Migrate from axum::Extension to axum::extract::State

This somehow allowed me to shrink the construction phase of Kittybox
by a huge amount of code.

9 files changed, 378 insertions, 372 deletions

diff --git a/src/admin/mod.rs b/src/admin/mod.rs
index abc4515..7f8c9cf 100644
--- a/src/admin/mod.rs
+++ b/src/admin/mod.rs
@@ -10,9 +10,9 @@
 // prevent collisions with future well-known scopes).
 use std::collections::HashSet;
 
-use axum::extract::Host;
+use axum::extract::{State, Host};
 use axum::response::{Response, IntoResponse};
-use axum::{Extension, Form};
+use axum::Form;
 use axum_extra::extract::CookieJar;
 use hyper::StatusCode;
 
@@ -36,19 +36,19 @@ static SESSION_STORE: std::sync::LazyLock<tokio::sync::RwLock<HashSet<uuid::Uuid
 
 async fn set_name<D: Storage + 'static>(
     Host(host): Host,
-    Extension(db): Extension<D>,
+    State(db): State<D>,
     Form(NameChange { name }): Form<NameChange>
 ) -> Result<(), StorageError> {
     db.set_setting::<SiteName>(&host, name).await
 }
 
-async fn get_name<D: Storage + 'static>(Host(host): Host, Extension(db): Extension<D>) -> Result<String, StorageError> {
+async fn get_name<D: Storage + 'static>(Host(host): Host, State(db): State<D>) -> Result<String, StorageError> {
     db.get_setting::<SiteName>(&host).await.map(|name| name.as_ref().to_owned())
 }
 
 async fn change_password<A: AuthBackend>(
     Host(host): Host,
-    Extension(auth): Extension<A>,
+    State(auth): State<A>,
     Form(PasswordChange { old_password, new_password }): Form<PasswordChange>
 ) -> StatusCode {
     let website = url::Url::parse(&format!("https://{host}/")).unwrap();
@@ -84,8 +84,8 @@ impl axum::response::IntoResponse for StorageError {
 async fn dashboard<D: Storage + 'static, A: AuthBackend>(
     Host(host): Host,
     cookies: CookieJar,
-    Extension(db): Extension<D>,
-    Extension(auth): Extension<A>
+    State(db): State<D>,
+    State(auth): State<A>
 ) -> axum::response::Response {
 
     let page = kittybox_frontend_renderer::admin::AdminHome {};
@@ -94,21 +94,26 @@ async fn dashboard<D: Storage + 'static, A: AuthBackend>(
 }
 
 
-pub fn router<D: Storage + 'static, A: AuthBackend>(db: D, auth: A) -> axum::Router {
+pub fn router<St, A, S, M>() -> axum::Router<St>
+where
+    A: AuthBackend + FromRef<St> + 'static,
+    S: Storage + FromRef<St> + 'static,
+    M: MediaStore + FromRef<St> + 'static,
+    Q: crate::webmentions::JobQueue<crate::webmentions::Webmention> + FromRef<St> + 'static,
+    axum_extra::extract::cookie::Key: FromRef<St>
+{
     axum::Router::new()
         .nest("/.kittybox/admin", axum::Router::new()
             // routes go here
             .route(
                 "/",
-                axum::routing::get(dashboard::<D, A>)
+                axum::routing::get(dashboard::<S, A>)
             )
             .route(
                 "/api/settings/name",
-                axum::routing::post(set_name::<D>)
-                    .get(get_name::<D>)
+                axum::routing::post(set_name::<S>)
+                    .get(get_name::<S>)
             )
             .route("/api/settings/password", axum::routing::post(change_password::<A>))
-            .layer(Extension(db))
-            .layer(Extension(auth))
         )
 }
diff --git a/src/frontend/mod.rs b/src/frontend/mod.rs
index 0292171..42e8754 100644
--- a/src/frontend/mod.rs
+++ b/src/frontend/mod.rs
@@ -1,9 +1,8 @@
 use crate::database::{Storage, StorageError};
 use axum::{
-    extract::{Host, Path, Query},
+    extract::{Host, Query, State},
     http::{StatusCode, Uri},
     response::IntoResponse,
-    Extension,
 };
 use futures_util::FutureExt;
 use serde::Deserialize;
@@ -239,7 +238,7 @@ async fn get_post_from_database<S: Storage>(
 pub async fn homepage<D: Storage>(
     Host(host): Host,
     Query(query): Query<QueryParams>,
-    Extension(db): Extension<D>,
+    State(db): State<D>,
 ) -> impl IntoResponse {
     let user = None; // TODO authentication
     // This is stupid, but there is no other way.
@@ -333,7 +332,7 @@ pub async fn homepage<D: Storage>(
 
 #[tracing::instrument(skip(db))]
 pub async fn catchall<D: Storage>(
-    Extension(db): Extension<D>,
+    State(db): State<D>,
     Host(host): Host,
     Query(query): Query<QueryParams>,
     uri: Uri,
diff --git a/src/frontend/onboarding.rs b/src/frontend/onboarding.rs
index faf8cdd..9f3f36b 100644
--- a/src/frontend/onboarding.rs
+++ b/src/frontend/onboarding.rs
@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use crate::database::{settings, Storage};
 use axum::{
-    extract::{Extension, Host},
+    extract::{FromRef, Host, State},
     http::StatusCode,
     response::{Html, IntoResponse},
     Json,
@@ -131,10 +131,10 @@ async fn onboard<D: Storage + 'static>(
 }
 
 pub async fn post<D: Storage + 'static>(
-    Extension(db): Extension<D>,
+    State(db): State<D>,
     Host(host): Host,
-    Extension(http): Extension<reqwest::Client>,
-    Extension(jobset): Extension<Arc<Mutex<JoinSet<()>>>>,
+    State(http): State<reqwest::Client>,
+    State(jobset): State<Arc<Mutex<JoinSet<()>>>>,
     Json(data): Json<OnboardingData>,
 ) -> axum::response::Response {
     let user_uid = format!("https://{}/", host.as_str());
@@ -168,14 +168,13 @@ pub async fn post<D: Storage + 'static>(
     }
 }
 
