use std::{future::ready, net::SocketAddr};

use axum::{
    extract::Extension,
    http::StatusCode,
    middleware,
    routing::{get, get_service},
    Router,
};
use tower_http::{auth::RequireAuthorizationLayer, services::ServeDir, trace::TraceLayer};
use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};

mod api;
mod matrix;
mod metrics;

const DEFAULT_STATIC_DIR_NAME: &str = "static";

#[tokio::main]
async fn main()
{
    // Enable tracing
    tracing_subscriber::registry()
        .with(tracing_subscriber::EnvFilter::new(
            std::env::var("RUST_LOG").unwrap_or_else(|_| "site=debug,tower_http=debug".into()),
        ))
        .with(tracing_subscriber::fmt::layer())
        .init();

    // Get required variables from env vars
    let api_key = std::env::var("API_KEY").expect("No API_KEY was provided.");
    let data_dir = std::env::var("DATA_DIR").expect("No DATA_DIR was provided.");
    let static_dir = format!("{}/{}", data_dir, DEFAULT_STATIC_DIR_NAME);

    std::fs::create_dir_all(&static_dir);

    let recorder_handle = metrics::setup_metrics_recorder();

    let app = Router::new()
        // Handle Matrix .well-known files
        .nest("/", matrix::router())
        // Routes under /api path
        .nest(
            "/api",
            api::router().layer(RequireAuthorizationLayer::bearer(&api_key)),
        )
        .route("/metrics", get(move || ready(recorder_handle.render())))
        // The fallback option is to serve the actual static files
        .fallback(get_service(ServeDir::new(static_dir)).handle_error(
            |error: std::io::Error| async move {
                (
                    StatusCode::INTERNAL_SERVER_ERROR,
                    format!("Unhandled internal error: {}", error),
                )
            },
        ))
        .layer(middleware::from_fn(metrics::track_metrics))
        .layer(Extension(data_dir))
        .layer(TraceLayer::new_for_http());

    let addr = SocketAddr::from(([0, 0, 0, 0], 3000));
    tracing::debug!("listening on {}", addr);
    axum::Server::bind(&addr)
        .serve(app.into_make_service())
        .await
        .unwrap();
}