//! This example registers an ACM device, which can be connected
//! too using a serial terminal program, e.g. `screen`.
//! All printable characters are sent back, therefore, this program acts
//! as a serial echo.

use usb_device::{bus::UsbBusAllocator, device::StringDescriptors, prelude::*};
use usbd_serial::{SerialPort, USB_CLASS_CDC};
use usbip_device::UsbIpBus;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    pretty_env_logger::init();

    log::info!("initializing allocator");

    let bus_allocator = UsbBusAllocator::new(UsbIpBus::new());
    let mut usb_serial = SerialPort::new(&bus_allocator);
    let mut usb_bus = UsbDeviceBuilder::new(&bus_allocator, UsbVidPid(0x16c0, 0x27dd))
        .strings(&[StringDescriptors::new(usb_device::LangID::EN)
            .manufacturer("Fake company")
            .product("Serial port")
            .serial_number("TEST")])
        .unwrap()
        .device_class(USB_CLASS_CDC)
        .build();

    loop {
        usb_bus.poll(&mut [&mut usb_serial]);
        std::thread::sleep(std::time::Duration::from_millis(5));

        let mut buf = [0; 64];
        if let Ok(count) = usb_serial.read(&mut buf) {
            let text = String::from_utf8_lossy(&buf);
            log::info!("read {} bytes: {}", count, text);

            // Send back, poll usb until we are ready
            loop {
                if let Ok(count) = usb_serial.write(&buf[0..count]) {
                    log::debug!("sent back {} bytes", count);
                    break;
                }
                usb_bus.poll(&mut [&mut usb_serial]);
            }
        }
    }
}