-pub fn router<S: Storage + 'static>(
-    database: S,
-    http: reqwest::Client,
-    jobset: Arc<Mutex<JoinSet<()>>>,
-) -> axum::routing::MethodRouter {
+pub fn router<St, S>() -> axum::routing::MethodRouter<St>
+where
+    S: Storage + FromRef<St> + 'static,
+    Arc<Mutex<JoinSet<()>>>: FromRef<St>,
+    reqwest::Client: FromRef<St>,
+    St: Clone + Send + Sync + 'static,
+{
     axum::routing::get(get)
         .post(post::<S>)
-        .layer::<_, _, std::convert::Infallible>(axum::Extension(database))
-        .layer::<_, _, std::convert::Infallible>(axum::Extension(http))
-        .layer(axum::Extension(jobset))
 }
diff --git a/src/indieauth/mod.rs b/src/indieauth/mod.rs
index 26879bb..2550df0 100644
--- a/src/indieauth/mod.rs
+++ b/src/indieauth/mod.rs
@@ -1,12 +1,10 @@
 use std::marker::PhantomData;
 
+use microformats::types::Class;
 use tracing::error;
 use serde::Deserialize;
 use axum::{
-    extract::{Query, Json, Host, Form},
-    response::{Html, IntoResponse, Response},
-    http::StatusCode, TypedHeader, headers::{Authorization, authorization::Bearer},
-    Extension
+    extract::{Form, FromRef, Host, Json, Query, State}, headers::{authorization::Bearer, Authorization}, http::StatusCode, response::{Html, IntoResponse, Response}, Extension, TypedHeader
 };
 #[cfg_attr(not(feature = "webauthn"), allow(unused_imports))]
 use axum_extra::extract::cookie::{CookieJar, Cookie};
@@ -73,18 +71,16 @@ impl axum::response::IntoResponse for IndieAuthResourceError {
 }
 
 #[async_trait::async_trait]
-impl <S: Send + Sync, A: AuthBackend> axum::extract::FromRequestParts<S> for User<A> {
+impl <A: AuthBackend + FromRef<St>, St: Clone + Send + Sync + 'static> axum::extract::FromRequestParts<St> for User<A> {
     type Rejection = IndieAuthResourceError;
 
-    async fn from_request_parts(req: &mut axum::http::request::Parts, state: &S) -> Result<Self, Self::Rejection> {
+    async fn from_request_parts(req: &mut axum::http::request::Parts, state: &St) -> Result<Self, Self::Rejection> {
         let TypedHeader(Authorization(token)) =
             TypedHeader::<Authorization<Bearer>>::from_request_parts(req, state)
             .await
             .map_err(|_| IndieAuthResourceError::Unauthorized)?;
 
-        let axum::Extension(auth) = axum::Extension::<A>::from_request_parts(req, state)
-            .await
-            .unwrap();
+        let auth = A::from_ref(state);
 
         let Host(host) = Host::from_request_parts(req, state)
             .await
@@ -146,9 +142,9 @@ pub async fn metadata(
 async fn authorization_endpoint_get<A: AuthBackend, D: Storage + 'static>(
     Host(host): Host,
     Query(request): Query<AuthorizationRequest>,
-    Extension(db): Extension<D>,
-    Extension(http): Extension<reqwest::Client>,
-    Extension(auth): Extension<A>
+    State(db): State<D>,
+    State(http): State<reqwest::Client>,
+    State(auth): State<A>
 ) -> Response {
     let me = format!("https://{host}/").parse().unwrap();
     let h_app = {
@@ -802,8 +798,13 @@ async fn userinfo_endpoint_get<A: AuthBackend, D: Storage + 'static>(
     }
 }
 
-#[must_use]
-pub fn router<A: AuthBackend, D: Storage + 'static>(backend: A, db: D, http: reqwest::Client) -> axum::Router {
+pub fn router<St, A, S>() -> axum::Router<St>
+where
+    S: Storage + FromRef<St> + 'static,
+    A: AuthBackend + FromRef<St>,
+    reqwest::Client: FromRef<St>,
+    St: Clone + Send + Sync + 'static
+{
     use axum::routing::{Router, get, post};
 
     Router::new()
@@ -814,14 +815,14 @@ pub fn router<A: AuthBackend, D: Storage + 'static>(backend: A, db: D, http: req
                        get(metadata))
                 .route(
                     "/auth",
-                    get(authorization_endpoint_get::<A, D>)
-                        .post(authorization_endpoint_post::<A, D>))
+                    get(authorization_endpoint_get::<A, S>)
+                        .post(authorization_endpoint_post::<A, S>))
                 .route(
                     "/auth/confirm",
                     post(authorization_endpoint_confirm::<A>))
                 .route(
                     "/token",
-                    post(token_endpoint_post::<A, D>))
+                    post(token_endpoint_post::<A, S>))
                 .route(
                     "/token_status",
                     post(introspection_endpoint_post::<A>))
@@ -830,11 +831,11 @@ pub fn router<A: AuthBackend, D: Storage + 'static>(backend: A, db: D, http: req
                     post(revocation_endpoint_post::<A>))
                 .route(
                     "/userinfo",
-                    get(userinfo_endpoint_get::<A, D>))
+                    get(userinfo_endpoint_get::<A, S>))
 
