JSONGenerator.h

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/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *     http://aws.amazon.com/apache2.0/
 *
 * or in the "license" file accompanying this file. This file 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 ALEXA_CLIENT_SDK_AVSCOMMON_UTILS_INCLUDE_AVSCOMMON_UTILS_JSON_JSONGENERATOR_H_
#define ALEXA_CLIENT_SDK_AVSCOMMON_UTILS_INCLUDE_AVSCOMMON_UTILS_JSON_JSONGENERATOR_H_

#include <cstdint>
#include <string>
#include <type_traits>

#include <rapidjson/stringbuffer.h>
#include <rapidjson/writer.h>

namespace alexaClientSDK {
namespace avsCommon {
namespace utils {
namespace json {

class JsonGenerator {
public:
    JsonGenerator();

    ~JsonGenerator() = default;

    bool isFinalized();

    bool startObject(const std::string& key);

    bool finishObject();

    bool startArray(const std::string& key);

    bool startArrayElement();

    bool finishArrayElement();

    bool finishArray();


    bool addMember(const std::string& key, const char* value);
    bool addMember(const std::string& key, const std::string& value);
    bool addMember(const std::string& key, int64_t value);
    bool addMember(const std::string& key, uint64_t value);
    bool addMember(const std::string& key, int value);
    bool addMember(const std::string& key, unsigned int value);
    bool addMember(const std::string& key, bool value);
    bool addMember(const std::string& key, double value);

    template <typename CollectionT, typename ValueT = typename CollectionT::value_type>
    bool addStringArray(const std::string& key, const CollectionT& collection);

    template <typename CollectionT, typename ValueT = typename CollectionT::value_type>
    bool addMembersArray(const std::string& key, const CollectionT& collection);

    bool addRawJsonMember(const std::string& key, const std::string& json, bool validate = true);

    template <
        typename CollectionArrayT,
        typename CollectionValueT = typename CollectionArrayT::value_type,
        typename ValueT = typename CollectionValueT::value_type>
    bool addCollectionOfStringArray(const std::string& key, const CollectionArrayT& collection);

    std::string toString(bool finalize = true);

private:
    bool checkWriter();

    bool finalize();

    rapidjson::StringBuffer m_buffer;

    rapidjson::Writer<rapidjson::StringBuffer> m_writer;
};

template <typename CollectionT, typename ValueT>
bool JsonGenerator::addStringArray(const std::string& key, const CollectionT& collection) {
    auto keyLength = static_cast<rapidjson::SizeType>(key.length());
    if (!checkWriter() || !m_writer.Key(key.c_str(), keyLength)) {
        return false;
    }
    m_writer.StartArray();
    for (const auto& value : collection) {
        static_assert(std::is_same<ValueT, std::string>::value, "We only support string collection.");
        m_writer.String(value);
    }
    m_writer.EndArray();
    return true;
}

template <typename CollectionT, typename ValueT>
bool JsonGenerator::addMembersArray(const std::string& key, const CollectionT& collection) {
    auto keyLength = static_cast<rapidjson::SizeType>(key.length());
    if (!checkWriter() || !m_writer.Key(key.c_str(), keyLength)) {
        return false;
    }
    m_writer.StartArray();
    for (const auto& value : collection) {
        static_assert(std::is_same<ValueT, std::string>::value, "We only support string collection.");
        m_writer.RawValue(value.c_str(), value.length(), rapidjson::kStringType);
    }
    m_writer.EndArray();
    return true;
}

template <typename CollectionArrayT, typename CollectionValueT, typename ValueT>
bool JsonGenerator::addCollectionOfStringArray(const std::string& key, const CollectionArrayT& collection) {
    auto keyLength = static_cast<rapidjson::SizeType>(key.length());
    if (!checkWriter() || !m_writer.Key(key.c_str(), keyLength)) {
        return false;
    }
    m_writer.StartArray();
    for (const auto& stringArray : collection) {
        m_writer.StartArray();
        for (const auto& value : stringArray) {
            static_assert(std::is_same<ValueT, std::string>::value, "We only support string collection.");
            m_writer.String(value);
        }
        m_writer.EndArray();
    }
    m_writer.EndArray();
    return true;
}

}  // namespace json
}  // namespace utils
}  // namespace avsCommon
}  // namespace alexaClientSDK

#endif  // ALEXA_CLIENT_SDK_AVSCOMMON_UTILS_INCLUDE_AVSCOMMON_UTILS_JSON_JSONGENERATOR_H_