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

use crate::TestClock;
use glib::translate::*;
use gst::prelude::*;
use std::marker::PhantomData;
use std::mem;
use std::ops;
use std::path;
use std::ptr;

/// [`crate::Harness`] is meant to make writing unit test for GStreamer much easier.
/// It can be thought of as a way of treating a [`crate::gst::Element`] as a black box,
/// deterministically feeding it data, and controlling what data it outputs.
///
/// The basic structure of [`crate::Harness`] is two "floating" `GstPads` that connect
/// to the harnessed [`crate::gst::Element`] src and sink `GstPads` like so:
///
///
/// ```C
///   #include <gst/gst.h>
///   #include <gst/check/gstharness.h>
///   GstHarness *h;
///   GstBuffer *in_buf;
///   GstBuffer *out_buf;
///
///   // attach the harness to the src and sink pad of GstQueue
///   h = gst_harness_new ("queue");
///
///   // we must specify a caps before pushing buffers
///   gst_harness_set_src_caps_str (h, "mycaps");
///
///   // create a buffer of size 42
///   in_buf = gst_harness_create_buffer (h, 42);
///
///   // push the buffer into the queue
///   gst_harness_push (h, in_buf);
///
///   // pull the buffer from the queue
///   out_buf = gst_harness_pull (h);
///
///   // validate the buffer in is the same as buffer out
///   fail_unless (in_buf == out_buf);
///
///   // cleanup
///   gst_buffer_unref (out_buf);
///   gst_harness_teardown (h);
///
///   ]|
///
/// Another main feature of the #GstHarness is its integration with the
/// #GstTestClock. Operating the #GstTestClock can be very challenging, but
/// #GstHarness simplifies some of the most desired actions a lot, like wanting
/// to manually advance the clock while at the same time releasing a #GstClockID
/// that is waiting, with functions like gst_harness_crank_single_clock_wait().
///
/// #GstHarness also supports sub-harnesses, as a way of generating and
/// validating data. A sub-harness is another #GstHarness that is managed by
/// the "parent" harness, and can either be created by using the standard
/// gst_harness_new type functions directly on the (GstHarness *)->src_harness,
/// or using the much more convenient gst_harness_add_src() or
/// gst_harness_add_sink_parse(). If you have a decoder-element you want to test,
/// (like vp8dec) it can be very useful to add a src-harness with both a
/// src-element (videotestsrc) and an encoder (vp8enc) to feed the decoder data
/// with different configurations, by simply doing:
///
/// |[<!-- language="C" -->
///   GstHarness * h = gst_harness_new (h, "vp8dec");
///   gst_harness_add_src_parse (h, "videotestsrc is-live=1 ! vp8enc", TRUE);
/// ```
///
/// and then feeding it data with:
///
///
/// ```C
/// gst_harness_push_from_src (h);
/// ```
#[derive(Debug)]
pub struct Harness(ptr::NonNull<ffi::GstHarness>);

impl Drop for Harness {
    fn drop(&mut self) {
        unsafe {
            ffi::gst_harness_teardown(self.0.as_ptr());
        }
    }
}

unsafe impl Send for Harness {}
unsafe impl Sync for Harness {}

impl Harness {
    /// Adds a [`crate::gst::Element`] to an empty [`crate::Harness`]
    ///
    /// MT safe.
    /// ## `element`
    /// a [`crate::gst::Element`] to add to the harness (transfer none)
    /// ## `hsrc`
    /// a [`crate::gst::StaticPadTemplate`] describing the harness srcpad.
    /// [`None`] will not create a harness srcpad.
    /// ## `element_sinkpad_name`
    /// a `gchar` with the name of the element
    /// sinkpad that is then linked to the harness srcpad. Can be a static or request
    /// or a sometimes pad that has been added. [`None`] will not get/request a sinkpad
    /// from the element. (Like if the element is a src.)
    /// ## `hsink`
    /// a [`crate::gst::StaticPadTemplate`] describing the harness sinkpad.
    /// [`None`] will not create a harness sinkpad.
    /// ## `element_srcpad_name`
    /// a `gchar` with the name of the element
    /// srcpad that is then linked to the harness sinkpad, similar to the
    /// `element_sinkpad_name`.
    pub fn add_element_full<P: IsA<gst::Element>>(
        &mut self,
        element: &P,
        hsrc: Option<&gst::StaticPadTemplate>,
        element_sinkpad_name: Option<&str>,
        hsink: Option<&gst::StaticPadTemplate>,
        element_srcpad_name: Option<&str>,
    ) {
        let element_sinkpad_name = element_sinkpad_name.to_glib_none();
        let element_srcpad_name = element_srcpad_name.to_glib_none();
        unsafe {
            ffi::gst_harness_add_element_full(
                self.0.as_ptr(),
                element.as_ref().to_glib_none().0,
                hsrc.to_glib_none().0 as *mut _,
                element_sinkpad_name.0,
                hsink.to_glib_none().0 as *mut _,
                element_srcpad_name.0,
            );
        }
    }

    /// Links the specified [`crate::gst::Pad`] the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) srcpad.
    ///
    /// MT safe.
    /// ## `sinkpad`
    /// a [`crate::gst::Pad`] to link to the harness srcpad
    pub fn add_element_sink_pad<P: IsA<gst::Pad>>(&mut self, sinkpad: &P) {
        unsafe {
            ffi::gst_harness_add_element_sink_pad(
                self.0.as_ptr(),
                sinkpad.as_ref().to_glib_none().0,
            );
        }
    }

    /// Links the specified [`crate::gst::Pad`] the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) sinkpad. This can be useful if
    /// perhaps the srcpad did not exist at the time of creating the harness,
    /// like a demuxer that provides a sometimes-pad after receiving data.
    ///
    /// MT safe.
    /// ## `srcpad`
    /// a [`crate::gst::Pad`] to link to the harness sinkpad
    pub fn add_element_src_pad<P: IsA<gst::Pad>>(&mut self, srcpad: &P) {
        unsafe {
            ffi::gst_harness_add_element_src_pad(self.0.as_ptr(), srcpad.as_ref().to_glib_none().0);
        }
    }

