use crate::{heap_drop, heap_move, heap_move_nonnull, SPBitVec};
use servicepoint::{
    BinaryOperation, Bitmap, Brightness, BrightnessGrid, CharGrid,
    CompressionCode, Cp437Grid, GlobalBrightnessCommand, Packet, TypedCommand,
};
use std::ptr::NonNull;

/// Tries to turn a [Packet] into a [TypedCommand].
///
/// The packet is deallocated in the process.
///
/// Returns: pointer to new [TypedCommand] instance or NULL if parsing failed.
#[no_mangle]
pub unsafe extern "C" fn sp_command_try_from_packet(
    packet: NonNull<Packet>,
) -> *mut TypedCommand {
    let packet = *unsafe { Box::from_raw(packet.as_ptr()) };
    match servicepoint::TypedCommand::try_from(packet) {
        Err(_) => std::ptr::null_mut(),
        Ok(command) => heap_move(command),
    }
}

/// Clones a [TypedCommand] instance.
///
/// returns: new [TypedCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_clone(
    command: NonNull<TypedCommand>,
) -> NonNull<TypedCommand> {
    heap_move_nonnull(unsafe { command.as_ref().clone() })
}

/// Set all pixels to the off state.
///
/// Does not affect brightness.
///
/// Returns: a new [servicepoint::Command::Clear] instance.
///
/// # Examples
///
/// ```C
/// sp_udp_send_command(connection, sp_command_clear());
/// ```
#[no_mangle]
pub unsafe extern "C" fn sp_command_clear() -> NonNull<TypedCommand> {
    heap_move_nonnull(servicepoint::ClearCommand.into())
}

/// Kills the udp daemon on the display, which usually results in a restart.
///
/// Please do not send this in your normal program flow.
///
/// Returns: a new [servicepoint::Command::HardReset] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<TypedCommand> {
    heap_move_nonnull(servicepoint::HardResetCommand.into())
}

/// A yet-to-be-tested command.
///
/// Returns: a new [servicepoint::Command::FadeOut] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<TypedCommand> {
    heap_move_nonnull(servicepoint::FadeOutCommand.into())
}

/// Set the brightness of all tiles to the same value.
///
/// Returns: a new [servicepoint::Command::Brightness] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_global_brightness(
    brightness: Brightness,
) -> NonNull<TypedCommand> {
    heap_move_nonnull(GlobalBrightnessCommand::from(brightness).into())
}

/// Set the brightness of individual tiles in a rectangular area of the display.
///
/// The passed [BrightnessGrid] gets consumed.
///
/// Returns: a new [servicepoint::Command::CharBrightness] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_brightness_grid(
    x: usize,
    y: usize,
    grid: NonNull<BrightnessGrid>,
) -> NonNull<TypedCommand> {
    let grid = unsafe { *Box::from_raw(grid.as_ptr()) };
    let result = servicepoint::BrightnessGridCommand {
        origin: servicepoint::Origin::new(x, y),
        grid,
    }
    .into();
    heap_move_nonnull(result)
}

/// Set pixel data starting at the pixel offset on screen.
///
/// The screen will continuously overwrite more pixel data without regarding the offset, meaning
/// once the starting row is full, overwriting will continue on column 0.
///
/// The [`BinaryOperation`] will be applied on the display comparing old and sent bit.
///
/// `new_bit = old_bit op sent_bit`
///
/// For example, [`BinaryOperation::Or`] can be used to turn on some pixels without affecting other pixels.
///
/// The contained [`BitVecU8Msb0`] is always uncompressed.
#[no_mangle]
pub unsafe extern "C" fn sp_command_bitvec(
    offset: usize,
    bit_vec: NonNull<SPBitVec>,
    compression: CompressionCode,
    operation: BinaryOperation,
) -> *mut TypedCommand {
    let bit_vec = unsafe { *Box::from_raw(bit_vec.as_ptr()) };
    let command = servicepoint::BitVecCommand {
        offset,
        operation,
        bitvec: bit_vec.0,
        compression,
    }
    .into();
    heap_move(command)
}

/// Show codepage 437 encoded text on the screen.
///
/// The passed [Cp437Grid] gets consumed.
///
/// Returns: a new [servicepoint::Cp437GridCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_cp437_grid(
    x: usize,
    y: usize,
    grid: NonNull<Cp437Grid>,
) -> NonNull<TypedCommand> {
    let grid = *unsafe { Box::from_raw(grid.as_ptr()) };
    let result = servicepoint::Cp437GridCommand {
        origin: servicepoint::Origin::new(x, y),
        grid,
    }
    .into();
    heap_move_nonnull(result)
}

/// Show UTF-8 encoded text on the screen.
///
/// The passed [CharGrid] gets consumed.
///
/// Returns: a new [servicepoint::CharGridCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_char_grid(
    x: usize,
    y: usize,
    grid: NonNull<CharGrid>,
) -> NonNull<TypedCommand> {
    let grid = unsafe { *Box::from_raw(grid.as_ptr()) };
    let result = servicepoint::CharGridCommand {
        origin: servicepoint::Origin::new(x, y),
        grid,
    }
    .into();
    heap_move_nonnull(result)
}

/// Sets a window of pixels to the specified values.
///
/// The passed [Bitmap] gets consumed.
///
/// Returns: a new [servicepoint::BitmapCommand] instance.
#[no_mangle]
pub unsafe extern "C" fn sp_command_bitmap(
    x: usize,
    y: usize,
    bitmap: NonNull<Bitmap>,
    compression: CompressionCode,
) -> *mut TypedCommand {
    let bitmap = unsafe { *Box::from_raw(bitmap.as_ptr()) };
    let command = servicepoint::BitmapCommand {
        origin: servicepoint::Origin::new(x, y),
        bitmap,
        compression,
    }
    .into();
    heap_move(command)
}

/// Deallocates a [TypedCommand].
///
/// # Examples
///
/// ```C
/// TypedCommand c = sp_command_clear();
/// sp_command_free(c);
/// ```
#[no_mangle]
pub unsafe extern "C" fn sp_command_free(command: NonNull<TypedCommand>) {
    unsafe { heap_drop(command) }
}