use hyper::{Body, Request, Response, Server, StatusCode};
// Import the routerify prelude traits.
use routerify::prelude::*;
use routerify::{Middleware, RequestInfo, Router, RouterService};
use std::{convert::Infallible, net::SocketAddr};

// Define an app state to share it across the route handlers, middlewares
// and the error handler.
struct State(u64);

// A handler for "/" page.
async fn home_handler(req: Request<Body>) -> Result<Response<Body>, Infallible> {
    // Access the app state.
    let state = req.data::<State>().unwrap();
    println!("State value: {}", state.0);

    Ok(Response::new(Body::from("Home page")))
}

// A middleware which logs an http request.
async fn logger(req: Request<Body>) -> Result<Request<Body>, Infallible> {
    // You can also access the same state from middleware.
    let state = req.data::<State>().unwrap();
    println!("State value: {}", state.0);

    println!("{} {} {}", req.remote_addr(), req.method(), req.uri().path());
    Ok(req)
}

// Define an error handler function which will accept the `routerify::Error`
// and the request information and generates an appropriate response.
async fn error_handler(err: routerify::Error, req_info: RequestInfo) -> Response<Body> {
    // You can also access the same state from error handler.
    let state = req_info.data::<State>().unwrap();
    println!("State value: {}", state.0);

    eprintln!("{}", err);
    Response::builder()
        .status(StatusCode::INTERNAL_SERVER_ERROR)
        .body(Body::from(format!("Something went wrong: {}", err)))
        .unwrap()
}

// Create a `Router<Body, Infallible>` for response body type `hyper::Body`
// and for handler error type `Infallible`.
fn router() -> Router<Body, Infallible> {
    Router::builder()
        // Specify the state data which will be available to every route handlers,
        // error handler and middlewares.
        .data(State(100))
        .middleware(Middleware::pre(logger))
        .get("/", home_handler)
        .err_handler_with_info(error_handler)
        .build()
        .unwrap()
}

#[tokio::main]
async fn main() {
    let router = router();

    // Create a Service from the router above to handle incoming requests.
    let service = RouterService::new(router).unwrap();

    // The address on which the server will be listening.
    let addr = SocketAddr::from(([127, 0, 0, 1], 3001));

    // Create a server by passing the created service to `.serve` method.
    let server = Server::bind(&addr).serve(service);

    println!("App is running on: {}", addr);
    if let Err(err) = server.await {
        eprintln!("Server error: {}", err);
    }
}
