use std::marker::PhantomData;

use crate::{FfiValue, FfiValueMut};

#[repr(C)]
pub struct FfiFuture<Output> {
    poll_fn: unsafe extern "C" fn(FfiValueMut<FfiFuture<()>>, FfiValueMut<()>) -> RuntimeFuturePoll,
    wake_fn: unsafe extern "C" fn(FfiValueMut<FfiFuture<()>>, FfiValueMut<()>),

    poll_state: FfiValue<()>,
    waker_state: Option<FfiValue<()>>,

    _output_marker: PhantomData<Output>,
}

unsafe impl<Output> Send for FfiFuture<Output> where Output: Send {}
unsafe impl<Output> Sync for FfiFuture<Output> where Output: Sync {}

impl<Output> FfiFuture<Output> {
    /// Docs here!
    /// # SAFETY
    /// TODO :(
    pub unsafe fn poll(&mut self) -> RuntimeFuturePoll {
        todo!()
    }

    /// Docs here!
    /// # SAFETY
    /// TODO :(
    pub unsafe fn from_raw<PS>(
        _poll_fn: unsafe extern "C" fn(
            FfiValueMut<FfiFuture<()>>,
            FfiValueMut<()>,
        ) -> RuntimeFuturePoll,
        _poll_state: PS,
    ) -> Self {
        todo!()
    }

    /// Docs here!
    /// # SAFETY
    /// Very not in progress text :)
    pub unsafe fn write_waker<WS>(
        &mut self,
        _wake_fn: unsafe extern "C" fn(FfiValueMut<FfiFuture<()>>, FfiValueMut<()>),
        _waker_state: WS,
    ) {
        todo!()
    }
}

#[repr(C)]
pub enum RuntimeFuturePoll {
    Ready(FfiValue<()>),
    Pending,
}