use crate::{
    macros::{wrap_clone, wrap_free},
    mem::{heap_move_nonnull, heap_move_ok, heap_remove},
};
use servicepoint::{Cp437Grid, Cp437GridCommand, Origin, Packet};
use std::ptr::NonNull;

/// Show text on the screen.
///
/// The text is sent in the form of a 2D grid of [CP-437] encoded characters.
///
/// The origin is relative to the top-left of the display.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_new(
    grid: NonNull<Cp437Grid>,
    origin_x: usize,
    origin_y: usize,
) -> NonNull<Cp437GridCommand> {
    heap_move_nonnull(Cp437GridCommand {
        grid: unsafe { heap_remove(grid) },
        origin: Origin::new(origin_x, origin_y),
    })
}

/// Moves the provided [Cp437Grid] into a new [Cp437GridCommand],
/// leaving other fields as their default values.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_from_grid(
    grid: NonNull<Cp437Grid>,
) -> NonNull<Cp437GridCommand> {
    heap_move_nonnull(unsafe { heap_remove(grid) }.into())
}

/// Tries to turn a [Cp437GridCommand] into a [Packet].
///
/// Returns: NULL or a [Packet] containing the command.
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_try_into_packet(
    command: NonNull<Cp437GridCommand>,
) -> *mut Packet {
    heap_move_ok(unsafe { heap_remove(command) }.try_into())
}

wrap_clone!(sp_cmd_cp437_grid::Cp437GridCommand);
wrap_free!(sp_cmd_cp437_grid::Cp437GridCommand);

/// Moves the provided bitmap into the provided command.
///
/// This drops the previously contained [Cp437Grid].
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_set(
    mut command: NonNull<Cp437GridCommand>,
    grid: NonNull<Cp437Grid>,
) {
    unsafe {
        command.as_mut().grid = heap_remove(grid);
    }
}

/// Show text on the screen.
///
/// The text is sent in the form of a 2D grid of [CP-437] encoded characters.
/// For sending UTF-8 encoded characters, see [servicepoint::CharGridCommand].
///
/// [CP-437]: https://en.wikipedia.org/wiki/Code_page_437
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_get(
    mut command: NonNull<Cp437GridCommand>,
) -> *mut Cp437Grid {
    unsafe { &mut command.as_mut().grid }
}

/// Gets the origin field of the [Cp437GridCommand].
///
/// Rust equivalent: `cp437_command.origin`
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_get_origin(
    command: NonNull<Cp437GridCommand>,
    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;
    }
}

/// Sets the origin field of the [Cp437GridCommand].
///
/// Rust equivalent: `cp437_command.origin = Origin::new(origin_x, origin_y)`
#[no_mangle]
pub unsafe extern "C" fn sp_cmd_cp437_grid_set_origin(
    mut command: NonNull<Cp437GridCommand>,
    origin_x: usize,
    origin_y: usize,
) {
    unsafe {
        command.as_mut().origin = Origin::new(origin_x, origin_y);
    }
}