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

// rustdoc-stripper-ignore-next
//! Traits intended for subclassing [`ContentProvider`](crate::ContentProvider).

use crate::{prelude::*, subclass::prelude::*, Clipboard, ContentFormats, ContentProvider};
use glib::{translate::*, Value};
use std::{future::Future, pin::Pin};

pub trait ContentProviderImpl: ContentProviderImplExt + ObjectImpl {
    /// Emits the ::content-changed signal.
    fn content_changed(&self) {
        self.parent_content_changed()
    }

    fn attach_clipboard(&self, clipboard: &Clipboard) {
        self.parent_attach_clipboard(clipboard)
    }

    fn detach_clipboard(&self, clipboard: &Clipboard) {
        self.parent_detach_clipboard(clipboard)
    }

    /// Gets the formats that the provider can provide its current contents in.
    ///
    /// # Returns
    ///
    /// The formats of the provider
    fn formats(&self) -> ContentFormats {
        self.parent_formats()
    }

    /// Gets the formats that the provider suggests other applications to store
    /// the data in.
    ///
    /// An example of such an application would be a clipboard manager.
    ///
    /// This can be assumed to be a subset of [`ContentProviderExt::formats()`][crate::prelude::ContentProviderExt::formats()].
    ///
    /// # Returns
    ///
    /// The storable formats of the provider
    fn storable_formats(&self) -> ContentFormats {
        self.parent_storable_formats()
    }

    fn write_mime_type_future(
        &self,
        mime_type: &str,
        stream: &gio::OutputStream,
        io_priority: glib::Priority,
    ) -> Pin<Box<dyn Future<Output = Result<(), glib::Error>> + 'static>> {
        self.parent_write_mime_type_future(mime_type, stream, io_priority)
    }

    /// Gets the contents of @self stored in @value.
    ///
    /// The @value will have been initialized to the `GType` the value should be
    /// provided in. This given `GType` does not need to be listed in the formats
    /// returned by [`ContentProviderExt::formats()`][crate::prelude::ContentProviderExt::formats()]. However, if the
    /// given `GType` is not supported, this operation can fail and
    /// `G_IO_ERROR_NOT_SUPPORTED` will be reported.
    ///
    /// # Returns
    ///
    /// [`true`] if the value was set successfully. Otherwise
    ///   @error will be set to describe the failure.
    ///
    /// ## `value`
    /// the `GValue` to fill
    fn value(&self, type_: glib::Type) -> Result<Value, glib::Error> {
        self.parent_value(type_)
    }
}

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

pub trait ContentProviderImplExt: sealed::Sealed + ObjectSubclass {
    fn parent_content_changed(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            if let Some(f) = (*parent_class).content_changed {
                f(self
                    .obj()
                    .unsafe_cast_ref::<ContentProvider>()
                    .to_glib_none()
                    .0)
            }
        }
    }

    fn parent_attach_clipboard(&self, clipboard: &Clipboard) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            if let Some(f) = (*parent_class).attach_clipboard {
                f(
                    self.obj()
                        .unsafe_cast_ref::<ContentProvider>()
                        .to_glib_none()
                        .0,
                    clipboard.to_glib_none().0,
                )
            }
        }
    }

    fn parent_detach_clipboard(&self, clipboard: &Clipboard) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            if let Some(f) = (*parent_class).detach_clipboard {
                f(
                    self.obj()
                        .unsafe_cast_ref::<ContentProvider>()
                        .to_glib_none()
                        .0,
                    clipboard.to_glib_none().0,
                )
            }
        }
    }

    fn parent_formats(&self) -> ContentFormats {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            let f = (*parent_class)
                .ref_formats
                .expect("no parent \"ref_formats\" implementation");
            let ret = f(self
                .obj()
                .unsafe_cast_ref::<ContentProvider>()
                .to_glib_none()
                .0);

            from_glib_full(ret)
        }
    }

    fn parent_storable_formats(&self) -> ContentFormats {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            let f = (*parent_class)
                .ref_storable_formats
                .expect("no parent \"ref_storable_formats\" implementation");
            let ret = f(self
                .obj()
                .unsafe_cast_ref::<ContentProvider>()
                .to_glib_none()
                .0);

