use std::fmt;

use poulpy_hal::layouts::{Backend, Data, DataMut, DataRef, Module, VecZnx, VecZnxToMut, VecZnxToRef, ZnxInfos};

use crate::layouts::{
    Base2K, Degree, GLWE, GLWEInfos, GLWEToMut, GLWEToRef, GetDegree, LWEInfos, Rank, SetGLWEInfos, TorusPrecision,
};

#[derive(PartialEq, Eq, Copy, Clone, Debug)]
pub struct GLWEPlaintextLayout {
    pub n: Degree,
    pub base2k: Base2K,
    pub k: TorusPrecision,
}

impl LWEInfos for GLWEPlaintextLayout {
    fn base2k(&self) -> Base2K {
        self.base2k
    }

    fn k(&self) -> TorusPrecision {
        self.k
    }

    fn n(&self) -> Degree {
        self.n
    }
}

impl GLWEInfos for GLWEPlaintextLayout {
    fn rank(&self) -> Rank {
        Rank(0)
    }
}

pub struct GLWEPlaintext<D: Data> {
    pub data: VecZnx<D>,
    pub base2k: Base2K,
    pub k: TorusPrecision,
}

impl<D: DataMut> SetGLWEInfos for GLWEPlaintext<D> {
    fn set_base2k(&mut self, base2k: Base2K) {
        self.base2k = base2k
    }

    fn set_k(&mut self, k: TorusPrecision) {
        self.k = k
    }
}

impl<D: Data> LWEInfos for GLWEPlaintext<D> {
    fn base2k(&self) -> Base2K {
        self.base2k
    }

    fn k(&self) -> TorusPrecision {
        self.k
    }

    fn size(&self) -> usize {
        self.data.size()
    }

    fn n(&self) -> Degree {
        Degree(self.data.n() as u32)
    }
}

impl<D: Data> GLWEInfos for GLWEPlaintext<D> {
    fn rank(&self) -> Rank {
        Rank(self.data.cols() as u32 - 1)
    }
}

impl<D: DataRef> fmt::Display for GLWEPlaintext<D> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "GLWEPlaintext: base2k={} k={}: {}",
            self.base2k().0,
            self.k().0,
            self.data
        )
    }
}

pub trait GLWEPlaintextAlloc
where
    Self: GetDegree,
{
    fn alloc_glwe_plaintext(&self, base2k: Base2K, k: TorusPrecision) -> GLWEPlaintext<Vec<u8>> {
        GLWEPlaintext {
            data: VecZnx::alloc(self.n().into(), 1, k.0.div_ceil(base2k.0) as usize),
            base2k,
            k,
        }
    }

    fn alloc_glwe_plaintext_from_infos<A>(&self, infos: &A) -> GLWEPlaintext<Vec<u8>>
    where
        A: GLWEInfos,
    {
        self.alloc_glwe_plaintext(infos.base2k(), infos.k())
    }

    fn bytes_of_glwe_plaintext(&self, base2k: Base2K, k: TorusPrecision) -> usize {
        VecZnx::bytes_of(self.n().into(), 1, k.0.div_ceil(base2k.0) as usize)
    }

    fn bytes_of_glwe_plaintext_from_infos<A>(&self, infos: &A) -> usize
    where
        A: GLWEInfos,
    {
        self.bytes_of_glwe_plaintext(infos.base2k(), infos.k())
    }
}

impl GLWEPlaintext<Vec<u8>> {
    pub fn alloc_from_infos<A, B: Backend>(module: Module<B>, infos: &A) -> Self
    where
        A: GLWEInfos,
        Module<B>: GLWEPlaintextAlloc,
    {
        module.alloc_glwe_plaintext_from_infos(infos)
    }

    pub fn alloc<B: Backend>(module: Module<B>, base2k: Base2K, k: TorusPrecision) -> Self
    where
        Module<B>: GLWEPlaintextAlloc,
    {
        module.alloc_glwe_plaintext(base2k, k)
    }

    pub fn bytes_of_from_infos<A, B: Backend>(module: Module<B>, infos: &A) -> usize
    where
        A: GLWEInfos,
        Module<B>: GLWEPlaintextAlloc,
    {
        module.bytes_of_glwe_plaintext_from_infos(infos)
    }

    pub fn bytes_of<B: Backend>(module: Module<B>, base2k: Base2K, k: TorusPrecision) -> usize
    where
        Module<B>: GLWEPlaintextAlloc,
    {
        module.bytes_of_glwe_plaintext(base2k, k)
    }
}

impl<D: DataRef> GLWEToRef for GLWEPlaintext<D> {
    fn to_ref(&self) -> GLWE<&[u8]> {
        GLWE {
            k: self.k,
            base2k: self.base2k,
            data: self.data.to_ref(),
        }
    }
}

impl<D: DataMut> GLWEToMut for GLWEPlaintext<D> {
    fn to_mut(&mut self) -> GLWE<&mut [u8]> {
        GLWE {
            k: self.k,
            base2k: self.base2k,
            data: self.data.to_mut(),
        }
    }
}

pub trait GLWEPlaintextToRef {
    fn to_ref(&self) -> GLWEPlaintext<&[u8]>;
}

impl<D: DataRef> GLWEPlaintextToRef for GLWEPlaintext<D> {
    fn to_ref(&self) -> GLWEPlaintext<&[u8]> {
        GLWEPlaintext {
            data: self.data.to_ref(),
            base2k: self.base2k,
            k: self.k,
        }
    }
}

pub trait GLWEPlaintextToMut {
    fn to_ref(&mut self) -> GLWEPlaintext<&mut [u8]>;
}

impl<D: DataMut> GLWEPlaintextToMut for GLWEPlaintext<D> {
    fn to_ref(&mut self) -> GLWEPlaintext<&mut [u8]> {
        GLWEPlaintext {
            base2k: self.base2k,
            k: self.k,
            data: self.data.to_mut(),
        }
    }
}