// Copyright Contributors to the DNF5 project.
// Copyright Contributors to the libdnf project.
// SPDX-License-Identifier: LGPL-2.1-or-later
//
// This file is part of libdnf: https://github.com/rpm-software-management/libdnf/
//
// Libdnf is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// Libdnf is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with libdnf.  If not, see <https://www.gnu.org/licenses/>.

#ifndef LIBDNF5_COMMON_MESSAGE_HPP
#define LIBDNF5_COMMON_MESSAGE_HPP

#include "impl_ptr.hpp"

#include "libdnf5/defs.h"
#include "libdnf5/utils/locale.hpp"

#include <string>

namespace libdnf5 {

/// A base class for passing a message whose formatting, including localization
/// (translation, argument format) is done at the destination.
/// Usage: The user creates a child of this class and implements the `format` method.
class LIBDNF_API Message {
public:
    Message();
    Message(const Message & src);
    Message(Message && src) noexcept;
    virtual ~Message();

    Message & operator=(const Message & src);
    Message & operator=(Message && src) noexcept;

    /// Formats the contained message according to the specified arguments and returns the result as a string.
    ///
    /// @param translate  If `true`, it will attempt to translate the message to the requested locale.
    /// @param locale     requested locale for translation and argument formating, nullptr = use global/thread locale
    /// @return A string object holding the formatted result.
    virtual std::string format(bool translate, const libdnf5::utils::Locale * locale = nullptr) const = 0;

private:
    class LIBDNF_LOCAL Impl;
    ImplPtr<Impl> p_impl;
};


/// Class for passing an empty message.
class LIBDNF_API EmptyMessage final : public Message {
public:
    EmptyMessage();
    EmptyMessage(const EmptyMessage & src);
    EmptyMessage(EmptyMessage && src) noexcept;
    ~EmptyMessage() override;

    EmptyMessage & operator=(const EmptyMessage & src);
    EmptyMessage & operator=(EmptyMessage && src) noexcept;

    /// Returns empty string
    ///
    /// @param translate  ignored
    /// @param locale     ignored
    /// @return empty string object
    std::string format(bool translate, const libdnf5::utils::Locale * locale = nullptr) const override;
};

}  // namespace libdnf5

#endif  // LIBDNF5_COMMON_MESSAGE_HPP