            from_glib_full(ret)
        }
    }

    #[allow(clippy::type_complexity)]
    fn parent_write_mime_type_async<
        Q: IsA<gio::Cancellable>,
        R: FnOnce(Result<(), glib::Error>) + 'static,
    >(
        &self,
        mime_type: &str,
        stream: &gio::OutputStream,
        io_priority: glib::Priority,
        cancellable: Option<&Q>,
        callback: R,
    ) {
        unsafe {
            let main_context = glib::MainContext::ref_thread_default();
            let is_main_context_owner = main_context.is_owner();
            let has_acquired_main_context = (!is_main_context_owner)
                .then(|| main_context.acquire().ok())
                .flatten();
            assert!(
                is_main_context_owner || has_acquired_main_context.is_some(),
                "Async operations only allowed if the thread is owning the MainContext"
            );

            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            let f = (*parent_class)
                .write_mime_type_async
                .expect("no parent \"write_mime_type_async\" implementation");
            let finish = (*parent_class)
                .write_mime_type_finish
                .expect("no parent \"write_mime_type_finish\" implementation");

            let user_data: Box<(glib::thread_guard::ThreadGuard<R>, _)> =
                Box::new((glib::thread_guard::ThreadGuard::new(callback), finish));

            unsafe extern "C" fn parent_write_mime_type_async_trampoline<
                R: FnOnce(Result<(), glib::Error>) + 'static,
            >(
                source_object_ptr: *mut glib::gobject_ffi::GObject,
                res: *mut gio::ffi::GAsyncResult,
                user_data: glib::ffi::gpointer,
            ) {
                let mut error = std::ptr::null_mut();
                let cb: Box<(
                    glib::thread_guard::ThreadGuard<R>,
                    fn(
                        *mut ffi::GdkContentProvider,
                        *mut gio::ffi::GAsyncResult,
                        *mut *mut glib::ffi::GError,
                    ) -> glib::ffi::gboolean,
                )> = Box::from_raw(user_data as *mut _);
                cb.1(source_object_ptr as _, res, &mut error);
                let result = if error.is_null() {
                    Ok(())
                } else {
                    Err(from_glib_full(error))
                };
                let cb = cb.0.into_inner();
                cb(result);
            }

            let cancellable = cancellable.map(|p| p.as_ref());
            let callback = parent_write_mime_type_async_trampoline::<R>;
            f(
                self.obj()
                    .unsafe_cast_ref::<ContentProvider>()
                    .to_glib_none()
                    .0,
                mime_type.to_glib_none().0,
                stream.to_glib_none().0,
                io_priority.into_glib(),
                cancellable.to_glib_none().0,
                Some(callback),
                Box::into_raw(user_data) as *mut _,
            );
        }
    }

    fn parent_write_mime_type_future(
        &self,
        mime_type: &str,
        stream: &gio::OutputStream,
        io_priority: glib::Priority,
    ) -> Pin<Box<dyn Future<Output = Result<(), glib::Error>> + 'static>> {
        let stream = stream.clone();
        let mime_type = String::from(mime_type);
        Box::pin(gio::GioFuture::new(
            &self.ref_counted(),
            move |imp, cancellable, send| {
                imp.parent_write_mime_type_async(
                    &mime_type,
                    &stream,
                    io_priority,
                    Some(cancellable),
                    move |res| {
                        send.resolve(res);
                    },
                );
            },
        ))
    }

    fn parent_value(&self, type_: glib::Type) -> Result<Value, glib::Error> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GdkContentProviderClass;
            let f = (*parent_class)
                .get_value
                .expect("no parent \"get_value\" implementation");
            let mut value = Value::from_type(type_);

            let mut error = std::ptr::null_mut();
            f(
                self.obj()
                    .unsafe_cast_ref::<ContentProvider>()
                    .to_glib_none()
                    .0,
                value.to_glib_none_mut().0,
                &mut error,
            );

            if error.is_null() {
                Ok(value)
            } else {
                Err(from_glib_full(error))
            }
        }
    }
}

impl<T: ContentProviderImpl> ContentProviderImplExt for T {}

unsafe impl<T: ContentProviderImpl> IsSubclassable<T> for ContentProvider {
    fn class_init(class: &mut glib::Class<Self>) {
        Self::parent_class_init::<T>(class);

