json_settings.h

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2020 Jon Evans <jon@craftyjon.com>
 * Copyright (C) 2020 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _JSON_SETTINGS_H
#define _JSON_SETTINGS_H

#include <core/wx_stl_compat.h>

#include <nlohmann/json.hpp>
#include <utility>
#include <wx/string.h>

#include <core/optional.h>

class wxConfigBase;
class NESTED_SETTINGS;
class PARAM_BASE;
class SETTINGS_MANAGER;

extern const wxChar* const traceSettings;

enum class SETTINGS_LOC {
    USER,       
    PROJECT,    
    COLORS,     
    NESTED,     
    NONE,       
};


class JSON_SETTINGS : public nlohmann::json
{
public:
    JSON_SETTINGS( const wxString& aFilename, SETTINGS_LOC aLocation, int aSchemaVersion ) :
            JSON_SETTINGS( aFilename, aLocation, aSchemaVersion, true, true, true ) {}

    JSON_SETTINGS( const wxString& aFilename, SETTINGS_LOC aLocation, int aSchemaVersion,
                   bool aCreateIfMissing, bool aCreateIfDefault, bool aWriteFile );

    virtual ~JSON_SETTINGS();

    wxString GetFilename() const { return m_filename; }

    wxString GetFullFilename() const;

    void SetFilename( const wxString& aFilename ) { m_filename = aFilename; }

    SETTINGS_LOC GetLocation() const { return m_location; }

    void SetLegacyFilename( const wxString& aFilename ) { m_legacy_filename = aFilename; }

    bool IsReadOnly() const { return !m_writeFile; }
    void SetReadOnly( bool aReadOnly ) { m_writeFile = !aReadOnly; }

    virtual void Load();

    virtual bool Store();

    virtual bool LoadFromFile( const wxString& aDirectory = "" );

    virtual bool SaveToFile( const wxString& aDirectory = "", bool aForce = false );

    void ResetToDefaults();

    bool IsDefault( const std::string& aParamName );

    OPT<nlohmann::json> GetJson( const std::string& aPath ) const;

    template<typename ValueType>
    OPT<ValueType> Get( const std::string& aPath ) const
    {
        if( OPT<nlohmann::json> ret = GetJson( aPath ) )
        {
            try
            {
                return ret->get<ValueType>();
            }
            catch( ... )
            {
            }
        }

        return NULLOPT;
    }

    template<typename ValueType>
    void Set( const std::string& aPath, ValueType aVal )
    {
        ( *this )[PointerFromString( aPath ) ] = aVal;
    }

    bool Migrate();

    virtual bool MigrateFromLegacy( wxConfigBase* aLegacyConfig );

    void AddNestedSettings( NESTED_SETTINGS* aSettings );

    void ReleaseNestedSettings( NESTED_SETTINGS* aSettings );

    void SetManager( SETTINGS_MANAGER* aManager )
    {
        m_manager = aManager;
    }

    static nlohmann::json::json_pointer PointerFromString( std::string aPath );

    static bool SetIfPresent( const nlohmann::json& aObj, const std::string& aPath,
                              wxString& aTarget );

    static bool SetIfPresent( const nlohmann::json& aObj, const std::string& aPath, bool& aTarget );

    static bool SetIfPresent( const nlohmann::json& aObj, const std::string& aPath, int& aTarget );

    static bool SetIfPresent( const nlohmann::json& aObj, const std::string& aPath,
                              unsigned int& aTarget );
protected:

    void registerMigration( int aOldSchemaVersion, int aNewSchemaVersion,
                            std::function<bool(void)> aMigrator );

    template<typename ValueType>
    bool fromLegacy( wxConfigBase* aConfig, const std::string& aKey, const std::string& aDest );

    bool fromLegacyString( wxConfigBase* aConfig, const std::string& aKey,
                           const std::string& aDest );

    bool fromLegacyColor( wxConfigBase* aConfig, const std::string& aKey,
                          const std::string& aDest );

    virtual wxString getFileExt() const
    {
        return wxT( "json" );
    }

    virtual wxString getLegacyFileExt() const
    {
        return wxEmptyString;
    }

    wxString m_filename;

    wxString m_legacy_filename;

    SETTINGS_LOC m_location;

    std::vector<PARAM_BASE*> m_params;

    std::vector<NESTED_SETTINGS*> m_nested_settings;

    bool m_createIfMissing;

    bool m_createIfDefault;

    bool m_writeFile;

    bool m_deleteLegacyAfterMigration;

    bool m_resetParamsIfMissing;

    int m_schemaVersion;

    SETTINGS_MANAGER* m_manager;

    std::vector<nlohmann::json::json_pointer> m_preserved_paths;

    std::map<int, std::pair<int, std::function<bool()>>> m_migrators;
};

// Specializations to allow conversion between wxString and std::string via JSON_SETTINGS API

template<> OPT<wxString> JSON_SETTINGS::Get( const std::string& aPath ) const;

template<> void JSON_SETTINGS::Set<wxString>( const std::string& aPath, wxString aVal );

// Specializations to allow directly reading/writing wxStrings from JSON

void to_json( nlohmann::json& aJson, const wxString& aString );

void from_json( const nlohmann::json& aJson, wxString& aString );

#endif