variant.hpp

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/*
 * Copyright 2020 Robert Bosch GmbH
 *
 * 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#pragma once
 
#include <string>   // for string
#include <utility>  // for move
#include <vector>   // for vector<>
 
#include <fable/schema/interface.hpp>  // for Interface
 
namespace fable::schema {
 
using BoxVec = std::vector<Box>;
using BoxList = std::initializer_list<Box>;
 
class Variant : public Interface {
 public:  // Constructors
  Variant(std::initializer_list<Box> vec) : Variant("", vec) {}
  Variant(std::string desc, std::initializer_list<Box> vec)
      : Variant(std::move(desc), std::vector<Box>(vec)) {}
 
  Variant(std::vector<Box>&& vec) : Variant("", std::move(vec)) {}  // NOLINT(runtime/explicit)
  Variant(std::string desc, std::vector<Box>&& vec);
 
 public:  // Base
  [[nodiscard]] std::unique_ptr<Interface> clone() const override {
    return std::make_unique<Variant>(*this);
  }
  [[nodiscard]] operator Box() const { return Box{this->clone()}; }
  [[nodiscard]] JsonType type() const override { return type_; }
  [[nodiscard]] std::string type_string() const override { return type_string_; }
  [[nodiscard]] bool is_variant() const override { return true; }
  [[nodiscard]] Json usage() const override;
 
  [[nodiscard]] bool is_required() const override { return required_; }
  Variant require() && {
    required_ = true;
    return std::move(*this);
  }
  Variant required(bool value) && {
    required_ = value;
    return std::move(*this);
  }
 
  [[nodiscard]] bool has_description() const { return !desc_.empty(); }
  void set_description(std::string s) override { desc_ = std::move(s); }
  [[nodiscard]] const std::string& description() const override { return desc_; }
  Variant description(std::string desc) && {
    desc_ = std::move(desc);
    return std::move(*this);
  }
 
 public:  // Special
  Variant unique_match(bool value) && {
    unique_match_ = value;
    return std::move(*this);
  }
 
  Variant reset_pointer() && {
    reset_ptr();
    return std::move(*this);
  }
 
 public:  // Overrides
  using Interface::to_json;
  [[nodiscard]] Json json_schema() const override;
  bool validate(const Conf& c, std::optional<SchemaError>& err) const override {
    return validate_index(c, err).has_value();
  }
  void to_json(Json& j) const override { schemas_[0].to_json(j); }
  void from_conf(const Conf& c) override {
    auto index = variant_index(c);
    schemas_[index].from_conf(c);
  }
 
  // TODO: Implement or explain why we don't need the following methods:
  // - serialize
  // - serialize_into
  // - deserialize
  // - deserialize_into
 
  void reset_ptr() override;
 
 private:
  std::optional<size_t> validate_index(const Conf& c, std::optional<SchemaError>& err) const;
  [[nodiscard]] size_t variant_index(const Conf& c) const;
 
 private:
  std::string desc_{};
  std::vector<Box> schemas_;
  bool required_{false};
  JsonType type_{JsonType::null};
  std::string type_string_{};
  bool unique_match_{false};
};
 
inline Variant make_schema(std::initializer_list<Box> vec) { return {vec}; }
inline Variant make_schema(std::string desc, std::initializer_list<Box> vec) {
  return {std::move(desc), std::vector<Box>(vec)};
}
 
inline Variant make_schema(std::vector<Box>&& vec) { return {std::move(vec)}; }
inline Variant make_schema(std::string desc, std::vector<Box>&& vec) {
  return {std::move(desc), std::move(vec)};
}
 
}  // namespace fable::schema