pollymc/launcher/minecraft/Rule.h

/* Copyright 2013-2021 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License 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.
 */

#pragma once

#include <QString>
#include <QList>
#include <QJsonObject>
#include <memory>
#include "RuntimeContext.h"

class Library;
class Rule;

enum RuleAction
{
    Allow,
    Disallow,
    Defer
};

QList<std::shared_ptr<Rule>> rulesFromJsonV4(const QJsonObject &objectWithRules);

class Rule
{
protected:
    RuleAction m_result;
    virtual bool applies(const Library *parent, const RuntimeContext & runtimeContext) = 0;

public:
    Rule(RuleAction result) : m_result(result)
    {
    }
    virtual ~Rule() {};
    virtual QJsonObject toJson() = 0;
    RuleAction apply(const Library *parent, const RuntimeContext & runtimeContext)
    {
        if (applies(parent, runtimeContext))
            return m_result;
        else
            return Defer;
    }
};

class OsRule : public Rule
{
private:
    // the OS
    QString m_system;
    // the OS version regexp
    QString m_version_regexp;

protected:
    virtual bool applies(const Library *, const RuntimeContext & runtimeContext)
    {
        return runtimeContext.classifierMatches(m_system);
    }
    OsRule(RuleAction result, QString system, QString version_regexp)
        : Rule(result), m_system(system), m_version_regexp(version_regexp)
    {
    }

public:
    virtual QJsonObject toJson();
    static std::shared_ptr<OsRule> create(RuleAction result, QString system,
                                          QString version_regexp)
    {
        return std::shared_ptr<OsRule>(new OsRule(result, system, version_regexp));
    }
};

class ImplicitRule : public Rule
{
protected:
    virtual bool applies(const Library *, const RuntimeContext & runtimeContext)
    {
        return true;
    }
    ImplicitRule(RuleAction result) : Rule(result)
    {
    }

public:
    virtual QJsonObject toJson();
    static std::shared_ptr<ImplicitRule> create(RuleAction result)
    {
        return std::shared_ptr<ImplicitRule>(new ImplicitRule(result));
    }
};