rssn 0.2.9

//! Bincode-based FFI API for numerical geometric algebra operations.

use serde::Deserialize;
use serde::Serialize;

use crate::ffi_apis::common::BincodeBuffer;
use crate::numerical::geometric_algebra::Multivector3D;

#[derive(Deserialize)]
struct GaInput {
    mv: Multivector3D,
}

#[derive(Deserialize)]
struct TwoGaInput {
    mv1: Multivector3D,
    mv2: Multivector3D,
}

#[derive(Serialize)]
struct FfiResult<T> {
    ok: Option<T>,
    err: Option<String>,
}

pub(crate) fn decode<T: for<'de> Deserialize<'de>>(buffer: BincodeBuffer) -> Option<T> {
    let slice = unsafe { buffer.as_slice() };

    bincode_next::serde::decode_from_slice(slice, bincode_next::config::standard())
        .ok()
        .map(|(v, _)| v)
}

fn encode<T: Serialize>(val: T) -> BincodeBuffer {
    match bincode_next::serde::encode_to_vec(&val, bincode_next::config::standard()) {
        | Ok(bytes) => BincodeBuffer::from_vec(bytes),
        | Err(_) => BincodeBuffer::empty(),
    }
}

/// Bincode FFI for `ga_add`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_add_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: TwoGaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv1 + input.mv2),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_sub`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_sub_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: TwoGaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv1 - input.mv2),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_mul`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_mul_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: TwoGaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv1 * input.mv2),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_wedge`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_wedge_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: TwoGaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv1.wedge(input.mv2)),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_dot`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_dot_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: TwoGaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv1.dot(input.mv2)),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_reverse`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_reverse_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: GaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv.reverse()),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_norm`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_norm_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: GaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<f64> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    encode(FfiResult {
        ok: Some(input.mv.norm()),
        err: None::<String>,
    })
}

/// Bincode FFI for `ga_inv`.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_ga_inv_bincode(buffer: BincodeBuffer) -> BincodeBuffer {
    let input: GaInput = match decode(buffer) {
        | Some(v) => v,
        | None => {
            return encode(FfiResult::<Multivector3D> {
                ok: None,
                err: Some(
                    "Bincode decode \
                     error"
                        .to_string(),
                ),
            });
        },
    };

    let res = match input.mv.inv() {
        | Some(v) => {
            FfiResult {
                ok: Some(v),
                err: None,
            }
        },
        | None => {
            FfiResult {
                ok: None,
                err: Some(
                    "Multivector is \
                     not invertible"
                        .to_string(),
                ),
            }
        },
    };

    encode(res)
}