spawn-zk-snarks 0.1.5

// Copyright (c) 2023 spawn-zk-snarks developers
//
// Licensed under the MIT License
// <LICENSE-MIT or http://opensource.org/licenses/MIT>

use thiserror::Error;
use ark_ff::Field;
use ark_relations::r1cs::{
    ConstraintSynthesizer, ConstraintSystemRef, SynthesisError, LinearCombination,
};

/// Errors that can occur during circuit operations
#[derive(Error, Debug)]
pub enum CircuitError {
    /// Error during circuit compilation
    #[error("Circuit compilation failed")]
    CompilationError,
    /// Error in constraint system
    #[error("Constraint system error")]
    ConstraintError,
}

/// Basic arithmetic circuit for ZKP
#[derive(Debug, Clone)]
pub struct ArithmeticCircuit<F: Field> {
    /// Number of constraints in the circuit
    pub num_constraints: usize,
    /// Number of variables used in the circuit
    pub num_variables: usize,
    /// Number of public inputs
    pub num_inputs: usize,
    /// Private witness values
    pub witness: Vec<F>,
}

impl<F: Field> ArithmeticCircuit<F> {
    /// Create a new arithmetic circuit with specified parameters
    pub fn new(num_constraints: usize, num_variables: usize, num_inputs: usize) -> Self {
        Self {
            num_constraints,
            num_variables,
            num_inputs,
            witness: Vec::new(),
        }
    }

    /// Compile circuit for EVM verification
    pub fn compile_for_evm(&self) -> Result<Vec<u8>, CircuitError> {
        // TODO: Implement actual circuit compilation
        Ok(Vec::new())
    }
}

impl<F: Field> ConstraintSynthesizer<F> for ArithmeticCircuit<F> {
    fn generate_constraints(
        self,
        cs: ConstraintSystemRef<F>,
    ) -> Result<(), SynthesisError> {
        // Basit bir örnek: a * b = c kısıtlaması
        let a = cs.new_witness_variable(|| Ok(F::one()))?;
        let b = cs.new_witness_variable(|| Ok(F::one()))?;
        let c = cs.new_input_variable(|| Ok(F::one()))?;

        let lc_a = LinearCombination::<F>::from(a);
        let lc_b = LinearCombination::<F>::from(b);
        let lc_c = LinearCombination::<F>::from(c);

        cs.enforce_constraint(lc_a, lc_b, lc_c)?;

        Ok(())
    }
}

/// Circuit configuration for EVM
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct EVMCircuitConfig {
    pub max_constraint_complexity: usize,
    pub optimize_for_gas: bool,
}