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, GLWESecret, compressed::GGLWESwitchingKeyCompressed, prepared::GLWESecretPrepared},
 15};
 16
 17impl GGLWESwitchingKeyCompressed<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>: VecZnxNormalizeTmpBytes + VecZnxDftAllocBytes + VecZnxNormalizeTmpBytes + SvpPPolAllocBytes,
 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
 35impl<DataSelf: DataMut> GGLWESwitchingKeyCompressed<DataSelf> {
 36    #[allow(clippy::too_many_arguments)]
 37    pub fn encrypt_sk<DataSkIn: DataRef, DataSkOut: DataRef, B: Backend>(
 38        &mut self,
 39        module: &Module<B>,
 40        sk_in: &GLWESecret<DataSkIn>,
 41        sk_out: &GLWESecret<DataSkOut>,
 42        seed_xa: [u8; 32],
 43        source_xe: &mut Source,
 44        sigma: f64,
 45        scratch: &mut Scratch<B>,
 46    ) where
 47        Module<B>: SvpPrepare<B>
 48            + SvpPPolAllocBytes
 49            + VecZnxSwithcDegree
 50            + VecZnxDftAllocBytes
 51            + VecZnxBigNormalize<B>
 52            + VecZnxDftFromVecZnx<B>
 53            + SvpApplyInplace<B>
 54            + VecZnxDftToVecZnxBigConsume<B>
 55            + VecZnxNormalizeTmpBytes
 56            + VecZnxFillUniform
 57            + VecZnxSubABInplace
 58            + VecZnxAddInplace
 59            + VecZnxNormalizeInplace<B>
 60            + VecZnxAddNormal
 61            + VecZnxNormalize<B>
 62            + VecZnxSub
 63            + VecZnxAddScalarInplace,
 64        Scratch<B>: TakeVecZnxDft<B> + ScratchAvailable + TakeVecZnx + TakeScalarZnx + TakeGLWESecretPrepared<B>,
 65    {
 66        #[cfg(debug_assertions)]
 67        {
 68            use crate::layouts::{GGLWESwitchingKey, Infos};
 69
 70            assert!(sk_in.n() <= module.n());
 71            assert!(sk_out.n() <= module.n());
 72            assert!(
 73                scratch.available()
 74                    >= GGLWESwitchingKey::encrypt_sk_scratch_space(
 75                        module,
 76                        sk_out.n(),
 77                        self.basek(),
 78                        self.k(),
 79                        self.rank_in(),
 80                        self.rank_out()
 81                    ),
 82                "scratch.available()={} < GLWESwitchingKey::encrypt_sk_scratch_space={}",
 83                scratch.available(),
 84                GGLWESwitchingKey::encrypt_sk_scratch_space(
 85                    module,
 86                    sk_out.n(),
 87                    self.basek(),
 88                    self.k(),
 89                    self.rank_in(),
 90                    self.rank_out()
 91                )
 92            )
 93        }
 94
 95        let n: usize = sk_in.n().max(sk_out.n());
 96
 97        let (mut sk_in_tmp, scratch1) = scratch.take_scalar_znx(n, sk_in.rank());
 98        (0..sk_in.rank()).for_each(|i| {
 99            module.vec_znx_switch_degree(
100                &mut sk_in_tmp.as_vec_znx_mut(),
101                i,
102                &sk_in.data.as_vec_znx(),
103                i,
104            );
105        });
106
107        let (mut sk_out_tmp, scratch2) = scratch1.take_glwe_secret_prepared(n, sk_out.rank());
108        {
109            let (mut tmp, _) = scratch2.take_scalar_znx(n, 1);
110            (0..sk_out.rank()).for_each(|i| {
111                module.vec_znx_switch_degree(&mut tmp.as_vec_znx_mut(), 0, &sk_out.data.as_vec_znx(), i);
112                module.svp_prepare(&mut sk_out_tmp.data, i, &tmp, 0);
113            });
114        }
115
116        self.key.encrypt_sk(
117            module,
118            &sk_in_tmp,
119            &sk_out_tmp,
120            seed_xa,
121            source_xe,
122            sigma,
123            scratch2,
124        );
125        self.sk_in_n = sk_in.n();
126        self.sk_out_n = sk_out.n();
127    }
128}