                 .route("/webauthn/pre_register",
                        get(
-                           #[cfg(feature = "webauthn")] webauthn::webauthn_pre_register::<A, D>,
+                           #[cfg(feature = "webauthn")] webauthn::webauthn_pre_register::<A, S>,
                            #[cfg(not(feature = "webauthn"))] || std::future::ready(axum::http::StatusCode::NOT_FOUND)
                        )
                 )
@@ -844,12 +845,6 @@ pub fn router<A: AuthBackend, D: Storage + 'static>(backend: A, db: D, http: req
                            axum::http::Method::POST
                        ])
                        .allow_origin(tower_http::cors::Any))
-                .layer(Extension(backend))
-            // I don't really like the fact that I have to use the whole database
-            // If I could, I would've designed a separate trait for getting profiles
-            // And made databases implement it, for example
-                .layer(Extension(db))
-                .layer(Extension(http))
         )
         .route(
             "/.well-known/oauth-authorization-server",
diff --git a/src/lib.rs b/src/lib.rs
index 04b3298..1cc01c2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,17 @@
 #![forbid(unsafe_code)]
 #![warn(clippy::todo)]
 
+use std::sync::Arc;
+
+use axum::extract::FromRef;
+use axum_extra::extract::cookie::Key;
+use database::{FileStorage, PostgresStorage, Storage};
+use indieauth::backend::{AuthBackend, FileBackend as FileAuthBackend};
+use kittybox_util::queue::{JobItem, JobQueue};
+use media::storage::{MediaStore, file::FileStore as FileMediaStore};
+use tokio::{sync::Mutex, task::JoinSet};
+use webmentions::queue::{PostgresJobItem, PostgresJobQueue};
+
 /// Database abstraction layer for Kittybox, allowing the CMS to work with any kind of database.
 pub mod database;
 pub mod frontend;
@@ -9,6 +20,110 @@ pub mod micropub;
 pub mod indieauth;
 pub mod webmentions;
 pub mod login;
+//pub mod admin;
+
+#[derive(Clone)]
+pub struct AppState<A, S, M, Q>
+where
+A: AuthBackend + Sized + 'static,
+S: Storage + Sized + 'static,
+M: MediaStore + Sized + 'static,
+Q: JobQueue<webmentions::Webmention> + Sized
+{
+    pub auth_backend: A,
+    pub storage: S,
+    pub media_store: M,
+    pub job_queue: Q,
+    pub http: reqwest::Client,
+    pub background_jobs: Arc<Mutex<JoinSet<()>>>,
+    pub cookie_key: Key
+}
+
+// This is really regrettable, but I can't write:
+//
+// ```compile-error
+// impl <A, S, M> FromRef<AppState<A, S, M>> for A
+// where A: AuthBackend, S: Storage, M: MediaStore {
+//     fn from_ref(input: &AppState<A, S, M>) -> A {
+//         input.auth_backend.clone()
+//     }
+// }
+// ```
+//
+// ...because of the orphan rule.
+//
+// I wonder if this would stifle external implementations. I think it
+// shouldn't, because my AppState type is generic, and since the
+// target type is local, the orphan rule will not kick in. You just
+// have to repeat this magic invocation.
+
+impl<S, M, Q> FromRef<AppState<Self, S, M, Q>> for FileAuthBackend
+// where S: Storage, M: MediaStore
+where S: Storage, M: MediaStore, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<Self, S, M, Q>) -> Self {
+        input.auth_backend.clone()
+    }
+}
+
+impl<A, M, Q> FromRef<AppState<A, Self, M, Q>> for PostgresStorage
+// where A: AuthBackend, M: MediaStore
+where A: AuthBackend, M: MediaStore, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<A, Self, M, Q>) -> Self {
+        input.storage.clone()
+    }
+}
+
+impl<A, M, Q> FromRef<AppState<A, Self, M, Q>> for FileStorage
+where A: AuthBackend, M: MediaStore, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<A, Self, M, Q>) -> Self {
+        input.storage.clone()
+    }
+}
+
+impl<A, S, Q> FromRef<AppState<A, S, Self, Q>> for FileMediaStore
+// where A: AuthBackend, S: Storage
+where A: AuthBackend, S: Storage, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<A, S, Self, Q>) -> Self {
+        input.media_store.clone()
+    }
+}
+
+impl<A, S, M, Q> FromRef<AppState<A, S, M, Q>> for Key
+where A: AuthBackend, S: Storage, M: MediaStore, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<A, S, M, Q>) -> Self {
+        input.cookie_key.clone()
+    }
+}
+
+impl<A, S, M, Q> FromRef<AppState<A, S, M, Q>> for reqwest::Client
+where A: AuthBackend, S: Storage, M: MediaStore, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<A, S, M, Q>) -> Self {
+        input.http.clone()
+    }
+}
+
+impl<A, S, M, Q> FromRef<AppState<A, S, M, Q>> for Arc<Mutex<JoinSet<()>>>
+where A: AuthBackend, S: Storage, M: MediaStore, Q: JobQueue<webmentions::Webmention>
+{
+    fn from_ref(input: &AppState<A, S, M, Q>) -> Self {
+        input.background_jobs.clone()
+    }
+}
+
+#[cfg(feature = "sqlx")]
+impl<A, S, M> FromRef<AppState<A, S, M, Self>> for PostgresJobQueue<webmentions::Webmention>
+where A: AuthBackend, S: Storage, M: MediaStore
+{
+    fn from_ref(input: &AppState<A, S, M, Self>) -> Self {
+        input.job_queue.clone()
+    }
+}
 
 pub mod companion {
     use std::{collections::HashMap, sync::Arc};
@@ -52,8 +167,7 @@ pub mod companion {
         }
     }
 
-    #[must_use]
-    pub fn router() -> axum::Router {
+    pub fn router<St: Clone + Send + Sync + 'static>() -> axum::Router<St> {
         let resources: ResourceTable = {
             let mut map = HashMap::new();
 
diff --git a/src/main.rs b/src/main.rs
index 9e541b9..d10822b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,266 +1,58 @@
-use kittybox::database::FileStorage;
+use axum::extract::FromRef;
+use kittybox::{database::Storage, indieauth::backend::AuthBackend, media::storage::MediaStore, webmentions::Webmention};
+use tokio::{sync::Mutex, task::JoinSet};
 use std::{env, time::Duration, sync::Arc};
 use tracing::error;
 
