// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "qquicktextdocument.h"
#include "qquicktextdocument_p.h"

#include "qquicktextedit_p.h"
#include "qquicktextedit_p_p.h"
#include "qquicktext_p_p.h"

#include <QtQml/qqmlinfo.h>
#include <QtQml/qqmlcontext.h>
#include <QtQuick/private/qquickpixmapcache_p.h>

QT_BEGIN_NAMESPACE

/*!
    \class QQuickTextDocument
    \since 5.1
    \brief The QQuickTextDocument class provides access to the QTextDocument of QQuickTextEdit.
    \inmodule QtQuick

    This class provides access to the QTextDocument of QQuickTextEdit elements.
    This is provided to allow usage of the \l{Rich Text Processing} functionalities of Qt.
    You are not allowed to modify the document, but it can be used to output content, for example with \l{QTextDocumentWriter}),
    or provide additional formatting, for example with \l{QSyntaxHighlighter}.

    The class has to be used from C++ directly, using the property of the \l TextEdit.

    Warning: The QTextDocument provided is used internally by \l {Qt Quick} elements to provide text manipulation primitives.
    You are not allowed to perform any modification of the internal state of the QTextDocument. If you do, the element
    in question may stop functioning or crash.
*/

class QQuickTextDocumentPrivate : public QObjectPrivate
{
public:
    QPointer<QTextDocument> document;
};

/*!
   Constructs a QQuickTextDocument object with
   \a parent as the parent object.
*/
QQuickTextDocument::QQuickTextDocument(QQuickItem *parent)
    : QObject(*(new QQuickTextDocumentPrivate), parent)
{
    Q_D(QQuickTextDocument);
    Q_ASSERT(parent);
    Q_ASSERT(qobject_cast<QQuickTextEdit*>(parent));
    d->document = QPointer<QTextDocument>(qobject_cast<QQuickTextEdit*>(parent)->d_func()->document);
}

/*!
   Returns a pointer to the QTextDocument object.
*/
QTextDocument* QQuickTextDocument::textDocument() const
{
    Q_D(const QQuickTextDocument);
    return d->document.data();
}

QQuickTextDocumentWithImageResources::QQuickTextDocumentWithImageResources(QQuickItem *parent)
: QTextDocument(parent), outstanding(0)
{
    setUndoRedoEnabled(false);
    documentLayout()->registerHandler(QTextFormat::ImageObject, this);
    connect(this, &QTextDocument::baseUrlChanged, [this]() {
        clearResources();
        markContentsDirty(0, characterCount());
    });
}

QQuickTextDocumentWithImageResources::~QQuickTextDocumentWithImageResources()
{
    if (!m_resources.isEmpty())
        qDeleteAll(m_resources);
}

QVariant QQuickTextDocumentWithImageResources::loadResource(int type, const QUrl &name)
{
    QVariant resource = QTextDocument::loadResource(type, name);
    if (resource.isNull() && type == QTextDocument::ImageResource) {
        QQmlContext *context = qmlContext(parent());
        QUrl url = baseUrl().resolved(name);
        QQuickPixmap *p = loadPixmap(context, url);
        resource = p->image();
    }

    return resource;
}

void QQuickTextDocumentWithImageResources::requestFinished()
{
    outstanding--;
    if (outstanding == 0) {
        markContentsDirty(0, characterCount());
        emit imagesLoaded();
    }
}

QSizeF QQuickTextDocumentWithImageResources::intrinsicSize(
        QTextDocument *, int, const QTextFormat &format)
{
    if (format.isImageFormat()) {
        QTextImageFormat imageFormat = format.toImageFormat();

        const int width = qRound(imageFormat.width());
        const bool hasWidth = imageFormat.hasProperty(QTextFormat::ImageWidth) && width > 0;
        const int height = qRound(imageFormat.height());
        const bool hasHeight = imageFormat.hasProperty(QTextFormat::ImageHeight) && height > 0;

        QSizeF size(width, height);
        if (!hasWidth || !hasHeight) {
            QVariant res = resource(QTextDocument::ImageResource, QUrl(imageFormat.name()));
            QImage image = res.value<QImage>();
            if (image.isNull()) {
                if (!hasWidth)
                    size.setWidth(16);
                if (!hasHeight)
                    size.setHeight(16);
                return size;
            }
            QSize imgSize = image.size();

            if (!hasWidth) {
                if (!hasHeight)
                    size.setWidth(imgSize.width());
                else
                    size.setWidth(qRound(height * (imgSize.width() / (qreal) imgSize.height())));
            }
            if (!hasHeight) {
                if (!hasWidth)
                    size.setHeight(imgSize.height());
                else
                    size.setHeight(qRound(width * (imgSize.height() / (qreal) imgSize.width())));
            }
        }
        return size;
    }
    return QSizeF();
}

void QQuickTextDocumentWithImageResources::drawObject(
        QPainter *, const QRectF &, QTextDocument *, int, const QTextFormat &)
{
}

QImage QQuickTextDocumentWithImageResources::image(const QTextImageFormat &format) const
{
    QVariant res = resource(QTextDocument::ImageResource, QUrl(format.name()));
    return res.value<QImage>();
}

QQuickPixmap *QQuickTextDocumentWithImageResources::loadPixmap(
        QQmlContext *context, const QUrl &url)
{

    QHash<QUrl, QQuickPixmap *>::Iterator iter = m_resources.find(url);

    if (iter == m_resources.end()) {
        QQuickPixmap *p = new QQuickPixmap(context->engine(), url);
        iter = m_resources.insert(url, p);

        if (p->isLoading()) {
            p->connectFinished(this, SLOT(requestFinished()));
            outstanding++;
        }
    }

    QQuickPixmap *p = *iter;
    if (p->isError()) {
        if (!errors.contains(url)) {
            errors.insert(url);
            qmlWarning(parent()) << p->error();
        }
    }
    return p;
}

void QQuickTextDocumentWithImageResources::clearResources()
{
    for (QQuickPixmap *pixmap : std::as_const(m_resources))
        pixmap->clear(this);
    qDeleteAll(m_resources);
    m_resources.clear();
    outstanding = 0;
}

QSet<QUrl> QQuickTextDocumentWithImageResources::errors;

QT_END_NAMESPACE

#include "moc_qquicktextdocument.cpp"
#include "moc_qquicktextdocument_p.cpp"