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** Copyright (C) 2019 The Qt Company Ltd.
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** This file is part of the tools applications of the Qt Toolkit.
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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#include "pythonwriteimports.h"

#include <customwidgetsinfo.h>
#include <option.h>
#include <uic.h>

#include <ui4.h>

#include <QtCore/qtextstream.h>

QT_BEGIN_NAMESPACE

static const char *standardImports =
R"I(from PySide2.QtCore import (QCoreApplication, QDate, QDateTime, QMetaObject,
    QObject, QPoint, QRect, QSize, QTime, QUrl, Qt)
from PySide2.QtGui import (QBrush, QColor, QConicalGradient, QCursor, QFont,
    QFontDatabase, QIcon, QKeySequence, QLinearGradient, QPalette, QPainter,
    QPixmap, QRadialGradient)
from PySide2.QtWidgets import *
)I";

// Change the name of a qrc file "dir/foo.qrc" file to the Python
// module name "foo_rc" according to project conventions.
static QString pythonResource(QString resource)
{
    const int lastSlash = resource.lastIndexOf(QLatin1Char('/'));
    if (lastSlash != -1)
        resource.remove(0, lastSlash + 1);
    if (resource.endsWith(QLatin1String(".qrc"))) {
        resource.chop(4);
        resource.append(QLatin1String("_rc"));
    }
    return resource;
}

namespace Python {

WriteImports::WriteImports(Uic *uic) : m_uic(uic)
{
}

void WriteImports::acceptUI(DomUI *node)
{
    auto &output = m_uic->output();
    output << standardImports << '\n';
    if (auto customWidgets = node->elementCustomWidgets()) {
        TreeWalker::acceptCustomWidgets(customWidgets);
        output << '\n';
    }

    if (auto resources = node->elementResources()) {
        const auto includes = resources->elementInclude();
        for (auto include : includes) {
            if (include->hasAttributeLocation())
                writeImport(pythonResource(include->attributeLocation()));
        }
        output << '\n';
    }
}

void WriteImports::writeImport(const QString &module)
{

    if (m_uic->option().fromImports)
        m_uic->output() << "from  . ";
    m_uic->output() << "import " << module << '\n';
}

QString WriteImports::qtModuleOf(const DomCustomWidget *node) const
{
    if (m_uic->customWidgetsInfo()->extends(node->elementClass(), QLatin1String("QAxWidget")))
        return QStringLiteral("QtAxContainer");
    if (const auto headerElement = node->elementHeader()) {
        const auto &header = headerElement->text();
        if (header.startsWith(QLatin1String("Qt"))) {
            const int slash = header.indexOf(QLatin1Char('/'));
            if (slash != -1)
                return header.left(slash);
        }
    }
    return QString();
}

void WriteImports::acceptCustomWidget(DomCustomWidget *node)
{
    const auto &className = node->elementClass();
    if (className.contains(QLatin1String("::")))
        return; // Exclude namespaced names (just to make tests pass).
    const QString &importModule = qtModuleOf(node);
    auto &output = m_uic->output();
    // For starting importing PySide2 modules
    if (!importModule.isEmpty()) {
        output << "from ";
        if (importModule.startsWith(QLatin1String("Qt")))
            output << "PySide2.";
        output << importModule;
        if (!className.isEmpty())
            output << " import " << className << "\n\n";
    } else {
        // When the elementHeader is not set, we know it's the continuation
        // of a PySide2 import or a normal import of another module.
        if (!node->elementHeader() || node->elementHeader()->text().isEmpty()) {
            output << "import " << className << '\n';
        } else { // When we do have elementHeader, we know it's a relative import.
            QString modulePath = node->elementHeader()->text();
            // Replace the '/' by '.'
            modulePath.replace(QLatin1Char('/'), QLatin1Char('.'));
            // '.h' is added by default on headers for <customwidget>
            if (modulePath.endsWith(QLatin1String(".h")))
                modulePath.chop(2);
            output << "from " << modulePath << " import " << className << '\n';
        }
    }
}

} // namespace Python

QT_END_NAMESPACE
