#![no_std]
#![no_main]

use defmt::{info, panic};
use embassy_executor::Spawner;
use embassy_futures::join::join;
use embassy_nrf::usb::Driver;
use embassy_nrf::usb::vbus_detect::{HardwareVbusDetect, VbusDetect};
use embassy_nrf::{bind_interrupts, pac, peripherals, usb};
use embassy_usb::class::cdc_acm::{CdcAcmClass, State};
use embassy_usb::driver::EndpointError;
use embassy_usb::msos::{self, windows_version};
use embassy_usb::types::InterfaceNumber;
use embassy_usb::{Builder, Config};
use {defmt_rtt as _, panic_probe as _};

bind_interrupts!(struct Irqs {
    USBD => usb::InterruptHandler<peripherals::USBD>;
    CLOCK_POWER => usb::vbus_detect::InterruptHandler;
});

// This is a randomly generated GUID to allow clients on Windows to find our device
const DEVICE_INTERFACE_GUIDS: &[&str] = &["{EAA9A5DC-30BA-44BC-9232-606CDC875321}"];

#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    let p = embassy_nrf::init(Default::default());

    info!("Enabling ext hfosc...");
    pac::CLOCK.tasks_hfclkstart().write_value(1);
    while pac::CLOCK.events_hfclkstarted().read() != 1 {}

    // Create the driver, from the HAL.
    let driver = Driver::new(p.USBD, Irqs, HardwareVbusDetect::new(Irqs));

    // Create embassy-usb Config
    let mut config = Config::new(0xc0de, 0xcafe);
    config.manufacturer = Some("Embassy");
    config.product = Some("USB-serial example");
    config.serial_number = Some("12345678");
    config.max_power = 100;
    config.max_packet_size_0 = 64;

    // Create embassy-usb DeviceBuilder using the driver and config.
    // It needs some buffers for building the descriptors.
    let mut config_descriptor = [0; 256];
    let mut bos_descriptor = [0; 256];
    let mut msos_descriptor = [0; 256];
    let mut control_buf = [0; 64];

    let mut state = State::new();

    let mut builder = Builder::new(
        driver,
        config,
        &mut config_descriptor,
        &mut bos_descriptor,
        &mut msos_descriptor,
        &mut control_buf,
    );

    builder.msos_descriptor(windows_version::WIN8_1, 2);

    // Create classes on the builder.
    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);

    // Since we want to create MS OS feature descriptors that apply to a function that has already been added to the
    // builder, need to get the MsOsDescriptorWriter from the builder and manually add those descriptors.
    // Inside a class constructor, you would just need to call `FunctionBuilder::msos_feature` instead.
    let msos_writer = builder.msos_writer();
    msos_writer.configuration(0);
    msos_writer.function(InterfaceNumber(0));
    msos_writer.function_feature(msos::CompatibleIdFeatureDescriptor::new("WINUSB", ""));
    msos_writer.function_feature(msos::RegistryPropertyFeatureDescriptor::new(
        "DeviceInterfaceGUIDs",
        msos::PropertyData::RegMultiSz(DEVICE_INTERFACE_GUIDS),
    ));

    // Build the builder.
    let mut usb = builder.build();

    // Run the USB device.
    let usb_fut = usb.run();

    // Do stuff with the class!
    let echo_fut = async {
        loop {
            class.wait_connection().await;
            info!("Connected");
            let _ = echo(&mut class).await;
            info!("Disconnected");
        }
    };

    // Run everything concurrently.
    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
    join(usb_fut, echo_fut).await;
}

struct Disconnected {}

impl From<EndpointError> for Disconnected {
    fn from(val: EndpointError) -> Self {
        match val {
            EndpointError::BufferOverflow => panic!("Buffer overflow"),
            EndpointError::Disabled => Disconnected {},
        }
    }
}

async fn echo<'d, V: VbusDetect + 'd>(class: &mut CdcAcmClass<'d, Driver<'d, V>>) -> Result<(), Disconnected> {
    let mut buf = [0; 64];
    loop {
        let n = class.read_packet(&mut buf).await?;
        let data = &buf[..n];
        info!("data: {:x}", data);
        class.write_packet(data).await?;
    }
}
