BOOL GetEnumeratedFileName()

in src/modules/powerrename/lib/Helpers.cpp [360:521]
146 lines of code
33 McCabe index (conditional complexity)

BOOL GetEnumeratedFileName(__out_ecount(cchMax) PWSTR pszUniqueName, UINT cchMax, __in PCWSTR pszTemplate, __in_opt PCWSTR pszDir, unsigned long ulMinLong, __inout unsigned long* pulNumUsed)
{
    PWSTR pszName = nullptr;
    HRESULT hr = S_OK;
    BOOL fRet = FALSE;
    int cchDir = 0;

    if (0 != cchMax && pszUniqueName)
    {
        *pszUniqueName = 0;
        if (pszDir)
        {
            hr = StringCchCopy(pszUniqueName, cchMax, pszDir);
            if (SUCCEEDED(hr))
            {
                hr = PathCchAddBackslashEx(pszUniqueName, cchMax, &pszName, nullptr);
                if (SUCCEEDED(hr))
                {
                    cchDir = lstrlen(pszDir);
                }
            }
        }
        else
        {
            cchDir = 0;
            pszName = pszUniqueName;
        }
    }
    else
    {
        hr = E_INVALIDARG;
    }

    int cchTmp = 0;
    int cchStem = 0;
    PCWSTR pszStem = nullptr;
    PCWSTR pszRest = nullptr;
    wchar_t szFormat[MAX_PATH] = { 0 };

    if (SUCCEEDED(hr))
    {
        pszStem = pszTemplate;

        pszRest = StrChr(pszTemplate, L'(');
        while (pszRest)
        {
            PCWSTR pszEndUniq = CharNext(pszRest);
            while (*pszEndUniq && *pszEndUniq >= L'0' && *pszEndUniq <= L'9')
            {
                pszEndUniq++;
            }

            if (*pszEndUniq == L')')
            {
                break;
            }

            pszRest = StrChr(CharNext(pszRest), L'(');
        }

        if (!pszRest)
        {
            pszRest = PathFindExtension(pszTemplate);
            cchStem = (int)(pszRest - pszTemplate);

            hr = StringCchCopy(szFormat, ARRAYSIZE(szFormat), L" (%lu)");
        }
        else
        {
            pszRest++;

            cchStem = (int)(pszRest - pszTemplate);

            while (*pszRest && *pszRest >= L'0' && *pszRest <= L'9')
            {
                pszRest++;
            }

            hr = StringCchCopy(szFormat, ARRAYSIZE(szFormat), L"%lu");
        }
    }

    unsigned long ulMax = 0;
    unsigned long ulMin = 0;
    if (SUCCEEDED(hr))
    {
        int cchFormat = lstrlen(szFormat);
        if (cchFormat < 3)
        {
            *pszUniqueName = L'\0';
            return FALSE;
        }
        ulMin = ulMinLong;
        cchTmp = cchMax - cchDir - cchStem - (cchFormat - 3);
        switch (cchTmp)
        {
        case 1:
            ulMax = 10;
            break;
        case 2:
            ulMax = 100;
            break;
        case 3:
            ulMax = 1000;
            break;
        case 4:
            ulMax = 10000;
            break;
        case 5:
            ulMax = 100000;
            break;
        default:
            if (cchTmp <= 0)
            {
                ulMax = ulMin;
            }
            else
            {
                ulMax = 1000000;
            }
            break;
        }
    }

    if (SUCCEEDED(hr))
    {
        hr = StringCchCopyN(pszName, pszUniqueName + cchMax - pszName, pszStem, cchStem);
        if (SUCCEEDED(hr))
        {
            PWSTR pszDigit = pszName + cchStem;

            for (unsigned long ul = ulMin; ((ul < ulMax) && (!fRet)); ul++)
            {
                wchar_t szTemp[MAX_PATH] = { 0 };
                hr = StringCchPrintf(szTemp, ARRAYSIZE(szTemp), szFormat, ul);
                if (SUCCEEDED(hr))
                {
                    hr = StringCchCat(szTemp, ARRAYSIZE(szTemp), pszRest);
                    if (SUCCEEDED(hr))
                    {
                        hr = StringCchCopy(pszDigit, pszUniqueName + cchMax - pszDigit, szTemp);
                        if (SUCCEEDED(hr))
                        {
                            if (!PathFileExists(pszUniqueName))
                            {
                                (*pulNumUsed) = ul;
                                fRet = TRUE;
                            }
                        }
                    }
                }
            }
        }
    }

    if (!fRet)
    {
        *pszUniqueName = L'\0';
    }

    return fRet;
}