1use poulpy_backend::hal::{
  2    api::{
  3        ScratchAvailable, SvpApplyInplace, SvpPPolAllocBytes, SvpPrepare, TakeScalarZnx, TakeVecZnx, TakeVecZnxDft,
  4        VecZnxAddInplace, VecZnxAddNormal, VecZnxAddScalarInplace, VecZnxBigNormalize, VecZnxDftAllocBytes, VecZnxDftFromVecZnx,
  5        VecZnxDftToVecZnxBigConsume, VecZnxFillUniform, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes,
  6        VecZnxSub, VecZnxSubABInplace, VecZnxSwithcDegree,
  7    },
  8    layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, Scratch},
  9    source::Source,
 10};
 11
 12use crate::{
 13    TakeGLWESecretPrepared,
 14    layouts::{GGLWECiphertext, GGLWESwitchingKey, GLWESecret, prepared::GLWESecretPrepared},
 15};
 16
 17impl GGLWESwitchingKey<Vec<u8>> {
 18    pub fn encrypt_sk_scratch_space<B: Backend>(
 19        module: &Module<B>,
 20        n: usize,
 21        basek: usize,
 22        k: usize,
 23        rank_in: usize,
 24        rank_out: usize,
 25    ) -> usize
 26    where
 27        Module<B>: SvpPPolAllocBytes + VecZnxNormalizeTmpBytes + VecZnxDftAllocBytes + VecZnxNormalizeTmpBytes,
 28    {
 29        (GGLWECiphertext::encrypt_sk_scratch_space(module, n, basek, k) | ScalarZnx::alloc_bytes(n, 1))
 30            + ScalarZnx::alloc_bytes(n, rank_in)
 31            + GLWESecretPrepared::bytes_of(module, n, rank_out)
 32    }
 33
 34    pub fn encrypt_pk_scratch_space<B: Backend>(
 35        module: &Module<B>,
 36        _n: usize,
 37        _basek: usize,
 38        _k: usize,
 39        _rank_in: usize,
 40        _rank_out: usize,
 41    ) -> usize {
 42        GGLWECiphertext::encrypt_pk_scratch_space(module, _n, _basek, _k, _rank_out)
 43    }
 44}
 45
 46impl<DataSelf: DataMut> GGLWESwitchingKey<DataSelf> {
 47    #[allow(clippy::too_many_arguments)]
 48    pub fn encrypt_sk<DataSkIn: DataRef, DataSkOut: DataRef, B: Backend>(
 49        &mut self,
 50        module: &Module<B>,
 51        sk_in: &GLWESecret<DataSkIn>,
 52        sk_out: &GLWESecret<DataSkOut>,
 53        source_xa: &mut Source,
 54        source_xe: &mut Source,
 55        sigma: f64,
 56        scratch: &mut Scratch<B>,
 57    ) where
 58        Module<B>: VecZnxAddScalarInplace
 59            + VecZnxDftAllocBytes
 60            + VecZnxBigNormalize<B>
 61            + VecZnxDftFromVecZnx<B>
 62            + SvpApplyInplace<B>
 63            + VecZnxDftToVecZnxBigConsume<B>
 64            + VecZnxNormalizeTmpBytes
 65            + VecZnxFillUniform
 66            + VecZnxSubABInplace
 67            + VecZnxAddInplace
 68            + VecZnxNormalizeInplace<B>
 69            + VecZnxAddNormal
 70            + VecZnxNormalize<B>
 71            + VecZnxSub
 72            + SvpPrepare<B>
 73            + VecZnxSwithcDegree
 74            + SvpPPolAllocBytes,
 75        Scratch<B>: TakeVecZnxDft<B> + ScratchAvailable + TakeVecZnx + TakeScalarZnx + TakeGLWESecretPrepared<B>,
 76    {
 77        #[cfg(debug_assertions)]
 78        {
 79            use crate::layouts::Infos;
 80
 81            assert!(sk_in.n() <= module.n());
 82            assert!(sk_out.n() <= module.n());
 83            assert!(
 84                scratch.available()
 85                    >= GGLWESwitchingKey::encrypt_sk_scratch_space(
 86                        module,
 87                        sk_out.n(),
 88                        self.basek(),
 89                        self.k(),
 90                        self.rank_in(),
 91                        self.rank_out()
 92                    ),
 93                "scratch.available()={} < GLWESwitchingKey::encrypt_sk_scratch_space={}",
 94                scratch.available(),
 95                GGLWESwitchingKey::encrypt_sk_scratch_space(
 96                    module,
 97                    sk_out.n(),
 98                    self.basek(),
 99                    self.k(),
100                    self.rank_in(),
101                    self.rank_out()
102                )
103            )
104        }
105
106        let n: usize = sk_in.n().max(sk_out.n());
107
108        let (mut sk_in_tmp, scratch1) = scratch.take_scalar_znx(n, sk_in.rank());
109        (0..sk_in.rank()).for_each(|i| {
110            module.vec_znx_switch_degree(
111                &mut sk_in_tmp.as_vec_znx_mut(),
112                i,
113                &sk_in.data.as_vec_znx(),
114                i,
115            );
116        });
117
118        let (mut sk_out_tmp, scratch2) = scratch1.take_glwe_secret_prepared(n, sk_out.rank());
119        {
120            let (mut tmp, _) = scratch2.take_scalar_znx(n, 1);
121            (0..sk_out.rank()).for_each(|i| {
122                module.vec_znx_switch_degree(&mut tmp.as_vec_znx_mut(), 0, &sk_out.data.as_vec_znx(), i);
123                module.svp_prepare(&mut sk_out_tmp.data, i, &tmp, 0);
124            });
125        }
126
127        self.key.encrypt_sk(
128            module,
129            &sk_in_tmp,
130            &sk_out_tmp,
131            source_xa,
132            source_xe,
133            sigma,
134            scratch2,
135        );
136        self.sk_in_n = sk_in.n();
137        self.sk_out_n = sk_out.n();
138    }
139}