-fn init_media<A: kittybox::indieauth::backend::AuthBackend>(auth_backend: A, blobstore_uri: &str) -> axum::Router {
-    match blobstore_uri.split_once(':').unwrap().0 {
-        "file" => {
-            let folder = std::path::PathBuf::from(
-                blobstore_uri.strip_prefix("file://").unwrap()
-            );
-            let blobstore = kittybox::media::storage::file::FileStore::new(folder);
 
-            kittybox::media::router::<_, _>(blobstore, auth_backend)
-        },
-        other => unimplemented!("Unsupported backend: {other}")
-    }
+async fn teapot_route() -> impl axum::response::IntoResponse {
+    use axum::http::{header, StatusCode};
+    (StatusCode::IM_A_TEAPOT, [(header::CONTENT_TYPE, "text/plain")], "Sorry, can't brew coffee yet!")
 }
 
-async fn compose_kittybox_with_auth<A>(
-    http: reqwest::Client,
-    auth_backend: A,
-    backend_uri: &str,
-    blobstore_uri: &str,
-    job_queue_uri: &str,
-    jobset: &Arc<tokio::sync::Mutex<tokio::task::JoinSet<()>>>,
-    cancellation_token: &tokio_util::sync::CancellationToken
-) -> (axum::Router, kittybox::webmentions::SupervisedTask)
-where A: kittybox::indieauth::backend::AuthBackend
+async fn health_check<D>(
+    axum::extract::State(data): axum::extract::State<D>,
+) -> impl axum::response::IntoResponse
+where
+    D: kittybox::database::Storage
 {
-    match backend_uri.split_once(':').unwrap().0 {
-        "file" => {
-            let database = {
-                let folder = backend_uri.strip_prefix("file://").unwrap();
-                let path = std::path::PathBuf::from(folder);
-
-                match kittybox::database::FileStorage::new(path).await {
-                    Ok(db) => db,
-                    Err(err) => {
-                        error!("Error creating database: {:?}", err);
-                        std::process::exit(1);
-                    }
-                }
-            };
-
-            // Technically, if we don't construct the micropub router,
-            // we could use some wrapper that makes the database
-            // read-only.
-            //
-            // This would allow to exclude all code to write to the
-            // database and separate reader and writer processes of
-            // Kittybox to improve security.
-            let homepage: axum::routing::MethodRouter<_> = axum::routing::get(
-                kittybox::frontend::homepage::<FileStorage>
-            )
-                .layer(axum::Extension(database.clone()));
-            let fallback = axum::routing::get(
-                kittybox::frontend::catchall::<FileStorage>
-            )
-                .layer(axum::Extension(database.clone()));
-
-            let micropub = kittybox::micropub::router(
-                database.clone(),
-                http.clone(),
-                auth_backend.clone(),
-                Arc::clone(jobset)
-            );
-            let onboarding = kittybox::frontend::onboarding::router(
-                database.clone(), http.clone(), Arc::clone(jobset)
-            );
-
-
-            let (webmention, task) = kittybox::webmentions::router(
-                kittybox::webmentions::queue::PostgresJobQueue::new(job_queue_uri).await.unwrap(),
-                database.clone(),
-                http.clone(),
-                cancellation_token.clone()
-            );
-
-            let router = axum::Router::new()
-                .route("/", homepage)
-                .fallback(fallback)
-                .route("/.kittybox/micropub", micropub)
-                .route("/.kittybox/onboarding", onboarding)
-                .nest("/.kittybox/media", init_media(auth_backend.clone(), blobstore_uri))
-                .merge(kittybox::indieauth::router(auth_backend.clone(), database.clone(), http.clone()))
-                .merge(webmention)
-                .route(
-                    "/.kittybox/health",
-                    axum::routing::get(health_check::<kittybox::database::FileStorage>)
-                        .layer(axum::Extension(database))
-                );
-
-            (router, task)
-        },
-        "redis" => unimplemented!("Redis backend is not supported."),
-        #[cfg(feature = "postgres")]
-        "postgres" => {
-            use kittybox::database::PostgresStorage;
-
-            let database = {
-                match PostgresStorage::new(backend_uri).await {
-                    Ok(db) => db,
-                    Err(err) => {
-                        error!("Error creating database: {:?}", err);
-                        std::process::exit(1);
-                    }
-                }
-            };
-
-            // Technically, if we don't construct the micropub router,
-            // we could use some wrapper that makes the database
-            // read-only.
-            //
-            // This would allow to exclude all code to write to the
-            // database and separate reader and writer processes of
-            // Kittybox to improve security.
-            let homepage: axum::routing::MethodRouter<_> = axum::routing::get(
-                kittybox::frontend::homepage::<PostgresStorage>
-            )
-                .layer(axum::Extension(database.clone()));
-            let fallback = axum::routing::get(
-                kittybox::frontend::catchall::<PostgresStorage>
-            )
-                .layer(axum::Extension(database.clone()));
-
-            let micropub = kittybox::micropub::router(
-                database.clone(),
-                http.clone(),
-                auth_backend.clone(),
-                Arc::clone(jobset)
-            );
-            let onboarding = kittybox::frontend::onboarding::router(
-                database.clone(), http.clone(), Arc::clone(jobset)
-            );
-
-            let (webmention, task) = kittybox::webmentions::router(
-                kittybox::webmentions::queue::PostgresJobQueue::new(job_queue_uri).await.unwrap(),
-                database.clone(),
-                http.clone(),
-                cancellation_token.clone()
-            );
-
-            let router = axum::Router::new()
-                .route("/", homepage)
-                .fallback(fallback)
-                .route("/.kittybox/micropub", micropub)
-                .route("/.kittybox/onboarding", onboarding)
-                .nest("/.kittybox/media", init_media(auth_backend.clone(), blobstore_uri))
-                .merge(kittybox::indieauth::router(auth_backend.clone(), database.clone(), http.clone()))
-                .merge(webmention)
-                .route(
-                    "/.kittybox/health",
-                    axum::routing::get(health_check::<kittybox::database::PostgresStorage>)
-                        .layer(axum::Extension(database))
-                );
-
-            (router, task)
-        },
-        other => unimplemented!("Unsupported backend: {other}")
-    }
+    (axum::http::StatusCode::OK, std::borrow::Cow::Borrowed("OK"))
 }
 
