//! Connects to l2cap_server and sends and receives test data.

use bluer::{
    l2cap::{SocketAddr, Stream, PSM_LE_DYN_START},
    Address, AddressType,
};
use rand::prelude::*;
use std::{env, process::exit};
use tokio::io::{AsyncReadExt, AsyncWriteExt};

include!("l2cap.inc");

#[tokio::main]
async fn main() -> bluer::Result<()> {
    env_logger::init();
    let session = bluer::Session::new().await?;
    let adapter = session.default_adapter().await?;
    adapter.set_powered(true).await?;

    let args: Vec<_> = env::args().collect();
    if args.len() != 2 {
        eprintln!("Specify target Bluetooth address as argment");
        exit(1);
    }

    let target_addr: Address = args[1].parse().expect("invalid address");
    let target_sa = SocketAddr::new(target_addr, AddressType::LePublic, PSM);

    println!("Connecting to {:?}", &target_sa);
    let mut stream = Stream::connect(target_sa).await.expect("connection failed");
    println!("Local address: {:?}", stream.as_ref().local_addr()?);
    println!("Remote address: {:?}", stream.peer_addr()?);
    println!("Send MTU: {:?}", stream.as_ref().send_mtu());
    println!("Recv MTU: {}", stream.as_ref().recv_mtu()?);
    println!("Security: {:?}", stream.as_ref().security()?);
    println!("Flow control: {:?}", stream.as_ref().flow_control());

    println!("\nReceiving hello");
    let mut hello_buf = [0u8; HELLO_MSG.len()];
    stream.read_exact(&mut hello_buf).await.expect("read failed");
    println!("Received: {}", String::from_utf8_lossy(&hello_buf));
    if hello_buf != HELLO_MSG {
        panic!("Wrong hello message");
    }

    let (mut rh, mut wh) = stream.into_split();
    let mut rng = rand::thread_rng();
    for i in 0..15 {
        let len = rng.gen_range(0..50000);
        let data: Vec<u8> = (0..len).map(|_| rng.gen()).collect();

        println!("\nTest iteration {} with data size {}", i, len);

        // We must read back the data while sending, otherwise the connection
        // buffer will overrun and we will lose data.
        let read_task = tokio::spawn(async move {
            let mut echo_buf = vec![0u8; len];
            let res = match rh.read_exact(&mut echo_buf).await {
                Ok(_) => Ok(echo_buf),
                Err(err) => Err(err),
            };
            (rh, res)
        });

        // Note that write_all will automatically split the buffer into
        // multiple writes of MTU size.
        wh.write_all(&data).await.expect("write failed");

        println!("Waiting for echo");
        let (rh_back, res) = read_task.await.unwrap();
        rh = rh_back;
        let echo_buf = res.expect("read failed");

        if echo_buf != data {
            panic!("Echoed data does not match sent data");
        }
        println!("Data matches");
    }

    println!("Done");
    Ok(())
}