// 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_REPO_REPO_CACHE_HPP
#define LIBDNF5_REPO_REPO_CACHE_HPP

#include "repo_cache_errors.hpp"

#include "libdnf5/base/base_weak.hpp"
#include "libdnf5/common/impl_ptr.hpp"
#include "libdnf5/defs.h"

#include <filesystem>
#include <string>


namespace libdnf5::repo {


struct LIBDNF_API RepoCacheRemoveStatistics {
    RepoCacheRemoveStatistics();
    ~RepoCacheRemoveStatistics();

    RepoCacheRemoveStatistics(const RepoCacheRemoveStatistics & src);
    RepoCacheRemoveStatistics & operator=(const RepoCacheRemoveStatistics & src);

    RepoCacheRemoveStatistics(RepoCacheRemoveStatistics && src) noexcept;
    RepoCacheRemoveStatistics & operator=(RepoCacheRemoveStatistics && src) noexcept;

    std::size_t get_files_removed();     // Number of removed files and links.
    std::size_t get_dirs_removed();      // Number of removed directorires.
    std::uintmax_t get_bytes_removed();  // Number of removed bytes.
    std::size_t get_errors();            // Numbes of errors.

    RepoCacheRemoveStatistics & operator+=(const RepoCacheRemoveStatistics & rhs) noexcept;

private:
    friend class RepoCache;

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


/// Repository cache management class.
class LIBDNF_API RepoCache {
public:
    using RemoveStatistics = RepoCacheRemoveStatistics;

    /// The name of the attribute used to mark the cache as expired.
    static constexpr const char * ATTRIBUTE_EXPIRED = "expired";

    /// Construct a new repository cache management instance.
    ///
    /// @param base            WeakPtr on the Base instance.
    /// @param repo_cache_dir  Path to repository cache directory.
    RepoCache(const libdnf5::BaseWeakPtr & base, const std::filesystem::path & repo_cache_dir);

    ~RepoCache();

    RepoCache(const RepoCache & src);
    RepoCache & operator=(const RepoCache & src);

    RepoCache(RepoCache && src) noexcept;
    RepoCache & operator=(RepoCache && src) noexcept;

    /// Construct a new repository cache management instance.
    ///
    /// @param base            Base instance reference.
    /// @param repo_cache_dir  Path to repository cache directory.
    RepoCache(libdnf5::Base & base, const std::string & repo_cache_dir);

    /// Removes metadata from the cache.
    ///
    /// @return Number of deleted files and directories. Number of errors.
    RemoveStatistics remove_metadata();

    /// Removes packages from the cache.
    ///
    /// @return Number of deleted files and directories. Number of errors.
    RemoveStatistics remove_packages();

    /// Removes solvable files from the cache.
    ///
    /// @return Number of deleted files and directories. Number of errors.
    RemoveStatistics remove_solv_files();

    /// Removes metadata, packages, solvable files, and attributes from the cache.
    /// If the repository cache directory becomes empty, it will also be deleted.
    ///
    /// @return Number of deleted files and directories. Number of errors.
    RemoveStatistics remove_all();

    /// Writes `value` to the` name` attribute.
    /// If the attribute does not exist, it is created. If it already existed, its value is overwritten.
    ///
    /// @param name   Attribute name.
    /// @param value  Attribute value.
    /// @exception std::runtime_exception  An error occurred while writing the attribute.
    void write_attribute(const std::string & name, const std::string & value = "");

    /// Returns the value of the `name` attribute.
    ///
    /// @param name  Attribute name.
    /// @return The value of the `name` attribute.
    /// @exception std::runtime_exception  The `name` attribute does not exist or an error occurred while reading it.
    std::string read_attribute(const std::string & name);

    /// Tests if the `name` attribute exists.
    ///
    /// @param name  Attribute name.
    /// @return If the `name` attribute exists, it returns true otherwise false.
    bool is_attribute(const std::string & name);

    /// Removes the `name` attribute.
    ///
    /// @param name  Attribute name.
    /// @return true if the attribute was deleted, false if the attribute did not exist.
    /// @exception std::runtime_exception An error occurred while removing the attribute.
    bool remove_attribute(const std::string & name);

    /// Gets the id of the cached repository.
    ///
    /// @return id of the cached repository.
    /// @exception RepoCacheException Throws an exception if the reposiitory id cannot be determined.
    std::string get_repoid();

private:
    friend RepoCacheRemoveStatistics;

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


}  // namespace libdnf5::repo

#endif
