//! BLE interface.

#![no_std]
#![no_main]

mod logger;
mod macros;
mod rtc;

use clint::HandlerArray;
use core::mem;
use cortex_m::asm::wfi;
use cortex_m_rt::entry;
use log::{info, trace, LevelFilter};

#[allow(unused_imports)]
extern crate panic_semihosting;

use nrf52840_mdk_bsp::{
    hal::{
        target::{interrupt, Interrupt, UARTE0},
        Clocks, Rtc,
    },
    Board,
};

// TODO:
//   * set up serial reader for trinket
//   * set up i²c interface for keyboard reports
//   * and, finally, bluetooth

// Interrupt handler table.
static HANDLERS: HandlerArray = HandlerArray::new();

#[entry]
fn main() -> ! {
    let nrf52 = Board::take().unwrap();

    let uart_wrapped = logger::WriteWrapper::new(nrf52.cdc);
    let logger = logger::SerialLogger::new(uart_wrapped);
    let logger_ref: &'static logger::SerialLogger<UARTE0> = unsafe { mem::transmute(&logger) };
    log::set_logger(logger_ref).expect("setting logger");
    log::set_max_level(LevelFilter::Trace);

    nrf52.RTC0.intenset.write(|w| w.tick().set());

    let mut nvic = nrf52.NVIC;
    let mut rtc_handler = rtc::setup(Rtc::new(nrf52.RTC0), Clocks::new(nrf52.CLOCK));

    logln_now!("logln_now?");
    HANDLERS.with_overrides(|hs| {
        hs.register(0, &mut rtc_handler);
        nvic.enable(Interrupt::RTC0);

        info!("Bootstrap complete.");
        let mut last_tick = rtc::millis();
        last_tick -= last_tick % 1024;
        loop {
            let tick = rtc::millis();
            if tick >= last_tick + 1024 {
                last_tick = tick;
                last_tick -= last_tick % 1024;
                trace!(".");
            }
            wfi();
        }
    });
    unreachable!();
}

// TODO: RTC0/1/2 exist. See which is best, if it matters.
#[interrupt]
fn RTC0() {
    HANDLERS.call(0);
}