From 6be5525bae122a1afc410d025b3012dfc10e5ad2 Mon Sep 17 00:00:00 2001
From: Adrian Hedqvist <adrian@tollyx.net>
Date: Wed, 29 Mar 2023 18:19:39 +0200
Subject: [PATCH] implement post aliases

---
 src/handlers/mod.rs   |  3 ++-
 src/handlers/posts.rs | 17 ++++++++++++++++-
 src/main.rs           |  3 ++-
 templates/index.html  |  2 +-
 4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index e4fe2b2..97d1238 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -20,10 +20,11 @@ lazy_static! {
     .unwrap();
 }
 
-pub fn routes() -> Router<Arc<AppState>> {
+pub fn routes(state: &Arc<AppState>) -> Router<Arc<AppState>> {
     Router::new()
         .route("/", get(index))
         .nest("/posts", posts::router())
+        .merge(posts::alias_router(state.posts.values()))
         .route("/healthcheck", get(healthcheck))
         .route("/metrics", get(metrics))
         .nest_service("/static", tower_http::services::ServeDir::new("./static"))
diff --git a/src/handlers/posts.rs b/src/handlers/posts.rs
index c49c8bf..f5652b0 100644
--- a/src/handlers/posts.rs
+++ b/src/handlers/posts.rs
@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use axum::{extract::{Path, State}, response::Html, routing::get, Extension, Router};
+use axum::{extract::{Path, State}, response::{Html, Redirect}, routing::get, Extension, Router};
 use serde_derive::Serialize;
 use tracing::{instrument, log::*};
 
@@ -17,6 +17,21 @@ pub fn router() -> Router<Arc<AppState>> {
         .fallback_service(tower_http::services::ServeDir::new("./posts"))
 }
 
+pub fn alias_router<'a>(posts: impl IntoIterator<Item=&'a Post>) -> Router<Arc<AppState>> {
+    let mut router = Router::new();
+
+    for post in posts {
+        for alias in &post.aliases {
+            let path = post.absolute_path.to_owned();
+            router = router.route(alias, get(move || async {
+                let path = path;
+                Redirect::permanent(&path)
+            }));
+        }
+    }
+    router
+}
+
 #[derive(Serialize, Debug)]
 struct PageContext<'a> {
     title: &'a str,
diff --git a/src/main.rs b/src/main.rs
index e7fbbef..0123040 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -27,7 +27,8 @@ async fn main() -> Result<()> {
     let posts = post::load_all().await?;
     let state = Arc::new(AppState { tera, posts });
 
-    let app = handlers::routes()
+
+    let app = handlers::routes(&state)
         .layer(TraceLayer::new_for_http())
         .layer(CompressionLayer::new())
         .with_state(state);
diff --git a/templates/index.html b/templates/index.html
index d6b3d4c..127a21d 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -11,7 +11,7 @@
         <li>✅ post metadata (frontmatter, toml)</li>
         <li>✅ app metrics (page hits, etc)</li>
         <li>✅ tests</li>
-        <li>⬜ page aliases (redirects, for back-compat with old routes)</li>
+        <li>✅ page aliases (redirects, for back-compat with old routes)</li>
         <li>⬜ sass compilation (using rsass? grass?)</li>
         <li>⬜ rss/atom/jsonfeed</li>
         <li>✅ proper error handling (i guess??)</li>