    /// Parses the `launchline` and puts that in a [`crate::gst::Bin`],
    /// and then attches the supplied [`crate::Harness`] to the bin.
    ///
    /// MT safe.
    /// ## `launchline`
    /// a `gchar` describing a gst-launch type line
    pub fn add_parse(&mut self, launchline: &str) {
        unsafe {
            ffi::gst_harness_add_parse(self.0.as_ptr(), launchline.to_glib_none().0);
        }
    }

    /// A convenience function to allows you to call gst_pad_add_probe on a
    /// [`crate::gst::Pad`] of a [`crate::gst::Element`] that are residing inside the [`crate::Harness`],
    /// by using normal gst_pad_add_probe syntax
    ///
    /// MT safe.
    /// ## `element_name`
    /// a `gchar` with a [`crate::gst::ElementFactory`] name
    /// ## `pad_name`
    /// a `gchar` with the name of the pad to attach the probe to
    /// ## `mask`
    /// a [`crate::gst::PadProbeType`] (see gst_pad_add_probe)
    /// ## `callback`
    /// a `GstPadProbeCallback` (see gst_pad_add_probe)
    /// ## `user_data`
    /// a `gpointer` (see gst_pad_add_probe)
    /// ## `destroy_data`
    /// a `GDestroyNotify` (see gst_pad_add_probe)
    pub fn add_probe<F>(
        &mut self,
        element_name: &str,
        pad_name: &str,
        mask: gst::PadProbeType,
        func: F,
    ) where
        F: Fn(&gst::Pad, &mut gst::PadProbeInfo) -> gst::PadProbeReturn + Send + Sync + 'static,
    {
        // Reimplementation of the C code so we don't have to duplicate all the callback code

        let element = self.find_element(element_name).expect("Element not found");
        let pad = element.static_pad(pad_name).expect("Pad not found");
        pad.add_probe(mask, func);
    }

    /// Add api with params as one of the supported metadata API to propose when
    /// receiving an allocation query.
    ///
    /// MT safe.
    /// ## `api`
    /// a metadata API
    /// ## `params`
    /// API specific parameters
    #[cfg(any(feature = "v1_16", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_16")))]
    pub fn add_propose_allocation_meta(
        &mut self,
        api: glib::types::Type,
        params: Option<&gst::StructureRef>,
    ) {
        unsafe {
            let params = params.map(|p| p.as_ptr()).unwrap_or(ptr::null_mut());
            ffi::gst_harness_add_propose_allocation_meta(self.0.as_ptr(), api.into_glib(), params);
        }
    }

    /// Similar to gst_harness_add_sink_harness, this is a convenience to
    /// directly create a sink-harness using the `sink_element_name` name specified.
    ///
    /// MT safe.
    /// ## `sink_element_name`
    /// a `gchar` with the name of a [`crate::gst::Element`]
    pub fn add_sink(&mut self, sink_element_name: &str) {
        unsafe {
            ffi::gst_harness_add_sink(self.0.as_ptr(), sink_element_name.to_glib_none().0);
        }
    }

    /// Similar to gst_harness_add_src, this allows you to send the data coming out
    /// of your harnessed [`crate::gst::Element`] to a sink-element, allowing to test different
    /// responses the element output might create in sink elements. An example might
    /// be an existing sink providing some analytical data on the input it receives that
    /// can be useful to your testing. If the goal is to test a sink-element itself,
    /// this is better achieved using gst_harness_new directly on the sink.
    ///
    /// If a sink-harness already exists it will be replaced.
    ///
    /// MT safe.
    /// ## `sink_harness`
    /// a [`crate::Harness`] to be added as a sink-harness.
    pub fn add_sink_harness(&mut self, sink_harness: Harness) {
        unsafe {
            let sink_harness = mem::ManuallyDrop::new(sink_harness);
            ffi::gst_harness_add_sink_harness(self.0.as_ptr(), sink_harness.0.as_ptr());
        }
    }

    /// Similar to gst_harness_add_sink, this allows you to specify a launch-line
    /// instead of just an element name. See gst_harness_add_src_parse for details.
    ///
    /// MT safe.
    /// ## `launchline`
    /// a `gchar` with the name of a [`crate::gst::Element`]
    pub fn add_sink_parse(&mut self, launchline: &str) {
        unsafe {
            ffi::gst_harness_add_sink_parse(self.0.as_ptr(), launchline.to_glib_none().0);
        }
    }

    /// Similar to gst_harness_add_src_harness, this is a convenience to
    /// directly create a src-harness using the `src_element_name` name specified.
    ///
    /// MT safe.
    /// ## `src_element_name`
    /// a `gchar` with the name of a [`crate::gst::Element`]
    /// ## `has_clock_wait`
    /// a `gboolean` specifying if the [`crate::gst::Element`] uses
    /// gst_clock_wait_id internally.
    pub fn add_src(&mut self, src_element_name: &str, has_clock_wait: bool) {
        unsafe {
            ffi::gst_harness_add_src(
                self.0.as_ptr(),
                src_element_name.to_glib_none().0,
                has_clock_wait.into_glib(),
            );
        }
    }

    /// A src-harness is a great way of providing the [`crate::Harness`] with data.
    /// By adding a src-type [`crate::gst::Element`], it is then easy to use functions like
    /// gst_harness_push_from_src or gst_harness_src_crank_and_push_many
    /// to provide your harnessed element with input. The `has_clock_wait` variable
    /// is a great way to control you src-element with, in that you can have it
    /// produce a buffer for you by simply cranking the clock, and not have it
    /// spin out of control producing buffers as fast as possible.
    ///
    /// If a src-harness already exists it will be replaced.
    ///
    /// MT safe.
    /// ## `src_harness`
    /// a [`crate::Harness`] to be added as a src-harness.
    /// ## `has_clock_wait`
    /// a `gboolean` specifying if the [`crate::gst::Element`] uses
    /// gst_clock_wait_id internally.
    pub fn add_src_harness(&mut self, src_harness: Harness, has_clock_wait: bool) {
        unsafe {
            let src_harness = mem::ManuallyDrop::new(src_harness);
            ffi::gst_harness_add_src_harness(
                self.0.as_ptr(),
                src_harness.0.as_ptr(),
                has_clock_wait.into_glib(),
            );
        }
    }

