#include "util.h"

#include "QDebug"
#include <QString>
#include <QGestureEvent>
#include <QTouchEvent>
#include <QContextMenuEvent>
#include <QApplication>
#include <QPlainTextEdit>
#include <QLineEdit>
#include <QFileInfo>
#ifdef Q_OS_ANDROID
#include <QtAndroid>
#include <QAndroidJniEnvironment>
#endif

Util::Util()
{

}

const char Util::unescapeTable[] = "a007円b010円e033円f014円n012円r015円t011円v013円\\134円\'047円\"042円\?077円";

int Util::unescapeHelper(QStringRef text, int& result, int baseBits)
{
 int i, n = 0;
 result = 0;
 for(i = 0; i < text.size(); i++)
 {
 n = text[i].toLatin1();
 if(n >= 'a' && n <= 'z' && n - 'a' + 10 < (1 << baseBits))
 {
 result <<= baseBits;
 result += n - 'a' + 10;
 }
 else if(n >= 'A' && n <= 'Z' && n - 'A' + 10 < (1 << baseBits))
 {
 result <<= baseBits;
 result += n - 'A' + 10;
 }
 else if(n >= '0' && n <= '9' && n - '0' < (1 << baseBits))
 {
 result <<= baseBits;
 result += n - '0';
 }
 else
 break;
 }
 return qMin(i, text.size());
}

QByteArray Util::unescape(const QString &text, QTextCodec* codec)
{
 QByteArray result;

 for(int i = 0; i < text.size(); i++)
 {
 // keep the normal string unchanged
 if(text[i] != '\\' || i + 1 >= text.size())
 {
 int end = i;
 while(end < text.size() && text[end] != '\\')
 end++;
 result += codec->fromUnicode(text.constData() + i, end - i);
 i = end - 1;
 continue;
 }
 // '\' is not at the end, process
 // see https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences

 // 1. \a, \b, \e, \f, \n, \r, \t, \v, \,円 \', \", \?
 size_t j;
 for(j = 0; j < sizeof(unescapeTable) / 2; j++)
 {
 if(text[i + 1] == unescapeTable[j * 2])
 {
 result += unescapeTable[j * 2 + 1];
 i++;
 break;
 }
 }
 if(j < sizeof(unescapeTable) / 2) // processed
 continue;

 int handled, ch;
 // 2. \nnn, 1~3 octal digits for a byte
 if(i + 1 < text.size() && text[i + 1] >= '0' && text[i + 1] <= '7')
 {
 handled = unescapeHelper(text.midRef(i + 1, qMin(3, text.size() - (i + 1))), ch, 3);
 i += handled;
 if(handled)
 result += ch & 0xFF;
 }
 // 3. \xHH, 1~2 hexadecimal digits for a byte
 else if(i + 2 < text.size() && text[i + 1] == 'x')
 {
 handled = unescapeHelper(text.midRef(i + 2, qMin(2, text.size() - (i + 2))), ch, 4);
 if(handled)
 {
 result += ch & 0xFF;
 i += handled + 1; // including 'x'
 }
 }
 // 4. \uHHHH, exact 4 hexadecimal digits for a unicode char
 // might be slow
 else if(i + 5 < text.size() && text[i + 1] == 'u')
 {
 bool isOk;
 ch = text.midRef(i + 2, 4).toInt(&isOk, 16);
 if(isOk)
 {
 QChar qch(ch); // treat it like QString with length=1
 result += codec->fromUnicode(&qch, 1);
 i += 5;
 }
 }
 // 5. invalid ,円 keep it unchanged
 else
 {
 result += codec->fromUnicode(text.constData() + i, 1);
 }
 }
// qDebug() << result.toHex(' ');
// qDebug() << result;
 return result;
}

void Util::disableItem(QStandardItemModel* model, int id, bool enabled)
{
 if(model == nullptr)
 return;
 QStandardItem *item = model->item(id);
 Qt::ItemFlags flags = item->flags();
 flags.setFlag(Qt::ItemIsEnabled, enabled);
 item->setFlags(flags);
}


#ifdef Q_OS_ANDROID
void Util::showToast(const QString& message, bool isLong)
{
 // all the magic must happen on Android UI thread
 // don't capture by reference there
 QtAndroid::runOnAndroidThread([ = ]
 {
 QAndroidJniObject javaString = QAndroidJniObject::fromString(message);
 QAndroidJniObject toast = QAndroidJniObject::callStaticObjectMethod("android/widget/Toast", "makeText",
 "(Landroid/content/Context;Ljava/lang/CharSequence;I)Landroid/widget/Toast;",
 QtAndroid::androidActivity().object(),
 javaString.object(),
 jint(isLong ? 1 : 0));
 toast.callMethod<void>("show");
 });
}
#endif

QString Util::getValidLocalFilename(const QList<QUrl>& urlList)
{
 for(const auto& url : urlList)
 {
 if(url.isLocalFile() && QFileInfo(url.toLocalFile()).isFile())
 return url.toLocalFile();
 }
 return QString();
}

// use TapAndHold gesture to show the context menu
// call widget->grabGesture(Qt::TapAndHoldGesture) then use the event filter
// for QLineEdit, the edit menu will be shown
// for QPlainTextEdit, the parent's context menu will be shown
// useless now...

bool GestureConverter::eventFilter(QObject *obj, QEvent *event)
{
 qDebug() << obj->objectName() << event->type();
 if(event->type() == QEvent::Gesture || event->type() == QEvent::GestureOverride)
 {
 QGestureEvent *ge = static_cast<QGestureEvent*>(event);
 qDebug() << obj->objectName() << ge->gestures();
 QGesture *ges = ge->gesture(Qt::TapAndHoldGesture);
 if(ges->state() == Qt::GestureFinished)
 {
 QContextMenuEvent newEvent(QContextMenuEvent::Mouse, ge->mapToGraphicsScene(ges->hotSpot()).toPoint());
 QApplication::sendEvent(obj, &newEvent);
 }
 }
 return false;
}