#![no_std]
#![no_main]

use defmt::*;
use embassy_executor::Spawner;
use embassy_stm32::time::Hertz;
use embassy_stm32::usb::Driver;
use embassy_stm32::{bind_interrupts, peripherals, usb, Config};
use embassy_time::Timer;
use embassy_usb::class::hid::{HidWriter, ReportId, RequestHandler, State};
use embassy_usb::control::OutResponse;
use embassy_usb::Builder;
use futures::future::join;
use usbd_hid::descriptor::{MouseReport, SerializedDescriptor};
use {defmt_rtt as _, panic_probe as _};

bind_interrupts!(struct Irqs {
    OTG_FS => usb::InterruptHandler<peripherals::USB_OTG_FS>;
});

// If you are trying this and your USB device doesn't connect, the most
// common issues are the RCC config and vbus_detection
//
// See https://embassy.dev/book/dev/faq.html#_the_usb_examples_are_not_working_on_my_board_is_there_anything_else_i_need_to_configure
// for more information.
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    let mut config = Config::default();
    {
        use embassy_stm32::rcc::*;
        config.rcc.hse = Some(Hse {
            freq: Hertz(8_000_000),
            mode: HseMode::Bypass,
        });
        config.rcc.pll_src = PllSource::HSE;
        config.rcc.pll = Some(Pll {
            prediv: PllPreDiv::DIV4,
            mul: PllMul::MUL168,
            divp: Some(PllPDiv::DIV2), // 8mhz / 4 * 168 / 2 = 168Mhz.
            divq: Some(PllQDiv::DIV7), // 8mhz / 4 * 168 / 7 = 48Mhz.
            divr: None,
        });
        config.rcc.ahb_pre = AHBPrescaler::DIV1;
        config.rcc.apb1_pre = APBPrescaler::DIV4;
        config.rcc.apb2_pre = APBPrescaler::DIV2;
        config.rcc.sys = Sysclk::PLL1_P;
        config.rcc.mux.clk48sel = mux::Clk48sel::PLL1_Q;
    }
    let p = embassy_stm32::init(config);

    // Create the driver, from the HAL.
    let mut ep_out_buffer = [0u8; 256];
    let mut config = embassy_stm32::usb::Config::default();

    // Enable vbus_detection
    // Note: some boards don't have this wired up and might not require it,
    // as they are powered through usb! 
    // If you hang on boot, try setting this to "false"!
    // See https://embassy.dev/book/dev/faq.html#_the_usb_examples_are_not_working_on_my_board_is_there_anything_else_i_need_to_configure
    // for more information
    config.vbus_detection = true;

    let driver = Driver::new_fs(p.USB_OTG_FS, Irqs, p.PA12, p.PA11, &mut ep_out_buffer, config);

    // Create embassy-usb Config
    let mut config = embassy_usb::Config::new(0xc0de, 0xcafe);
    config.manufacturer = Some("Embassy");
    config.product = Some("HID mouse example");
    config.serial_number = Some("12345678");

    // Required for windows compatibility.
    // https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.9.1/kconfig/CONFIG_CDC_ACM_IAD.html#help
    config.device_class = 0xEF;
    config.device_sub_class = 0x02;
    config.device_protocol = 0x01;
    config.composite_with_iads = true;

    // 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 control_buf = [0; 64];

    let request_handler = MyRequestHandler {};

    let mut state = State::new();

    let mut builder = Builder::new(
        driver,
        config,
        &mut config_descriptor,
        &mut bos_descriptor,
        &mut [], // no msos descriptors
        &mut control_buf,
    );

    // Create classes on the builder.
    let config = embassy_usb::class::hid::Config {
        report_descriptor: MouseReport::desc(),
        request_handler: Some(&request_handler),
        poll_ms: 60,
        max_packet_size: 8,
    };

    let mut writer = HidWriter::<_, 5>::new(&mut builder, &mut state, config);

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

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

    // Do stuff with the class!
    let hid_fut = async {
        let mut y: i8 = 5;
        loop {
            Timer::after_millis(500).await;

            y = -y;
            let report = MouseReport {
                buttons: 0,
                x: 0,
                y,
                wheel: 0,
                pan: 0,
            };
            match writer.write_serialize(&report).await {
                Ok(()) => {}
                Err(e) => warn!("Failed to send report: {:?}", e),
            }
        }
    };

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

struct MyRequestHandler {}

impl RequestHandler for MyRequestHandler {
    fn get_report(&self, id: ReportId, _buf: &mut [u8]) -> Option<usize> {
        info!("Get report for {:?}", id);
        None
    }

    fn set_report(&self, id: ReportId, data: &[u8]) -> OutResponse {
        info!("Set report for {:?}: {=[u8]}", id, data);
        OutResponse::Accepted
    }

    fn set_idle_ms(&self, id: Option<ReportId>, dur: u32) {
        info!("Set idle rate for {:?} to {:?}", id, dur);
    }

    fn get_idle_ms(&self, id: Option<ReportId>) -> Option<u32> {
        info!("Get idle rate for {:?}", id);
        None
    }
}