ctoolbox/

network.rs

use crate::utilities::*;
use anyhow::{Context as _, Result, bail};
use async_trait::async_trait;
use futures::FutureExt;
use futures::select;
use futures_timer::Delay;
use matchbox_socket::PeerState;
use matchbox_socket::WebRtcSocket;
use std::time::Duration;
use tracing::info;

pub async fn get_url(key: &str) -> Result<Vec<u8>> {
    return DefaultNetworkBackend.fetch(key.to_string()).await;
}

/// Networking backend that the IPC layer depends on.
#[async_trait]
pub trait NetworkBackend: Send + Sync {
    /// Fetch bytes from the given URL.
    async fn fetch(&self, url: String) -> Result<Vec<u8>>;

    /// Fetch bytes over HTTP.
    async fn fetch_http(&self, url: &str) -> Result<Vec<u8>>;

    /// Fetch bytes over HTTPS.
    async fn fetch_https(&self, url: &str) -> Result<Vec<u8>>;

    /// Read a local file into memory.
    async fn read_file(&self, path: String) -> Result<Vec<u8>>;
}

/// Default implementation. This will eventually include APIs for a
/// WebRTC transport, but for now returns clear errors for unimplemented paths.
#[derive(Debug, Default)]
pub struct DefaultNetworkBackend;

#[async_trait]
impl NetworkBackend for DefaultNetworkBackend {
    async fn fetch(&self, url: String) -> Result<Vec<u8>> {
        if url.starts_with("https://") {
            return self.fetch_https(&url).await;
        }

        if url.starts_with("http://") {
            return self.fetch_http(&url).await;
        }

        bail!("unsupported scheme for url {url}");
    }

    async fn fetch_http(&self, url: &str) -> Result<Vec<u8>> {
        let resp = reqwest::get(url)
            .await
            .with_context(|| format!("http(s) GET {url}"))?;
        let status = resp.status();
        if !status.is_success() {
            bail!("http(s) GET {url} failed: {status}");
        }
        let bytes = resp.bytes().await.with_context(|| "read http(s) body")?;
        Ok(bytes.to_vec())
    }

    async fn fetch_https(&self, url: &str) -> Result<Vec<u8>> {
        // HTTPS is handled similarly; reqwest negotiates TLS.
        return self.fetch_http(url).await;
    }

    async fn read_file(&self, path: String) -> Result<Vec<u8>> {
        tokio::fs::read(&path)
            .await
            .with_context(|| format!("read file at {path}"))
    }
}

#[derive(Debug, Default)]
pub struct MockNetworkBackend;
#[async_trait]
impl NetworkBackend for MockNetworkBackend {
    async fn fetch(&self, url: String) -> Result<Vec<u8>> {
        if url.starts_with("https://") {
            return self.fetch_https(&url).await;
        }

        if url.starts_with("http://") {
            return self.fetch_http(&url).await;
        }

        bail!("unsupported scheme for url {url}");
    }

    async fn fetch_http(&self, url: &str) -> Result<Vec<u8>> {
        if url == "http://example.com" {
            return Ok(b"Example HTTP Fetch".to_vec());
        }
        bail!(
            "MockNetworkingBackend only supports http and https fetches of http://example.com"
        );
    }

    async fn fetch_https(&self, url: &str) -> Result<Vec<u8>> {
        if url == "https://example.com" {
            return Ok(b"Example HTTPS Fetch".to_vec());
        }
        bail!(
            "MockNetworkingBackend only supports http and https fetches of https://example.com"
        );
    }

    async fn read_file(&self, path: String) -> Result<Vec<u8>> {
        if path == "/tmp/example/file.txt" {
            return Ok(b"Example File Read".to_vec());
        }
        bail!("MockNetworkingBackend only provides /tmp/example/file.txt");
    }
}

pub async fn data_channel_test() {
    data_channel_inner().await;
}

pub fn start_signaling_server() {
    // TODO: implement signaling server for WebRTC peers.
}

async fn data_channel_inner() {
    // Copied from https://github.com/johanhelsing/matchbox/blob/main/examples/simple/src/main.rs
    /*
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    let (mut socket, loop_fut) =
        WebRtcSocket::new_reliable("ws://localhost:3536/");

    let loop_fut = loop_fut.fuse();
    futures::pin_mut!(loop_fut);

    let timeout = Delay::new(Duration::from_millis(100));
    futures::pin_mut!(timeout);

    const CHANNEL_ID: usize = 0;

    loop {
        // log_string("polling".to_string());
        // Handle any new peers
        for (peer, state) in socket.update_peers() {
            match state {
                PeerState::Connected => {
                    info!("Peer joined: {peer}");
                    let packet =
                        "hello friend!".as_bytes().to_vec().into_boxed_slice();
                    socket.channel_mut(CHANNEL_ID).send(packet, peer);
                }
                PeerState::Disconnected => {
                    info!("Peer left: {peer}");
                }
            }
        }

        // Accept any messages incoming
        for (peer, packet) in socket.channel_mut(CHANNEL_ID).receive() {
            let message = String::from_utf8_lossy(&packet);
            info!("Message from {peer}: {message:?}");
        }

        select! {
            // Restart this loop every 100ms
            () = (&mut timeout).fuse() => {
                timeout.reset(Duration::from_millis(100));
            }

            // Or break if the message loop ends (disconnected, closed, etc.)
            _ = &mut loop_fut => {
                break;
            }
        }
    }
}

#[cfg(test)]
mod tests {}