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

use std::{boxed::Box as Box_, mem, pin::Pin, ptr};

use glib::{prelude::*, translate::*, GString};

use crate::{Cancellable, DataInputStream};

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

pub trait DataInputStreamExtManual: sealed::Sealed + IsA<DataInputStream> + 'static {
    /// Reads a line from the data input stream. Note that no encoding
    /// checks or conversion is performed; the input is not guaranteed to
    /// be UTF-8, and may in fact have embedded NUL characters.
    ///
    /// 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.
    /// ## `cancellable`
    /// optional [`Cancellable`][crate::Cancellable] object, [`None`] to ignore.
    ///
    /// # Returns
    ///
    ///
    ///  a NUL terminated byte array with the line that was read in
    ///  (without the newlines). Set `length` to a `gsize` to get the length
    ///  of the read line. On an error, it will return [`None`] and `error`
    ///  will be set. If there's no content to read, it will still return
    ///  [`None`], but `error` won't be set.
    ///
    /// ## `length`
    /// a `gsize` to get the length of the data read in.
    #[doc(alias = "g_data_input_stream_read_line")]
    fn read_line<P: IsA<Cancellable>>(
        &self,
        cancellable: Option<&P>,
    ) -> Result<Vec<u8>, glib::Error> {
        unsafe {
            let mut length = mem::MaybeUninit::uninit();
            let mut error = ptr::null_mut();
            let ret = ffi::g_data_input_stream_read_line(
                self.as_ref().to_glib_none().0,
                length.as_mut_ptr(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                &mut error,
            );
            let length = length.assume_init();
            if error.is_null() {
                Ok(FromGlibContainer::from_glib_full_num(ret, length))
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    /// The asynchronous version of [`read_line()`][Self::read_line()]. It is
    /// an error to have two outstanding calls to this function.
    ///
    /// When the operation is finished, `callback` will be called. You
    /// can then call `g_data_input_stream_read_line_finish()` to get
    /// the result of the operation.
    /// ## `io_priority`
    /// the [I/O priority][io-priority] of the request
    /// ## `cancellable`
    /// optional [`Cancellable`][crate::Cancellable] object, [`None`] to ignore.
    /// ## `callback`
    /// callback to call when the request is satisfied.
    #[doc(alias = "g_data_input_stream_read_line_async")]
    fn read_line_async<P: IsA<Cancellable>, Q: FnOnce(Result<Vec<u8>, glib::Error>) + 'static>(
        &self,
        io_priority: glib::Priority,
        cancellable: Option<&P>,
        callback: Q,
    ) {
        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 user_data: Box_<glib::thread_guard::ThreadGuard<Q>> =
            Box_::new(glib::thread_guard::ThreadGuard::new(callback));
        unsafe extern "C" fn read_line_async_trampoline<
            Q: FnOnce(Result<Vec<u8>, glib::Error>) + 'static,
        >(
            _source_object: *mut glib::gobject_ffi::GObject,
            res: *mut ffi::GAsyncResult,
            user_data: glib::ffi::gpointer,
        ) {
            let mut error = ptr::null_mut();
            let mut length = mem::MaybeUninit::uninit();
            let ret = ffi::g_data_input_stream_read_line_finish(
                _source_object as *mut _,
                res,
                length.as_mut_ptr(),
                &mut error,
            );
            let length = length.assume_init();
            let result = if error.is_null() {
                Ok(FromGlibContainer::from_glib_full_num(ret, length))
            } else {
                Err(from_glib_full(error))
            };
            let callback: Box_<glib::thread_guard::ThreadGuard<Q>> =
                Box_::from_raw(user_data as *mut _);
            let callback = callback.into_inner();
            callback(result);
        }
        let callback = read_line_async_trampoline::<Q>;
        unsafe {
            ffi::g_data_input_stream_read_line_async(
                self.as_ref().to_glib_none().0,
                io_priority.into_glib(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                Some(callback),
                Box_::into_raw(user_data) as *mut _,
            );
        }
    }

    fn read_line_future(
        &self,
        io_priority: glib::Priority,
    ) -> Pin<Box_<dyn std::future::Future<Output = Result<Vec<u8>, glib::Error>> + 'static>> {
        Box_::pin(crate::GioFuture::new(
            self,
            move |obj, cancellable, send| {
                obj.read_line_async(io_priority, Some(cancellable), move |res| {
                    send.resolve(res);
                });
            },
        ))
    }

