use crate::{
    containers::ByteSlice,
    macros::{wrap_clone, wrap_free, wrap_method},
    mem::{heap_move_nonnull, heap_move_ok, heap_move_some, heap_remove},
};
use servicepoint::{
    Brightness, BrightnessGrid, BrightnessGridCommand, ByteGrid, DataRef, Grid,
    Origin, Packet,
};
use std::{mem::transmute, ptr::NonNull};

/// Creates a new [BrightnessGrid] with the specified dimensions.
///
/// returns: [BrightnessGrid] initialized to 0.
///
/// # Examples
/// ```C
/// UdpSocket *connection = sp_udp_open("127.0.0.1:2342");
/// if (connection == NULL)
///     return 1;
///
/// BrightnessGrid *grid = sp_brightness_grid_new(2, 2);
/// sp_brightness_grid_set(grid, 0, 0, 0);
/// sp_brightness_grid_set(grid, 1, 1, 10);
///
/// TypedCommand *command = sp_command_char_brightness(grid);
/// sp_udp_free(connection);
/// ```
#[no_mangle]
pub unsafe extern "C" fn sp_brightness_grid_new(
    width: usize,
    height: usize,
) -> NonNull<BrightnessGrid> {
    heap_move_nonnull(BrightnessGrid::new(width, height))
}

/// Loads a [BrightnessGrid] with the specified dimensions from the provided data.
///
/// Any out of range values will be set to [Brightness::MAX] or [Brightness::MIN].
///
/// returns: new [BrightnessGrid] instance, or NULL in case of an error.
#[no_mangle]
pub unsafe extern "C" fn sp_brightness_grid_load(
    width: usize,
    height: usize,
    data: ByteSlice,
) -> *mut BrightnessGrid {
    let data = unsafe { data.as_slice() };
    heap_move_some(
        ByteGrid::load(width, height, data)
            .map(move |grid| grid.map(Brightness::saturating_from)),
    )
}

wrap_clone!(sp_brightness_grid::BrightnessGrid);
wrap_free!(sp_brightness_grid::BrightnessGrid);

wrap_method!(
    sp_brightness_grid::BrightnessGrid;
    /// Gets the current value at the specified position.
    ///
    /// # Arguments
    ///
    /// - `x` and `y`: position of the cell to read
    ///
    /// returns: value at position
    ///
    /// # Panics
    /// - When accessing `x` or `y` out of bounds.
    ref fn get(x: usize, y: usize) -> Brightness;
);

wrap_method!(
    sp_brightness_grid::BrightnessGrid;
    /// Sets the value of the specified position.
    ///
    /// # Arguments
    ///
    /// - `x` and `y`: position of the cell
    /// - `value`: the value to write to the cell
    ///
    /// returns: old value of the cell
    ///
    /// # Panics
    ///
    /// - When accessing `x` or `y` out of bounds.
    mut fn set(x: usize, y: usize, value: Brightness);
);

wrap_method!(
    sp_brightness_grid::BrightnessGrid;
    /// Sets the value of all cells.
    ///
    /// # Arguments
    ///
    /// - `value`: the value to set all cells to
    mut fn fill(value: Brightness);
);

wrap_method!(
    sp_brightness_grid::BrightnessGrid;
    /// Gets the width of the grid.
    ref fn width() -> usize;
);

wrap_method!(
    sp_brightness_grid::BrightnessGrid;
    /// Gets the height of the grid.
    ref fn height() -> usize;
);

wrap_method!(
    sp_brightness_grid::BrightnessGrid;
    /// Gets an unsafe reference to the data of the instance.
    ///
    /// The returned memory is valid for the lifetime of the grid.
    mut fn data_ref_mut() -> ByteSlice;
    |br_slice| unsafe {
        //noinspection RsAssertEqual
        const _: () = assert!(size_of::<Brightness>() == 1);

        ByteSlice::from_slice(transmute::<&mut [Brightness], &mut [u8]>(br_slice))
    };
);

/// Creates a [BrightnessGridCommand] and immediately turns that into a [Packet].
///
/// The provided [BrightnessGrid] gets consumed.
///
/// Returns NULL in case of an error.
#[no_mangle]
pub unsafe extern "C" fn sp_brightness_grid_into_packet(
    grid: NonNull<BrightnessGrid>,
    x: usize,
    y: usize,
) -> *mut Packet {
    let grid = unsafe { heap_remove(grid) };
    heap_move_ok(Packet::try_from(BrightnessGridCommand {
        grid,
        origin: Origin::new(x, y),
    }))
}