state.stations.contains_key(&dest_station_id) {
-        return Err(String::from(""));
+        return Err((StatusCode::NOT_FOUND, String::from("Unknown destination station")));
     }
 
     let station_properties = match state.stations.get(&station_id) {
         Some(v) => v,
-        None => return Err(String::from("")),
+        None => return Err((StatusCode::INTERNAL_SERVER_ERROR, String::from("Station properties for departing station missing"))),
     };
 
     let dest_station_properties = match state.stations.get(&dest_station_id) {
         Some(v) => v,
-        None => return Err(String::from("")),
+        None => return Err((StatusCode::INTERNAL_SERVER_ERROR, String::from("Station properties for destination station missing"))),
     };
 
 
     let client = reqwest::Client::new();
     let stationdata_req = client.get(format!("https://bahn.expert/api/iris/v2/abfahrten/{}?lookahead=150&lookbehind=10", station_properties.code))
         .send().await
-        .map_err(|_err| String::from("Station Data cannot be fetched"))?;
+        .map_err(|_err| (StatusCode::INTERNAL_SERVER_ERROR, String::from("Station Data cannot be fetched")))?;
     
     if stationdata_req.status() != reqwest::StatusCode::OK {
-        return Err(String::from("Station Data returned an unexpected response"));
+        return Err((StatusCode::INTERNAL_SERVER_ERROR, String::from("Station Data returned an unexpected response")));
     }
 
     let stationdata_body = stationdata_req.text().await
-        .map_err(|_err| "Station Data cannot be read")?;
+        .map_err(|_err| (StatusCode::INTERNAL_SERVER_ERROR, String::from("Station Data cannot be read")))?;
 
     let stationdata: Departures = serde_json::from_str(stationdata_body.as_str())
-        .map_err(|err| format!("{}", err))?;
+        .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, format!("{}", err)))?;
     
     let mut out = String::new();