// Copyright 2018 Parity Technologies (UK) Ltd.
// Copyright 2020 Netwarps Ltd.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Transports with timeouts on the connection setup.
//!
//! The connection setup includes all protocol upgrades applied on the
//! underlying `Transport`.
// TODO: add example

use crate::transport::{ConnectionInfo, IListener, ITransport, ListenerEvent, TransportListener};
use crate::{transport::TransportError, Multiaddr, Transport};
use async_trait::async_trait;
use futures::future::{select, Either};
use futures_timer::Delay;
use log::trace;
use std::time::Duration;

/// A `TransportTimeout` is a `Transport` that wraps another `Transport` and adds
/// timeouts to all inbound and outbound connection attempts.
///
/// **Note**: `listen_on` is never subject to a timeout, only the setup of each
/// individual accepted connection.
#[derive(Debug, Clone)]
pub struct TransportTimeout<InnerTrans> {
    inner: InnerTrans,
    outgoing_timeout: Duration,
    incoming_timeout: Duration,
}

impl<InnerTrans> TransportTimeout<InnerTrans> {
    /// Wraps around a `Transport` to add timeouts to all the sockets created by it.
    pub fn new(trans: InnerTrans, timeout: Duration) -> Self {
        TransportTimeout {
            inner: trans,
            outgoing_timeout: timeout,
            incoming_timeout: timeout,
        }
    }

    /// Wraps around a `Transport` to add timeouts to the outgoing connections.
    pub fn with_outgoing_timeout(trans: InnerTrans, timeout: Duration) -> Self {
        TransportTimeout {
            inner: trans,
            outgoing_timeout: timeout,
            incoming_timeout: Duration::from_secs(100 * 365 * 24 * 3600), // 100 years
        }
    }

    /// Wraps around a `Transport` to add timeouts to the ingoing connections.
    pub fn with_ingoing_timeout(trans: InnerTrans, timeout: Duration) -> Self {
        TransportTimeout {
            inner: trans,
            outgoing_timeout: Duration::from_secs(100 * 365 * 24 * 3600), // 100 years
            incoming_timeout: timeout,
        }
    }
}

#[async_trait]
impl<InnerTrans> Transport for TransportTimeout<InnerTrans>
where
    InnerTrans: Transport + Clone + 'static,
    InnerTrans::Output: ConnectionInfo + 'static,
{
    type Output = InnerTrans::Output;

    /// Creates a IListener with timeout parameter, which will be used for Ilistener to accept new connections.
    fn listen_on(&mut self, addr: Multiaddr) -> Result<IListener<Self::Output>, TransportError> {
        let listener = self.inner.listen_on(addr)?;

        let listener = TimeoutListener {
            inner: listener,
            timeout: self.incoming_timeout,
        };

        Ok(Box::new(listener))
    }

    /// Creates a new outgoing connection, with the specified timeout parameter.
    async fn dial(&mut self, addr: Multiaddr) -> Result<Self::Output, TransportError> {
        let output = select(self.inner.dial(addr), Delay::new(self.outgoing_timeout)).await;
        match output {
            Either::Left((stream, _)) => {
                trace!("dialing connected first");
                Ok(stream?)
            }
            Either::Right(_) => {
                trace!("dialing timeout first");
                Err(TransportError::Timeout)
            }
        }
    }

    fn box_clone(&self) -> ITransport<Self::Output> {
        Box::new(self.clone())
    }

    fn protocols(&self) -> Vec<u32> {
        self.inner.protocols()
    }
}

pub struct TimeoutListener<TOutput> {
    inner: IListener<TOutput>,
    timeout: Duration,
}

#[async_trait]
impl<TOutput: Send> TransportListener for TimeoutListener<TOutput> {
    type Output = TOutput;

    async fn accept(&mut self) -> Result<ListenerEvent<Self::Output>, TransportError> {
        let output = select(self.inner.accept(), Delay::new(self.timeout)).await;
        match output {
            Either::Left((r, _)) => {
                trace!("accepted first");
                r
            }
            Either::Right(_) => {
                trace!("accept timeout first");
                Err(TransportError::Timeout)
            }
        }
    }

    fn multi_addr(&self) -> Option<&Multiaddr> {
        self.inner.multi_addr()
    }
}

#[cfg(test)]
mod tests {
    use crate::transport::memory::MemoryTransport;
    use crate::{Multiaddr, Transport};
    use libp2prs_runtime::task;
    use std::time::Duration;

    #[test]
    fn dialer_and_listener_timeout() {
        fn test1(addr: Multiaddr) {
            task::block_on(async move {
                let mut timeout_listener = MemoryTransport::default().timeout(Duration::from_secs(1)).listen_on(addr).unwrap();
                assert!(timeout_listener.accept().await.is_err());
            });
        }

        fn test2(addr: Multiaddr) {
            task::block_on(async move {
                let mut tcp = MemoryTransport::default().timeout(Duration::from_secs(1));
                assert!(tcp.dial(addr.clone()).await.is_err());
            });
        }

        test1("/memory/1111".parse().unwrap());
        test2("/memory/1111".parse().unwrap());
    }
}