-async fn compose_kittybox(
-    backend_uri: &str,
-    blobstore_uri: &str,
-    authstore_uri: &str,
-    job_queue_uri: &str,
-    jobset: &Arc<tokio::sync::Mutex<tokio::task::JoinSet<()>>>,
-    cancellation_token: &tokio_util::sync::CancellationToken
-) -> (axum::Router, kittybox::webmentions::SupervisedTask) {
-    let http: reqwest::Client = {
-        #[allow(unused_mut)]
-        let mut builder = reqwest::Client::builder()
-            .user_agent(concat!(
-                env!("CARGO_PKG_NAME"),
-                "/",
-                env!("CARGO_PKG_VERSION")
-            ));
-        if let Ok(certs) = std::env::var("KITTYBOX_CUSTOM_PKI_ROOTS") {
-            // TODO: add a root certificate if there's an environment variable pointing at it
-            for path in certs.split(':') {
-                let metadata = match tokio::fs::metadata(path).await {
-                    Ok(metadata) => metadata,
-                    Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
-                        tracing::error!("TLS root certificate {} not found, skipping...", path);
-                        continue;
-                    }
-                    Err(err) => panic!("Error loading TLS certificates: {}", err)
-                };
-                if metadata.is_dir() {
-                    let mut dir = tokio::fs::read_dir(path).await.unwrap();
-                    while let Ok(Some(file)) = dir.next_entry().await {
-                        let pem = tokio::fs::read(file.path()).await.unwrap();
-                        builder = builder.add_root_certificate(
-                            reqwest::Certificate::from_pem(&pem).unwrap()
-                        );
-                    }
-                } else {
-                    let pem = tokio::fs::read(path).await.unwrap();
-                    builder = builder.add_root_certificate(
-                        reqwest::Certificate::from_pem(&pem).unwrap()
-                    );
-                }
-            }
-        }
-
-        builder.build().unwrap()
-    };
-
-    let (router, task) = match authstore_uri.split_once(':').unwrap().0 {
-        "file" => {
-            let auth_backend = {
-                let folder = authstore_uri
-                    .strip_prefix("file://")
-                    .unwrap();
-                kittybox::indieauth::backend::fs::FileBackend::new(folder)
-            };
-
-            compose_kittybox_with_auth(http, auth_backend, backend_uri, blobstore_uri, job_queue_uri, jobset, cancellation_token).await
-        }
-        other => unimplemented!("Unsupported backend: {other}")
-    };
-
-    // TODO: load from environment
-    let cookie_key = axum_extra::extract::cookie::Key::generate();
 
-    let router = router
+async fn compose_stateful_kittybox<St, A, S, M, Q>() -> axum::Router<St>
+where
+A: AuthBackend + 'static + FromRef<St>,
+S: Storage + 'static + FromRef<St>,
+M: MediaStore + 'static + FromRef<St>,
+Q: kittybox_util::queue::JobQueue<kittybox::webmentions::Webmention> + FromRef<St>,
+reqwest::Client: FromRef<St>,
+Arc<Mutex<JoinSet<()>>>: FromRef<St>,
+St: Clone + Send + Sync + 'static
+{
+    use axum::routing::get;
+    axum::Router::new()
+        .route("/", get(kittybox::frontend::homepage::<S>))
+        .fallback(get(kittybox::frontend::catchall::<S>))
+        .route("/.kittybox/micropub", kittybox::micropub::router::<A, S, St>())
+        .route("/.kittybox/onboarding", kittybox::frontend::onboarding::router::<St, S>())
+        .nest("/.kittybox/media", kittybox::media::router::<St, A, M>())
+        .merge(kittybox::indieauth::router::<St, A, S>())
+        .merge(kittybox::webmentions::router::<St, Q>())
+        .route("/.kittybox/health", get(health_check::<S>))
         .route(
             "/.kittybox/static/:path",
             axum::routing::get(kittybox::frontend::statics)
         )
-        .route("/.kittybox/coffee", teapot_route())
-        .nest("/.kittybox/micropub/client", kittybox::companion::router())
-        .nest("/.kittybox/login", kittybox::login::router(cookie_key))
+        .route("/.kittybox/coffee", get(teapot_route))
+        .nest("/.kittybox/micropub/client", kittybox::companion::router::<St>())
         .layer(tower_http::trace::TraceLayer::new_for_http())
         .layer(tower_http::catch_panic::CatchPanicLayer::new())
         .layer(tower_http::sensitive_headers::SetSensitiveHeadersLayer::new([
             axum::http::header::AUTHORIZATION,
             axum::http::header::COOKIE,
             axum::http::header::SET_COOKIE,
-        ]));
-
-    (router, task)
-}
-
-fn teapot_route() -> axum::routing::MethodRouter {
-    axum::routing::get(|| async {
-        use axum::http::{header, StatusCode};
-        (StatusCode::IM_A_TEAPOT, [(header::CONTENT_TYPE, "text/plain")], "Sorry, can't brew coffee yet!")
-    })
-}
-
-async fn health_check</*A, B, */D>(
-    //axum::Extension(auth): axum::Extension<A>,
-    //axum::Extension(blob): axum::Extension<B>,
-    axum::Extension(data): axum::Extension<D>,
-) -> impl axum::response::IntoResponse
-where
-    //A: kittybox::indieauth::backend::AuthBackend,
-    //B: kittybox::media::storage::MediaStore,
-    D: kittybox::database::Storage
-{
-    (axum::http::StatusCode::OK, std::borrow::Cow::Borrowed("OK"))
+        ]))
 }
 
