tasm-lib 2.0.0

use std::collections::HashMap;

use rand::prelude::*;
use triton_vm::prelude::*;

use crate::InitVmState;
use crate::linker::execute_bench;
use crate::prelude::Tip5;
use crate::snippet_bencher::BenchmarkCase;
use crate::snippet_bencher::NamedBenchmarkResult;
use crate::snippet_bencher::write_benchmarks;
use crate::test_helpers::test_rust_equivalence_given_complete_state;
use crate::traits::basic_snippet::BasicSnippet;
use crate::traits::rust_shadow::RustShadow;

/// A trait that can modify all parts of the VM state.
///
/// A Procedure is a piece of tasm code that can do almost anything: modify stack, read
/// from and write to memory, take in nondeterminism, and read and write from standard
/// input/output. What it cannot do is stand alone. In other words, it is still wrapped
/// in a function (lower case f, as in 'labelled scope'); and cannot be proved as
/// a standalone program.
///
/// See also: [closure], [function], [algorithm], [read_only_algorithm],
///           [accessor], [mem_preserver]
///
/// [closure]: crate::traits::closure::Closure
/// [function]: crate::traits::function::Function
/// [algorithm]: crate::traits::algorithm::Algorithm
/// [read_only_algorithm]: crate::traits::read_only_algorithm::ReadOnlyAlgorithm
/// [accessor]: crate::traits::accessor::Accessor
/// [mem_preserver]: crate::traits::mem_preserver::MemPreserver
pub trait Procedure: BasicSnippet {
    /// Returns standard output
    fn rust_shadow(
        &self,
        stack: &mut Vec<BFieldElement>,
        memory: &mut HashMap<BFieldElement, BFieldElement>,
        nondeterminism: &NonDeterminism,
        public_input: &[BFieldElement],
        sponge: &mut Option<Tip5>,
    ) -> Vec<BFieldElement>;

    fn preprocess<T: BFieldCodec>(_meta_input: T, _nondeterminism: &mut NonDeterminism) {}

    fn pseudorandom_initial_state(
        &self,
        seed: [u8; 32],
        bench_case: Option<BenchmarkCase>,
    ) -> ProcedureInitialState;

    fn corner_case_initial_states(&self) -> Vec<ProcedureInitialState> {
        vec![]
    }
}

#[derive(Debug, Clone, Default)]
pub struct ProcedureInitialState {
    pub stack: Vec<BFieldElement>,
    pub nondeterminism: NonDeterminism,
    pub public_input: Vec<BFieldElement>,
    pub sponge: Option<Tip5>,
}

impl From<ProcedureInitialState> for InitVmState {
    fn from(value: ProcedureInitialState) -> Self {
        Self {
            stack: value.stack,
            public_input: value.public_input,
            nondeterminism: value.nondeterminism,
            sponge: value.sponge,
        }
    }
}

pub struct ShadowedProcedure<P: Procedure> {
    procedure: P,
}

impl<P: Procedure> ShadowedProcedure<P> {
    pub fn new(procedure: P) -> Self {
        Self { procedure }
    }
}

impl<P: Procedure> RustShadow for ShadowedProcedure<P> {
    fn inner(&self) -> &dyn BasicSnippet {
        &self.procedure
    }

    fn rust_shadow_wrapper(
        &self,
        stdin: &[BFieldElement],
        nondeterminism: &NonDeterminism,
        stack: &mut Vec<BFieldElement>,
        memory: &mut HashMap<BFieldElement, BFieldElement>,
        sponge: &mut Option<Tip5>,
    ) -> Vec<BFieldElement> {
        self.procedure
            .rust_shadow(stack, memory, nondeterminism, stdin, sponge)
    }

    fn test(&self) {
        let num_states = 5;
        let seed: [u8; 32] = rand::rng().random();
        let mut rng = StdRng::from_seed(seed);
        let procedure = &self.procedure;

        for corner_case in procedure.corner_case_initial_states().into_iter() {
            self.test_initial_state(corner_case);
        }

        for _ in 0..num_states {
            let seed: [u8; 32] = rng.random();
            let state = procedure.pseudorandom_initial_state(seed, None);

            self.test_initial_state(state);
        }
    }

    fn bench(&self) {
        let mut rng = StdRng::from_seed(
            hex::decode("73a24b6b8b32e4d7d563a4d9a85f476573a24b6b8b32e4d7d563a4d9a85f4765")
                .unwrap()
                .try_into()
                .unwrap(),
        );
        let mut benchmarks = Vec::with_capacity(2);

        for bench_case in [BenchmarkCase::CommonCase, BenchmarkCase::WorstCase] {
            let ProcedureInitialState {
                stack,
                nondeterminism,
                public_input,
                sponge,
            } = self
                .procedure
                .pseudorandom_initial_state(rng.random(), Some(bench_case));
            let program = self.procedure.link_for_isolated_run();
            let benchmark = execute_bench(&program, &stack, public_input, nondeterminism, sponge);
            let benchmark = NamedBenchmarkResult {
                name: self.procedure.entrypoint(),
                benchmark_result: benchmark,
                case: bench_case,
            };
            benchmarks.push(benchmark);
        }

        write_benchmarks(benchmarks);
    }
}

impl<P: Procedure> ShadowedProcedure<P> {
    fn test_initial_state(&self, state: ProcedureInitialState) {
        test_rust_equivalence_given_complete_state(
            self,
            &state.stack,
            &state.public_input,
            &state.nondeterminism,
            &state.sponge,
            None,
        );
    }
}