use std::borrow::Cow;
use std::convert::Into;

use mio;
use mio::Token;
use mio_extras::timer::Timeout;
use url;

use io::ALL;
use message;
use protocol::CloseCode;
use result::{Error, Result};
use std::cmp::PartialEq;
use std::fmt;

#[derive(Debug, Clone)]
pub enum Signal {
    Message(message::Message),
    Close(CloseCode, Cow<'static, str>),
    Ping(Vec<u8>),
    Pong(Vec<u8>),
    Connect(url::Url),
    Shutdown,
    Timeout { delay: u64, token: Token },
    Cancel(Timeout),
}

#[derive(Debug, Clone)]
pub struct Command {
    token: Token,
    signal: Signal,
    connection_id: u32,
}

impl Command {
    pub fn token(&self) -> Token {
        self.token
    }

    pub fn into_signal(self) -> Signal {
        self.signal
    }

    pub fn connection_id(&self) -> u32 {
        self.connection_id
    }
}

/// A representation of the output of the WebSocket connection. Use this to send messages to the
/// other endpoint.
#[derive(Clone)]
pub struct Sender {
    token: Token,
    channel: mio::channel::SyncSender<Command>,
    connection_id: u32,
}

impl fmt::Debug for Sender {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f,
            "Sender {{ token: {:?}, channel: mio::channel::SyncSender<Command>, connection_id: {:?} }}",
            self.token, self.connection_id)
    }
}

impl PartialEq for Sender {
    fn eq(&self, other: &Sender) -> bool {
        self.token == other.token && self.connection_id == other.connection_id
    }
}

impl Sender {
    #[doc(hidden)]
    #[inline]
    pub fn new(
        token: Token,
        channel: mio::channel::SyncSender<Command>,
        connection_id: u32,
    ) -> Sender {
        Sender {
            token,
            channel,
            connection_id,
        }
    }

    /// A Token identifying this sender within the WebSocket.
    #[inline]
    pub fn token(&self) -> Token {
        self.token
    }

    /// A connection_id identifying this sender within the WebSocket.
    #[inline]
    pub fn connection_id(&self) -> u32 {
        self.connection_id
    }

    /// Send a message over the connection.
    #[inline]
    pub fn send<M>(&self, msg: M) -> Result<()>
    where
        M: Into<message::Message>,
    {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Message(msg.into()),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Send a message to the endpoints of all connections.
    ///
    /// Be careful with this method. It does not discriminate between client and server connections.
    /// If your WebSocket is only functioning as a server, then usage is simple, this method will
    /// send a copy of the message to each connected client. However, if you have a WebSocket that
    /// is listening for connections and is also connected to another WebSocket, this method will
    /// broadcast a copy of the message to all the clients connected and to that WebSocket server.
    #[inline]
    pub fn broadcast<M>(&self, msg: M) -> Result<()>
    where
        M: Into<message::Message>,
    {
        self.channel
            .send(Command {
                token: ALL,
                signal: Signal::Message(msg.into()),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Send a close code to the other endpoint.
    #[inline]
    pub fn close(&self, code: CloseCode) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Close(code, "".into()),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Send a close code and provide a descriptive reason for closing.
    #[inline]
    pub fn close_with_reason<S>(&self, code: CloseCode, reason: S) -> Result<()>
    where
        S: Into<Cow<'static, str>>,
    {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Close(code, reason.into()),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Send a ping to the other endpoint with the given test data.
    #[inline]
    pub fn ping(&self, data: Vec<u8>) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Ping(data),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Send a pong to the other endpoint responding with the given test data.
    #[inline]
    pub fn pong(&self, data: Vec<u8>) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Pong(data),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Queue a new connection on this WebSocket to the specified URL.
    #[inline]
    pub fn connect(&self, url: url::Url) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Connect(url),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Request that all connections terminate and that the WebSocket stop running.
    #[inline]
    pub fn shutdown(&self) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Shutdown,
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Schedule a `token` to be sent to the WebSocket Handler's `on_timeout` method
    /// after `ms` milliseconds
    #[inline]
    pub fn timeout(&self, ms: u64, token: Token) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Timeout { delay: ms, token },
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }

    /// Queue the cancellation of a previously scheduled timeout.
    ///
    /// This method is not guaranteed to prevent the timeout from occurring, because it is
    /// possible to call this method after a timeout has already occurred. It is still necessary to
    /// handle spurious timeouts.
    #[inline]
    pub fn cancel(&self, timeout: Timeout) -> Result<()> {
        self.channel
            .send(Command {
                token: self.token,
                signal: Signal::Cancel(timeout),
                connection_id: self.connection_id,
            })
            .map_err(Error::from)
    }
}