// Copyright 2021 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_INTERNAL_STATUS_BUILDER_H_

#define THIRD_PARTY_CEL_CPP_INTERNAL_STATUS_BUILDER_H_

#include <type_traits>

#include <utility>

#include "absl/base/attributes.h"

#include "absl/status/status.h"

namespace cel::internal {

class StatusBuilder;

template <typename Fn, typename Arg, typename Expected>

inline constexpr bool StatusBuilderResultMatches =

    std::is_same_v<std::decay_t<std::invoke_result_t<Fn, Arg>>, Expected>;

template <typename Adaptor, typename Builder>

using StatusBuilderPurePolicy = std::enable_if_t<

    StatusBuilderResultMatches<Adaptor, Builder, StatusBuilder>,

    std::invoke_result_t<Adaptor, Builder>>;

template <typename Adaptor, typename Builder>

using StatusBuilderSideEffect =

    std::enable_if_t<StatusBuilderResultMatches<Adaptor, Builder, absl::Status>,

                     std::invoke_result_t<Adaptor, Builder>>;

template <typename Adaptor, typename Builder>

using StatusBuilderConversion = std::enable_if_t<

    !StatusBuilderResultMatches<Adaptor, Builder, StatusBuilder> &&

        !StatusBuilderResultMatches<Adaptor, Builder, absl::Status>,

    std::invoke_result_t<Adaptor, Builder>>;

class StatusBuilder final {

 public:

  StatusBuilder() = default;

  explicit StatusBuilder(const absl::Status& status) : status_(status) {}

  StatusBuilder(const StatusBuilder&) = default;

  StatusBuilder(StatusBuilder&&) = default;

  ~StatusBuilder() = default;

  StatusBuilder& operator=(const StatusBuilder&) = default;

  StatusBuilder& operator=(StatusBuilder&&) = default;

  bool ok() const { return status_.ok(); }

  absl::StatusCode code() const { return status_.code(); }

  operator absl::Status() const& { return status_; }  // NOLINT

  operator absl::Status() && { return std::move(status_); }  // NOLINT

  template <typename Adaptor>

  auto With(

      Adaptor&& adaptor) & -> StatusBuilderPurePolicy<Adaptor, StatusBuilder&> {

    return std::forward<Adaptor>(adaptor)(*this);

  }

  template <typename Adaptor>

  ABSL_MUST_USE_RESULT auto With(

      Adaptor&&

          adaptor) && -> StatusBuilderPurePolicy<Adaptor, StatusBuilder&&> {

    return std::forward<Adaptor>(adaptor)(std::move(*this));

  }

  template <typename Adaptor>

  auto With(

      Adaptor&& adaptor) & -> StatusBuilderSideEffect<Adaptor, StatusBuilder&> {

    return std::forward<Adaptor>(adaptor)(*this);

  }

  template <typename Adaptor>

  ABSL_MUST_USE_RESULT auto With(

      Adaptor&&

          adaptor) && -> StatusBuilderSideEffect<Adaptor, StatusBuilder&&> {

    return std::forward<Adaptor>(adaptor)(std::move(*this));

  }

  template <typename Adaptor>

  auto With(

      Adaptor&& adaptor) & -> StatusBuilderConversion<Adaptor, StatusBuilder&> {

    return std::forward<Adaptor>(adaptor)(*this);

  }

  template <typename Adaptor>

  ABSL_MUST_USE_RESULT auto With(

      Adaptor&&

          adaptor) && -> StatusBuilderConversion<Adaptor, StatusBuilder&&> {

    return std::forward<Adaptor>(adaptor)(std::move(*this));

  }

 private:

  absl::Status status_;

};

}  // namespace cel::internal

#endif  // THIRD_PARTY_CEL_CPP_INTERNAL_STATUS_BUILDER_H_