ARMSX2/common/SettingsWrapper.h

// SPDX-FileCopyrightText: 2002-2026 PCSX2 Dev Team
// SPDX-License-Identifier: GPL-3.0+

#pragma once

#include "MemorySettingsInterface.h"
#include "SettingsInterface.h"

#include "common/EnumOps.h"
#include "common/SmallString.h"

#include <optional>
#include <vector>

// Helper class which loads or saves depending on the derived class.
class SettingsWrapper
{
public:
	SettingsWrapper(SettingsInterface& si);

	virtual bool IsLoading() const = 0;
	virtual bool IsSaving() const = 0;

	virtual void Entry(const char* section, const char* var, int& value, const int defvalue = 0) = 0;
	virtual void Entry(const char* section, const char* var, uint& value, const uint defvalue = 0) = 0;
	virtual void Entry(const char* section, const char* var, bool& value, const bool defvalue = false) = 0;
	virtual void Entry(const char* section, const char* var, float& value, const float defvalue = 0.0) = 0;
	virtual void Entry(const char* section, const char* var, std::string& value, const std::string& default_value = std::string()) = 0;
	virtual void Entry(const char* section, const char* var, SmallStringBase& value, std::string_view default_value = std::string_view()) = 0;

	// This special form of Entry is provided for bitfields, which cannot be passed by reference.
	virtual bool EntryBitBool(const char* section, const char* var, bool value, const bool defvalue = false) = 0;
	virtual int EntryBitfield(const char* section, const char* var, int value, const int defvalue = 0) = 0;

	template <typename T>
	void EnumEntry(const char* section, const char* var, T& value, const char* const* enumArray = nullptr, const T defvalue = (T)0)
	{
		int tstore = (int)value;
		auto defaultvalue = enum_cast(defvalue);
		if (enumArray == NULL)
			Entry(section, var, tstore, defaultvalue);
		else
			_EnumEntry(section, var, tstore, enumArray, defaultvalue);
		value = (T)tstore;
	}

	template <typename T>
	void EnumEntry(const char* section, const char* var, T& value, std::optional<T> (*parse_function)(const char*),
		const char*(name_function)(T value), T default_value)
	{
		TinyString str_value(name_function(value));
		Entry(section, var, str_value, name_function(default_value));
		if (std::optional<T> parsed_value = parse_function(str_value); parsed_value.has_value())
			value = parsed_value.value();
	}

protected:
	virtual void _EnumEntry(const char* section, const char* var, int& value, const char* const* enumArray, int defvalue) = 0;

	SettingsInterface& m_si;
};

class SettingsLoadWrapper final : public SettingsWrapper
{
public:
	SettingsLoadWrapper(SettingsInterface& si);

	bool IsLoading() const override;
	bool IsSaving() const override;

	void Entry(const char* section, const char* var, int& value, const int defvalue = 0) override;
	void Entry(const char* section, const char* var, uint& value, const uint defvalue = 0) override;
	void Entry(const char* section, const char* var, bool& value, const bool defvalue = false) override;
	void Entry(const char* section, const char* var, float& value, const float defvalue = 0.0) override;
	void Entry(const char* section, const char* var, std::string& value, const std::string& default_value = std::string()) override;
	void Entry(const char* section, const char* var, SmallStringBase& value, std::string_view default_value = std::string_view()) override;

	bool EntryBitBool(const char* section, const char* var, bool value, const bool defvalue = false) override;
	int EntryBitfield(const char* section, const char* var, int value, const int defvalue = 0) override;

protected:
	void _EnumEntry(const char* section, const char* var, int& value, const char* const* enumArray, int defvalue) override;
};

class SettingsSaveWrapper final : public SettingsWrapper
{
public:
	SettingsSaveWrapper(SettingsInterface& si);

	bool IsLoading() const override;
	bool IsSaving() const override;

	void Entry(const char* section, const char* var, int& value, const int defvalue = 0) override;
	void Entry(const char* section, const char* var, uint& value, const uint defvalue = 0) override;
	void Entry(const char* section, const char* var, bool& value, const bool defvalue = false) override;
	void Entry(const char* section, const char* var, float& value, const float defvalue = 0.0) override;
	void Entry(const char* section, const char* var, std::string& value, const std::string& default_value = std::string()) override;
	void Entry(const char* section, const char* var, SmallStringBase& value, std::string_view default_value = std::string_view()) override;

	bool EntryBitBool(const char* section, const char* var, bool value, const bool defvalue = false) override;
	int EntryBitfield(const char* section, const char* var, int value, const int defvalue = 0) override;

protected:
	void _EnumEntry(const char* section, const char* var, int& value, const char* const* enumArray, int defvalue) override;
};

