Add translation languages endpoint

src/main.rs

@@ -8,7 +8,7 @@
 
 use std::{fmt::Display, str::FromStr, sync::OnceLock};
 
-use axum::{http::header::HeaderValue, response::Response};
+use axum::{http::header::HeaderValue, response::Response, routing::get, Json};
 use bytes::Bytes;
 use deadpool_redis::redis::AsyncCommands;
 use serde_json::to_value;
@@ -62,6 +62,18 @@ async fn get_voices(
     }))
 }
 
+async fn get_translation_languages() -> ResponseResult<Json<Vec<(FixedString, FixedString)>>> {
+    let state = STATE.get().unwrap();
+    let Some(token) = &state.translation_key else {
+        return Ok(Json(Vec::new()));
+    };
+
+    match translation::get_languages(&state.reqwest, token).await {
+        Ok(languages) => Ok(Json(languages)),
+        Err(err) => Err(Error::Unknown(err)),
+    }
+}
+
 #[derive(serde::Deserialize)]
 struct GetTTS {
     text: FixedString,
@@ -342,11 +354,12 @@ async fn main() -> Result<()> {
     }
 
     let app = axum::Router::new()
-        .route("/tts", axum::routing::get(get_tts))
-        .route("/voices", axum::routing::get(get_voices))
+        .route("/tts", get(get_tts))
+        .route("/voices", get(get_voices))
+        .route("/translation_languages", get(get_translation_languages))
         .route(
             "/modes",
-            axum::routing::get(|| async {
+            get(|| async {
                 axum::Json([
                     TTSMode::gTTS.to_string(),
                     TTSMode::Polly.to_string(),

src/translation.rs

@@ -1,6 +1,7 @@
 use std::marker::PhantomData;
 
 use anyhow::Result;
+use serde::ser::SerializeStruct;
 use small_fixed_array::FixedString;
 
 fn deserialize_single_seq<'de, T, D>(deserializer: D) -> Result<Option<T>, D::Error>
@@ -47,9 +48,13 @@ struct TranslateResponse {
     pub translations: Option<Translation>,
 }
 
+fn auth_header(token: &str) -> String {
+    format!("DeepL-Auth-Key {token}")
+}
+
 pub async fn run(
     reqwest: &reqwest::Client,
-    translation_token: &str,
+    token: &str,
     content: &str,
     target_lang: &str,
 ) -> Result<Option<FixedString>> {
@@ -59,11 +64,10 @@ pub async fn run(
         preserve_formatting: 1,
     };
 
-    let auth_header = format!("DeepL-Auth-Key {translation_token}");
     let response: TranslateResponse = reqwest
         .get("https://api.deepl.com/v2/translate")
         .query(&request)
-        .header("Authorization", auth_header)
+        .header("Authorization", auth_header(token))
         .send()
         .await?
         .error_for_status()?
@@ -78,3 +82,44 @@ pub async fn run(
 
     Ok(None)
 }
+
+#[derive(serde::Deserialize)]
+struct Voice {
+    pub name: FixedString,
+    pub language: FixedString,
+}
+
+struct VoiceRequest;
+impl serde::Serialize for VoiceRequest {
+    fn serialize<S>(&self, serializer: S) -> std::prelude::v1::Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        let mut serializer = serializer.serialize_struct("DeeplVoiceRequest", 1)?;
+        serializer.serialize_field("type", "target")?;
+        serializer.end()
+    }
+}
+
+pub async fn get_languages(
+    reqwest: &reqwest::Client,
+    token: &str,
+) -> Result<Vec<(FixedString, FixedString)>> {
+    let languages: Vec<Voice> = reqwest
+        .get("https://api.deepl.com/v2/languages")
+        .query(&VoiceRequest)
+        .header("Authorization", auth_header(token))
+        .send()
+        .await?
+        .error_for_status()?
+        .json()
+        .await?;
+
+    let language_map = languages
+        .into_iter()
+        .map(|v| (v.language, v.name))
+        .collect();
+
+    println!("Loaded DeepL translation languages");
+    Ok(language_map)
+}