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

use std::ptr;

use glib::{prelude::*, translate::*};
use gst::subclass::prelude::*;

use crate::{ffi, Aggregator, AggregatorPad};

pub trait AggregatorImpl: AggregatorImplExt + ElementImpl {
    /// Optional.
    ///  Called after a successful flushing seek, once all the flush
    ///  stops have been received. Flush pad-specific data in
    ///  [`AggregatorPad`][crate::AggregatorPad]->flush.
    fn flush(&self) -> Result<gst::FlowSuccess, gst::FlowError> {
        self.parent_flush()
    }

    /// Optional.
    ///  Called when a buffer is received on a sink pad, the task of
    ///  clipping it and translating it to the current segment falls
    ///  on the subclass. The function should use the segment of data
    ///  and the negotiated media type on the pad to perform
    ///  clipping of input buffer. This function takes ownership of
    ///  buf and should output a buffer or return NULL in
    ///  if the buffer should be dropped.
    fn clip(&self, aggregator_pad: &AggregatorPad, buffer: gst::Buffer) -> Option<gst::Buffer> {
        self.parent_clip(aggregator_pad, buffer)
    }

    /// This method will push the provided output buffer list downstream. If needed,
    /// mandatory events such as stream-start, caps, and segment events will be
    /// sent before pushing the buffer.
    /// ## `bufferlist`
    /// the [`gst::BufferList`][crate::gst::BufferList] to push.
    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn finish_buffer_list(
        &self,
        buffer_list: gst::BufferList,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        self.parent_finish_buffer_list(buffer_list)
    }

    /// This method will push the provided output buffer downstream. If needed,
    /// mandatory events such as stream-start, caps, and segment events will be
    /// sent before pushing the buffer.
    /// ## `buffer`
    /// the [`gst::Buffer`][crate::gst::Buffer] to push.
    fn finish_buffer(&self, buffer: gst::Buffer) -> Result<gst::FlowSuccess, gst::FlowError> {
        self.parent_finish_buffer(buffer)
    }

    /// Optional.
    ///  Called when an event is received on a sink pad, the subclass
    ///  should always chain up.
    fn sink_event(&self, aggregator_pad: &AggregatorPad, event: gst::Event) -> bool {
        self.parent_sink_event(aggregator_pad, event)
    }

    /// Optional.
    ///  Called when an event is received on a sink pad before queueing up
    ///  serialized events. The subclass should always chain up (Since: 1.18).
    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn sink_event_pre_queue(
        &self,
        aggregator_pad: &AggregatorPad,
        event: gst::Event,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        self.parent_sink_event_pre_queue(aggregator_pad, event)
    }

    /// Optional.
    ///  Called when a query is received on a sink pad, the subclass
    ///  should always chain up.
    fn sink_query(&self, aggregator_pad: &AggregatorPad, query: &mut gst::QueryRef) -> bool {
        self.parent_sink_query(aggregator_pad, query)
    }

    /// Optional.
    ///  Called when a query is received on a sink pad before queueing up
    ///  serialized queries. The subclass should always chain up (Since: 1.18).
    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn sink_query_pre_queue(
        &self,
        aggregator_pad: &AggregatorPad,
        query: &mut gst::QueryRef,
    ) -> bool {
        self.parent_sink_query_pre_queue(aggregator_pad, query)
    }

    /// Optional.
    ///  Called when an event is received on the src pad, the subclass
    ///  should always chain up.
    fn src_event(&self, event: gst::Event) -> bool {
        self.parent_src_event(event)
    }

    /// Optional.
    ///  Called when a query is received on the src pad, the subclass
    ///  should always chain up.
    fn src_query(&self, query: &mut gst::QueryRef) -> bool {
        self.parent_src_query(query)
    }

    /// Optional.
    ///  Called when the src pad is activated, it will start/stop its
    ///  pad task right after that call.
    fn src_activate(&self, mode: gst::PadMode, active: bool) -> Result<(), gst::LoggableError> {
        self.parent_src_activate(mode, active)
    }

    /// Mandatory.
    ///  Called when buffers are queued on all sinkpads. Classes
    ///  should iterate the GstElement->sinkpads and peek or steal
    ///  buffers from the `GstAggregatorPads`. If the subclass returns
    ///  GST_FLOW_EOS, sending of the eos event will be taken care
    ///  of. Once / if a buffer has been constructed from the
    ///  aggregated buffers, the subclass should call _finish_buffer.
    fn aggregate(&self, timeout: bool) -> Result<gst::FlowSuccess, gst::FlowError> {
        self.parent_aggregate(timeout)
    }

