evcharger-app/evcharger-app/versionutils.cpp

#include "versionutils.h"

namespace
{
bool isVersionSeparator(QChar character)
{
    return character == u'.' || character == u',' || character == u'-' || character == u'+';
}
}

int VersionUtils::compareVersions(const QString &left, const QString &right) const
{
    return compareVersion(left, right);
}

qsizetype VersionUtils::separatorIndex(QStringView version)
{
    for (qsizetype index = 0; index < version.size(); ++index)
    {
        if (isVersionSeparator(version[index]))
            return index;
    }

    return -1;
}

int VersionUtils::compareVersionPart(QStringView left, QStringView right)
{
    while (!left.isEmpty() && left.front() == u'0')
        left = left.sliced(1);

    while (!right.isEmpty() && right.front() == u'0')
        right = right.sliced(1);

    if (left.size() < right.size())
        return -1;

    if (left.size() > right.size())
        return 1;

    const int comparison = left.compare(right, Qt::CaseSensitive);
    if (comparison < 0)
        return -1;
    if (comparison > 0)
        return 1;
    return 0;
}

int VersionUtils::compareVersion(QStringView left, QStringView right)
{
    while (true)
    {
        const qsizetype leftIndex = separatorIndex(left);
        const qsizetype rightIndex = separatorIndex(right);

        const QStringView leftPart = left.first(leftIndex < 0 ? left.size() : leftIndex);
        const QStringView rightPart = right.first(rightIndex < 0 ? right.size() : rightIndex);

        if (const int result = compareVersionPart(leftPart, rightPart); result != 0)
            return result;

        if (leftIndex < 0 && rightIndex < 0)
            return 0;

        if (leftIndex >= 0)
            left = left.sliced(leftIndex + 1);
        else
            return rightIndex < 0 ? 1 : -1;

        if (rightIndex >= 0)
            right = right.sliced(rightIndex + 1);
        else
            return leftIndex < 0 ? -1 : 1;
    }
}