add `/<uuid> route + backend handling

src/main.rs

@@ -1,3 +1,4 @@
+use crate::model::client::Client;
 use axum::{routing::get, Router};
 use axum_extra::extract::{cookie::Cookie, CookieJar};
 use sqlx::{pool::PoolOptions, sqlite::SqliteConnectOptions, SqlitePool};
@@ -14,19 +15,21 @@ pub(crate) enum Backend {
     Sqlite(SqlitePool),
 }
 
-fn client_id(cookies: CookieJar) -> (CookieJar, String) {
-    let mut cookies = cookies;
-    if cookies.get("client_id").is_none() {
-        let id = Uuid::new_v4().to_string();
-        cookies = cookies.add(Cookie::new("client_id", id))
+impl Backend {
+    async fn client(&self, cookies: CookieJar) -> (CookieJar, Client) {
+        let existing_uuid = cookies
+            .get("client_id")
+            .and_then(|cookie| Uuid::parse_str(cookie.value()).ok());
+
+        match existing_uuid {
+            Some(uuid) => (cookies, self.get_client(&uuid).await),
+            None => {
+                let new_id = Uuid::new_v4();
+                let updated_cookies = cookies.add(Cookie::new("client_id", new_id.to_string()));
+                (updated_cookies, self.get_client(&new_id).await)
+            }
+        }
     }
-
-    let id = cookies
-        .get("client_id")
-        .expect("can't happen, as we checked above")
-        .to_string();
-
-    (cookies, id)
 }
 
 #[tokio::main]