    /// Optional.
    ///  Called when the element goes from READY to PAUSED.
    ///  The subclass should get ready to process
    ///  aggregated buffers.
    fn start(&self) -> Result<(), gst::ErrorMessage> {
        self.parent_start()
    }

    /// Optional.
    ///  Called when the element goes from PAUSED to READY.
    ///  The subclass should free all resources and reset its state.
    fn stop(&self) -> Result<(), gst::ErrorMessage> {
        self.parent_stop()
    }

    /// Optional.
    ///  Called when the element needs to know the running time of the next
    ///  rendered buffer for live pipelines. This causes deadline
    ///  based aggregation to occur. Defaults to returning
    ///  GST_CLOCK_TIME_NONE causing the element to wait for buffers
    ///  on all sink pads before aggregating.
    fn next_time(&self) -> Option<gst::ClockTime> {
        self.parent_next_time()
    }

    /// Optional.
    ///  Called when a new pad needs to be created. Allows subclass that
    ///  don't have a single sink pad template to provide a pad based
    ///  on the provided information.
    fn create_new_pad(
        &self,
        templ: &gst::PadTemplate,
        req_name: Option<&str>,
        caps: Option<&gst::Caps>,
    ) -> Option<AggregatorPad> {
        self.parent_create_new_pad(templ, req_name, caps)
    }

    fn update_src_caps(&self, caps: &gst::Caps) -> Result<gst::Caps, gst::FlowError> {
        self.parent_update_src_caps(caps)
    }

    /// Optional.
    ///  Fixate and return the src pad caps provided. The function takes
    ///  ownership of `caps` and returns a fixated version of
    ///  `caps`. `caps` is not guaranteed to be writable.
    fn fixate_src_caps(&self, caps: gst::Caps) -> gst::Caps {
        self.parent_fixate_src_caps(caps)
    }

    /// Optional.
    ///  Notifies subclasses what caps format has been negotiated
    fn negotiated_src_caps(&self, caps: &gst::Caps) -> Result<(), gst::LoggableError> {
        self.parent_negotiated_src_caps(caps)
    }

    /// Optional.
    ///  Allows the subclass to handle the allocation query from upstream.
    fn propose_allocation(
        &self,
        pad: &AggregatorPad,
        decide_query: Option<&gst::query::Allocation>,
        query: &mut gst::query::Allocation,
    ) -> Result<(), gst::LoggableError> {
        self.parent_propose_allocation(pad, decide_query, query)
    }

    /// Optional.
    ///  Allows the subclass to influence the allocation choices.
    ///  Setup the allocation parameters for allocating output
    ///  buffers. The passed in query contains the result of the
    ///  downstream allocation query.
    fn decide_allocation(
        &self,
        query: &mut gst::query::Allocation,
    ) -> Result<(), gst::LoggableError> {
        self.parent_decide_allocation(query)
    }

    /// Negotiates src pad caps with downstream elements.
    /// Unmarks GST_PAD_FLAG_NEED_RECONFIGURE in any case. But marks it again
    /// if `GstAggregatorClass::negotiate` fails.
    ///
    /// # Returns
    ///
    /// [`true`] if the negotiation succeeded, else [`false`].
    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn negotiate(&self) -> bool {
        self.parent_negotiate()
    }

    /// Use this function to determine what input buffers will be aggregated
    /// to produce the next output buffer. This should only be called from
    /// a [`samples-selected`][struct@crate::Aggregator#samples-selected] handler, and can be used to precisely
    /// control aggregating parameters for a given set of input samples.
    ///
    /// # Returns
    ///
    /// The sample that is about to be aggregated. It may hold a [`gst::Buffer`][crate::gst::Buffer]
    ///  or a [`gst::BufferList`][crate::gst::BufferList]. The contents of its info structure is subclass-dependent,
    ///  and documented on a subclass basis. The buffers held by the sample are
    ///  not writable.
    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn peek_next_sample(&self, pad: &AggregatorPad) -> Option<gst::Sample> {
        self.parent_peek_next_sample(pad)
    }
}

mod sealed {
    pub trait Sealed {}
    impl<T: super::AggregatorImplExt> Sealed for T {}
}

pub trait AggregatorImplExt: sealed::Sealed + ObjectSubclass {
    fn parent_flush(&self) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .flush
                .map(|f| {
                    try_from_glib(f(self
                        .obj()
                        .unsafe_cast_ref::<Aggregator>()
                        .to_glib_none()
                        .0))
                })
                .unwrap_or(Ok(gst::FlowSuccess::Ok))
        }
    }

