// Copyright 2019, The Tari Project
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// Much of this module is inspired or (more or less) verbatim from the Libra codebase.
// Copyright (c) The Libra Core Contributors
// SPDX-License-Identifier: Apache-2.0

//! # Transports
//!
//! Provides an abstraction for [Transport](self::Transport)s and several implemenations:
//! - [TCP](self::TcpTransport) - communication over TCP and IP4/IP6 and DNS
//! - [SOCKS](self::SocksTransport) - communication over a SOCKS5 proxy.
//! - [Memory](self::MemoryTransport) - in-process communication (mpsc channel), typically for testing.

use multiaddr::Multiaddr;
use tokio_stream::Stream;

mod dns;

pub mod predicate;

mod memory;
pub use memory::MemoryTransport;

mod socks;
pub use socks::{SocksConfig, SocksTransport};

mod tcp;
pub use tcp::TcpTransport;

mod hidden_service_transport;
mod tcp_with_tor;
pub use hidden_service_transport::HiddenServiceTransport;
pub use tcp_with_tor::TcpWithTorTransport;

use crate::types::TransportProtocol;

/// Defines an abstraction for implementations that can dial and listen for connections over a provided address.
#[crate::async_trait]
pub trait Transport {
    /// The output of the transport after a connection is established
    type Output;
    /// Transport error type
    type Error: std::error::Error + Send + Sync;
    /// A stream which emits a (socket, source ip) tuple whenever a successful inbound connection is made
    type Listener: Stream<Item = Result<(Self::Output, Multiaddr), Self::Error>> + Send + Unpin;

    /// Listen for connections on the given multiaddr
    async fn listen(&self, addr: &Multiaddr) -> Result<(Self::Listener, Multiaddr), Self::Error>;

    /// Connect (dial) to the given multiaddr
    async fn dial(&self, addr: &Multiaddr) -> Result<Self::Output, Self::Error>;

    /// Returns the protocols that are supported by this transport
    fn supported_protocols(&self) -> Vec<TransportProtocol>;
}
