/****************************************************************
 * This file is distributed under the following license:
 *
 * Copyright (c) 2010, RetroShare Team
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA  02110-1301, USA.
 ****************************************************************/

#include <QMimeData>
#include <QTextDocumentFragment>
#include "MimeTextEdit.h"
#include "util/HandleRichText.h"
#include <QCompleter>
#include <QAbstractItemView>
#include <QKeyEvent>
#include <QScrollBar>

MimeTextEdit::MimeTextEdit(QWidget *parent)
    : QTextEdit(parent), mCompleter(0)
{
    mCompleterKeyModifiers=Qt::ControlModifier;
    mCompleterKey=Qt::Key_Space;
    mForceCompleterShowNextKeyEvent=false;
    mCompleterStartString="";
}

bool MimeTextEdit::canInsertFromMimeData(const QMimeData* source) const
{
#if QT_VERSION >= 0x040700
	// embedded images are not supported before QT 4.7.0
	if (source != NULL) {
		if (source->hasImage()) {
			return true;
		}
	}
#endif

	return QTextEdit::canInsertFromMimeData(source);
}

void MimeTextEdit::insertFromMimeData(const QMimeData* source)
{
#if QT_VERSION >= 0x040700
	// embedded images are not supported before QT 4.7.0
	if (source != NULL) {
		if (source->hasImage()) {
			// insert as embedded image
			QImage image = qvariant_cast<QImage>(source->imageData());
			if (image.isNull() == false) {
				QString	encodedImage;
				if (RsHtml::makeEmbeddedImage(image, encodedImage, 640*480)) {
					QTextDocumentFragment fragment = QTextDocumentFragment::fromHtml(encodedImage);
					this->textCursor().insertFragment(fragment);
					return;
				}
			}
		}
	}
#endif

	return QTextEdit::insertFromMimeData(source);
}

void MimeTextEdit::setCompleter(QCompleter *completer)
{
    if (mCompleter)
        QObject::disconnect(mCompleter, 0, this, 0);

    mCompleter = completer;

    if (!mCompleter)
        return;

    mCompleter->setWidget(this);
    mCompleter->setCompletionMode(QCompleter::PopupCompletion);
    mCompleter->setCaseSensitivity(Qt::CaseInsensitive);
    QObject::connect(mCompleter, SIGNAL(activated(QString)),
                     this, SLOT(insertCompletion(QString)));
}

QCompleter *MimeTextEdit::completer() const
{
    return mCompleter;
}

void MimeTextEdit::insertCompletion(const QString& completion)
{
    if (mCompleter->widget() != this)
        return;
    QTextCursor tc = textCursor();
    if (mCompleter->completionPrefix().length()>0) {
        tc.movePosition(QTextCursor::PreviousWord, QTextCursor::KeepAnchor);
    }
    tc.removeSelectedText();
    tc.insertText(mCompleterStartString+completion);
    mCompleterStartString="";
    setTextCursor(tc);
}

QString MimeTextEdit::textUnderCursor() const
{
    QTextCursor tc = textCursor();
    tc.select(QTextCursor::WordUnderCursor);
    return tc.selectedText();
}

void MimeTextEdit::focusInEvent(QFocusEvent *e)
{
    if (mCompleter)
        mCompleter->setWidget(this);
    QTextEdit::focusInEvent(e);
}

void MimeTextEdit::keyPressEvent(QKeyEvent *e)
{

    if (mCompleter && mCompleter->popup()->isVisible()) {
        // The following keys are forwarded by the completer to the widget
        switch (e->key()) {
        case Qt::Key_Enter:
        case Qt::Key_Return:
        case Qt::Key_Escape:
        case Qt::Key_Tab:
        case Qt::Key_Backtab:
            mCompleter->popup()->hide();
            mForceCompleterShowNextKeyEvent=false;
            e->ignore();
            return; // let the completer do default behavior
        default:
            break;
        }
    }

    bool isShortcut = ((e->modifiers() & mCompleterKeyModifiers) && e->key() == mCompleterKey);
    if (isShortcut && !mForceCompleterShowNextKeyEvent) {
        mCompleterStartString="";
    }
    isShortcut |= mForceCompleterShowNextKeyEvent;
    if (!mCompleter || !isShortcut) // do not process the shortcut when we have a completer
        QTextEdit::keyPressEvent(e);

    if (!mCompleter) return; //Nothing else to do if not mCompleter initialized

    if (!isShortcut && (mCompleter && !mCompleter->popup()->isVisible())) {
        return;
    }

    if (!mForceCompleterShowNextKeyEvent) {
        static QString eow(" ~!@#$%^&*()_+{}|:\"<>?,./;'[]\\-="); // end of word
        if (!isShortcut && !e->text().isEmpty() && eow.contains(e->text())){
            mCompleter->popup()->hide();
            return;
        }
    }

    QString completionPrefix = textUnderCursor();
    if (completionPrefix != mCompleter->completionPrefix()) {
        mCompleter->setCompletionPrefix(completionPrefix);
        mCompleter->popup()->setCurrentIndex(mCompleter->completionModel()->index(0, 0));
    }

    QRect cr = cursorRect();
    cr.setWidth(mCompleter->popup()->sizeHintForColumn(0)
                + mCompleter->popup()->verticalScrollBar()->sizeHint().width());
    mCompleter->complete(cr); // popup it up!

    if (mCompleter->completionCount()==0 && isShortcut){
        QTextEdit::keyPressEvent(e);// Process the key if no match
    }
    mForceCompleterShowNextKeyEvent=false;
}

void MimeTextEdit::setCompleterKeyModifiers(Qt::KeyboardModifier modifiers)
{
    mCompleterKeyModifiers=modifiers;
}
Qt::KeyboardModifier MimeTextEdit::getCompleterKeyModifiers() const
{
    return mCompleterKeyModifiers;
}

void MimeTextEdit::setCompleterKey(Qt::Key key)
{
    mCompleterKey=key;
}
Qt::Key MimeTextEdit::getCompleterKey() const
{
    return mCompleterKey;
}
void MimeTextEdit::forceCompleterShowNextKeyEvent(QString startString="")
{
    if (!mCompleter) return; //Nothing else to do if not mCompleter initialized

    if(!mCompleter->popup()->isVisible()){
    mForceCompleterShowNextKeyEvent=true;
    mCompleterStartString=startString;
}
}