    fn parent_clip(
        &self,
        aggregator_pad: &AggregatorPad,
        buffer: gst::Buffer,
    ) -> Option<gst::Buffer> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            match (*parent_class).clip {
                None => Some(buffer),
                Some(ref func) => from_glib_full(func(
                    self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                    aggregator_pad.to_glib_none().0,
                    buffer.into_glib_ptr(),
                )),
            }
        }
    }

    fn parent_finish_buffer(
        &self,
        buffer: gst::Buffer,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .finish_buffer
                .expect("Missing parent function `finish_buffer`");
            try_from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                buffer.into_glib_ptr(),
            ))
        }
    }

    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn parent_finish_buffer_list(
        &self,
        buffer_list: gst::BufferList,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .finish_buffer_list
                .expect("Missing parent function `finish_buffer_list`");
            try_from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                buffer_list.into_glib_ptr(),
            ))
        }
    }

    fn parent_sink_event(&self, aggregator_pad: &AggregatorPad, event: gst::Event) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .sink_event
                .expect("Missing parent function `sink_event`");
            from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                aggregator_pad.to_glib_none().0,
                event.into_glib_ptr(),
            ))
        }
    }

    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn parent_sink_event_pre_queue(
        &self,
        aggregator_pad: &AggregatorPad,
        event: gst::Event,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .sink_event_pre_queue
                .expect("Missing parent function `sink_event_pre_queue`");
            try_from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                aggregator_pad.to_glib_none().0,
                event.into_glib_ptr(),
            ))
        }
    }

    fn parent_sink_query(&self, aggregator_pad: &AggregatorPad, query: &mut gst::QueryRef) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .sink_query
                .expect("Missing parent function `sink_query`");
            from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                aggregator_pad.to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn parent_sink_query_pre_queue(
        &self,
        aggregator_pad: &AggregatorPad,
        query: &mut gst::QueryRef,
    ) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .sink_query_pre_queue
                .expect("Missing parent function `sink_query`");
            from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                aggregator_pad.to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn parent_src_event(&self, event: gst::Event) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .src_event
                .expect("Missing parent function `src_event`");
            from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                event.into_glib_ptr(),
            ))
        }
    }

    fn parent_src_query(&self, query: &mut gst::QueryRef) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .src_query
                .expect("Missing parent function `src_query`");
            from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn parent_src_activate(
        &self,
        mode: gst::PadMode,
        active: bool,
    ) -> Result<(), gst::LoggableError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            match (*parent_class).src_activate {
                None => Ok(()),
                Some(f) => gst::result_from_gboolean!(
                    f(
                        self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                        mode.into_glib(),
                        active.into_glib()
                    ),
                    gst::CAT_RUST,
                    "Parent function `src_activate` failed"
                ),
            }
        }
    }

    fn parent_aggregate(&self, timeout: bool) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .aggregate
                .expect("Missing parent function `aggregate`");
            try_from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                timeout.into_glib(),
            ))
        }
    }

    fn parent_start(&self) -> Result<(), gst::ErrorMessage> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .start
                .map(|f| {
                    if from_glib(f(self
                        .obj()
                        .unsafe_cast_ref::<Aggregator>()
                        .to_glib_none()
                        .0))
                    {
                        Ok(())
                    } else {
                        Err(gst::error_msg!(
                            gst::CoreError::Failed,
                            ["Parent function `start` failed"]
                        ))
                    }
                })
                .unwrap_or(Ok(()))
        }
    }

    fn parent_stop(&self) -> Result<(), gst::ErrorMessage> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .stop
                .map(|f| {
                    if from_glib(f(self
                        .obj()
                        .unsafe_cast_ref::<Aggregator>()
                        .to_glib_none()
                        .0))
                    {
                        Ok(())
                    } else {
                        Err(gst::error_msg!(
                            gst::CoreError::Failed,
                            ["Parent function `stop` failed"]
                        ))
                    }
                })
                .unwrap_or(Ok(()))
        }
    }

    fn parent_next_time(&self) -> Option<gst::ClockTime> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .get_next_time
                .map(|f| {
                    from_glib(f(self
                        .obj()
                        .unsafe_cast_ref::<Aggregator>()
                        .to_glib_none()
                        .0))
                })
                .unwrap_or(gst::ClockTime::NONE)
        }
    }

