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