 #[tokio::main]
@@ -306,40 +98,158 @@ async fn main() {
 
     tracing::info!("Starting the kittybox server...");
 
-    let backend_uri: String = env::var("BACKEND_URI")
+    let backend_uri: url::Url = env::var("BACKEND_URI")
+        .as_deref()
+        .map(|s| url::Url::parse(s).expect("BACKEND_URI malformed"))
         .unwrap_or_else(|_| {
             error!("BACKEND_URI is not set, cannot find a database");
             std::process::exit(1);
         });
-    let blobstore_uri: String = env::var("BLOBSTORE_URI")
+    let blobstore_uri: url::Url = env::var("BLOBSTORE_URI")
+        .as_deref()
+        .map(|s| url::Url::parse(s).expect("BLOBSTORE_URI malformed"))
         .unwrap_or_else(|_| {
             error!("BLOBSTORE_URI is not set, can't find media store");
             std::process::exit(1);
         });
 
-    let authstore_uri: String = env::var("AUTH_STORE_URI")
+    let authstore_uri: url::Url = env::var("AUTH_STORE_URI")
+        .as_deref()
+        .map(|s| url::Url::parse(s).expect("AUTH_STORE_URI malformed"))
         .unwrap_or_else(|_| {
             error!("AUTH_STORE_URI is not set, can't find authentication store");
             std::process::exit(1);
         });
 
-    let job_queue_uri: String = env::var("JOB_QUEUE_URI")
+    let job_queue_uri: url::Url = env::var("JOB_QUEUE_URI")
+        .as_deref()
+        .map(|s| url::Url::parse(s).expect("JOB_QUEUE_URI malformed"))
         .unwrap_or_else(|_| {
             error!("JOB_QUEUE_URI is not set, can't find job queue");
             std::process::exit(1);
         });
 
+    // TODO: load from environment
+    let cookie_key = axum_extra::extract::cookie::Key::generate();
+
     let cancellation_token = tokio_util::sync::CancellationToken::new();
-    let jobset = Arc::new(tokio::sync::Mutex::new(tokio::task::JoinSet::new()));
+    let jobset = Arc::new(tokio::sync::Mutex::new(tokio::task::JoinSet::<()>::new()));
+    let http: reqwest::Client = {
+        #[allow(unused_mut)]
+        let mut builder = reqwest::Client::builder()
+            .user_agent(concat!(
+                env!("CARGO_PKG_NAME"),
+                "/",
+                env!("CARGO_PKG_VERSION")
+            ));
+        if let Ok(certs) = std::env::var("KITTYBOX_CUSTOM_PKI_ROOTS") {
+            // TODO: add a root certificate if there's an environment variable pointing at it
+            for path in certs.split(':') {
+                let metadata = match tokio::fs::metadata(path).await {
+                    Ok(metadata) => metadata,
+                    Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
+                        tracing::error!("TLS root certificate {} not found, skipping...", path);
+                        continue;
+                    }
+                    Err(err) => panic!("Error loading TLS certificates: {}", err)
+                };
+                if metadata.is_dir() {
+                    let mut dir = tokio::fs::read_dir(path).await.unwrap();
+                    while let Ok(Some(file)) = dir.next_entry().await {
+                        let pem = tokio::fs::read(file.path()).await.unwrap();
+                        builder = builder.add_root_certificate(
+                            reqwest::Certificate::from_pem(&pem).unwrap()
+                        );
+                    }
+                } else {
+                    let pem = tokio::fs::read(path).await.unwrap();
+                    builder = builder.add_root_certificate(
+                        reqwest::Certificate::from_pem(&pem).unwrap()
+                    );
+                }
+            }
+        }
+
+        builder.build().unwrap()
+    };
+
+    let backend_type = backend_uri.scheme();
+    let blobstore_type = blobstore_uri.scheme();
+    let authstore_type = authstore_uri.scheme();
+    let job_queue_type = job_queue_uri.scheme();
+
+    macro_rules! compose_kittybox {
+        ($auth:ty, $store:ty, $media:ty, $queue:ty) => { {
+            type AuthBackend = $auth;
+            type Storage = $store;
+            type MediaStore = $media;
+            type JobQueue = $queue;
+
+            let state = kittybox::AppState {
+                auth_backend: match AuthBackend::new(&authstore_uri).await {
+                    Ok(auth) => auth,
+                    Err(err) => {
+                        error!("Error creating auth backend: {:?}", err);
+                        std::process::exit(1);
+                    }
+                },
+                storage: match Storage::new(&backend_uri).await {
+                    Ok(db) => db,
+                    Err(err) => {
+                        error!("Error creating database: {:?}", err);
+                        std::process::exit(1);
+                    }
+                },
+                media_store: match MediaStore::new(&blobstore_uri).await {
+                    Ok(media) => media,
+                    Err(err) => {
+                        error!("Error creating media store: {:?}", err);
+                        std::process::exit(1);
+                    }
+                },
+                job_queue: match JobQueue::new(&job_queue_uri).await {
+                    Ok(queue) => queue,
+                    Err(err) => {
+                        error!("Error creating webmention job queue: {:?}", err);
+                        std::process::exit(1);
+                    }
+                },
+                http,
+                background_jobs: jobset.clone(),
+                cookie_key
+            };
+
+            type St = kittybox::AppState<AuthBackend, Storage, MediaStore, JobQueue>;
+            let stateful_router = compose_stateful_kittybox::<St, AuthBackend, Storage, MediaStore, JobQueue>().await;
+            let task = kittybox::webmentions::supervised_webmentions_task::<St, Storage, JobQueue>(&state, cancellation_token.clone());
+            let router = stateful_router.with_state(state);
 
