//! This module defines a collection of traits that define the behavior of a polynomial evaluation engine
//! A vector of size N is treated as a multilinear polynomial in \log{N} variables,
//! and a commitment provided by the commitment engine is treated as a multilinear polynomial commitment
use crate::{
  errors::NovaError,
  traits::{commitment::CommitmentEngineTrait, Group},
};
use merlin::Transcript;
use serde::{Deserialize, Serialize};

/// A trait that ties different pieces of the commitment evaluation together
pub trait EvaluationEngineTrait<G: Group>:
  Clone + Send + Sync + Serialize + for<'de> Deserialize<'de>
{
  /// A type that holds the associated commitment engine
  type CE: CommitmentEngineTrait<G>;

  /// A type that holds generators
  type EvaluationGens: Clone + Send + Sync + Serialize + for<'de> Deserialize<'de>;

  /// A type that holds the evaluation argument
  type EvaluationArgument: Clone + Send + Sync + Serialize + for<'de> Deserialize<'de>;

  /// A method to perform any additional setup needed to produce proofs of evaluations
  fn setup(gens: &<Self::CE as CommitmentEngineTrait<G>>::CommitmentGens) -> Self::EvaluationGens;

  /// A method to prove evaluations of a batch of polynomials
  fn prove_batch(
    gens: &Self::EvaluationGens,
    transcript: &mut Transcript,
    comm: &[<Self::CE as CommitmentEngineTrait<G>>::Commitment],
    polys: &[Vec<G::Scalar>],
    points: &[Vec<G::Scalar>],
    evals: &[G::Scalar],
  ) -> Result<Self::EvaluationArgument, NovaError>;

  /// A method to verify purported evaluations of a batch of polynomials
  fn verify_batch(
    gens: &Self::EvaluationGens,
    transcript: &mut Transcript,
    comm: &[<Self::CE as CommitmentEngineTrait<G>>::Commitment],
    points: &[Vec<G::Scalar>],
    evals: &[G::Scalar],
    arg: &Self::EvaluationArgument,
  ) -> Result<(), NovaError>;
}