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#ifndef INSTALLERCALCULATOR_H
#define INSTALLERCALCULATOR_H

#include "installer_global.h"

#include <QHash>
#include <QList>
#include <QSet>
#include <QString>

namespace QInstaller {

class Component;

class INSTALLER_EXPORT InstallerCalculator
{
public:
    InstallerCalculator(const QList<Component *> &allComponents);

    enum InstallReasonType
    {
        Automatic, // "Component(s) added as automatic dependencies"
        Dependent, // "Added as dependency for %1."
        Resolved,  // "Component(s) that have resolved Dependencies"
        Selected   // "Selected Component(s) without Dependencies"
    };

    InstallReasonType installReasonType(Component *component) const;
    QString installReasonReferencedComponent(Component *component) const;
    QString installReason(Component *component) const;
    QList<Component*> orderedComponentsToInstall() const;
    QString componentsToInstallError() const;

    bool appendComponentsToInstall(const QList<Component*> &components);

private:
    void insertInstallReason(Component *component,
                             InstallReasonType installReasonType,
                             const QString &referencedComponentName = QString());
    void realAppendToInstallComponents(Component *component);
    bool appendComponentToInstall(Component *components);
    QString recursionError(Component *component);

    QList<Component*> m_allComponents;
    QHash<Component*, QSet<Component*> > m_visitedComponents;
    QSet<QString> m_toInstallComponentIds; //for faster lookups
    QString m_componentsToInstallError;
    //calculate installation order variables
    QList<Component*> m_orderedComponentsToInstall;
    //we can't use this reason hash as component id hash, because some reasons are ready before
    //the component is added
    QHash<QString, QPair<InstallReasonType, QString> > m_toInstallComponentIdReasonHash;
};

}


#endif // INSTALLERCALCULATOR_H