extern crate env_logger;
/// WebSocket server using trait objects to route
/// to an infinitely extensible number of handlers
extern crate ws;

// A WebSocket handler that routes connections to different boxed handlers by resource
struct Router {
    sender: ws::Sender,
    inner: Box<ws::Handler>,
}

impl ws::Handler for Router {
    fn on_request(&mut self, req: &ws::Request) -> ws::Result<(ws::Response)> {
        // Clone the sender so that we can move it into the child handler
        let out = self.sender.clone();

        match req.resource() {
            "/echo" => self.inner = Box::new(Echo { ws: out }),

            // Route to a data handler
            "/data/one" => {
                self.inner = Box::new(Data {
                    ws: out,
                    data: vec!["one", "two", "three", "four", "five"],
                })
            }

            // Route to another data handler
            "/data/two" => {
                self.inner = Box::new(Data {
                    ws: out,
                    data: vec!["いち", "二", "さん", "四", "ご"],
                })
            }

            // Use a closure as the child handler
            "/closure" => {
                self.inner = Box::new(move |msg: ws::Message| {
                    println!("Got a message on a closure handler: {}", msg);
                    out.close_with_reason(ws::CloseCode::Error, "Not Implemented.")
                })
            }

            // Use the default child handler, NotFound
            _ => (),
        }

        // Delegate to the child handler
        self.inner.on_request(req)
    }

    // Pass through any other methods that should be delegated to the child.
    //
    // You could probably use a macro for this if you have many different
    // routers or were building some sort of routing framework.

    fn on_shutdown(&mut self) {
        self.inner.on_shutdown()
    }

    fn on_open(&mut self, shake: ws::Handshake) -> ws::Result<()> {
        self.inner.on_open(shake)
    }

    fn on_message(&mut self, msg: ws::Message) -> ws::Result<()> {
        self.inner.on_message(msg)
    }

    fn on_close(&mut self, code: ws::CloseCode, reason: &str) {
        self.inner.on_close(code, reason)
    }

    fn on_error(&mut self, err: ws::Error) {
        self.inner.on_error(err);
    }
}

// This handler returns a 404 response to all handshake requests
struct NotFound;

impl ws::Handler for NotFound {
    fn on_request(&mut self, req: &ws::Request) -> ws::Result<(ws::Response)> {
        // This handler responds to all requests with a 404
        let mut res = try!(ws::Response::from_request(req));
        res.set_status(404);
        res.set_reason("Not Found");
        Ok(res)
    }
}

// This handler simply echoes all messages back to the client
struct Echo {
    ws: ws::Sender,
}

impl ws::Handler for Echo {
    fn on_message(&mut self, msg: ws::Message) -> ws::Result<()> {
        println!("Echo handler received a message: {}", msg);
        self.ws.send(msg)
    }
}

// This handler sends some data to the client and then terminates the connection on the first
// message received, presumably confirming receipt of the data
struct Data {
    ws: ws::Sender,
    data: Vec<&'static str>,
}

impl ws::Handler for Data {
    fn on_open(&mut self, _: ws::Handshake) -> ws::Result<()> {
        for msg in self.data.iter() {
            try!(self.ws.send(*msg))
        }
        Ok(())
    }

    fn on_message(&mut self, msg: ws::Message) -> ws::Result<()> {
        println!("Data handler received a message: {}", msg);
        println!("Data handler going down.");
        self.ws.close(ws::CloseCode::Normal)
    }
}

fn main() {
    env_logger::init().unwrap();

    // Listen on an address and call the closure for each connection
    if let Err(error) = ws::listen("127.0.0.1:3012", |out| {
        // Use our router as the handler to route the new connection
        Router {
            sender: out,
            // Default to returning a 404 when the route doesn't match.
            // You could default to any handler here.
            inner: Box::new(NotFound),
        }
    }) {
        // Inform the user of failure
        println!("Failed to create WebSocket due to {:?}", error);
    }
}