use core::sync::atomic::{AtomicU64, Ordering};

use alloc::{boxed::Box, collections::BTreeMap};

use device_api::gpio::PinHandle;
use libk_util::{ring::LossyRingQueue, sync::spin_rwlock::IrqSafeRwLock};
use yggdrasil_abi::error::Error;

static GPIO_EVENT_QUEUE: LossyRingQueue<u64> = LossyRingQueue::with_capacity(64);
static GPIO_EVENT_MAP: IrqSafeRwLock<BTreeMap<u64, Box<dyn Fn() + Send>>> =
    IrqSafeRwLock::new(BTreeMap::new());
static GPIO_EVENT_ID: AtomicU64 = AtomicU64::new(1);

pub trait GpioEvent {
    fn configure_with_interrupt(&self, handler: Box<dyn Fn() + Send>) -> Result<(), Error>;
}

impl GpioEvent for PinHandle {
    fn configure_with_interrupt(&self, handler: Box<dyn Fn() + Send>) -> Result<(), Error> {
        let ev = bind_gpio_event(handler);
        self.parent.setup_gpio(self, Some(ev))
    }
}

pub async fn gpio_event_handler_task() {
    loop {
        let id = GPIO_EVENT_QUEUE.read().await;

        let lock = GPIO_EVENT_MAP.read();
        if let Some(handler) = lock.get(&id) {
            handler();
        }
    }
}

pub fn bind_gpio_event(handler: Box<dyn Fn() + Send>) -> u64 {
    let id = GPIO_EVENT_ID.fetch_add(1, Ordering::Acquire);
    GPIO_EVENT_MAP.write().insert(id, handler);
    id
}

pub fn signal_gpio_event(ev: u64) {
    GPIO_EVENT_QUEUE.write(ev);
}