    /// Similar to gst_harness_add_src, this allows you to specify a launch-line,
    /// which can be useful for both having more then one [`crate::gst::Element`] acting as your
    /// src (Like a src producing raw buffers, and then an encoder, providing encoded
    /// data), but also by allowing you to set properties like "is-live" directly on
    /// the elements.
    ///
    /// MT safe.
    /// ## `launchline`
    /// a `gchar` describing a gst-launch type line
    /// ## `has_clock_wait`
    /// a `gboolean` specifying if the [`crate::gst::Element`] uses
    /// gst_clock_wait_id internally.
    pub fn add_src_parse(&mut self, launchline: &str, has_clock_wait: bool) {
        unsafe {
            ffi::gst_harness_add_src_parse(
                self.0.as_ptr(),
                launchline.to_glib_none().0,
                has_clock_wait.into_glib(),
            );
        }
    }

    /// The number of `GstBuffers` currently in the [`crate::Harness`] sinkpad [`crate::glib::AsyncQueue`]
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `guint` number of buffers in the queue
    pub fn buffers_in_queue(&self) -> u32 {
        unsafe { ffi::gst_harness_buffers_in_queue(self.0.as_ptr()) }
    }

    /// The total number of `GstBuffers` that has arrived on the [`crate::Harness`] sinkpad.
    /// This number includes buffers that have been dropped as well as buffers
    /// that have already been pulled out.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `guint` number of buffers received
    pub fn buffers_received(&self) -> u32 {
        unsafe { ffi::gst_harness_buffers_received(self.0.as_ptr()) }
    }

    /// Similar to [`Self::crank_single_clock_wait()`], this is the function to use
    /// if your harnessed element(s) are using more then one gst_clock_id_wait.
    /// Failing to do so can (and will) make it racy which [`crate::gst::ClockID`] you actually
    /// are releasing, where as this function will process all the waits at the
    /// same time, ensuring that one thread can't register another wait before
    /// both are released.
    ///
    /// MT safe.
    /// ## `waits`
    /// a `guint` describing the number of `GstClockIDs` to crank
    ///
    /// # Returns
    ///
    /// a `gboolean` [`true`] if the "crank" was successful, [`false`] if not.
    pub fn crank_multiple_clock_waits(&mut self, waits: u32) -> Result<(), glib::BoolError> {
        unsafe {
            glib::result_from_gboolean!(
                ffi::gst_harness_crank_multiple_clock_waits(self.0.as_ptr(), waits),
                "Failed to crank multiple clock waits",
            )
        }
    }

    /// A "crank" consists of three steps:
    /// 1: Wait for a [`crate::gst::ClockID`] to be registered with the [`crate::TestClock`].
    /// 2: Advance the [`crate::TestClock`] to the time the [`crate::gst::ClockID`] is waiting for.
    /// 3: Release the [`crate::gst::ClockID`] wait.
    /// Together, this provides an easy way to not have to think about the details
    /// around clocks and time, but still being able to write deterministic tests
    /// that are dependent on this. A "crank" can be though of as the notion of
    /// manually driving the clock forward to its next logical step.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `gboolean` [`true`] if the "crank" was successful, [`false`] if not.
    pub fn crank_single_clock_wait(&mut self) -> Result<(), glib::BoolError> {
        unsafe {
            glib::result_from_gboolean!(
                ffi::gst_harness_crank_single_clock_wait(self.0.as_ptr()),
                "Failed to crank single clock wait",
            )
        }
    }

    /// Allocates a buffer using a [`crate::gst::BufferPool`] if present, or else using the
    /// configured [`crate::gst::Allocator`] and [`crate::gst::AllocationParams`]
    ///
    /// MT safe.
    /// ## `size`
    /// a `gsize` specifying the size of the buffer
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Buffer`] of size `size`
    pub fn create_buffer(&mut self, size: usize) -> Result<gst::Buffer, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_create_buffer(self.0.as_ptr(), size))
                .ok_or_else(|| glib::bool_error!("Failed to create new buffer"))
        }
    }

    /// Allows you to dump the `GstBuffers` the [`crate::Harness`] sinkpad [`crate::glib::AsyncQueue`]
    /// to a file.
    ///
    /// MT safe.
    /// ## `filename`
    /// a `gchar` with a the name of a file
    pub fn dump_to_file<P: AsRef<path::Path>>(&mut self, filename: P) {
        let filename = filename.as_ref();
        unsafe {
            ffi::gst_harness_dump_to_file(self.0.as_ptr(), filename.to_glib_none().0);
        }
    }

    /// The number of `GstEvents` currently in the [`crate::Harness`] sinkpad [`crate::glib::AsyncQueue`]
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `guint` number of events in the queue
    pub fn events_in_queue(&self) -> u32 {
        unsafe { ffi::gst_harness_events_in_queue(self.0.as_ptr()) }
    }

    /// The total number of `GstEvents` that has arrived on the [`crate::Harness`] sinkpad
    /// This number includes events handled by the harness as well as events
    /// that have already been pulled out.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `guint` number of events received
    pub fn events_received(&self) -> u32 {
        unsafe { ffi::gst_harness_events_received(self.0.as_ptr()) }
    }

    /// Most useful in conjunction with gst_harness_new_parse, this will scan the
    /// `GstElements` inside the [`crate::Harness`], and check if any of them matches
    /// `element_name`. Typical usecase being that you need to access one of the
    /// harnessed elements for properties and/or signals.
    ///
    /// MT safe.
    /// ## `element_name`
    /// a `gchar` with a [`crate::gst::ElementFactory`] name
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Element`] or [`None`] if not found
    pub fn find_element(&mut self, element_name: &str) -> Option<gst::Element> {
        unsafe {
            // Work around https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/31
            let ptr = ffi::gst_harness_find_element(self.0.as_ptr(), element_name.to_glib_none().0);

            if ptr.is_null() {
                return None;
            }

            // Clear floating flag if it is set
            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
            }

            from_glib_full(ptr)
        }
    }

    //pub fn get(&mut self, element_name: &str, first_property_name: &str, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) {
    //    unsafe { TODO: call ffi::gst_harness_get() }
    //}

    //pub fn get_allocator(&mut self, allocator: /*Ignored*/gst::Allocator, params: /*Ignored*/gst::AllocationParams) {
    //    unsafe { TODO: call ffi::gst_harness_get_allocator() }
    //}

    #[doc(alias = "get_last_pushed_timestamp")]
    pub fn last_pushed_timestamp(&self) -> gst::ClockTime {
        unsafe { from_glib(ffi::gst_harness_get_last_pushed_timestamp(self.0.as_ptr())) }
    }

