use crate::mem::{
    heap_clone, heap_drop, heap_move_nonnull, heap_move_ok, heap_remove,
};
use servicepoint::{Bitmap, BitmapCommand, CompressionCode, Origin, Packet};
use std::ptr::NonNull;

/// Sets a window of pixels to the specified values.
///
/// The passed [Bitmap] gets consumed.
///
/// Returns: a new [BitmapCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_new(
    bitmap: NonNull<Bitmap>,
    origin_x: usize,
    origin_y: usize,
    compression: CompressionCode,
) -> NonNull<BitmapCommand> {
    heap_move_nonnull(BitmapCommand {
        bitmap: unsafe { heap_remove(bitmap) },
        origin: Origin::new(origin_x, origin_y),
        compression,
    })
}

/// Move the provided [Bitmap] into a new [BitmapCommand],
/// leaving other fields as their default values.
///
/// Rust equivalent: `BitmapCommand::from(bitmap)`
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_from_bitmap(
    bitmap: NonNull<Bitmap>,
) -> NonNull<BitmapCommand> {
    heap_move_nonnull(unsafe { heap_remove(bitmap) }.into())
}

/// Tries to turn a [BitmapCommand] into a [Packet].
///
/// Returns: NULL or a [Packet] containing the command.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_try_into_packet(
    command: NonNull<BitmapCommand>,
) -> *mut Packet {
    heap_move_ok(unsafe { heap_remove(command) }.try_into())
}

/// Clones an [BitmapCommand] instance.
///
/// returns: a new [BitmapCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_clone(
    command: NonNull<BitmapCommand>,
) -> NonNull<BitmapCommand> {
    unsafe { heap_clone(command) }
}

/// Deallocates a [BitmapCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_free(command: NonNull<BitmapCommand>) {
    unsafe { heap_drop(command) }
}

/// Returns a pointer to the provided `BitmapCommand`.
///
/// # Safety
///
/// - The returned bitmap inherits the lifetime of the command in which it is contained.
/// - The returned pointer may not be used in a function that consumes the instance, e.g. to create a command.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_get(
    mut command: NonNull<BitmapCommand>,
) -> NonNull<Bitmap> {
    unsafe { NonNull::from(&mut (command.as_mut().bitmap)) }
}

/// Moves the provided [Bitmap] to be contained in the [BitmapCommand].
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_set(
    mut command: NonNull<BitmapCommand>,
    bitmap: NonNull<Bitmap>,
) {
    unsafe {
        command.as_mut().bitmap = heap_remove(bitmap);
    }
}

/// Reads the origin field of the [BitmapCommand].
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_get_origin(
    command: NonNull<BitmapCommand>,
    origin_x: NonNull<usize>,
    origin_y: NonNull<usize>,
) {
    unsafe {
        let origin = &command.as_ref().origin;
        *origin_x.as_ptr() = origin.x;
        *origin_y.as_ptr() = origin.y;
    }
}

/// Overwrites the origin field of the [BitmapCommand].
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_set_origin(
    mut command: NonNull<BitmapCommand>,
    origin_x: usize,
    origin_y: usize,
) {
    unsafe {
        command.as_mut().origin = Origin::new(origin_x, origin_y);
    }
}

/// Overwrites the compression kind of the [BitmapCommand].
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_set_compression(
    mut command: NonNull<BitmapCommand>,
    compression: CompressionCode,
) {
    unsafe {
        command.as_mut().compression = compression;
    }
}

/// Reads the compression kind of the [BitmapCommand].
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_bitmap_get_compression(
    command: NonNull<BitmapCommand>,
) -> CompressionCode {
    unsafe { command.as_ref().compression }
}