use std::future::Future;

use giterated_models::{
    error::OperationError, object::GiteratedObject, settings::Setting, value::GiteratedObjectValue,
};

use crate::{
    new_stack::PluginState,
    vtable::{AnyObject, NewAnyValue},
};

use super::CallbackPtr;

#[derive(Copy, Clone)]
pub struct ValueGetterCallback {
    pub callback_ptr: CallbackPtr,
    pub func: unsafe extern "C" fn(
        CallbackPtr,
        &PluginState,
        object: AnyObject,
    ) -> Result<NewAnyValue, ()>,
}

impl ValueGetterCallback {
    pub fn new<S, O, V, T: IntoPluginValueGetter<S, O, V>>(handler: T) -> Self {
        Self {
            func: T::get_value,
            callback_ptr: handler.callback_ptr(),
        }
    }
}

pub trait IntoPluginValueGetter<S, O, V> {
    unsafe extern "C" fn get_value(
        callback: CallbackPtr,
        state: &PluginState,
        object: AnyObject,
    ) -> Result<NewAnyValue, ()>;

    fn callback_ptr(&self) -> CallbackPtr;
}

impl<F, S, O, V, Fut> IntoPluginValueGetter<S, O, V> for F
where
    Fut: Future<Output = Result<V, OperationError<anyhow::Error>>>,
    S: Clone,
    O: GiteratedObject,
    V: GiteratedObjectValue<Object = O>,
    F: Fn(S, O) -> Fut,
{
    unsafe extern "C" fn get_value(
        callback: CallbackPtr,
        state: &PluginState,
        mut object: AnyObject,
    ) -> Result<NewAnyValue, ()> {
        let _guard = trace_span!(
            "get_value handler",
            object = O::object_name(),
            value = V::value_name()
        )
        .entered();
        let state = unsafe { state.transmute_ref::<S>() };

        let object = unsafe { object.transmute_owned::<O>() };

        // Cast the callback ptr to ourselves
        let callback: *const F = std::mem::transmute(callback.0);
        let callback = callback.as_ref().unwrap();

        let result = callback(state.clone(), *object);

        // match result {
        //     Ok(value) => Ok(NewAnyValue::new(value)),
        //     Err(_) => todo!(),
        // }

        todo!()
    }

    fn callback_ptr(&self) -> CallbackPtr {
        unsafe { CallbackPtr::from_raw(self as *const _ as *const ()) }
    }
}

pub struct ValueChangeCallback {
    func: unsafe extern "C" fn(
        &PluginState,
        object: AnyObject,
        value_name: &str,
        new_value: NewAnyValue,
    ),
}

pub trait IntoValueChangeCallback<S, O> {
    unsafe extern "C" fn value_changed(
        state: &PluginState,
        object: AnyObject,
        value_name: &str,
        new_value: NewAnyValue,
    );
}

impl<F, S, O> IntoValueChangeCallback<S, O> for F {
    unsafe extern "C" fn value_changed(
        state: &PluginState,
        object: AnyObject,
        value_name: &str,
        new_value: NewAnyValue,
    ) {
        todo!()
    }
}

impl ValueChangeCallback {
    pub fn new<S, O, T: IntoValueChangeCallback<S, O>>() -> Self {
        Self {
            func: T::value_changed,
        }
    }
}