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

use crate::Cancellable;
use crate::File;
use crate::FileCreateFlags;
use crate::FileEnumerator;
use crate::FileQueryInfoFlags;
use glib::object::IsA;
use glib::translate::*;
use std::pin::Pin;
use std::ptr;

pub trait FileExtManual: Sized {
    /// Starts an asynchronous replacement of `self` with the given
    /// `contents` of `length` bytes. `etag` will replace the document's
    /// current entity tag.
    ///
    /// When this operation has completed, `callback` will be called with
    /// `user_user` data, and the operation can be finalized with
    /// `g_file_replace_contents_finish()`.
    ///
    /// If `cancellable` is not [`None`], then the operation can be cancelled by
    /// triggering the cancellable object from another thread. If the operation
    /// was cancelled, the error [`IOErrorEnum::Cancelled`][crate::IOErrorEnum::Cancelled] will be returned.
    ///
    /// If `make_backup` is [`true`], this function will attempt to
    /// make a backup of `self`.
    ///
    /// Note that no copy of `contents` will be made, so it must stay valid
    /// until `callback` is called. See `g_file_replace_contents_bytes_async()`
    /// for a [`glib::Bytes`][crate::glib::Bytes] version that will automatically hold a reference to the
    /// contents (without copying) for the duration of the call.
    /// ## `contents`
    /// string of contents to replace the file with
    /// ## `etag`
    /// a new [entity tag][gfile-etag] for the `self`, or [`None`]
    /// ## `make_backup`
    /// [`true`] if a backup should be created
    /// ## `flags`
    /// a set of [`FileCreateFlags`][crate::FileCreateFlags]
    /// ## `cancellable`
    /// optional [`Cancellable`][crate::Cancellable] object, [`None`] to ignore
    /// ## `callback`
    /// a `GAsyncReadyCallback` to call when the request is satisfied
    #[doc(alias = "g_file_replace_contents_async")]
    fn replace_contents_async<
        B: AsRef<[u8]> + Send + 'static,
        R: FnOnce(Result<(B, glib::GString), (B, glib::Error)>) + Send + 'static,
        C: IsA<Cancellable>,
    >(
        &self,
        contents: B,
        etag: Option<&str>,
        make_backup: bool,
        flags: FileCreateFlags,
        cancellable: Option<&C>,
        callback: R,
    );

    fn replace_contents_async_future<B: AsRef<[u8]> + Send + 'static>(
        &self,
        contents: B,
        etag: Option<&str>,
        make_backup: bool,
        flags: FileCreateFlags,
    ) -> Pin<
        Box<
            dyn std::future::Future<Output = Result<(B, glib::GString), (B, glib::Error)>>
                + 'static,
        >,
    >;

    #[doc(alias = "g_file_enumerate_children_async")]
    fn enumerate_children_async<
        P: IsA<Cancellable>,
        Q: FnOnce(Result<FileEnumerator, glib::Error>) + Send + 'static,
    >(
        &self,
        attributes: &'static str,
        flags: FileQueryInfoFlags,
        io_priority: glib::Priority,
        cancellable: Option<&P>,
        callback: Q,
    );

    fn enumerate_children_async_future(
        &self,
        attributes: &'static str,
        flags: FileQueryInfoFlags,
        io_priority: glib::Priority,
    ) -> Pin<Box<dyn std::future::Future<Output = Result<FileEnumerator, glib::Error>> + 'static>>;
}

impl<O: IsA<File>> FileExtManual for O {
    fn replace_contents_async<
        B: AsRef<[u8]> + Send + 'static,
        R: FnOnce(Result<(B, glib::GString), (B, glib::Error)>) + Send + 'static,
        C: IsA<Cancellable>,
    >(
        &self,
        contents: B,
        etag: Option<&str>,
        make_backup: bool,
        flags: FileCreateFlags,
        cancellable: Option<&C>,
        callback: R,
    ) {
        let etag = etag.to_glib_none();
        let cancellable = cancellable.map(|c| c.as_ref());
        let gcancellable = cancellable.to_glib_none();
        let user_data: Box<Option<(R, B)>> = Box::new(Some((callback, contents)));
        // Need to do this after boxing as the contents pointer might change by moving into the box
        let (count, contents_ptr) = {
            let contents = &(*user_data).as_ref().unwrap().1;
            let slice = contents.as_ref();
            (slice.len(), slice.as_ptr())
        };
        unsafe extern "C" fn replace_contents_async_trampoline<
            B: AsRef<[u8]> + Send + 'static,
            R: FnOnce(Result<(B, glib::GString), (B, glib::Error)>) + Send + 'static,
        >(
            _source_object: *mut glib::gobject_ffi::GObject,
            res: *mut ffi::GAsyncResult,
            user_data: glib::ffi::gpointer,
        ) {
            let mut user_data: Box<Option<(R, B)>> = Box::from_raw(user_data as *mut _);
            let (callback, contents) = user_data.take().unwrap();