    #[doc(alias = "get_testclock")]
    pub fn testclock(&self) -> Option<TestClock> {
        unsafe { from_glib_full(ffi::gst_harness_get_testclock(self.0.as_ptr())) }
    }

    /// This will set the harnessed [`crate::gst::Element`] to [`crate::gst::State::Playing`].
    /// `GstElements` without a sink-[`crate::gst::Pad`] and with the [`crate::gst::ElementFlags::Source`]
    /// flag set is considered a src [`crate::gst::Element`]
    /// Non-src `GstElements` (like sinks and filters) are automatically set to
    /// playing by the [`crate::Harness`], but src `GstElements` are not to avoid them
    /// starting to produce buffers.
    /// Hence, for src [`crate::gst::Element`] you must call [`Self::play()`] explicitly.
    ///
    /// MT safe.
    pub fn play(&mut self) {
        unsafe {
            ffi::gst_harness_play(self.0.as_ptr());
        }
    }

    /// Pulls a [`crate::gst::Buffer`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] sinkpad. The pull
    /// will timeout in 60 seconds. This is the standard way of getting a buffer
    /// from a harnessed [`crate::gst::Element`].
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Buffer`] or [`None`] if timed out.
    pub fn pull(&mut self) -> Result<gst::Buffer, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_pull(self.0.as_ptr()))
                .ok_or_else(|| glib::bool_error!("Failed to pull buffer"))
        }
    }

    /// Pulls a [`crate::gst::Buffer`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] sinkpad. The pull
    /// will block until an EOS event is received, or timeout in 60 seconds.
    /// MT safe.
    /// ## `buf`
    /// A [`crate::gst::Buffer`], or [`None`] if EOS or timeout occures
    ///  first.
    ///
    /// # Returns
    ///
    /// [`true`] on success, [`false`] on timeout.
    #[cfg(any(feature = "v1_18", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_18")))]
    pub fn pull_until_eos(&mut self) -> Result<Option<gst::Buffer>, glib::BoolError> {
        unsafe {
            let mut buffer = ptr::null_mut();
            let res = ffi::gst_harness_pull_until_eos(self.0.as_ptr(), &mut buffer);
            if from_glib(res) {
                Ok(from_glib_full(buffer))
            } else {
                Err(glib::bool_error!("Failed to pull buffer or EOS"))
            }
        }
    }

    /// Pulls an [`crate::gst::Event`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] sinkpad.
    /// Timeouts after 60 seconds similar to gst_harness_pull.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Event`] or [`None`] if timed out.
    pub fn pull_event(&mut self) -> Result<gst::Event, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_pull_event(self.0.as_ptr()))
                .ok_or_else(|| glib::bool_error!("Failed to pull event"))
        }
    }

    /// Pulls an [`crate::gst::Event`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] srcpad.
    /// Timeouts after 60 seconds similar to gst_harness_pull.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Event`] or [`None`] if timed out.
    pub fn pull_upstream_event(&mut self) -> Result<gst::Event, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_pull_upstream_event(self.0.as_ptr()))
                .ok_or_else(|| glib::bool_error!("Failed to pull event"))
        }
    }

    /// Pushes a [`crate::gst::Buffer`] on the [`crate::Harness`] srcpad. The standard way of
    /// interacting with an harnessed element.
    ///
    /// MT safe.
    /// ## `buffer`
    /// a [`crate::gst::Buffer`] to push
    ///
    /// # Returns
    ///
    /// a [`crate::gst::FlowReturn`] with the result from the push
    pub fn push(&mut self, buffer: gst::Buffer) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            gst::FlowSuccess::try_from_glib(ffi::gst_harness_push(
                self.0.as_ptr(),
                buffer.into_ptr(),
            ))
        }
    }

    /// Basically a gst_harness_push and a gst_harness_pull in one line. Reflects
    /// the fact that you often want to do exactly this in your test: Push one buffer
    /// in, and inspect the outcome.
    ///
    /// MT safe.
    /// ## `buffer`
    /// a [`crate::gst::Buffer`] to push
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Buffer`] or [`None`] if timed out.
    pub fn push_and_pull(&mut self, buffer: gst::Buffer) -> Result<gst::Buffer, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_push_and_pull(
                self.0.as_ptr(),
                buffer.into_ptr(),
            ))
            .ok_or_else(|| glib::bool_error!("Failed to push and pull buffer"))
        }
    }

    /// Pushes an [`crate::gst::Event`] on the [`crate::Harness`] srcpad.
    ///
    /// MT safe.
    /// ## `event`
    /// a [`crate::gst::Event`] to push
    ///
    /// # Returns
    ///
    /// a `gboolean` with the result from the push
    pub fn push_event(&mut self, event: gst::Event) -> bool {
        unsafe {
            from_glib(ffi::gst_harness_push_event(
                self.0.as_ptr(),
                event.into_ptr(),
            ))
        }
    }

    /// Transfer data from the src-[`crate::Harness`] to the main-[`crate::Harness`]. It consists
    /// of 4 steps:
    /// 1: Make sure the src is started. (see: gst_harness_play)
    /// 2: Crank the clock (see: gst_harness_crank_single_clock_wait)
    /// 3: Pull a [`crate::gst::Buffer`] from the src-[`crate::Harness`] (see: gst_harness_pull)
    /// 4: Push the same [`crate::gst::Buffer`] into the main-[`crate::Harness`] (see: gst_harness_push)
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::FlowReturn`] with the result of the push
    pub fn push_from_src(&mut self) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe { gst::FlowSuccess::try_from_glib(ffi::gst_harness_push_from_src(self.0.as_ptr())) }
    }

    /// Transfer one [`crate::gst::Buffer`] from the main-[`crate::Harness`] to the sink-[`crate::Harness`].
    /// See gst_harness_push_from_src for details.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::FlowReturn`] with the result of the push
    pub fn push_to_sink(&mut self) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe { gst::FlowSuccess::try_from_glib(ffi::gst_harness_push_to_sink(self.0.as_ptr())) }
    }

    /// Pushes an [`crate::gst::Event`] on the [`crate::Harness`] sinkpad.
    ///
    /// MT safe.
    /// ## `event`
    /// a [`crate::gst::Event`] to push
    ///
    /// # Returns
    ///
    /// a `gboolean` with the result from the push
    pub fn push_upstream_event(&mut self, event: gst::Event) -> bool {
        unsafe {
            from_glib(ffi::gst_harness_push_upstream_event(
                self.0.as_ptr(),
                event.into_ptr(),
            ))
        }
    }