-    let (router, webmentions_task) = compose_kittybox(
-        backend_uri.as_str(),
-        blobstore_uri.as_str(),
-        authstore_uri.as_str(),
-        job_queue_uri.as_str(),
-        &jobset,
-        &cancellation_token
-    ).await;
+            (router, task)
+        } }
+    }
+
+    let (router, webmentions_task): (axum::Router<()>, kittybox::webmentions::SupervisedTask) = match (authstore_type, backend_type, blobstore_type, job_queue_type) {
+        ("file", "file", "file", "postgres") => {
+            compose_kittybox!(
+                kittybox::indieauth::backend::fs::FileBackend,
+                kittybox::database::FileStorage,
+                kittybox::media::storage::file::FileStore,
+                kittybox::webmentions::queue::PostgresJobQueue<Webmention>
+            )
+        },
+        ("file", "postgres", "file", "postgres") => {
+            compose_kittybox!(
+                kittybox::indieauth::backend::fs::FileBackend,
+                kittybox::database::PostgresStorage,
+                kittybox::media::storage::file::FileStore,
+                kittybox::webmentions::queue::PostgresJobQueue<Webmention>
+            )
+        },
+        (_, _, _, _) => {
+            // TODO: refine this error.
+            panic!("Invalid type for AUTH_STORE_URI, BACKEND_URI, BLOBSTORE_URI or JOB_QUEUE_URI");
+        }
+    };
 
     let mut servers: Vec<hyper::server::Server<hyper::server::conn::AddrIncoming, _>> = vec![];
 
@@ -494,5 +404,4 @@ async fn main() {
     while (jobset.join_next().await).is_some() {}
     tracing::info!("Shutdown complete, exiting.");
     std::process::exit(exitcode);
-
 }
diff --git a/src/media/mod.rs b/src/media/mod.rs
index 71f875e..47f456a 100644
--- a/src/media/mod.rs
+++ b/src/media/mod.rs
@@ -1,14 +1,9 @@
-use std::convert::TryFrom;
-
 use axum::{
-    extract::{Extension, Host, multipart::Multipart, Path},
-    response::{IntoResponse, Response},
-    headers::{Header, HeaderValue, IfNoneMatch, HeaderMapExt},
-    TypedHeader,
+    extract::{multipart::Multipart, FromRef, Host, Path, State}, headers::{HeaderMapExt, HeaderValue, IfNoneMatch}, response::{IntoResponse, Response}, TypedHeader
 };
 use kittybox_util::error::{MicropubError, ErrorType};
 use kittybox_indieauth::Scope;
-use crate::indieauth::{User, backend::AuthBackend};
+use crate::indieauth::{backend::AuthBackend, User};
 
 pub mod storage;
 use storage::{MediaStore, MediaStoreError, Metadata, ErrorKind};
@@ -25,7 +20,7 @@ impl From<MediaStoreError> for MicropubError {
 
 #[tracing::instrument(skip(blobstore))]
 pub(crate) async fn upload<S: MediaStore, A: AuthBackend>(
-    Extension(blobstore): Extension<S>,
+    State(blobstore): State<S>,
     user: User<A>,
     mut upload: Multipart
 ) -> Response {
@@ -70,7 +65,7 @@ pub(crate) async fn serve<S: MediaStore>(
     Host(host): Host,
     Path(path): Path<String>,
     if_none_match: Option<TypedHeader<IfNoneMatch>>,
-    Extension(blobstore): Extension<S>
+    State(blobstore): State<S>
 ) -> Response {
     use axum::http::StatusCode;
     tracing::debug!("Searching for file...");
@@ -131,11 +126,12 @@ pub(crate) async fn serve<S: MediaStore>(
     }
 }
 
-#[must_use]
-pub fn router<S: MediaStore, A: AuthBackend>(blobstore: S, auth: A) -> axum::Router {
+pub fn router<St, A, M>() -> axum::Router<St> where
+    A: AuthBackend + FromRef<St>,
+    M: MediaStore + FromRef<St>,
+    St: Clone + Send + Sync + 'static
+{
     axum::Router::new()
-        .route("/", axum::routing::post(upload::<S, A>))
-        .route("/uploads/*file", axum::routing::get(serve::<S>))
-        .layer(axum::Extension(blobstore))
-        .layer(axum::Extension(auth))
+        .route("/", axum::routing::post(upload::<M, A>))
+        .route("/uploads/*file", axum::routing::get(serve::<M>))
 }
diff --git a/src/micropub/mod.rs b/src/micropub/mod.rs
index 624c239..fc5dd10 100644
--- a/src/micropub/mod.rs
+++ b/src/micropub/mod.rs
@@ -5,12 +5,13 @@ use std::sync::Arc;
 use crate::database::{MicropubChannel, Storage, StorageError};
 use crate::indieauth::backend::AuthBackend;
 use crate::indieauth::User;
+use crate::media::storage::MediaStore;
 use crate::micropub::util::form_to_mf2_json;
-use axum::extract::{BodyStream, Query, Host};
+use axum::extract::{BodyStream, FromRef, Host, Query, State};
 use axum::headers::ContentType;
 use axum::response::{IntoResponse, Response};
 use axum::TypedHeader;
-use axum::{http::StatusCode, Extension};
+use axum::http::StatusCode;
 use serde::{Deserialize, Serialize};
 use serde_json::json;
 use tokio::sync::Mutex;
@@ -515,9 +516,9 @@ async fn dispatch_body(
 
 #[tracing::instrument(skip(db, http))]
 pub(crate) async fn post<D: Storage + 'static, A: AuthBackend>(
-    Extension(db): Extension<D>,
-    Extension(http): Extension<reqwest::Client>,
-    Extension(jobset): Extension<Arc<Mutex<JoinSet<()>>>>,
+    State(db): State<D>,
+    State(http): State<reqwest::Client>,
+    State(jobset): State<Arc<Mutex<JoinSet<()>>>>,
     TypedHeader(content_type): TypedHeader<ContentType>,
     user: User<A>,
     body: BodyStream,
@@ -540,7 +541,7 @@ pub(crate) async fn post<D: Storage + 'static, A: AuthBackend>(
 