        let klass = class.as_mut();
        klass.content_changed = Some(content_provider_content_changed::<T>);
        klass.attach_clipboard = Some(content_provider_attach_clipboard::<T>);
        klass.detach_clipboard = Some(content_provider_detach_clipboard::<T>);
        klass.ref_formats = Some(content_provider_formats::<T>);
        klass.ref_storable_formats = Some(content_provider_storable_formats::<T>);
        klass.write_mime_type_async = Some(content_provider_write_mime_type_async::<T>);
        klass.write_mime_type_finish = Some(content_provider_write_mime_type_finish);
        klass.get_value = Some(content_provider_get_value::<T>);
    }
}

unsafe extern "C" fn content_provider_content_changed<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    imp.content_changed()
}

unsafe extern "C" fn content_provider_attach_clipboard<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
    clipboard_ptr: *mut ffi::GdkClipboard,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let clipboard = from_glib_borrow(clipboard_ptr);

    imp.attach_clipboard(&clipboard)
}

unsafe extern "C" fn content_provider_detach_clipboard<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
    clipboard_ptr: *mut ffi::GdkClipboard,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let clipboard = from_glib_borrow(clipboard_ptr);

    imp.detach_clipboard(&clipboard)
}

unsafe extern "C" fn content_provider_formats<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
) -> *mut ffi::GdkContentFormats {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    imp.formats().into_glib_ptr()
}

unsafe extern "C" fn content_provider_storable_formats<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
) -> *mut ffi::GdkContentFormats {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    imp.storable_formats().into_glib_ptr()
}

unsafe extern "C" fn content_provider_write_mime_type_async<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
    mime_type_ptr: *const libc::c_char,
    stream_ptr: *mut gio::ffi::GOutputStream,
    priority: libc::c_int,
    cancellable_ptr: *mut gio::ffi::GCancellable,
    callback: gio::ffi::GAsyncReadyCallback,
    user_data: glib::ffi::gpointer,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let wrap: ContentProvider = from_glib_none(ptr);
    let cancellable: Option<gio::Cancellable> = from_glib_none(cancellable_ptr);
    let mime_type: glib::GString = from_glib_none(mime_type_ptr);
    let stream: gio::OutputStream = from_glib_none(stream_ptr);

    let closure = move |task: gio::LocalTask<bool>, source_object: Option<&glib::Object>| {
        let result: *mut gio::ffi::GAsyncResult =
            task.upcast_ref::<gio::AsyncResult>().to_glib_none().0;
        let source_object: *mut glib::gobject_ffi::GObject = source_object.to_glib_none().0;
        callback.unwrap()(source_object, result, user_data)
    };

    let t = gio::LocalTask::new(
        Some(wrap.upcast_ref::<glib::Object>()),
        cancellable.as_ref(),
        closure,
    );

    glib::MainContext::default().spawn_local(async move {
        let res = imp
            .write_mime_type_future(
                mime_type.as_str(),
                stream.unsafe_cast_ref::<gio::OutputStream>(),
                from_glib(priority),
            )
            .await;
        t.return_result(res.map(|_t| true));
    });
}

unsafe extern "C" fn content_provider_write_mime_type_finish(
    _ptr: *mut ffi::GdkContentProvider,
    res_ptr: *mut gio::ffi::GAsyncResult,
    error_ptr: *mut *mut glib::ffi::GError,
) -> glib::ffi::gboolean {
    let res: gio::AsyncResult = from_glib_none(res_ptr);
    let t = res.downcast::<gio::LocalTask<bool>>().unwrap();
    let ret = t.propagate();
    match ret {
        Ok(v) => {
            debug_assert!(v);
            true.into_glib()
        }
        Err(e) => {
            *error_ptr = e.into_glib_ptr();
            false.into_glib()
        }
    }
}

unsafe extern "C" fn content_provider_get_value<T: ContentProviderImpl>(
    ptr: *mut ffi::GdkContentProvider,
    value_ptr: *mut glib::gobject_ffi::GValue,
    error_ptr: *mut *mut glib::ffi::GError,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let value: Value = from_glib_none(value_ptr);

    let ret = imp.value(value.type_());
    match ret {
        Ok(v) => {
            glib::gobject_ffi::g_value_copy(v.to_glib_none().0, value_ptr);
            true.into_glib()
        }
        Err(e) => {
            *error_ptr = e.into_glib_ptr();
            false.into_glib()
        }
    }
}