* Support for lang in URL as /fr/recipe/view/42

* Create a pages module in the frontend crate

backend/src/main.rs

@@ -1,10 +1,10 @@
 use std::{net::SocketAddr, path::Path};
 
 use axum::{
-    BoxError, Router,
+    BoxError, Router, ServiceExt,
     error_handling::HandleErrorLayer,
     extract::{ConnectInfo, Extension, FromRef, Request, State},
-    http::StatusCode,
+    http::{StatusCode, Uri},
     middleware::{self, Next},
     response::Response,
     routing::{delete, get, patch, post, put},
@@ -14,6 +14,7 @@ use chrono::prelude::*;
 use clap::Parser;
 use config::Config;
 use itertools::Itertools;
+use tower::layer::Layer;
 use tower::{ServiceBuilder, buffer::BufferLayer, limit::RateLimitLayer};
 use tower_http::{
     services::{ServeDir, ServeFile},
@@ -290,13 +291,20 @@ async fn main() {
         .with_state(state)
         .nest_service("/favicon.ico", ServeFile::new("static/favicon.ico"))
         .nest_service("/static", ServeDir::new("static"))
-        .layer(TraceLayer::new_for_http())
-        .into_make_service_with_connect_info::<SocketAddr>();
+        .layer(TraceLayer::new_for_http());
+
+    let url_rewriting_middleware = tower::util::MapRequestLayer::new(url_rewriting);
+    let app_with_url_rewriting = url_rewriting_middleware.layer(app);
 
     let addr = SocketAddr::from(([0, 0, 0, 0], port));
     let listener = tokio::net::TcpListener::bind(addr).await.unwrap();
 
-    axum::serve(listener, app).await.unwrap();
+    axum::serve(
+        listener,
+        app_with_url_rewriting.into_make_service_with_connect_info::<SocketAddr>(),
+    )
+    .await
+    .unwrap();
 }
 
 async fn user_authentication(
@@ -312,54 +320,65 @@ async fn user_authentication(
     Ok(next.run(req).await)
 }
 
+#[derive(Debug, Clone)]
+struct Lang(Option<String>);
+
+fn url_rewriting(mut req: Request) -> Request {
+    // Here we are extracting the language from the url then rewriting it.
+    // For example:
+    // "/fr/recipe/view/1"
+    //  lang = "fr" and uri rewritten as = "/recipe/view/1"
+    let lang_and_new_uri = 'lang_and_new_uri: {
+        if let Some(path_query) = req.uri().path_and_query() {
+            let mut parts = path_query.path().split('/');
+            let _ = parts.next(); // Empty part due to the first '/'.
+            if let Some(lang) = parts.next() {
+                let available_codes = translation::available_codes();
+                if available_codes.contains(&lang) {
+                    let mut rest: String = String::from("");
+                    for part in parts {
+                        rest.push('/');
+                        rest.push_str(part);
+                    }
+                    if let Some(query) = path_query.query() {
+                        rest.push('?');
+                        rest.push_str(query);
+                    }
+
+                    if let Ok(new_uri) = rest.parse::<Uri>() {
+                        break 'lang_and_new_uri Some((lang.to_string(), new_uri));
+                    }
+                }
+            }
+        }
+        None
+    };
+
+    if let Some((lang, new_uri)) = lang_and_new_uri {
+        *req.uri_mut() = new_uri;
+        req.extensions_mut().insert(Lang(Some(lang)));
+    } else {
+        req.extensions_mut().insert(Lang(None));
+    }
+
+    req
+}
+
 /// The language of the current HTTP request is defined in the current order:
-/// - Extraction from the url: like in '/fr/recipe/view/42' (Not yet implemented).
+/// - Extraction from the url: like in '/fr/recipe/view/42'
 /// - Get from the user database record.
 /// - Get from the cookie.
 /// - Get from the HTTP header `accept-language`.
 /// - Set as `translation::DEFAULT_LANGUAGE_CODE`.
 async fn translation(
+    Extension(lang): Extension<Lang>,
     Extension(user): Extension<Option<model::User>>,
     mut req: Request,
     next: Next,
 ) -> Result<Response> {
-    // Here we are extracting the language from the url then rewriting it.
-    // For example:
-    // "/fr/recipe/view/1"
-    //  lang = "fr" and uri rewritten as = "/recipe/view/1"
-    // Disable because it doesn't work at this level, see:
-    // https://docs.rs/axum/latest/axum/middleware/index.html#rewriting-request-uri-in-middleware
-
-    // let lang_and_new_uri = 'lang_from_uri: {
-    //     if let Some(path_query) = req.uri().path_and_query() {
-    //         event!(Level::INFO, "path: {:?}", path_query.path());
-    //         let mut parts = path_query.path().split('/');
-    //         let _ = parts.next(); // Empty part due to the first '/'.
-    //         if let Some(lang) = parts.next() {
-    //             let available_codes = translation::available_codes();
-    //             if available_codes.contains(&lang) {
-    //                 let mut rest: String = String::from("");
-    //                 for part in parts {
-    //                     rest.push('/');
-    //                     rest.push_str(part);
-    //                 }
-    //                 // let uri_builder = Uri::builder()
-    //                 if let Ok(new_uri) = rest.parse::<Uri>() {
-    //                     event!(Level::INFO, "path rewrite: {:?}", new_uri.path());
-    //                     break 'lang_from_uri Some((lang.to_string(), new_uri));
-    //                 }
-    //             }
-    //         }
-    //     }
-    //     None
-    // };
-    // let language = if let Some((lang, uri)) = lang_and_new_uri {
-    //     *req.uri_mut() = uri; // Replace the URI without the language.
-    //     event!(Level::INFO, "URI: {:?}", req.uri());
-    //     lang
-    // } else
-
-    let language = if let Some(user) = user {
+    let language = if let Some(lang) = lang.0 {
+        lang
+    } else if let Some(user) = user {
         user.lang
     } else {
         let available_codes = translation::available_codes();