    fn parent_create_new_pad(
        &self,
        templ: &gst::PadTemplate,
        req_name: Option<&str>,
        caps: Option<&gst::Caps>,
    ) -> Option<AggregatorPad> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .create_new_pad
                .expect("Missing parent function `create_new_pad`");
            from_glib_full(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                templ.to_glib_none().0,
                req_name.to_glib_none().0,
                caps.to_glib_none().0,
            ))
        }
    }

    fn parent_update_src_caps(&self, caps: &gst::Caps) -> Result<gst::Caps, gst::FlowError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            let f = (*parent_class)
                .update_src_caps
                .expect("Missing parent function `update_src_caps`");

            let mut out_caps = ptr::null_mut();
            gst::FlowSuccess::try_from_glib(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                caps.as_mut_ptr(),
                &mut out_caps,
            ))
            .map(|_| from_glib_full(out_caps))
        }
    }

    fn parent_fixate_src_caps(&self, caps: gst::Caps) -> gst::Caps {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;

            let f = (*parent_class)
                .fixate_src_caps
                .expect("Missing parent function `fixate_src_caps`");
            from_glib_full(f(
                self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                caps.into_glib_ptr(),
            ))
        }
    }

    fn parent_negotiated_src_caps(&self, caps: &gst::Caps) -> Result<(), gst::LoggableError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .negotiated_src_caps
                .map(|f| {
                    gst::result_from_gboolean!(
                        f(
                            self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                            caps.to_glib_none().0
                        ),
                        gst::CAT_RUST,
                        "Parent function `negotiated_src_caps` failed"
                    )
                })
                .unwrap_or(Ok(()))
        }
    }

    fn parent_propose_allocation(
        &self,
        pad: &AggregatorPad,
        decide_query: Option<&gst::query::Allocation>,
        query: &mut gst::query::Allocation,
    ) -> Result<(), gst::LoggableError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .propose_allocation
                .map(|f| {
                    gst::result_from_gboolean!(
                        f(
                            self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                            pad.to_glib_none().0,
                            decide_query
                                .as_ref()
                                .map(|q| q.as_mut_ptr())
                                .unwrap_or(ptr::null_mut()),
                            query.as_mut_ptr()
                        ),
                        gst::CAT_RUST,
                        "Parent function `propose_allocation` failed",
                    )
                })
                .unwrap_or(Ok(()))
        }
    }

    fn parent_decide_allocation(
        &self,
        query: &mut gst::query::Allocation,
    ) -> Result<(), gst::LoggableError> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .decide_allocation
                .map(|f| {
                    gst::result_from_gboolean!(
                        f(
                            self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                            query.as_mut_ptr(),
                        ),
                        gst::CAT_RUST,
                        "Parent function `decide_allocation` failed",
                    )
                })
                .unwrap_or(Ok(()))
        }
    }

    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn parent_negotiate(&self) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .negotiate
                .map(|f| {
                    from_glib(f(self
                        .obj()
                        .unsafe_cast_ref::<Aggregator>()
                        .to_glib_none()
                        .0))
                })
                .unwrap_or(true)
        }
    }

    #[cfg(feature = "v1_18")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
    fn parent_peek_next_sample(&self, pad: &AggregatorPad) -> Option<gst::Sample> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GstAggregatorClass;
            (*parent_class)
                .peek_next_sample
                .map(|f| {
                    from_glib_full(f(
                        self.obj().unsafe_cast_ref::<Aggregator>().to_glib_none().0,
                        pad.to_glib_none().0,
                    ))
                })
                .unwrap_or(None)
        }
    }
}

