use ark_ff::PrimeField;
use ark_std::{end_timer, rand::RngCore, start_timer};
use std::rc::Rc;

pub use ark_poly::DenseMultilinearExtension;

// Build a randomize list of mle-s whose sum is zero.
pub fn random_zero_mle_list<F: PrimeField, R: RngCore>(
    nv: usize,
    degree: usize,
    rng: &mut R,
) -> Vec<Rc<DenseMultilinearExtension<F>>> {
    let start = start_timer!(|| "sample random zero mle list");

    let mut multiplicands = Vec::with_capacity(degree);
    for _ in 0..degree {
        multiplicands.push(Vec::with_capacity(1 << nv))
    }
    for _ in 0..(1 << nv) {
        multiplicands[0].push(F::zero());
        for e in multiplicands.iter_mut().skip(1) {
            e.push(F::rand(rng));
        }
    }

    let list = multiplicands
        .into_iter()
        .map(|x| Rc::new(DenseMultilinearExtension::from_evaluations_vec(nv, x)))
        .collect();

    end_timer!(start);
    list
}