use std::convert::Infallible;
use hyper::service::{service_fn, make_service_fn};
use hyper::{Method, Server};
use serde::Deserialize;
use sputnik::security::CsrfToken;
use sputnik::{Error, request::{Parts, Body}, response::Response};

async fn route(req: &mut Parts, body: Body) -> Result<Response,Error> {
    match (req.method(), req.uri().path()) {
        (&Method::GET, "/form") => get_form(req).await,
        (&Method::POST, "/form") => post_form(req, body).await,
        _ => return Err(Error::not_found("page not found".to_owned()))
    }
}

async fn get_form(req: &mut Parts) -> Result<Response, Error> {
    let mut response = Response::new();
    let csrf_token = CsrfToken::from_parts(req, &mut response);
    *response.body() = format!("<form method=post>
        <input name=text>{}<button>Submit</button></form>", csrf_token.html_input()).into();
    Ok(response)
}

#[derive(Deserialize)]
struct FormData {text: String}

async fn post_form(req: &mut Parts, body: Body) -> Result<Response, Error> {
    let mut response = Response::new();
    let csrf_token = CsrfToken::from_parts(req, &mut response);
    let msg: FormData = body.into_form_csrf(&csrf_token).await?;
    *response.body() = format!("hello {}", msg.text).into();
    Ok(response)
}

/// adapt between Hyper's types and Sputnik's convenience types
async fn service(req: hyper::Request<hyper::Body>) -> Result<hyper::Response<hyper::Body>, Infallible> {
    let (mut parts, body) = sputnik::request::adapt(req);
    match route(&mut parts, body).await {
        Ok(res) => Ok(res.into()),
        Err(err) => match err {
            Error::Simple(err) => {
                Ok(err.response_builder().body(err.message.into()).unwrap())
                // you can easily wrap or log errors here
            }
            Error::Response(err) => Ok(err)
        }
    }
}

#[tokio::main]
async fn main() {
    let service = make_service_fn(move |_| {
        async move {
            Ok::<_, hyper::Error>(service_fn(move |req| {
                service(req)
            }))
        }
    });

    let addr = ([127, 0, 0, 1], 8000).into();
    let server = Server::bind(&addr).serve(service);
    println!("Listening on http://{}", addr);
    server.await;
}