impl<T: AggregatorImpl> AggregatorImplExt for T {}

unsafe impl<T: AggregatorImpl> IsSubclassable<T> for Aggregator {
    fn class_init(klass: &mut glib::Class<Self>) {
        Self::parent_class_init::<T>(klass);
        let klass = klass.as_mut();
        klass.flush = Some(aggregator_flush::<T>);
        klass.clip = Some(aggregator_clip::<T>);
        klass.finish_buffer = Some(aggregator_finish_buffer::<T>);
        klass.sink_event = Some(aggregator_sink_event::<T>);
        klass.sink_query = Some(aggregator_sink_query::<T>);
        klass.src_event = Some(aggregator_src_event::<T>);
        klass.src_query = Some(aggregator_src_query::<T>);
        klass.src_activate = Some(aggregator_src_activate::<T>);
        klass.aggregate = Some(aggregator_aggregate::<T>);
        klass.start = Some(aggregator_start::<T>);
        klass.stop = Some(aggregator_stop::<T>);
        klass.get_next_time = Some(aggregator_get_next_time::<T>);
        klass.create_new_pad = Some(aggregator_create_new_pad::<T>);
        klass.update_src_caps = Some(aggregator_update_src_caps::<T>);
        klass.fixate_src_caps = Some(aggregator_fixate_src_caps::<T>);
        klass.negotiated_src_caps = Some(aggregator_negotiated_src_caps::<T>);
        klass.propose_allocation = Some(aggregator_propose_allocation::<T>);
        klass.decide_allocation = Some(aggregator_decide_allocation::<T>);
        #[cfg(feature = "v1_18")]
        {
            klass.sink_event_pre_queue = Some(aggregator_sink_event_pre_queue::<T>);
            klass.sink_query_pre_queue = Some(aggregator_sink_query_pre_queue::<T>);
            klass.negotiate = Some(aggregator_negotiate::<T>);
            klass.peek_next_sample = Some(aggregator_peek_next_sample::<T>);
            klass.finish_buffer_list = Some(aggregator_finish_buffer_list::<T>);
        }
    }
}

unsafe extern "C" fn aggregator_flush<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
) -> gst::ffi::GstFlowReturn {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::FlowReturn::Error, { imp.flush().into() }).into_glib()
}

unsafe extern "C" fn aggregator_clip<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    aggregator_pad: *mut ffi::GstAggregatorPad,
    buffer: *mut gst::ffi::GstBuffer,
) -> *mut gst::ffi::GstBuffer {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    let ret = gst::panic_to_error!(imp, None, {
        imp.clip(&from_glib_borrow(aggregator_pad), from_glib_full(buffer))
    });

    ret.map(|r| r.into_glib_ptr()).unwrap_or(ptr::null_mut())
}

unsafe extern "C" fn aggregator_finish_buffer<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    buffer: *mut gst::ffi::GstBuffer,
) -> gst::ffi::GstFlowReturn {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::FlowReturn::Error, {
        imp.finish_buffer(from_glib_full(buffer)).into()
    })
    .into_glib()
}

#[cfg(feature = "v1_18")]
#[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
unsafe extern "C" fn aggregator_finish_buffer_list<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    buffer_list: *mut gst::ffi::GstBufferList,
) -> gst::ffi::GstFlowReturn {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::FlowReturn::Error, {
        imp.finish_buffer_list(from_glib_full(buffer_list)).into()
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_sink_event<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    aggregator_pad: *mut ffi::GstAggregatorPad,
    event: *mut gst::ffi::GstEvent,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        imp.sink_event(&from_glib_borrow(aggregator_pad), from_glib_full(event))
    })
    .into_glib()
}

#[cfg(feature = "v1_18")]
#[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
unsafe extern "C" fn aggregator_sink_event_pre_queue<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    aggregator_pad: *mut ffi::GstAggregatorPad,
    event: *mut gst::ffi::GstEvent,
) -> gst::ffi::GstFlowReturn {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::FlowReturn::Error, {
        imp.sink_event_pre_queue(&from_glib_borrow(aggregator_pad), from_glib_full(event))
            .into()
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_sink_query<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    aggregator_pad: *mut ffi::GstAggregatorPad,
    query: *mut gst::ffi::GstQuery,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        imp.sink_query(
            &from_glib_borrow(aggregator_pad),
            gst::QueryRef::from_mut_ptr(query),
        )
    })
    .into_glib()
}

#[cfg(feature = "v1_18")]
#[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
unsafe extern "C" fn aggregator_sink_query_pre_queue<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    aggregator_pad: *mut ffi::GstAggregatorPad,
    query: *mut gst::ffi::GstQuery,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        imp.sink_query_pre_queue(
            &from_glib_borrow(aggregator_pad),
            gst::QueryRef::from_mut_ptr(query),
        )
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_src_event<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    event: *mut gst::ffi::GstEvent,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, { imp.src_event(from_glib_full(event)) }).into_glib()
}