    /// Reads a UTF-8 encoded line from the data input stream.
    ///
    /// 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.
    /// ## `cancellable`
    /// optional [`Cancellable`][crate::Cancellable] object, [`None`] to ignore.
    ///
    /// # Returns
    ///
    /// a NUL terminated UTF-8 string
    ///  with the line that was read in (without the newlines). Set
    ///  `length` to a `gsize` to get the length of the read line. On an
    ///  error, it will return [`None`] and `error` will be set. For UTF-8
    ///  conversion errors, the set error domain is `G_CONVERT_ERROR`. If
    ///  there's no content to read, it will still return [`None`], but `error`
    ///  won't be set.
    ///
    /// ## `length`
    /// a `gsize` to get the length of the data read in.
    #[doc(alias = "g_data_input_stream_read_line_utf8")]
    fn read_line_utf8<P: IsA<Cancellable>>(
        &self,
        cancellable: Option<&P>,
    ) -> Result<Option<GString>, glib::Error> {
        unsafe {
            let mut error = ptr::null_mut();
            let ret = ffi::g_data_input_stream_read_line_utf8(
                self.as_ref().to_glib_none().0,
                ptr::null_mut(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                &mut error,
            );
            if error.is_null() {
                Ok(from_glib_full(ret))
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    fn read_line_utf8_async<
        P: IsA<Cancellable>,
        Q: FnOnce(Result<Option<GString>, glib::Error>) + 'static,
    >(
        &self,
        io_priority: glib::Priority,
        cancellable: Option<&P>,
        callback: Q,
    ) {
        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 user_data: Box_<glib::thread_guard::ThreadGuard<Q>> =
            Box_::new(glib::thread_guard::ThreadGuard::new(callback));
        unsafe extern "C" fn read_line_async_trampoline<
            Q: FnOnce(Result<Option<GString>, glib::Error>) + 'static,
        >(
            _source_object: *mut glib::gobject_ffi::GObject,
            res: *mut ffi::GAsyncResult,
            user_data: glib::ffi::gpointer,
        ) {
            let mut error = ptr::null_mut();
            let ret = ffi::g_data_input_stream_read_line_finish(
                _source_object as *mut _,
                res,
                ptr::null_mut(),
                &mut error,
            );
            let result = if error.is_null() {
                Ok(from_glib_full(ret))
            } else {
                Err(from_glib_full(error))
            };
            let callback: Box_<glib::thread_guard::ThreadGuard<Q>> =
                Box_::from_raw(user_data as *mut _);
            let callback = callback.into_inner();
            callback(result);
        }
        let callback = read_line_async_trampoline::<Q>;
        unsafe {
            ffi::g_data_input_stream_read_line_async(
                self.as_ref().to_glib_none().0,
                io_priority.into_glib(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                Some(callback),
                Box_::into_raw(user_data) as *mut _,
            );
        }
    }

    fn read_line_utf8_future(
        &self,
        io_priority: glib::Priority,
    ) -> Pin<Box_<dyn std::future::Future<Output = Result<Option<GString>, glib::Error>> + 'static>>
    {
        Box_::pin(crate::GioFuture::new(
            self,
            move |obj, cancellable, send| {
                obj.read_line_utf8_async(io_priority, Some(cancellable), move |res| {
                    send.resolve(res);
                });
            },
        ))
    }

