1use poulpy_hal::{
 2    api::{ScratchOwnedAlloc, ScratchOwnedBorrow, ZnNormalizeInplace},
 3    layouts::{Backend, DataMut, DataRef, Module, ScratchOwned, ZnxView, ZnxViewMut},
 4    oep::{ScratchOwnedAllocImpl, ScratchOwnedBorrowImpl},
 5};
 6
 7use crate::layouts::{LWE, LWEInfos, LWEPlaintext, LWESecret, LWEToMut, LWEPlaintextToMut, LWESecretToRef};
 8
 9impl<DataSelf: DataRef + DataMut> LWE<DataSelf>
10{
11    pub fn decrypt<P, S, M, B>(&mut self, module: &M, pt: &mut P, sk: S)
12    where
13        P: LWEPlaintextToMut,
14        S: LWESecretToRef,
15        M: LWEDecrypt<B>,
16        B: Backend + ScratchOwnedAllocImpl<B> + ScratchOwnedBorrowImpl<B>,
17    {
18        module.lwe_decrypt(self, pt, sk);
19    }
20}
21
22pub trait LWEDecrypt<BE: Backend>
23where
24    Self: Sized + ZnNormalizeInplace<BE>
25{
26    fn lwe_decrypt<R, P, S>(&self, res: &mut R, pt: &mut P, sk: S)
27    where
28            R: LWEToMut,
29            P: LWEPlaintextToMut,
30            S: LWESecretToRef,
31            BE: Backend + ScratchOwnedAllocImpl<BE> + ScratchOwnedBorrowImpl<BE>,
32    {
33
34        let res: &mut LWE<&mut [u8]> = &mut res.to_mut();
35        let pt: &mut LWEPlaintext<&mut [u8]> = &mut pt.to_mut();
36        let sk: LWESecret<&[u8]> = sk.to_ref();
37
38        #[cfg(debug_assertions)]
39        {
40            assert_eq!(res.n(), sk.n());
41        }
42
43        (0..pt.size().min(res.size())).for_each(|i| {
44            pt.data.at_mut(0, i)[0] = res.data.at(0, i)[0]
45                + res.data.at(0, i)[1..]
46                    .iter()
47                    .zip(sk.data.at(0, 0))
48                    .map(|(x, y)| x * y)
49                    .sum::<i64>();
50        });
51        self.zn_normalize_inplace(
52            1,
53            res.base2k().into(),
54            &mut pt.data,
55            0,
56            ScratchOwned::alloc(size_of::<i64>()).borrow(),
57        );
58        pt.base2k = res.base2k();
59        pt.k = crate::layouts::TorusPrecision(res.k().0.min(pt.size() as u32 * res.base2k().0));
60    }
61}
62
63impl<BE: Backend> LWEDecrypt<BE> for Module<BE> where 
64    Self: Sized + ZnNormalizeInplace<BE>
65{
66    
67}