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#include "filenamevalidatinglineedit.h"
#include "qtcassert.h"

#include <QRegularExpression>

/*!
  \class Utils::FileNameValidatingLineEdit

  \brief The FileNameValidatingLineEdit class is a control that lets the user
  choose a (base) file name, based on a QLineEdit.

  The class has
   some validation logic for embedding into QWizardPage.
*/

namespace Utils {

#define WINDOWS_DEVICES_PATTERN "(CON|AUX|PRN|NUL|COM[1-9]|LPT[1-9])(\\..*)?"

// Naming a file like a device name will break on Windows, even if it is
// "com1.txt". Since we are cross-platform, we generally disallow such file
//  names.
static const QRegularExpression &windowsDeviceNoSubDirPattern()
{
    static const QRegularExpression rc(QString("^" WINDOWS_DEVICES_PATTERN "$"),
                                       QRegularExpression::CaseInsensitiveOption);
    QTC_ASSERT(rc.isValid(), return rc);
    return rc;
}

static const QRegularExpression &windowsDeviceSubDirPattern()
{
    static const QRegularExpression rc(QString("^.*[/\\\\]" WINDOWS_DEVICES_PATTERN "$"),
                                       QRegularExpression::CaseInsensitiveOption);
    QTC_ASSERT(rc.isValid(), return rc);
    return rc;
}

// ----------- FileNameValidatingLineEdit
FileNameValidatingLineEdit::FileNameValidatingLineEdit(QWidget *parent) :
    FancyLineEdit(parent),
    m_allowDirectories(false),
    m_forceFirstCapitalLetter(false)
{
    setValidationFunction([this](FancyLineEdit *edit, QString *errorMessage) {
        return validateFileNameExtension(edit->text(), requiredExtensions(), errorMessage)
                && validateFileName(edit->text(), allowDirectories(), errorMessage);
    });
}

bool FileNameValidatingLineEdit::allowDirectories() const
{
    return m_allowDirectories;
}

void FileNameValidatingLineEdit::setAllowDirectories(bool v)
{
    m_allowDirectories = v;
}

bool FileNameValidatingLineEdit::forceFirstCapitalLetter() const
{
    return m_forceFirstCapitalLetter;
}

void FileNameValidatingLineEdit::setForceFirstCapitalLetter(bool b)
{
    m_forceFirstCapitalLetter = b;
}

/* Validate a file base name, check for forbidden characters/strings. */


#define SLASHES "/\\"

static const char notAllowedCharsSubDir[]   = ",^@={}[]~!?:&*\"|#%<>$\"'();`' ";
static const char notAllowedCharsNoSubDir[] = ",^@={}[]~!?:&*\"|#%<>$\"'();`' " SLASHES;

static const char *notAllowedSubStrings[] = {".."};

bool FileNameValidatingLineEdit::validateFileName(const QString &name,
                                                  bool allowDirectories,
                                                  QString *errorMessage /* = 0*/)
{
    if (name.isEmpty()) {
        if (errorMessage)
            *errorMessage = tr("Name is empty.");
        return false;
    }
    // Characters
    const char *notAllowedChars = allowDirectories ? notAllowedCharsSubDir : notAllowedCharsNoSubDir;
    for (const char *c = notAllowedChars; *c; c++)
        if (name.contains(QLatin1Char(*c))) {
            if (errorMessage) {
                const QChar qc = QLatin1Char(*c);
                if (qc.isSpace())
                    *errorMessage = tr("Name contains white space.");
                else
                    *errorMessage = tr("Invalid character \"%1\".").arg(qc);
            }
            return false;
        }
    // Substrings
    const int notAllowedSubStringCount = sizeof(notAllowedSubStrings)/sizeof(const char *);
    for (int s = 0; s < notAllowedSubStringCount; s++) {
        const QLatin1String notAllowedSubString(notAllowedSubStrings[s]);
        if (name.contains(notAllowedSubString)) {
            if (errorMessage)
                *errorMessage = tr("Invalid characters \"%1\".").arg(QString(notAllowedSubString));
            return false;
        }
    }
    // Windows devices
    bool matchesWinDevice = name.contains(windowsDeviceNoSubDirPattern());
    if (!matchesWinDevice && allowDirectories)
        matchesWinDevice = name.contains(windowsDeviceSubDirPattern());
    if (matchesWinDevice) {
        if (errorMessage)
            *errorMessage = tr("Name matches MS Windows device"
                               " (CON, AUX, PRN, NUL,"
                               " COM1, COM2, ..., COM9,"
                               " LPT1, LPT2, ..., LPT9)");
        return false;
    }
    return true;
}

QString FileNameValidatingLineEdit::fixInputString(const QString &string)
{
    if (!forceFirstCapitalLetter())
        return string;

    QString fixedString = string;
    if (!string.isEmpty() && string.at(0).isLower())
        fixedString[0] = string.at(0).toUpper();

    return fixedString;
}

bool FileNameValidatingLineEdit::validateFileNameExtension(const QString &fileName,
                                                           const QStringList &requiredExtensions,
                                                           QString *errorMessage)
{
    // file extension
    if (!requiredExtensions.isEmpty()) {
        for (const QString &requiredExtension : requiredExtensions) {
            QString extension = QLatin1Char('.') + requiredExtension;
            if (fileName.endsWith(extension, Qt::CaseSensitive) && extension.count() < fileName.count())
                return true;
        }

        if (errorMessage) {
            if (requiredExtensions.count() == 1)
                *errorMessage = tr("File extension %1 is required:").arg(requiredExtensions.first());
            else
                *errorMessage = tr("File extensions %1 are required:").arg(requiredExtensions.join(QLatin1String(", ")));
        }

        return false;
    }

    return true;
}

QStringList FileNameValidatingLineEdit::requiredExtensions() const
{
    return m_requiredExtensionList;
}

void FileNameValidatingLineEdit::setRequiredExtensions(const QStringList &extensions)
{
    m_requiredExtensionList = extensions;
}

} // namespace Utils