    /// Get the min latency reported by any harnessed [`crate::gst::Element`].
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::ClockTime`] with min latency
    pub fn query_latency(&self) -> gst::ClockTime {
        unsafe { from_glib(ffi::gst_harness_query_latency(self.0.as_ptr())) }
    }

    //pub fn set(&mut self, element_name: &str, first_property_name: &str, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) {
    //    unsafe { TODO: call ffi::gst_harness_set() }
    //}

    /// Setting this will make the harness block in the chain-function, and
    /// then release when [`Self::pull()`] or [`Self::try_pull()`] is called.
    /// Can be useful when wanting to control a src-element that is not implementing
    /// [`crate::gst::Clock::id_wait()`] so it can't be controlled by the [`crate::TestClock`], since
    /// it otherwise would produce buffers as fast as possible.
    ///
    /// MT safe.
    pub fn set_blocking_push_mode(&mut self) {
        unsafe {
            ffi::gst_harness_set_blocking_push_mode(self.0.as_ptr());
        }
    }

    /// Sets the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) srcpad and sinkpad caps.
    ///
    /// MT safe.
    /// ## `in_`
    /// a [`crate::gst::Caps`] to set on the harness srcpad
    /// ## `out`
    /// a [`crate::gst::Caps`] to set on the harness sinkpad
    pub fn set_caps(&mut self, in_: gst::Caps, out: gst::Caps) {
        unsafe {
            ffi::gst_harness_set_caps(self.0.as_ptr(), in_.into_ptr(), out.into_ptr());
        }
    }

    /// Sets the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) srcpad and sinkpad caps using strings.
    ///
    /// MT safe.
    /// ## `in_`
    /// a `gchar` describing a [`crate::gst::Caps`] to set on the harness srcpad
    /// ## `out`
    /// a `gchar` describing a [`crate::gst::Caps`] to set on the harness sinkpad
    pub fn set_caps_str(&mut self, in_: &str, out: &str) {
        unsafe {
            ffi::gst_harness_set_caps_str(
                self.0.as_ptr(),
                in_.to_glib_none().0,
                out.to_glib_none().0,
            );
        }
    }

    /// When set to [`true`], instead of placing the buffers arriving from the harnessed
    /// [`crate::gst::Element`] inside the sinkpads [`crate::glib::AsyncQueue`], they are instead unreffed.
    ///
    /// MT safe.
    /// ## `drop_buffers`
    /// a `gboolean` specifying to drop outgoing buffers or not
    pub fn set_drop_buffers(&mut self, drop_buffers: bool) {
        unsafe {
            ffi::gst_harness_set_drop_buffers(self.0.as_ptr(), drop_buffers.into_glib());
        }
    }

    /// As a convenience, a src-harness will forward [`crate::gst::EventType::StreamStart`],
    /// [`crate::gst::EventType::Caps`] and [`crate::gst::EventType::Segment`] to the main-harness if forwarding
    /// is enabled, and forward any sticky-events from the main-harness to
    /// the sink-harness. It will also forward the [`crate::gst::QueryType::Allocation`].
    ///
    /// If forwarding is disabled, the user will have to either manually push
    /// these events from the src-harness using [`Self::src_push_event()`], or
    /// create and push them manually. While this will allow full control and
    /// inspection of these events, for the most cases having forwarding enabled
    /// will be sufficient when writing a test where the src-harness' main function
    /// is providing data for the main-harness.
    ///
    /// Forwarding is enabled by default.
    ///
    /// MT safe.
    /// ## `forwarding`
    /// a `gboolean` to enable/disable forwarding
    pub fn set_forwarding(&mut self, forwarding: bool) {
        unsafe {
            ffi::gst_harness_set_forwarding(self.0.as_ptr(), forwarding.into_glib());
        }
    }

    //pub fn set_propose_allocator<P: IsA<gst::Allocator>>(&mut self, allocator: Option<&P>, params: Option<&gst::AllocationParams>) {
    //    unsafe { TODO: call ffi::gst_harness_set_propose_allocator() }
    //}

    /// Sets the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) sinkpad caps.
    ///
    /// MT safe.
    /// ## `caps`
    /// a [`crate::gst::Caps`] to set on the harness sinkpad
    pub fn set_sink_caps(&mut self, caps: gst::Caps) {
        unsafe {
            ffi::gst_harness_set_sink_caps(self.0.as_ptr(), caps.into_ptr());
        }
    }

    /// Sets the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) sinkpad caps using a string.
    ///
    /// MT safe.
    /// ## `str`
    /// a `gchar` describing a [`crate::gst::Caps`] to set on the harness sinkpad
    pub fn set_sink_caps_str(&mut self, str: &str) {
        unsafe {
            ffi::gst_harness_set_sink_caps_str(self.0.as_ptr(), str.to_glib_none().0);
        }
    }

    /// Sets the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) srcpad caps. This must be done before any buffers
    /// can legally be pushed from the harness to the element.
    ///
    /// MT safe.
    /// ## `caps`
    /// a [`crate::gst::Caps`] to set on the harness srcpad
    pub fn set_src_caps(&mut self, caps: gst::Caps) {
        unsafe {
            ffi::gst_harness_set_src_caps(self.0.as_ptr(), caps.into_ptr());
        }
    }

    /// Sets the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) srcpad caps using a string. This must be done before
    /// any buffers can legally be pushed from the harness to the element.
    ///
    /// MT safe.
    /// ## `str`
    /// a `gchar` describing a [`crate::gst::Caps`] to set on the harness srcpad
    pub fn set_src_caps_str(&mut self, str: &str) {
        unsafe {
            ffi::gst_harness_set_src_caps_str(self.0.as_ptr(), str.to_glib_none().0);
        }
    }

    /// Advance the [`crate::TestClock`] to a specific time.
    ///
    /// MT safe.
    /// ## `time`
    /// a [`crate::gst::ClockTime`] to advance the clock to
    ///
    /// # Returns
    ///
    /// a `gboolean` [`true`] if the time could be set. [`false`] if not.
    pub fn set_time(&mut self, time: gst::ClockTime) -> Result<(), glib::BoolError> {
        unsafe {
            glib::result_from_gboolean!(
                ffi::gst_harness_set_time(self.0.as_ptr(), time.into_glib()),
                "Failed to set time",
            )
        }
    }

