rust_cast 0.6.0

use std::borrow::Cow;
use std::cell::RefCell;
use std::io::Write;
use std::rc::Rc;

use serde_json;

use cast::proxies;
use errors::Error;
use message_manager::{CastMessage, CastMessagePayload, MessageManager};

const CHANNEL_NAMESPACE: &'static str = "urn:x-cast:com.google.cast.tp.connection";
const CHANNEL_USER_AGENT: &'static str = "RustCast";

const MESSAGE_TYPE_CONNECT: &'static str = "CONNECT";
const MESSAGE_TYPE_CLOSE: &'static str = "CLOSE";

#[derive(Debug)]
pub enum ConnectionResponse {
    Connect,
    Close,
    NotImplemented(String, serde_json::Value),
}

pub struct ConnectionChannel<'a, W> where W: Write {
    sender: Cow<'a, str>,
    writer: Rc<RefCell<W>>,
}

impl<'a, W> ConnectionChannel<'a, W> where W: Write {
    pub fn new<S>(sender: S, writer: Rc<RefCell<W>>)
        -> ConnectionChannel<'a, W> where S: Into<Cow<'a, str>> {
        ConnectionChannel {
            sender: sender.into(),
            writer: writer,
        }
    }

    pub fn connect<S>(&self, destination: S) -> Result<(), Error> where S: Into<Cow<'a, str>> {
        let payload = try!(serde_json::to_string(
            &proxies::connection::ConnectionRequest {
                typ: MESSAGE_TYPE_CONNECT.to_owned(),
                user_agent: CHANNEL_USER_AGENT.to_owned(),
            }));

        MessageManager::send(&mut *self.writer.borrow_mut(), CastMessage {
            namespace: CHANNEL_NAMESPACE.to_owned(),
            source: self.sender.to_string(),
            destination: destination.into().to_string(),
            payload: CastMessagePayload::String(payload),
        })
    }

    pub fn disconnect<S>(&self, destination: S) -> Result<(), Error> where S: Into<Cow<'a, str>> {
        let payload = try!(serde_json::to_string(
            &proxies::connection::ConnectionRequest {
                typ: MESSAGE_TYPE_CLOSE.to_owned(),
                user_agent: CHANNEL_USER_AGENT.to_owned(),
            }));

        MessageManager::send(&mut *self.writer.borrow_mut(), CastMessage {
            namespace: CHANNEL_NAMESPACE.to_owned(),
            source: self.sender.to_string(),
            destination: destination.into().to_string(),
            payload: CastMessagePayload::String(payload),
        })
    }

    pub fn can_handle(&self, message: &CastMessage) -> bool {
        message.namespace == CHANNEL_NAMESPACE
    }

    pub fn parse(&self, message: &CastMessage) -> Result<ConnectionResponse, Error> {
        let reply = match message.payload {
            CastMessagePayload::String(ref payload) => try!(
                serde_json::from_str::<serde_json::Value>(payload)),
            _ => return Err(Error::Internal("Binary payload is not supported!".to_owned())),
        };

        let message_type = reply.as_object()
            .and_then(|object| object.get("type"))
            .and_then(|property| property.as_string())
            .unwrap_or("")
            .to_owned();

        let response = match message_type.as_ref() {
            MESSAGE_TYPE_CONNECT => ConnectionResponse::Connect,
            MESSAGE_TYPE_CLOSE => ConnectionResponse::Close,
            _ => ConnectionResponse::NotImplemented(message_type.to_owned(), reply),
        };

        Ok(response)
    }
}