    /// Reads a string from the data input stream, up to the first
    /// occurrence of any of the stop characters.
    ///
    /// In contrast to `g_data_input_stream_read_until()`, this function
    /// does not consume the stop character. You have to use
    /// [`DataInputStreamExt::read_byte()`][crate::prelude::DataInputStreamExt::read_byte()] to get it before calling
    /// [`read_upto()`][Self::read_upto()] again.
    ///
    /// Note that `stop_chars` may contain '\0' if `stop_chars_len` is
    /// specified.
    ///
    /// The returned string will always be nul-terminated on success.
    /// ## `stop_chars`
    /// characters to terminate the read
    /// ## `stop_chars_len`
    /// length of `stop_chars`. May be -1 if `stop_chars` is
    ///  nul-terminated
    /// ## `cancellable`
    /// optional [`Cancellable`][crate::Cancellable] object, [`None`] to ignore
    ///
    /// # Returns
    ///
    /// a string with the data that was read
    ///  before encountering any of the stop characters. Set `length` to
    ///  a `gsize` to get the length of the string. This function will
    ///  return [`None`] on an error
    ///
    /// ## `length`
    /// a `gsize` to get the length of the data read in
    #[doc(alias = "g_data_input_stream_read_upto")]
    fn read_upto<P: IsA<Cancellable>>(
        &self,
        stop_chars: &[u8],
        cancellable: Option<&P>,
    ) -> Result<Vec<u8>, glib::Error> {
        let stop_chars_len = stop_chars.len() as isize;
        unsafe {
            let mut error = ptr::null_mut();
            let mut length = mem::MaybeUninit::uninit();
            let ret = ffi::g_data_input_stream_read_upto(
                self.as_ref().to_glib_none().0,
                stop_chars.to_glib_none().0 as *const _,
                stop_chars_len,
                length.as_mut_ptr(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                &mut error,
            );
            if error.is_null() {
                let length = length.assume_init();
                Ok(FromGlibContainer::from_glib_full_num(
                    ret as *mut u8,
                    length,
                ))
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    /// The asynchronous version of [`read_upto()`][Self::read_upto()].
    /// It is an error to have two outstanding calls to this function.
    ///
    /// In contrast to `g_data_input_stream_read_until()`, this function
    /// does not consume the stop character. You have to use
    /// [`DataInputStreamExt::read_byte()`][crate::prelude::DataInputStreamExt::read_byte()] to get it before calling
    /// [`read_upto()`][Self::read_upto()] again.
    ///
    /// Note that `stop_chars` may contain '\0' if `stop_chars_len` is
    /// specified.
    ///
    /// When the operation is finished, `callback` will be called. You
    /// can then call `g_data_input_stream_read_upto_finish()` to get
    /// the result of the operation.
    /// ## `stop_chars`
    /// characters to terminate the read
    /// ## `stop_chars_len`
    /// length of `stop_chars`. May be -1 if `stop_chars` is
    ///  nul-terminated
    /// ## `io_priority`
    /// the [I/O priority][io-priority] of the request
    /// ## `cancellable`
    /// optional [`Cancellable`][crate::Cancellable] object, [`None`] to ignore
    /// ## `callback`
    /// callback to call when the request is satisfied
    #[doc(alias = "g_data_input_stream_read_upto_async")]
    fn read_upto_async<P: IsA<Cancellable>, Q: FnOnce(Result<Vec<u8>, glib::Error>) + 'static>(
        &self,
        stop_chars: &[u8],
        io_priority: glib::Priority,
        cancellable: Option<&P>,
        callback: Q,
    ) {
        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 stop_chars_len = stop_chars.len() as isize;
        let user_data: Box_<glib::thread_guard::ThreadGuard<Q>> =
            Box_::new(glib::thread_guard::ThreadGuard::new(callback));
        unsafe extern "C" fn read_upto_async_trampoline<
            Q: FnOnce(Result<Vec<u8>, glib::Error>) + 'static,
        >(
            _source_object: *mut glib::gobject_ffi::GObject,
            res: *mut ffi::GAsyncResult,
            user_data: glib::ffi::gpointer,
        ) {
            let mut error = ptr::null_mut();
            let mut length = mem::MaybeUninit::uninit();
            let ret = ffi::g_data_input_stream_read_upto_finish(
                _source_object as *mut _,
                res,
                length.as_mut_ptr(),
                &mut error,
            );
            let result = if error.is_null() {
                let length = length.assume_init();
                Ok(FromGlibContainer::from_glib_full_num(
                    ret as *mut u8,
                    length,
                ))
            } else {
                Err(from_glib_full(error))
            };
            let callback: Box_<glib::thread_guard::ThreadGuard<Q>> =
                Box_::from_raw(user_data as *mut _);
            let callback = callback.into_inner();
            callback(result);
        }
        let callback = read_upto_async_trampoline::<Q>;
        unsafe {
            ffi::g_data_input_stream_read_upto_async(
                self.as_ref().to_glib_none().0,
                stop_chars.to_glib_none().0 as *const _,
                stop_chars_len,
                io_priority.into_glib(),
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                Some(callback),
                Box_::into_raw(user_data) as *mut _,
            );
        }
    }

    fn read_upto_future(
        &self,
        stop_chars: &[u8],
        io_priority: glib::Priority,
    ) -> Pin<Box_<dyn std::future::Future<Output = Result<Vec<u8>, glib::Error>> + 'static>> {
        let stop_chars = Vec::from(stop_chars);
        Box_::pin(crate::GioFuture::new(
            self,
            move |obj, cancellable, send| {
                obj.read_upto_async(&stop_chars, io_priority, Some(cancellable), move |res| {
                    send.resolve(res);
                });
            },
        ))
    }
}

impl<O: IsA<DataInputStream>> DataInputStreamExtManual for O {}