// Copyright 2022 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "src/tint/fuzzers/shuffle_transform.h"

#include <random>
#include <utility>

#include "src/tint/lang/wgsl/program/program_builder.h"

namespace tint::fuzzers {

ShuffleTransform::ShuffleTransform(size_t seed) : seed_(seed) {}

ast::transform::Transform::ApplyResult ShuffleTransform::Apply(const Program* src,
                                                               const ast::transform::DataMap&,
                                                               ast::transform::DataMap&) const {
    ProgramBuilder b;
    CloneContext ctx{&b, src, /* auto_clone_symbols */ true};

    auto decls = src->AST().GlobalDeclarations();
    auto rng = std::mt19937_64{seed_};
    std::shuffle(std::begin(decls), std::end(decls), rng);
    for (auto* decl : decls) {
        b.AST().AddGlobalDeclaration(ctx.Clone(decl));
    }

    ctx.Clone();
    return Program(std::move(b));
}

}  // namespace tint::fuzzers