// Copyright 2017 Google LLC

//

// 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

//

//     https://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.

#ifndef THIRD_PARTY_CEL_CPP_EVAL_EVAL_JUMP_STEP_H_

#define THIRD_PARTY_CEL_CPP_EVAL_EVAL_JUMP_STEP_H_

#include <cstdint>

#include <memory>

#include "cel/expr/syntax.pb.h"

#include "absl/status/status.h"

#include "absl/types/optional.h"

#include "eval/eval/evaluator_core.h"

#include "eval/eval/expression_step_base.h"

namespace google::api::expr::runtime {

class JumpStepBase : public ExpressionStepBase {

 public:

  JumpStepBase(absl::optional<int> jump_offset, int64_t expr_id)

      : ExpressionStepBase(expr_id, false), jump_offset_(jump_offset) {}

  void set_jump_offset(int offset) { jump_offset_ = offset; }

  absl::Status Jump(ExecutionFrame* frame) const {

    if (!jump_offset_.has_value()) {

      return absl::Status(absl::StatusCode::kInternal, "Jump offset not set");

    }

    return frame->JumpTo(jump_offset_.value());

  }

 private:

  absl::optional<int> jump_offset_;

};

// Factory method for Jump step.

std::unique_ptr<JumpStepBase> CreateJumpStep(absl::optional<int> jump_offset,

                                             int64_t expr_id);

// Factory method for Conditional Jump step.

// Conditional Jump requires a boolean value to sit on the stack.

// It is compared to jump_condition, and if matched, jump is performed.

// leave on stack indicates whether value should be kept on top of the stack or

// removed.

std::unique_ptr<JumpStepBase> CreateCondJumpStep(

    bool jump_condition, bool leave_on_stack, absl::optional<int> jump_offset,

    int64_t expr_id);

// Factory method for ErrorJump step.

// This step performs a Jump when an Error is on the top of the stack.

// Value is left on stack if it is a bool or an error.

std::unique_ptr<JumpStepBase> CreateBoolCheckJumpStep(

    absl::optional<int> jump_offset, int64_t expr_id);

}  // namespace google::api::expr::runtime

#endif  // THIRD_PARTY_CEL_CPP_EVAL_EVAL_JUMP_STEP_H_