    /// Sets the min latency reported by [`crate::Harness`] when receiving a latency-query
    /// ## `latency`
    /// a [`crate::gst::ClockTime`] specifying the latency
    pub fn set_upstream_latency(&mut self, latency: gst::ClockTime) {
        unsafe {
            ffi::gst_harness_set_upstream_latency(self.0.as_ptr(), latency.into_glib());
        }
    }

    /// Convenience that calls gst_harness_push_to_sink `pushes` number of times.
    /// Will abort the pushing if any one push fails.
    ///
    /// MT safe.
    /// ## `pushes`
    /// a `gint` with the number of calls to gst_harness_push_to_sink
    ///
    /// # Returns
    ///
    /// a [`crate::gst::FlowReturn`] with the result of the push
    pub fn sink_push_many(&mut self, pushes: u32) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            gst::FlowSuccess::try_from_glib(ffi::gst_harness_sink_push_many(
                self.0.as_ptr(),
                pushes as i32,
            ))
        }
    }

    /// Transfer data from the src-[`crate::Harness`] to the main-[`crate::Harness`]. Similar to
    /// gst_harness_push_from_src, this variant allows you to specify how many cranks
    /// and how many pushes to perform. This can be useful for both moving a lot
    /// of data at the same time, as well as cases when one crank does not equal one
    /// buffer to push and v.v.
    ///
    /// MT safe.
    /// ## `cranks`
    /// a `gint` with the number of calls to gst_harness_crank_single_clock_wait
    /// ## `pushes`
    /// a `gint` with the number of calls to gst_harness_push
    ///
    /// # Returns
    ///
    /// a [`crate::gst::FlowReturn`] with the result of the push
    pub fn src_crank_and_push_many(
        &mut self,
        cranks: u32,
        pushes: u32,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            gst::FlowSuccess::try_from_glib(ffi::gst_harness_src_crank_and_push_many(
                self.0.as_ptr(),
                cranks as i32,
                pushes as i32,
            ))
        }
    }

    /// Similar to what gst_harness_src_push does with `GstBuffers`, this transfers
    /// a [`crate::gst::Event`] from the src-[`crate::Harness`] to the main-[`crate::Harness`]. Note that
    /// some `GstEvents` are being transferred automagically. Look at sink_forward_pad
    /// for details.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `gboolean` with the result of the push
    pub fn src_push_event(&mut self) -> bool {
        unsafe { from_glib(ffi::gst_harness_src_push_event(self.0.as_ptr())) }
    }

    //pub fn stress_custom_start<'a, P: Into<Option<&'a /*Ignored*/glib::Func>>, Q: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, init: P, callback: /*Unknown conversion*//*Unimplemented*/Func, data: Q, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_custom_start() }
    //}

    //pub fn stress_property_start_full(&mut self, name: &str, value: /*Ignored*/&glib::Value, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_property_start_full() }
    //}

    //pub fn stress_push_buffer_start_full(&mut self, caps: &mut gst::Caps, segment: /*Ignored*/&gst::Segment, buf: &mut gst::Buffer, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_push_buffer_start_full() }
    //}

    //pub fn stress_push_buffer_with_cb_start_full<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, caps: &mut gst::Caps, segment: /*Ignored*/&gst::Segment, func: /*Unknown conversion*//*Unimplemented*/HarnessPrepareBufferFunc, data: P, notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_push_buffer_with_cb_start_full() }
    //}

    //pub fn stress_push_event_start_full(&mut self, event: &mut gst::Event, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_push_event_start_full() }
    //}

    //pub fn stress_push_event_with_cb_start_full<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, func: /*Unknown conversion*//*Unimplemented*/HarnessPrepareEventFunc, data: P, notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_push_event_with_cb_start_full() }
    //}

    //pub fn stress_push_upstream_event_start_full(&mut self, event: &mut gst::Event, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_push_upstream_event_start_full() }
    //}

    //pub fn stress_push_upstream_event_with_cb_start_full<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, func: /*Unknown conversion*//*Unimplemented*/HarnessPrepareEventFunc, data: P, notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_push_upstream_event_with_cb_start_full() }
    //}

    //pub fn stress_requestpad_start_full(&mut self, templ: /*Ignored*/&gst::PadTemplate, name: &str, caps: &mut gst::Caps, release: bool, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_requestpad_start_full() }
    //}

    //pub fn stress_statechange_start_full(&mut self, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
    //    unsafe { TODO: call ffi::gst_harness_stress_statechange_start_full() }
    //}

    /// Pulls all pending data from the harness and returns it as a single buffer.
    ///
    /// # Returns
    ///
    /// the data as a buffer. Unref with `gst_buffer_unref()`
    ///  when no longer needed.
    #[cfg(any(feature = "v1_14", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_14")))]
    pub fn take_all_data_as_buffer(&mut self) -> Result<gst::Buffer, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_take_all_data_as_buffer(self.0.as_ptr()))
                .ok_or_else(|| glib::bool_error!("Failed to take all data as buffer"))
        }
    }

    /// Pulls all pending data from the harness and returns it as a single [`crate::glib::Bytes`].
    ///
    /// # Returns
    ///
    /// a pointer to the data, newly allocated. Free
    ///  with `g_free()` when no longer needed.
    #[cfg(any(feature = "v1_14", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_14")))]
    pub fn take_all_data_as_bytes(&mut self) -> Result<glib::Bytes, glib::BoolError> {
        unsafe {
            Option::<_>::from_glib_full(ffi::gst_harness_take_all_data_as_bytes(self.0.as_ptr()))
                .ok_or_else(|| glib::bool_error!("Failed to take all data as bytes"))
        }
    }

    /// Pulls a [`crate::gst::Buffer`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] sinkpad. Unlike
    /// gst_harness_pull this will not wait for any buffers if not any are present,
    /// and return [`None`] straight away.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Buffer`] or [`None`] if no buffers are present in the [`crate::glib::AsyncQueue`]
    pub fn try_pull(&mut self) -> Option<gst::Buffer> {
        unsafe { from_glib_full(ffi::gst_harness_try_pull(self.0.as_ptr())) }
    }