            let mut error = ptr::null_mut();
            let mut new_etag = ptr::null_mut();
            let _ = ffi::g_file_replace_contents_finish(
                _source_object as *mut _,
                res,
                &mut new_etag,
                &mut error,
            );
            let result = if error.is_null() {
                Ok((contents, from_glib_full(new_etag)))
            } else {
                Err((contents, from_glib_full(error)))
            };
            callback(result);
        }
        let callback = replace_contents_async_trampoline::<B, R>;
        unsafe {
            ffi::g_file_replace_contents_async(
                self.as_ref().to_glib_none().0,
                mut_override(contents_ptr),
                count,
                etag.0,
                make_backup.into_glib(),
                flags.into_glib(),
                gcancellable.0,
                Some(callback),
                Box::into_raw(user_data) as *mut _,
            );
        }
    }

    fn replace_contents_async_future<B: AsRef<[u8]> + Send + 'static>(
        &self,
        contents: B,
        etag: Option<&str>,
        make_backup: bool,
        flags: FileCreateFlags,
    ) -> Pin<
        Box<
            dyn std::future::Future<Output = Result<(B, glib::GString), (B, glib::Error)>>
                + 'static,
        >,
    > {
        let etag = etag.map(glib::GString::from);
        Box::pin(crate::GioFuture::new(
            self,
            move |obj, cancellable, send| {
                obj.replace_contents_async(
                    contents,
                    etag.as_ref().map(|s| s.as_str()),
                    make_backup,
                    flags,
                    Some(cancellable),
                    move |res| {
                        send.resolve(res);
                    },
                );
            },
        ))
    }

    fn enumerate_children_async<
        P: IsA<Cancellable>,
        Q: FnOnce(Result<FileEnumerator, glib::Error>) + Send + 'static,
    >(
        &self,
        attributes: &'static str,
        flags: FileQueryInfoFlags,
        io_priority: glib::Priority,
        cancellable: Option<&P>,
        callback: Q,
    ) {
        let user_data: Box<Q> = Box::new(callback);
        unsafe extern "C" fn create_async_trampoline<
            Q: FnOnce(Result<FileEnumerator, glib::Error>) + Send + 'static,
        >(
            _source_object: *mut glib::gobject_ffi::GObject,
            res: *mut crate::ffi::GAsyncResult,
            user_data: glib::ffi::gpointer,
        ) {
            let mut error = ptr::null_mut();
            let ret =
                ffi::g_file_enumerate_children_finish(_source_object as *mut _, res, &mut error);
            let result = if error.is_null() {
                Ok(from_glib_full(ret))
            } else {
                Err(from_glib_full(error))
            };
            let callback: Box<Q> = Box::from_raw(user_data as *mut _);
            callback(result);
        }
        let callback = create_async_trampoline::<Q>;
        unsafe {
            ffi::g_file_enumerate_children_async(
                self.as_ref().to_glib_none().0,
                attributes.to_glib_none().0,
                flags.into_glib(),
                io_priority.into_glib(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                Some(callback),
                Box::into_raw(user_data) as *mut _,
            );
        }
    }

    fn enumerate_children_async_future(
        &self,
        attributes: &'static str,
        flags: FileQueryInfoFlags,
        io_priority: glib::Priority,
    ) -> Pin<Box<dyn std::future::Future<Output = Result<FileEnumerator, glib::Error>> + 'static>>
    {
        Box::pin(crate::GioFuture::new(
            self,
            move |obj, cancellable, send| {
                obj.enumerate_children_async(
                    attributes,
                    flags,
                    io_priority,
                    Some(cancellable),
                    move |res| {
                        send.resolve(res);
                    },
                );
            },
        ))
    }
}