1use poulpy_hal::{
  2    api::{
  3        ScratchAvailable, SvpApplyDftToDftInplace, SvpPPolAllocBytes, SvpPrepare, TakeScalarZnx, TakeVecZnx, TakeVecZnxDft,
  4        VecZnxAddInplace, VecZnxAddNormal, VecZnxAddScalarInplace, VecZnxBigNormalize, VecZnxDftAllocBytes, VecZnxDftApply,
  5        VecZnxFillUniform, VecZnxIdftApplyConsume, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub,
  6        VecZnxSubInplace, VecZnxSwitchRing,
  7    },
  8    layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, Scratch},
  9    source::Source,
 10};
 11
 12use crate::{
 13    TakeGLWESecretPrepared,
 14    layouts::{
 15        Degree, GGLWECiphertext, GGLWEInfos, GLWEInfos, GLWESecret, LWEInfos, compressed::GGLWESwitchingKeyCompressed,
 16        prepared::GLWESecretPrepared,
 17    },
 18};
 19
 20impl GGLWESwitchingKeyCompressed<Vec<u8>> {
 21    pub fn encrypt_sk_scratch_space<B: Backend, A>(module: &Module<B>, infos: &A) -> usize
 22    where
 23        A: GGLWEInfos,
 24        Module<B>: VecZnxNormalizeTmpBytes + VecZnxDftAllocBytes + VecZnxNormalizeTmpBytes + SvpPPolAllocBytes,
 25    {
 26        (GGLWECiphertext::encrypt_sk_scratch_space(module, infos) | ScalarZnx::alloc_bytes(module.n(), 1))
 27            + ScalarZnx::alloc_bytes(module.n(), infos.rank_in().into())
 28            + GLWESecretPrepared::alloc_bytes_with(module, infos.rank_out())
 29    }
 30}
 31
 32impl<DataSelf: DataMut> GGLWESwitchingKeyCompressed<DataSelf> {
 33    #[allow(clippy::too_many_arguments)]
 34    pub fn encrypt_sk<DataSkIn: DataRef, DataSkOut: DataRef, B: Backend>(
 35        &mut self,
 36        module: &Module<B>,
 37        sk_in: &GLWESecret<DataSkIn>,
 38        sk_out: &GLWESecret<DataSkOut>,
 39        seed_xa: [u8; 32],
 40        source_xe: &mut Source,
 41        scratch: &mut Scratch<B>,
 42    ) where
 43        Module<B>: SvpPrepare<B>
 44            + SvpPPolAllocBytes
 45            + VecZnxSwitchRing
 46            + VecZnxDftAllocBytes
 47            + VecZnxBigNormalize<B>
 48            + VecZnxDftApply<B>
 49            + SvpApplyDftToDftInplace<B>
 50            + VecZnxIdftApplyConsume<B>
 51            + VecZnxNormalizeTmpBytes
 52            + VecZnxFillUniform
 53            + VecZnxSubInplace
 54            + VecZnxAddInplace
 55            + VecZnxNormalizeInplace<B>
 56            + VecZnxAddNormal
 57            + VecZnxNormalize<B>
 58            + VecZnxSub
 59            + VecZnxAddScalarInplace,
 60        Scratch<B>: TakeVecZnxDft<B> + ScratchAvailable + TakeVecZnx + TakeScalarZnx + TakeGLWESecretPrepared<B>,
 61    {
 62        #[cfg(debug_assertions)]
 63        {
 64            use crate::layouts::GGLWESwitchingKey;
 65
 66            assert!(sk_in.n().0 <= module.n() as u32);
 67            assert!(sk_out.n().0 <= module.n() as u32);
 68            assert!(
 69                scratch.available() >= GGLWESwitchingKey::encrypt_sk_scratch_space(module, self),
 70                "scratch.available()={} < GLWESwitchingKey::encrypt_sk_scratch_space={}",
 71                scratch.available(),
 72                GGLWESwitchingKey::encrypt_sk_scratch_space(module, self)
 73            )
 74        }
 75
 76        let n: usize = sk_in.n().max(sk_out.n()).into();
 77
 78        let (mut sk_in_tmp, scratch_1) = scratch.take_scalar_znx(n, sk_in.rank().into());
 79        (0..sk_in.rank().into()).for_each(|i| {
 80            module.vec_znx_switch_ring(
 81                &mut sk_in_tmp.as_vec_znx_mut(),
 82                i,
 83                &sk_in.data.as_vec_znx(),
 84                i,
 85            );
 86        });
 87
 88        let (mut sk_out_tmp, scratch_2) = scratch_1.take_glwe_secret_prepared(Degree(n as u32), sk_out.rank());
 89        {
 90            let (mut tmp, _) = scratch_2.take_scalar_znx(n, 1);
 91            (0..sk_out.rank().into()).for_each(|i| {
 92                module.vec_znx_switch_ring(&mut tmp.as_vec_znx_mut(), 0, &sk_out.data.as_vec_znx(), i);
 93                module.svp_prepare(&mut sk_out_tmp.data, i, &tmp, 0);
 94            });
 95        }
 96
 97        self.key.encrypt_sk(
 98            module,
 99            &sk_in_tmp,
100            &sk_out_tmp,
101            seed_xa,
102            source_xe,
103            scratch_2,
104        );
105        self.sk_in_n = sk_in.n().into();
106        self.sk_out_n = sk_out.n().into();
107    }
108}