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

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

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

use crate::Bin;
use crate::Element;
use crate::LoggableError;
use crate::Message;

pub trait BinImpl: BinImplExt + ElementImpl {
    fn add_element(&self, bin: &Self::Type, element: &Element) -> Result<(), LoggableError> {
        self.parent_add_element(bin, element)
    }

    fn remove_element(&self, bin: &Self::Type, element: &Element) -> Result<(), LoggableError> {
        self.parent_remove_element(bin, element)
    }

    fn handle_message(&self, bin: &Self::Type, message: Message) {
        self.parent_handle_message(bin, message)
    }
}

pub trait BinImplExt: ObjectSubclass {
    fn parent_add_element(&self, bin: &Self::Type, element: &Element) -> Result<(), LoggableError>;

    fn parent_remove_element(
        &self,
        bin: &Self::Type,
        element: &Element,
    ) -> Result<(), LoggableError>;

    fn parent_handle_message(&self, bin: &Self::Type, message: Message);
}

impl<T: BinImpl> BinImplExt for T {
    fn parent_add_element(&self, bin: &Self::Type, element: &Element) -> Result<(), LoggableError> {
        unsafe {
            let data = T::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstBinClass;
            let f = (*parent_class).add_element.ok_or_else(|| {
                loggable_error!(
                    crate::CAT_RUST,
                    "Parent function `add_element` is not defined"
                )
            })?;
            result_from_gboolean!(
                f(
                    bin.unsafe_cast_ref::<crate::Bin>().to_glib_none().0,
                    element.to_glib_none().0
                ),
                crate::CAT_RUST,
                "Failed to add the element using the parent function"
            )
        }
    }

    fn parent_remove_element(
        &self,
        bin: &Self::Type,
        element: &Element,
    ) -> Result<(), LoggableError> {
        unsafe {
            let data = T::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstBinClass;
            let f = (*parent_class).remove_element.ok_or_else(|| {
                loggable_error!(
                    crate::CAT_RUST,
                    "Parent function `remove_element` is not defined"
                )
            })?;
            result_from_gboolean!(
                f(
                    bin.unsafe_cast_ref::<crate::Bin>().to_glib_none().0,
                    element.to_glib_none().0
                ),
                crate::CAT_RUST,
                "Failed to remove the element using the parent function"
            )
        }
    }

    fn parent_handle_message(&self, bin: &Self::Type, message: Message) {
        unsafe {
            let data = T::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstBinClass;
            if let Some(ref f) = (*parent_class).handle_message {
                f(
                    bin.unsafe_cast_ref::<crate::Bin>().to_glib_none().0,
                    message.into_ptr(),
                );
            }
        }
    }
}

unsafe impl<T: BinImpl> IsSubclassable<T> for Bin {
    fn class_init(klass: &mut glib::Class<Self>) {
        <crate::Element as IsSubclassable<T>>::class_init(klass);
        let klass = klass.as_mut();
        klass.add_element = Some(bin_add_element::<T>);
        klass.remove_element = Some(bin_remove_element::<T>);
        klass.handle_message = Some(bin_handle_message::<T>);
    }

    fn instance_init(instance: &mut glib::subclass::InitializingObject<T>) {
        <crate::Element as IsSubclassable<T>>::instance_init(instance);
    }
}

unsafe extern "C" fn bin_add_element<T: BinImpl>(
    ptr: *mut ffi::GstBin,
    element: *mut ffi::GstElement,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.impl_();
    let wrap: Borrowed<Bin> = from_glib_borrow(ptr);

    panic_to_error!(&wrap, &imp.panicked(), false, {
        match imp.add_element(wrap.unsafe_cast_ref(), &from_glib_none(element)) {
            Ok(()) => true,
            Err(err) => {
                err.log_with_object(&*wrap);
                false
            }
        }
    })
    .to_glib()
}

unsafe extern "C" fn bin_remove_element<T: BinImpl>(
    ptr: *mut ffi::GstBin,
    element: *mut ffi::GstElement,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.impl_();
    let wrap: Borrowed<Bin> = from_glib_borrow(ptr);

    // If we get a floating reference passed simply return FALSE here. It can't be
    // stored inside this bin, and if we continued to use it we would take ownership
    // of this floating reference.
    if glib::gobject_ffi::g_object_is_floating(element as *mut glib::gobject_ffi::GObject)
        != glib::ffi::GFALSE
    {
        return glib::ffi::GFALSE;
    }

    panic_to_error!(&wrap, &imp.panicked(), false, {
        match imp.remove_element(wrap.unsafe_cast_ref(), &from_glib_none(element)) {
            Ok(()) => true,
            Err(err) => {
                err.log_with_object(&*wrap);
                false
            }
        }
    })
    .to_glib()
}

unsafe extern "C" fn bin_handle_message<T: BinImpl>(
    ptr: *mut ffi::GstBin,
    message: *mut ffi::GstMessage,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.impl_();
    let wrap: Borrowed<Bin> = from_glib_borrow(ptr);

    panic_to_error!(&wrap, &imp.panicked(), (), {
        imp.handle_message(wrap.unsafe_cast_ref(), from_glib_full(message))
    });
}