    /// Pulls an [`crate::gst::Event`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] sinkpad.
    /// See gst_harness_try_pull for details.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Event`] or [`None`] if no buffers are present in the [`crate::glib::AsyncQueue`]
    pub fn try_pull_event(&mut self) -> Option<gst::Event> {
        unsafe { from_glib_full(ffi::gst_harness_try_pull_event(self.0.as_ptr())) }
    }

    /// Pulls an [`crate::gst::Event`] from the [`crate::glib::AsyncQueue`] on the [`crate::Harness`] srcpad.
    /// See gst_harness_try_pull for details.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::gst::Event`] or [`None`] if no buffers are present in the [`crate::glib::AsyncQueue`]
    pub fn try_pull_upstream_event(&mut self) -> Option<gst::Event> {
        unsafe { from_glib_full(ffi::gst_harness_try_pull_upstream_event(self.0.as_ptr())) }
    }

    /// The number of `GstEvents` currently in the [`crate::Harness`] srcpad [`crate::glib::AsyncQueue`]
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `guint` number of events in the queue
    pub fn upstream_events_in_queue(&self) -> u32 {
        unsafe { ffi::gst_harness_upstream_events_in_queue(self.0.as_ptr()) }
    }

    /// The total number of `GstEvents` that has arrived on the [`crate::Harness`] srcpad
    /// This number includes events handled by the harness as well as events
    /// that have already been pulled out.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a `guint` number of events received
    pub fn upstream_events_received(&self) -> u32 {
        unsafe { ffi::gst_harness_upstream_events_received(self.0.as_ptr()) }
    }

    /// Sets the system [`crate::gst::Clock`] on the [`crate::Harness`] (XXX: @-reference does not belong to Harness!) [`crate::gst::Element`]
    ///
    /// MT safe.
    pub fn use_systemclock(&mut self) {
        unsafe {
            ffi::gst_harness_use_systemclock(self.0.as_ptr());
        }
    }

    /// Sets the [`crate::TestClock`] on the [`crate::Harness`] [`crate::gst::Element`]
    ///
    /// MT safe.
    pub fn use_testclock(&mut self) {
        unsafe {
            ffi::gst_harness_use_testclock(self.0.as_ptr());
        }
    }

    /// Waits for `timeout` seconds until `waits` number of [`crate::gst::ClockID`] waits is
    /// registered with the [`crate::TestClock`]. Useful for writing deterministic tests,
    /// where you want to make sure that an expected number of waits have been
    /// reached.
    ///
    /// MT safe.
    /// ## `waits`
    /// a `guint` describing the numbers of [`crate::gst::ClockID`] registered with
    /// the [`crate::TestClock`]
    /// ## `timeout`
    /// a `guint` describing how many seconds to wait for `waits` to be true
    ///
    /// # Returns
    ///
    /// a `gboolean` [`true`] if the waits have been registered, [`false`] if not.
    /// (Could be that it timed out waiting or that more waits than waits was found)
    pub fn wait_for_clock_id_waits(
        &mut self,
        waits: u32,
        timeout: u32,
    ) -> Result<(), glib::BoolError> {
        unsafe {
            glib::result_from_gboolean!(
                ffi::gst_harness_wait_for_clock_id_waits(self.0.as_ptr(), waits, timeout),
                "Failed to wait for clock id waits",
            )
        }
    }

    unsafe fn from_glib_full(ptr: *mut ffi::GstHarness) -> Harness {
        assert!(!ptr.is_null());

        Harness(ptr::NonNull::new_unchecked(ptr))
    }

    /// Creates a new harness. Works like [`Self::new_with_padnames()`], except it
    /// assumes the [`crate::gst::Element`] sinkpad is named "sink" and srcpad is named "src"
    ///
    /// MT safe.
    /// ## `element_name`
    /// a `gchar` describing the [`crate::gst::Element`] name
    ///
    /// # Returns
    ///
    /// a [`crate::Harness`], or [`None`] if the harness could
    /// not be created
    pub fn new(element_name: &str) -> Harness {
        assert_initialized_main_thread!();
        unsafe { Self::from_glib_full(ffi::gst_harness_new(element_name.to_glib_none().0)) }
    }

    /// Creates a new empty harness. Use [`Self::add_element_full()`] to add
    /// an [`crate::gst::Element`] to it.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// a [`crate::Harness`], or [`None`] if the harness could
    /// not be created
    pub fn new_empty() -> Harness {
        assert_initialized_main_thread!();
        unsafe { Self::from_glib_full(ffi::gst_harness_new_empty()) }
    }

    /// Creates a new harness.
    ///
    /// MT safe.
    /// ## `element`
    /// a [`crate::gst::Element`] to attach the harness to (transfer none)
    /// ## `hsrc`
    /// a [`crate::gst::StaticPadTemplate`] describing the harness srcpad.
    /// [`None`] will not create a harness srcpad.
    /// ## `element_sinkpad_name`
    /// a `gchar` with the name of the element
    /// sinkpad that is then linked to the harness srcpad. Can be a static or request
    /// or a sometimes pad that has been added. [`None`] will not get/request a sinkpad
    /// from the element. (Like if the element is a src.)
    /// ## `hsink`
    /// a [`crate::gst::StaticPadTemplate`] describing the harness sinkpad.
    /// [`None`] will not create a harness sinkpad.
    /// ## `element_srcpad_name`
    /// a `gchar` with the name of the element
    /// srcpad that is then linked to the harness sinkpad, similar to the
    /// `element_sinkpad_name`.
    ///
    /// # Returns
    ///
    /// a [`crate::Harness`], or [`None`] if the harness could
    /// not be created
    pub fn new_full<P: IsA<gst::Element>>(
        element: &P,
        hsrc: Option<&gst::StaticPadTemplate>,
        element_sinkpad_name: Option<&str>,
        hsink: Option<&gst::StaticPadTemplate>,
        element_srcpad_name: Option<&str>,
    ) -> Harness {
        assert_initialized_main_thread!();
        let element_sinkpad_name = element_sinkpad_name.to_glib_none();
        let element_srcpad_name = element_srcpad_name.to_glib_none();
        unsafe {
            Self::from_glib_full(ffi::gst_harness_new_full(
                element.as_ref().to_glib_none().0,
                hsrc.to_glib_none().0 as *mut _,
                element_sinkpad_name.0,
                hsink.to_glib_none().0 as *mut _,
                element_srcpad_name.0,
            ))
        }
    }

