use std::rc::Rc;

use futures::future::LocalBoxFuture;
use orchid_base::binary::future_to_vt;

use crate::api;
use crate::entrypoint::ExtensionBuilder;
use crate::ext_port::ExtPort;

pub type ExtCx = api::binary::ExtensionContext;

struct Spawner(api::binary::SpawnerBin);
impl Drop for Spawner {
	fn drop(&mut self) { (self.0.drop)(self.0.data) }
}
impl Spawner {
	pub fn spawn(&self, fut: LocalBoxFuture<'static, ()>) {
		(self.0.spawn)(self.0.data, future_to_vt(fut))
	}
}

pub fn orchid_extension_main_body(cx: ExtCx, builder: ExtensionBuilder) {
	let spawner = Spawner(cx.spawner);
	builder.build(ExtPort {
		input: Box::pin(cx.input),
		output: Box::pin(cx.output),
		log: Box::pin(cx.log),
		spawn: Rc::new(move |fut| spawner.spawn(fut)),
	});
}

/// Generate entrypoint for the dylib extension loader
///
/// # Usage
///
/// ```
/// #[macro_use]
/// use orchid_extension::dylib_main;
/// use orchid_extension::entrypoint::ExtensionBuilder;
///
/// dylib_main! {
///   ExtensionBuilder::new("orchid-std::main")
/// }
/// ```
#[macro_export]
macro_rules! dylib_main {
	($builder:expr) => {
		#[unsafe(no_mangle)]
		pub extern "C" fn orchid_extension_main(cx: ::orchid_api::binary::ExtensionContext) {
			$crate::binary::orchid_extension_main_body(cx, $builder);
		}
	};
}