/// Saves only the values that differ from every reference, and deletes the rest.
///
/// A per-game settings file is a record of decisions. Copying a whole configuration
/// into one verbatim writes hundreds of keys the player never chose and never saw,
/// and each of those then reads back as a deliberate choice — which is exactly how
/// a copy of the global settings ends up suppressing every automatic fix a game had.
/// Give this the values that would apply anyway and only the real deviations land.
///
/// Comparison goes through the string form rather than the typed value, so a float
/// or an enum name compares the way it will actually be stored. That is why the
/// references must be MemorySettingsInterfaces built the same way: same class, same
/// formatting, exact comparison.
class SettingsSaveDeviationsWrapper final : public SettingsWrapper
{
public:
	SettingsSaveDeviationsWrapper(SettingsInterface& si, std::vector<const MemorySettingsInterface*> references);
	~SettingsSaveDeviationsWrapper();

	bool IsLoading() const override;
	bool IsSaving() const override;

	void Entry(const char* section, const char* var, int& value, const int defvalue = 0) override;
	void Entry(const char* section, const char* var, uint& value, const uint defvalue = 0) override;
	void Entry(const char* section, const char* var, bool& value, const bool defvalue = false) override;
	void Entry(const char* section, const char* var, float& value, const float defvalue = 0.0) override;
	void Entry(const char* section, const char* var, std::string& value, const std::string& default_value = std::string()) override;
	void Entry(const char* section, const char* var, SmallStringBase& value, std::string_view default_value = std::string_view()) override;

	bool EntryBitBool(const char* section, const char* var, bool value, const bool defvalue = false) override;
	int EntryBitfield(const char* section, const char* var, int value, const int defvalue = 0) override;

protected:
	void _EnumEntry(const char* section, const char* var, int& value, const char* const* enumArray, int defvalue) override;

private:
	/// Stages the value with `write`, then keeps it only if no reference already says
	/// the same thing.
	template <typename WriteFn>
	void Keep(const char* section, const char* var, const WriteFn& write);

	std::vector<const MemorySettingsInterface*> m_references;
	/// Holds the candidate long enough to be rendered the same way a reference is.
	MemorySettingsInterface m_staging;
};

class SettingsClearWrapper final : public SettingsWrapper
{
public:
	SettingsClearWrapper(SettingsInterface& si);

	bool IsLoading() const override;
	bool IsSaving() const override;

	void Entry(const char* section, const char* var, int& value, const int defvalue = 0) override;
	void Entry(const char* section, const char* var, uint& value, const uint defvalue = 0) override;
	void Entry(const char* section, const char* var, bool& value, const bool defvalue = false) override;
	void Entry(const char* section, const char* var, float& value, const float defvalue = 0.0) override;
	void Entry(const char* section, const char* var, std::string& value, const std::string& default_value = std::string()) override;
	void Entry(const char* section, const char* var, SmallStringBase& value, std::string_view default_value = std::string_view()) override;

	bool EntryBitBool(const char* section, const char* var, bool value, const bool defvalue = false) override;
	int EntryBitfield(const char* section, const char* var, int value, const int defvalue = 0) override;

protected:
	void _EnumEntry(const char* section, const char* var, int& value, const char* const* enumArray, int defvalue) override;
};

#define SettingsWrapSection(section) const char* CURRENT_SETTINGS_SECTION = section;
#define SettingsWrapEntry(var) wrap.Entry(CURRENT_SETTINGS_SECTION, #var, var, var)
#define SettingsWrapEntryEx(var, name) wrap.Entry(CURRENT_SETTINGS_SECTION, name, var, var)
#define SettingsWrapBitfield(varname) varname = wrap.EntryBitfield(CURRENT_SETTINGS_SECTION, #varname, varname, varname)
#define SettingsWrapBitBool(varname) varname = wrap.EntryBitBool(CURRENT_SETTINGS_SECTION, #varname, !!varname, varname)
#define SettingsWrapBitfieldEx(varname, textname) varname = wrap.EntryBitfield(CURRENT_SETTINGS_SECTION, textname, varname, varname)
#define SettingsWrapBitBoolEx(varname, textname) varname = wrap.EntryBitBool(CURRENT_SETTINGS_SECTION, textname, !!varname, varname)
#define SettingsWrapEnumEx(varname, textname, names) wrap.EnumEntry(CURRENT_SETTINGS_SECTION, textname, varname, names, varname)
#define SettingsWrapParsedEnum(varname, textname, parse_func, name_func) wrap.EnumEntry(CURRENT_SETTINGS_SECTION, textname, varname, parse_func, name_func, varname)
#define SettingsWrapIntEnumEx(varname, textname) varname = static_cast<decltype(varname)>(wrap.EntryBitfield(CURRENT_SETTINGS_SECTION, textname, static_cast<int>(varname), static_cast<int>(varname)))