    /// Creates a new harness, parsing the `launchline` and putting that in a [`crate::gst::Bin`],
    /// and then attches the harness to the bin.
    ///
    /// MT safe.
    /// ## `launchline`
    /// a `gchar` describing a gst-launch type line
    ///
    /// # Returns
    ///
    /// a [`crate::Harness`], or [`None`] if the harness could
    /// not be created
    pub fn new_parse(launchline: &str) -> Harness {
        assert_initialized_main_thread!();
        unsafe { Self::from_glib_full(ffi::gst_harness_new_parse(launchline.to_glib_none().0)) }
    }

    pub fn with_element<P: IsA<gst::Element>>(
        element: &P,
        element_sinkpad_name: Option<&str>,
        element_srcpad_name: Option<&str>,
    ) -> Harness {
        assert_initialized_main_thread!();
        let element_sinkpad_name = element_sinkpad_name.to_glib_none();
        let element_srcpad_name = element_srcpad_name.to_glib_none();
        unsafe {
            Self::from_glib_full(ffi::gst_harness_new_with_element(
                element.as_ref().to_glib_none().0,
                element_sinkpad_name.0,
                element_srcpad_name.0,
            ))
        }
    }

    pub fn with_padnames(
        element_name: &str,
        element_sinkpad_name: Option<&str>,
        element_srcpad_name: Option<&str>,
    ) -> Harness {
        assert_initialized_main_thread!();
        let element_sinkpad_name = element_sinkpad_name.to_glib_none();
        let element_srcpad_name = element_srcpad_name.to_glib_none();
        unsafe {
            Self::from_glib_full(ffi::gst_harness_new_with_padnames(
                element_name.to_glib_none().0,
                element_sinkpad_name.0,
                element_srcpad_name.0,
            ))
        }
    }

    pub fn with_templates(
        element_name: &str,
        hsrc: Option<&gst::StaticPadTemplate>,
        hsink: Option<&gst::StaticPadTemplate>,
    ) -> Harness {
        assert_initialized_main_thread!();
        unsafe {
            Self::from_glib_full(ffi::gst_harness_new_with_templates(
                element_name.to_glib_none().0,
                hsrc.to_glib_none().0 as *mut _,
                hsink.to_glib_none().0 as *mut _,
            ))
        }
    }

    //pub fn stress_thread_stop(t: /*Ignored*/&mut HarnessThread) -> u32 {
    //    unsafe { TODO: call ffi::gst_harness_stress_thread_stop() }
    //}

    #[doc(alias = "get_element")]
    pub fn element(&self) -> Option<gst::Element> {
        unsafe {
            // Work around https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/31
            let ptr = (*self.0.as_ptr()).element;

            if ptr.is_null() {
                return None;
            }

            // Clear floating flag if it is set
            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
            }

            from_glib_none(ptr)
        }
    }

    #[doc(alias = "get_sinkpad")]
    pub fn sinkpad(&self) -> Option<gst::Pad> {
        unsafe {
            // Work around https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/31
            let ptr = (*self.0.as_ptr()).sinkpad;

            if ptr.is_null() {
                return None;
            }

            // Clear floating flag if it is set
            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
            }

            from_glib_none(ptr)
        }
    }

    #[doc(alias = "get_srcpad")]
    pub fn srcpad(&self) -> Option<gst::Pad> {
        unsafe {
            // Work around https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/31
            let ptr = (*self.0.as_ptr()).srcpad;

            if ptr.is_null() {
                return None;
            }

            // Clear floating flag if it is set
            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
            }

            from_glib_none(ptr)
        }
    }

    #[doc(alias = "get_sink_harness")]
    pub fn sink_harness(&self) -> Option<Ref> {
        unsafe {
            let sink_harness = (*self.0.as_ptr()).sink_harness;
            if sink_harness.is_null() {
                None
            } else {
                Some(Ref(
                    mem::ManuallyDrop::new(Harness(ptr::NonNull::new_unchecked(sink_harness))),
                    PhantomData,
                ))
            }
        }
    }

    #[doc(alias = "get_src_harness")]
    pub fn src_harness(&self) -> Option<Ref> {
        unsafe {
            let src_harness = (*self.0.as_ptr()).src_harness;
            if src_harness.is_null() {
                None
            } else {
                Some(Ref(
                    mem::ManuallyDrop::new(Harness(ptr::NonNull::new_unchecked(src_harness))),
                    PhantomData,
                ))
            }
        }
    }

    #[doc(alias = "get_mut_sink_harness")]
    pub fn sink_harness_mut(&mut self) -> Option<RefMut> {
        unsafe {
            let sink_harness = (*self.0.as_ptr()).sink_harness;
            if sink_harness.is_null() {
                None
            } else {
                Some(RefMut(
                    mem::ManuallyDrop::new(Harness(ptr::NonNull::new_unchecked(sink_harness))),
                    PhantomData,
                ))
            }
        }
    }

    #[doc(alias = "get_mut_src_harness")]
    pub fn src_harness_mut(&mut self) -> Option<RefMut> {
        unsafe {
            let src_harness = (*self.0.as_ptr()).src_harness;
            if src_harness.is_null() {
                None
            } else {
                Some(RefMut(
                    mem::ManuallyDrop::new(Harness(ptr::NonNull::new_unchecked(src_harness))),
                    PhantomData,
                ))
            }
        }
    }
}

#[derive(Debug)]
pub struct Ref<'a>(mem::ManuallyDrop<Harness>, PhantomData<&'a Harness>);

impl<'a> ops::Deref for Ref<'a> {
    type Target = Harness;

    fn deref(&self) -> &Harness {
        &*self.0
    }
}

#[derive(Debug)]
pub struct RefMut<'a>(mem::ManuallyDrop<Harness>, PhantomData<&'a mut Harness>);

impl<'a> ops::Deref for RefMut<'a> {
    type Target = Harness;

    fn deref(&self) -> &Harness {
        &*self.0
    }
}

impl<'a> ops::DerefMut for RefMut<'a> {
    fn deref_mut(&mut self) -> &mut Harness {
        &mut *self.0
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_identity_push_pull() {
        gst::init().unwrap();

        let mut h = Harness::new("identity");
        h.set_src_caps_str("application/test");
        let buf = gst::Buffer::new();
        let buf = h.push_and_pull(buf);
        assert!(buf.is_ok());
    }
}