#[macro_use]
extern crate log;
extern crate env_logger;
extern crate getopts;
extern crate smoltcp;

mod utils;

use std::str::{self, FromStr};
use std::collections::BTreeMap;
use std::time::Instant;
use std::os::unix::io::AsRawFd;
use smoltcp::phy::wait as phy_wait;
use smoltcp::wire::{EthernetAddress, Ipv4Address, IpAddress, IpCidr};
use smoltcp::iface::{NeighborCache, EthernetInterface};
use smoltcp::socket::{SocketSet, TcpSocket, TcpSocketBuffer};

fn main() {
    utils::setup_logging("");

    let (mut opts, mut free) = utils::create_options();
    utils::add_tap_options(&mut opts, &mut free);
    utils::add_middleware_options(&mut opts, &mut free);
    free.push("ADDRESS");
    free.push("PORT");

    let mut matches = utils::parse_options(&opts, free);
    let device = utils::parse_tap_options(&mut matches);
    let fd = device.as_raw_fd();
    let device = utils::parse_middleware_options(&mut matches, device, /*loopback=*/false);
    let address = IpAddress::from_str(&matches.free[0]).expect("invalid address format");
    let port = u16::from_str(&matches.free[1]).expect("invalid port format");

    let startup_time = Instant::now();

    let neighbor_cache = NeighborCache::new(BTreeMap::new());

    let tcp_rx_buffer = TcpSocketBuffer::new(vec![0; 64]);
    let tcp_tx_buffer = TcpSocketBuffer::new(vec![0; 128]);
    let tcp_socket = TcpSocket::new(tcp_rx_buffer, tcp_tx_buffer);

    let ethernet_addr = EthernetAddress([0x02, 0x00, 0x00, 0x00, 0x00, 0x02]);
    let ip_addrs = [IpCidr::new(IpAddress::v4(192, 168, 69, 2), 24)];
    let default_v4_gw = Ipv4Address::new(192, 168, 69, 100);
    let mut iface = EthernetInterface::new(
        device, neighbor_cache, ethernet_addr, ip_addrs, Some(default_v4_gw));

    let mut sockets = SocketSet::new(vec![]);
    let tcp_handle = sockets.add(tcp_socket);

    {
        let mut socket = sockets.get::<TcpSocket>(tcp_handle);
        socket.connect((address, port), 49500).unwrap();
    }

    let mut tcp_active = false;
    loop {
        {
            let mut socket = sockets.get::<TcpSocket>(tcp_handle);
            if socket.is_active() && !tcp_active {
                debug!("connected");
            } else if !socket.is_active() && tcp_active {
                debug!("disconnected");
                break
            }
            tcp_active = socket.is_active();

            if socket.may_recv() {
                let data = socket.recv(|data| {
                    let mut data = data.to_owned();
                    if data.len() > 0 {
                        debug!("recv data: {:?}",
                               str::from_utf8(data.as_ref()).unwrap_or("(invalid utf8)"));
                        data = data.split(|&b| b == b'\n').collect::<Vec<_>>().concat();
                        data.reverse();
                        data.extend(b"\n");
                    }
                    (data.len(), data)
                }).unwrap();
                if socket.can_send() && data.len() > 0 {
                    debug!("send data: {:?}",
                           str::from_utf8(data.as_ref()).unwrap_or("(invalid utf8)"));
                    socket.send_slice(&data[..]).unwrap();
                }
            } else if socket.may_send() {
                debug!("close");
                socket.close();
            }
        }

        let timestamp = utils::millis_since(startup_time);
        let poll_at = iface.poll(&mut sockets, timestamp).expect("poll error");
        phy_wait(fd, poll_at.map(|at| at.saturating_sub(timestamp))).expect("wait error");
    }
}