// Take a look at the license at the top of the repository in the LICENSE file.

use glib::prelude::*;
use glib::translate::*;

use glib::subclass::prelude::*;

use gst::ffi::GstStructure;

use crate::Navigation;

pub trait NavigationImpl: ObjectImpl {
    fn send_event(&self, nav: &Self::Type, structure: gst::Structure);
}

pub trait NavigationImplExt: ObjectSubclass {
    fn parent_send_event(&self, nav: &Self::Type, structure: gst::Structure);
}

impl<T: NavigationImpl> NavigationImplExt for T {
    fn parent_send_event(&self, nav: &Self::Type, structure: gst::Structure) {
        unsafe {
            let type_data = Self::type_data();
            let parent_iface = type_data.as_ref().parent_interface::<Navigation>()
                as *const ffi::GstNavigationInterface;

            let func = match (*parent_iface).send_event {
                Some(func) => func,
                None => return,
            };

            func(
                nav.unsafe_cast_ref::<Navigation>().to_glib_none().0,
                structure.into_ptr(),
            );
        }
    }
}

unsafe impl<T: NavigationImpl> IsImplementable<T> for Navigation {
    fn interface_init(iface: &mut glib::Interface<Self>) {
        let iface = iface.as_mut();

        iface.send_event = Some(navigation_send_event::<T>);
    }
}

unsafe extern "C" fn navigation_send_event<T: NavigationImpl>(
    nav: *mut ffi::GstNavigation,
    structure: *mut GstStructure,
) {
    let instance = &*(nav as *mut T::Instance);
    let imp = instance.imp();

    imp.send_event(
        from_glib_borrow::<_, Navigation>(nav).unsafe_cast_ref(),
        from_glib_full(structure),
    );
}