 #[tracing::instrument(skip(db))]
 pub(crate) async fn query<D: Storage, A: AuthBackend>(
-    Extension(db): Extension<D>,
+    State(db): State<D>,
     query: Option<Query<MicropubQuery>>,
     Host(host): Host,
     user: User<A>,
@@ -662,16 +663,13 @@ pub(crate) async fn query<D: Storage, A: AuthBackend>(
     }
 }
 
-#[must_use]
-pub fn router<S, A>(
-    storage: S,
-    http: reqwest::Client,
-    auth: A,
-    jobset: Arc<Mutex<JoinSet<()>>>
-) -> axum::routing::MethodRouter
+
+pub fn router<A, S, St: Send + Sync + Clone + 'static>() -> axum::routing::MethodRouter<St>
 where
-    S: Storage + 'static,
-    A: AuthBackend
+    S: Storage + FromRef<St> + 'static,
+    A: AuthBackend + FromRef<St>,
+    reqwest::Client: FromRef<St>,
+    Arc<Mutex<JoinSet<()>>>: FromRef<St>
 {
     axum::routing::get(query::<S, A>)
         .post(post::<S, A>)
@@ -680,11 +678,7 @@ where
                    axum::http::Method::GET,
                    axum::http::Method::POST,
                ])
-               .allow_origin(tower_http::cors::Any))
-        .layer::<_, _, std::convert::Infallible>(axum::Extension(storage))
-        .layer::<_, _, std::convert::Infallible>(axum::Extension(http))
-        .layer::<_, _, std::convert::Infallible>(axum::Extension(auth))
-        .layer::<_, _, std::convert::Infallible>(axum::Extension(jobset))
+            .allow_origin(tower_http::cors::Any))
 }
 
 #[cfg(test)]
@@ -716,7 +710,7 @@ mod tests {
 
     use super::FetchedPostContext;
     use kittybox_indieauth::{Scopes, Scope, TokenData};
-    use axum::extract::Host;
+    use axum::extract::{Host, State};
 
     #[test]
     fn test_populate_reply_context() {
@@ -850,7 +844,7 @@ mod tests {
     #[tokio::test]
     async fn test_query_foreign_url() {
         let mut res = super::query(
-            axum::Extension(crate::database::MemoryStorage::default()),
+            State(crate::database::MemoryStorage::default()),
             Some(axum::extract::Query(super::MicropubQuery::source(
                 "https://aaronparecki.com/feeds/main",
             ))),
diff --git a/src/webmentions/mod.rs b/src/webmentions/mod.rs
index 3e9b094..d5a617e 100644
--- a/src/webmentions/mod.rs
+++ b/src/webmentions/mod.rs
@@ -1,4 +1,4 @@
-use axum::{Form, response::{IntoResponse, Response}, Extension};
+use axum::{extract::{FromRef, State}, response::{IntoResponse, Response}, routing::post, Form};
 use axum::http::StatusCode;
 use tracing::error;
 
@@ -20,7 +20,7 @@ impl queue::PostgresJobItem for Webmention {
 }
 
 async fn accept_webmention<Q: JobQueue<Webmention>>(
-    Extension(queue): Extension<Q>,
+    State(queue): State<Q>,
     Form(webmention): Form<Webmention>,
 ) -> Response {
     if let Err(err) = webmention.source.parse::<url::Url>() {
@@ -31,27 +31,16 @@ async fn accept_webmention<Q: JobQueue<Webmention>>(
     }
 
     match queue.put(&webmention).await {
-        Ok(id) => StatusCode::ACCEPTED.into_response(),
+        Ok(_id) => StatusCode::ACCEPTED.into_response(),
         Err(err) => (StatusCode::INTERNAL_SERVER_ERROR, [
             ("Content-Type", "text/plain")
         ], err.to_string()).into_response()
     }
 }
 
-pub fn router<Q: JobQueue<Webmention>, S: Storage + 'static>(
-    queue: Q, db: S, http: reqwest::Client,
-    cancellation_token: tokio_util::sync::CancellationToken
-) -> (axum::Router, SupervisedTask) {
-    // Automatically spawn a background task to handle webmentions
-    let bgtask_handle = supervised_webmentions_task(queue.clone(), db, http, cancellation_token);
-
-    let router = axum::Router::new()
-        .route("/.kittybox/webmention",
-            axum::routing::post(accept_webmention::<Q>)
-        )
-        .layer(Extension(queue));
-
-    (router, bgtask_handle)
+pub fn router<St: Clone + Send + Sync + 'static, Q: JobQueue<Webmention> + FromRef<St>>() -> axum::Router<St> {
+    axum::Router::new()
+        .route("/.kittybox/webmention", post(accept_webmention::<Q>))
 }
 
 #[derive(thiserror::Error, Debug)]
@@ -184,10 +173,16 @@ async fn process_webmentions_from_queue<Q: JobQueue<Webmention>, S: Storage + 's
     unreachable!()
 }
 
-fn supervised_webmentions_task<Q: JobQueue<Webmention>, S: Storage + 'static>(
-    queue: Q, db: S,
-    http: reqwest::Client,
+pub fn supervised_webmentions_task<St: Send + Sync + 'static, S: Storage + FromRef<St> + 'static, Q: JobQueue<Webmention> + FromRef<St> + 'static>(
+    state: &St,
     cancellation_token: tokio_util::sync::CancellationToken
-) -> SupervisedTask {
-    supervisor::<Error<Q::Error>, _, _>(move || process_webmentions_from_queue(queue.clone(), db.clone(), http.clone()), cancellation_token)
+) -> SupervisedTask
+where reqwest::Client: FromRef<St>
+{
+    let queue = Q::from_ref(state);
+    let storage = S::from_ref(state);
+    let http = reqwest::Client::from_ref(state);
+    supervisor::<Error<Q::Error>, _, _>(move || process_webmentions_from_queue(
+        queue.clone(), storage.clone(), http.clone()
+    ), cancellation_token)
 }