refactor: update AppState references to use state module

- Change all instances of AppState to reference the new state module across multiple files for consistency.
- Clean up imports in auth, books, index_jobs, libraries, pages, search, settings, thumbnails, and tokens modules.
- Simplify main.rs by removing unused code and organizing middleware and route handlers under the new handlers module.

apps/api/src/main.rs

@@ -1,91 +1,36 @@
 mod auth;
 mod books;
 mod error;
+mod handlers;
 mod index_jobs;
 mod libraries;
+mod api_middleware;
 mod openapi;
 mod pages;
 mod search;
 mod settings;
+mod state;
 mod thumbnails;
 mod tokens;
 
-use std::{
-    num::NonZeroUsize,
-    sync::{
-        atomic::{AtomicU64, Ordering},
-        Arc,
-    },
-    time::{Duration, Instant},
-};
+use std::sync::Arc;
+use std::time::Instant;
 
 use axum::{
     middleware,
-    response::IntoResponse,
     routing::{delete, get},
-    Json, Router,
+    Router,
 };
 use utoipa::OpenApi;
 use utoipa_swagger_ui::SwaggerUi;
 use lru::LruCache;
+use std::num::NonZeroUsize;
 use stripstream_core::config::ApiConfig;
 use sqlx::postgres::PgPoolOptions;
 use tokio::sync::{Mutex, Semaphore};
 use tracing::info;
-use sqlx::{Pool, Postgres, Row};
-use serde_json::Value;
 
-#[derive(Clone)]
-struct AppState {
-    pool: sqlx::PgPool,
-    bootstrap_token: Arc<str>,
-    meili_url: Arc<str>,
-    meili_master_key: Arc<str>,
-    page_cache: Arc<Mutex<LruCache<String, Arc<Vec<u8>>>>>,
-    page_render_limit: Arc<Semaphore>,
-    metrics: Arc<Metrics>,
-    read_rate_limit: Arc<Mutex<ReadRateLimit>>,
-}
-
-struct Metrics {
-    requests_total: AtomicU64,
-    page_cache_hits: AtomicU64,
-    page_cache_misses: AtomicU64,
-}
-
-struct ReadRateLimit {
-    window_started_at: Instant,
-    requests_in_window: u32,
-}
-
-impl Metrics {
-    fn new() -> Self {
-        Self {
-            requests_total: AtomicU64::new(0),
-            page_cache_hits: AtomicU64::new(0),
-            page_cache_misses: AtomicU64::new(0),
-        }
-    }
-}
-
-async fn load_concurrent_renders(pool: &Pool<Postgres>) -> usize {
-    let default_concurrency = 8;
-    let row = sqlx::query(r#"SELECT value FROM app_settings WHERE key = 'limits'"#)
-        .fetch_optional(pool)
-        .await;
-
-    match row {
-        Ok(Some(row)) => {
-            let value: Value = row.get("value");
-            value
-                .get("concurrent_renders")
-                .and_then(|v: &Value| v.as_u64())
-                .map(|v| v as usize)
-                .unwrap_or(default_concurrency)
-        }
-        _ => default_concurrency,
-    }
-}
+use crate::state::{load_concurrent_renders, AppState, Metrics, ReadRateLimit};
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
@@ -150,21 +95,21 @@ async fn main() -> anyhow::Result<()> {
         .route("/books/:id/pages/:n", get(pages::get_page))
         .route("/libraries/:library_id/series", get(books::list_series))
         .route("/search", get(search::search_books))
-        .route_layer(middleware::from_fn_with_state(state.clone(), read_rate_limit))
+        .route_layer(middleware::from_fn_with_state(state.clone(), api_middleware::read_rate_limit))
         .route_layer(middleware::from_fn_with_state(
             state.clone(),
             auth::require_read,
         ));
 
     let app = Router::new()
-        .route("/health", get(health))
-        .route("/ready", get(ready))
-        .route("/metrics", get(metrics))
-        .route("/docs", get(docs_redirect))
+        .route("/health", get(handlers::health))
+        .route("/ready", get(handlers::ready))
+        .route("/metrics", get(handlers::metrics))
+        .route("/docs", get(handlers::docs_redirect))
         .merge(SwaggerUi::new("/swagger-ui").url("/openapi.json", openapi::ApiDoc::openapi()))
         .merge(admin_routes)
         .merge(read_routes)
-        .layer(middleware::from_fn_with_state(state.clone(), request_counter))
+        .layer(middleware::from_fn_with_state(state.clone(), api_middleware::request_counter))
         .with_state(state);
 
     let listener = tokio::net::TcpListener::bind(&config.listen_addr).await?;
@@ -173,57 +118,3 @@ async fn main() -> anyhow::Result<()> {
     Ok(())
 }
 
-async fn health() -> &'static str {
-    "ok"
-}
-
-async fn docs_redirect() -> impl axum::response::IntoResponse {
-    axum::response::Redirect::to("/swagger-ui/")
-}
-
-async fn ready(axum::extract::State(state): axum::extract::State<AppState>) -> Result<Json<serde_json::Value>, error::ApiError> {
-    sqlx::query("SELECT 1").execute(&state.pool).await?;
-    Ok(Json(serde_json::json!({"status": "ready"})))
-}
-
-async fn metrics(axum::extract::State(state): axum::extract::State<AppState>) -> String {
-    format!(
-        "requests_total {}\npage_cache_hits {}\npage_cache_misses {}\n",
-        state.metrics.requests_total.load(Ordering::Relaxed),
-        state.metrics.page_cache_hits.load(Ordering::Relaxed),
-        state.metrics.page_cache_misses.load(Ordering::Relaxed),
-    )
-}
-
-async fn request_counter(
-    axum::extract::State(state): axum::extract::State<AppState>,
-    req: axum::extract::Request,
-    next: axum::middleware::Next,
-) -> axum::response::Response {
-    state.metrics.requests_total.fetch_add(1, Ordering::Relaxed);
-    next.run(req).await
-}
-
-async fn read_rate_limit(
-    axum::extract::State(state): axum::extract::State<AppState>,
-    req: axum::extract::Request,
-    next: axum::middleware::Next,
-) -> axum::response::Response {
-    let mut limiter = state.read_rate_limit.lock().await;
-    if limiter.window_started_at.elapsed() >= Duration::from_secs(1) {
-        limiter.window_started_at = Instant::now();
-        limiter.requests_in_window = 0;
-    }
-
-    if limiter.requests_in_window >= 120 {
-        return (
-            axum::http::StatusCode::TOO_MANY_REQUESTS,
-            "rate limit exceeded",
-        )
-            .into_response();
-    }
-
-    limiter.requests_in_window += 1;
-    drop(limiter);
-    next.run(req).await
-}