// The library will have build errors when built on its own (due to not having embassy-stm32 feature for a specific microcontroller)
// but it will work fine when used as a dependency for firmware that has the feature for a specific stm32 microcontroller.

use crate::comms;
use embassy_stm32::peripherals::USB_OTG_FS;
use embassy_stm32::usb::Driver as StmUsbDriver;
use embassy_usb::driver::{Driver as UsbDriverTrait, EndpointIn, EndpointOut};
use embassy_usb::UsbDevice;

type UsbDriver = StmUsbDriver<'static, USB_OTG_FS>;
pub type TypedInterIn = <UsbDriver as UsbDriverTrait<'static>>::EndpointIn;
pub type TypedInterOut = <UsbDriver as UsbDriverTrait<'static>>::EndpointOut;

pub type TypedUSB = UsbDevice<'static, UsbDriver>;

pub struct UsbIO {
    /// Send to master
    pub interrupt_in: TypedInterIn,
    /// Recieve from master
    pub interrupt_out: TypedInterOut,
}

impl<T: EndpointIn> comms::Sender for T {
    async fn send(&mut self, msg: &[u8]) -> Result<(), comms::Reset> {
        self.write(msg).await.map_err(|_| comms::Reset)
    }
}

impl<T: EndpointOut> comms::Receiver for T {
    #[cfg(feature = "single-packet-msgs")]
    async fn receive(&mut self, buffer: &mut [u8]) -> Result<(), comms::Reset> {
        // This is OK when all our messages are smaller than a single packet.
        self.read(buffer)
            .await
            .map(|_| ())
            .map_err(|_| comms::Reset)
    }

    #[cfg(not(feature = "single-packet-msgs"))]
    async fn receive(&mut self, buffer: &mut [u8]) -> Result<(), comms::Reset> {
        todo!("Decide if we want a general purpose multi-packet message receive")
    }
}