// Copyright 2020 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.

#ifndef SRC_TINT_INSPECTOR_SCALAR_H_
#define SRC_TINT_INSPECTOR_SCALAR_H_

#include <cstdint>

namespace tint::inspector {

/// Contains a literal scalar value
class Scalar {
 public:
  /// Null Constructor
  Scalar();
  /// @param val literal scalar value to contain
  explicit Scalar(bool val);
  /// @param val literal scalar value to contain
  explicit Scalar(uint32_t val);
  /// @param val literal scalar value to contain
  explicit Scalar(int32_t val);
  /// @param val literal scalar value to contain
  explicit Scalar(float val);

  /// @returns true if this is a null
  bool IsNull() const;
  /// @returns true if this is a bool
  bool IsBool() const;
  /// @returns true if this is a unsigned integer.
  bool IsU32() const;
  /// @returns true if this is a signed integer.
  bool IsI32() const;
  /// @returns true if this is a float.
  bool IsFloat() const;

  /// @returns scalar value if bool, otherwise undefined behaviour.
  bool AsBool() const;
  /// @returns scalar value if unsigned integer, otherwise undefined behaviour.
  uint32_t AsU32() const;
  /// @returns scalar value if signed integer, otherwise undefined behaviour.
  int32_t AsI32() const;
  /// @returns scalar value if float, otherwise undefined behaviour.
  float AsFloat() const;

 private:
  typedef enum {
    kNull,
    kBool,
    kU32,
    kI32,
    kFloat,
  } Type;

  typedef union {
    bool b;
    uint32_t u;
    int32_t i;
    float f;
  } Value;

  Type type_;
  Value value_;
};

}  // namespace tint::inspector

#endif  // SRC_TINT_INSPECTOR_SCALAR_H_