unsafe extern "C" fn aggregator_src_query<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    query: *mut gst::ffi::GstQuery,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        imp.src_query(gst::QueryRef::from_mut_ptr(query))
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_src_activate<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    mode: gst::ffi::GstPadMode,
    active: glib::ffi::gboolean,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        match imp.src_activate(from_glib(mode), from_glib(active)) {
            Ok(()) => true,
            Err(err) => {
                err.log_with_imp(imp);
                false
            }
        }
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_aggregate<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    timeout: glib::ffi::gboolean,
) -> gst::ffi::GstFlowReturn {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::FlowReturn::Error, {
        imp.aggregate(from_glib(timeout)).into()
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_start<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        match imp.start() {
            Ok(()) => true,
            Err(err) => {
                imp.post_error_message(err);
                false
            }
        }
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_stop<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        match imp.stop() {
            Ok(()) => true,
            Err(err) => {
                imp.post_error_message(err);
                false
            }
        }
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_get_next_time<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
) -> gst::ffi::GstClockTime {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::ClockTime::NONE, { imp.next_time() }).into_glib()
}

unsafe extern "C" fn aggregator_create_new_pad<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    templ: *mut gst::ffi::GstPadTemplate,
    req_name: *const libc::c_char,
    caps: *const gst::ffi::GstCaps,
) -> *mut ffi::GstAggregatorPad {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, None, {
        let req_name: Borrowed<Option<glib::GString>> = from_glib_borrow(req_name);

        imp.create_new_pad(
            &from_glib_borrow(templ),
            req_name.as_ref().as_ref().map(|s| s.as_str()),
            Option::<gst::Caps>::from_glib_borrow(caps)
                .as_ref()
                .as_ref(),
        )
    })
    .into_glib_ptr()
}

unsafe extern "C" fn aggregator_update_src_caps<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    caps: *mut gst::ffi::GstCaps,
    res: *mut *mut gst::ffi::GstCaps,
) -> gst::ffi::GstFlowReturn {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    *res = ptr::null_mut();

    gst::panic_to_error!(imp, gst::FlowReturn::Error, {
        match imp.update_src_caps(&from_glib_borrow(caps)) {
            Ok(res_caps) => {
                *res = res_caps.into_glib_ptr();
                gst::FlowReturn::Ok
            }
            Err(err) => err.into(),
        }
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_fixate_src_caps<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    caps: *mut gst::ffi::GstCaps,
) -> *mut gst::ffi::GstCaps {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, gst::Caps::new_empty(), {
        imp.fixate_src_caps(from_glib_full(caps))
    })
    .into_glib_ptr()
}

unsafe extern "C" fn aggregator_negotiated_src_caps<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    caps: *mut gst::ffi::GstCaps,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, {
        match imp.negotiated_src_caps(&from_glib_borrow(caps)) {
            Ok(()) => true,
            Err(err) => {
                err.log_with_imp(imp);
                false
            }
        }
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_propose_allocation<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    pad: *mut ffi::GstAggregatorPad,
    decide_query: *mut gst::ffi::GstQuery,
    query: *mut gst::ffi::GstQuery,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let decide_query = if decide_query.is_null() {
        None
    } else {
        match gst::QueryRef::from_ptr(decide_query).view() {
            gst::QueryView::Allocation(allocation) => Some(allocation),
            _ => unreachable!(),
        }
    };
    let query = match gst::QueryRef::from_mut_ptr(query).view_mut() {
        gst::QueryViewMut::Allocation(allocation) => allocation,
        _ => unreachable!(),
    };

    gst::panic_to_error!(imp, false, {
        match imp.propose_allocation(&from_glib_borrow(pad), decide_query, query) {
            Ok(()) => true,
            Err(err) => {
                err.log_with_imp(imp);
                false
            }
        }
    })
    .into_glib()
}

unsafe extern "C" fn aggregator_decide_allocation<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    query: *mut gst::ffi::GstQuery,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let query = match gst::QueryRef::from_mut_ptr(query).view_mut() {
        gst::QueryViewMut::Allocation(allocation) => allocation,
        _ => unreachable!(),
    };

    gst::panic_to_error!(imp, false, {
        match imp.decide_allocation(query) {
            Ok(()) => true,
            Err(err) => {
                err.log_with_imp(imp);
                false
            }
        }
    })
    .into_glib()
}

#[cfg(feature = "v1_18")]
#[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
unsafe extern "C" fn aggregator_negotiate<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, false, { imp.negotiate() }).into_glib()
}

#[cfg(feature = "v1_18")]
#[cfg_attr(docsrs, doc(cfg(feature = "v1_18")))]
unsafe extern "C" fn aggregator_peek_next_sample<T: AggregatorImpl>(
    ptr: *mut ffi::GstAggregator,
    pad: *mut ffi::GstAggregatorPad,
) -> *mut gst::ffi::GstSample {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    gst::panic_to_error!(imp, None, { imp.peek_next_sample(&from_glib_borrow(pad)) })
        .into_glib_ptr()
}