//! Router assembly. Public API is versioned under `/v1` from day one; `/health` is
//! unversioned for infrastructure probes.

mod auth_routes;
mod feed;
mod health;
mod ingest;
mod interests;
mod sources;
mod tokens;

use axum::Router;
use axum::http::{Method, header};
use axum::routing::{delete, get, post};
use tower_http::compression::CompressionLayer;
use tower_http::cors::CorsLayer;
use tower_http::trace::TraceLayer;

use crate::state::AppState;

/// Build the full application router.
pub fn router(state: AppState) -> Router {
    let cors = build_cors(&state);

    let v1 = Router::new()
        // auth
        .route("/auth/register", post(auth_routes::register))
        .route("/auth/login", post(auth_routes::login))
        .route("/auth/logout", post(auth_routes::logout))
        .route("/auth/me", get(auth_routes::me))
        // feed
        .route("/feed", get(feed::get_feed))
        .route("/feed/signals", post(feed::post_signal))
        // sources
        .route("/sources", get(sources::list).post(sources::create))
        .route("/sources/discover", post(sources::discover))
        .route("/sources/import", post(sources::import))
        .route("/sources/{id}", delete(sources::remove))
        // interests
        .route("/interests", get(interests::list).put(interests::upsert))
        .route("/interests/{id}", delete(interests::remove))
        // api tokens
        .route("/tokens", get(tokens::list).post(tokens::create))
        .route("/tokens/{id}", delete(tokens::revoke))
        // ingest (bearer-token authenticated)
        .route("/ingest/candidates", post(ingest::submit));

    Router::new()
        .route("/health", get(health::health))
        .nest("/v1", v1)
        .layer(TraceLayer::new_for_http())
        .layer(CompressionLayer::new())
        .layer(cors)
        .with_state(state)
}

/// CORS is only needed in development, where the Vite dev server is a different origin
/// from the API. In production nginx serves the SPA and proxies the API under one origin,
/// so `cors_origins` is empty and no cross-origin headers are emitted.
fn build_cors(state: &AppState) -> CorsLayer {
    if state.config.cors_origins.is_empty() {
        return CorsLayer::new();
    }
    let origins = state
        .config
        .cors_origins
        .iter()
        .filter_map(|o| o.parse().ok())
        .collect::<Vec<_>>();
    // Credentialed CORS forbids wildcard method/header lists, so enumerate them.
    CorsLayer::new()
        .allow_origin(origins)
        .allow_methods([Method::GET, Method::POST, Method::PUT, Method::DELETE])
        .allow_headers([header::CONTENT_TYPE, header::AUTHORIZATION])
        .allow_credentials(true)
}