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

#include <QtCore/QRegExp>
#include <QtCore/QDebug>

/*!
  \class Utils::FileNameValidatingLineEdit

  \brief A control that let's the user choose a (base) file name, based on a QLineEdit. Has
   some validation logic for embedding into QWizardPage.
*/

namespace Utils {

#define WINDOWS_DEVICES "CON|AUX|PRN|COM1|COM2|LPT1|LPT2|NUL"

// 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 QRegExp &windowsDeviceNoSubDirPattern()
{
    static const QRegExp rc(QLatin1String(WINDOWS_DEVICES),
                      Qt::CaseInsensitive);
    QTC_ASSERT(rc.isValid(), return rc);
    return rc;
}

static const QRegExp &windowsDeviceSubDirPattern()
{
    static const QRegExp rc(QLatin1String(".*[/\\\\](" WINDOWS_DEVICES ")"), Qt::CaseInsensitive);
    QTC_ASSERT(rc.isValid(), return rc);
    return rc;
}

// ----------- FileNameValidatingLineEdit
FileNameValidatingLineEdit::FileNameValidatingLineEdit(QWidget *parent) :
    BaseValidatingLineEdit(parent),
    m_allowDirectories(false)
{
}

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

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

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

#ifdef Q_OS_WIN
#  define SLASHES "/\\"
#else
#  define SLASHES "/"
#endif

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) {
                if (QChar(*c).isSpace()) {
                    *errorMessage = tr("Name contains white space.");
                } else {
                    *errorMessage = tr("Invalid character '%1'.").arg(*c);
                }
            }
            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 = windowsDeviceNoSubDirPattern().exactMatch(name);
    if (!matchesWinDevice && allowDirectories)
        matchesWinDevice = windowsDeviceSubDirPattern().exactMatch(name);
    if (matchesWinDevice) {
        if (errorMessage)
            *errorMessage = tr("Name matches MS Windows device. (%1).").
                            arg(windowsDeviceNoSubDirPattern().pattern().replace(QLatin1Char('|'), QLatin1Char(',')));
        return false;
    }
    return true;
}

bool  FileNameValidatingLineEdit::validate(const QString &value, QString *errorMessage) const
{
    return validateFileNameExtension(value, requiredExtensions(), errorMessage)
            && validateFileName(value, allowDirectories(), errorMessage);
}


bool FileNameValidatingLineEdit::validateFileNameExtension(const QString &fileName,
                                                           const QStringList &requiredExtensions,
                                                           QString *errorMessage)
{
    // file extension
    if (!requiredExtensions.isEmpty()) {
        foreach (const QString &requiredExtension, requiredExtensions) {
            QString extension = QLatin1String(".") + 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(", "));
            }
        }

        return false;
    }

    return true;
}

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

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

} // namespace Utils
