use std::collections::HashMap;

use backend::hal::{
    api::{
        MatZnxAlloc, ScalarZnxAlloc, ScalarZnxAllocBytes, ScratchOwnedAlloc, ScratchOwnedBorrow, VecZnxAddScalarInplace,
        VecZnxAlloc, VecZnxAllocBytes, VecZnxAutomorphism, VecZnxBigAutomorphismInplace, VecZnxBigSubSmallBInplace, VecZnxCopy,
        VecZnxEncodeVeci64, VecZnxFillUniform, VecZnxNormalizeInplace, VecZnxRotateInplace, VecZnxRshInplace, VecZnxStd,
        VecZnxSubABInplace, VecZnxSwithcDegree, ZnxView, ZnxViewMut,
    },
    layouts::{Backend, Module, ScratchOwned},
    oep::{
        ScratchAvailableImpl, ScratchOwnedAllocImpl, ScratchOwnedBorrowImpl, TakeScalarZnxImpl, TakeSvpPPolImpl,
        TakeVecZnxBigImpl, TakeVecZnxDftImpl, TakeVecZnxImpl,
    },
};
use sampling::source::Source;

use crate::{
    AutomorphismKey, AutomorphismKeyExec, GGLWEExecLayoutFamily, GLWECiphertext, GLWEDecryptFamily, GLWEKeyswitchFamily,
    GLWEPlaintext, GLWESecret, GLWESecretExec, GLWESecretFamily, GLWESwitchingKeyEncryptSkFamily, Infos,
    noise::var_noise_gglwe_product,
};

pub(crate) trait TraceTestModuleFamily<B: Backend> = GLWESecretFamily<B>
    + GLWESwitchingKeyEncryptSkFamily<B>
    + GLWEKeyswitchFamily<B>
    + GLWEDecryptFamily<B>
    + GGLWEExecLayoutFamily<B>
    + MatZnxAlloc
    + VecZnxAlloc
    + ScalarZnxAlloc
    + ScalarZnxAllocBytes
    + VecZnxAllocBytes
    + VecZnxStd
    + VecZnxSwithcDegree
    + VecZnxAddScalarInplace
    + VecZnxEncodeVeci64
    + VecZnxRotateInplace
    + VecZnxBigSubSmallBInplace<B>
    + VecZnxBigAutomorphismInplace<B>
    + VecZnxCopy
    + VecZnxAutomorphism
    + VecZnxRshInplace;

pub(crate) trait TraceTestScratchFamily<B: Backend> = TakeVecZnxDftImpl<B>
    + TakeVecZnxBigImpl<B>
    + TakeSvpPPolImpl<B>
    + ScratchOwnedAllocImpl<B>
    + ScratchOwnedBorrowImpl<B>
    + ScratchAvailableImpl<B>
    + TakeScalarZnxImpl<B>
    + TakeVecZnxImpl<B>;

pub(crate) fn test_trace_inplace<B: Backend>(module: &Module<B>, basek: usize, k: usize, sigma: f64, rank: usize)
where
    Module<B>: TraceTestModuleFamily<B>,
    B: TraceTestScratchFamily<B>,
{
    let k_autokey: usize = k + basek;

    let digits: usize = 1;
    let rows: usize = k.div_ceil(basek * digits);

    let mut ct: GLWECiphertext<Vec<u8>> = GLWECiphertext::alloc(module, basek, k, rank);
    let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(module, basek, k);
    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(module, basek, k);

    let mut source_xs: Source = Source::new([0u8; 32]);
    let mut source_xe: Source = Source::new([0u8; 32]);
    let mut source_xa: Source = Source::new([0u8; 32]);

    let mut scratch: ScratchOwned<B> = ScratchOwned::alloc(
        GLWECiphertext::encrypt_sk_scratch_space(module, basek, ct.k())
            | GLWECiphertext::decrypt_scratch_space(module, basek, ct.k())
            | AutomorphismKey::encrypt_sk_scratch_space(module, basek, k_autokey, rank)
            | GLWECiphertext::trace_inplace_scratch_space(module, basek, ct.k(), k_autokey, digits, rank),
    );

    let mut sk: GLWESecret<Vec<u8>> = GLWESecret::alloc(module, rank);
    sk.fill_ternary_prob(0.5, &mut source_xs);
    let sk_dft: GLWESecretExec<Vec<u8>, B> = GLWESecretExec::from(module, &sk);

    let mut data_want: Vec<i64> = vec![0i64; module.n()];

    data_want
        .iter_mut()
        .for_each(|x| *x = source_xa.next_i64() & 0xFF);

    module.vec_znx_fill_uniform(basek, &mut pt_have.data, 0, k, &mut source_xa);

    ct.encrypt_sk(
        module,
        &pt_have,
        &sk_dft,
        &mut source_xa,
        &mut source_xe,
        sigma,
        scratch.borrow(),
    );

    let mut auto_keys: HashMap<i64, AutomorphismKeyExec<Vec<u8>, B>> = HashMap::new();
    let gal_els: Vec<i64> = GLWECiphertext::trace_galois_elements(module);
    let mut tmp: AutomorphismKey<Vec<u8>> = AutomorphismKey::alloc(module, basek, k_autokey, rows, digits, rank);
    gal_els.iter().for_each(|gal_el| {
        tmp.encrypt_sk(
            module,
            *gal_el,
            &sk,
            &mut source_xa,
            &mut source_xe,
            sigma,
            scratch.borrow(),
        );
        let atk_exec: AutomorphismKeyExec<Vec<u8>, B> = AutomorphismKeyExec::from(module, &tmp, scratch.borrow());
        auto_keys.insert(*gal_el, atk_exec);
    });

    ct.trace_inplace(module, 0, 5, &auto_keys, scratch.borrow());
    ct.trace_inplace(module, 5, module.log_n(), &auto_keys, scratch.borrow());

    (0..pt_want.size()).for_each(|i| pt_want.data.at_mut(0, i)[0] = pt_have.data.at(0, i)[0]);

    ct.decrypt(module, &mut pt_have, &sk_dft, scratch.borrow());

    module.vec_znx_sub_ab_inplace(&mut pt_want.data, 0, &pt_have.data, 0);
    module.vec_znx_normalize_inplace(basek, &mut pt_want.data, 0, scratch.borrow());

    let noise_have: f64 = module.vec_znx_std(basek, &pt_want.data, 0).log2();

    let mut noise_want: f64 = var_noise_gglwe_product(
        module.n() as f64,
        basek,
        0.5,
        0.5,
        1.0 / 12.0,
        sigma * sigma,
        0.0,
        rank as f64,
        k,
        k_autokey,
    );
    noise_want += sigma * sigma * (-2.0 * (k) as f64).exp2();
    noise_want += module.n() as f64 * 1.0 / 12.0 * 0.5 * rank as f64 * (-2.0 * (k) as f64).exp2();
    noise_want = noise_want.sqrt().log2();

    assert!(
        (noise_have - noise_want).abs() < 1.0,
        "{} > {}",
        noise_have,
        noise_want
    );
}