/*
 * Copyright (C) 2019 ~ 2019 Deepin Technology Co., Ltd.
 *
 * Author:     xuwenw <xuwenw@xuwenw.so>
 *
 * Maintainer: xuwenw <xuwenw@xuwenw.so>
 *
 * 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 3 of the License, or
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include "mainpanelcontrol.h"
#include "../item/dockitem.h"
#include "util/docksettings.h"

#include <DAnchors>

#include <QDrag>
#include <QTimer>

DWIDGET_USE_NAMESPACE

MainPanelControl::MainPanelControl(QWidget *parent)
    : QWidget(parent)
    , m_mainPanelLayout(new QBoxLayout(QBoxLayout::LeftToRight, this))
    , m_fixedAreaWidget(new QWidget(this))
    , m_appAreaWidget(new QWidget(this))
    , m_trayAreaWidget(new QWidget(this))
    , m_pluginAreaWidget(new QWidget(this))
    , m_fixedAreaLayout(new QBoxLayout(QBoxLayout::LeftToRight))
    , m_trayAreaLayout(new QBoxLayout(QBoxLayout::LeftToRight))
    , m_pluginLayout(new QBoxLayout(QBoxLayout::LeftToRight))
    , m_appAreaSonWidget(new QWidget(this))
    , m_appAreaSonLayout(new QBoxLayout(QBoxLayout::LeftToRight))
    , m_position(Qt::TopEdge)
{
    init();
    updateMainPanelLayout();
    setAcceptDrops(true);
}

MainPanelControl::~MainPanelControl()
{
}

void MainPanelControl::init()
{
    m_mainPanelLayout->setMargin(0);
    m_mainPanelLayout->setContentsMargins(0, 0, 0, 0);
    m_fixedAreaLayout->setMargin(0);
    m_fixedAreaLayout->setContentsMargins(0, 0, 0, 0);
    m_pluginLayout->setMargin(0);
    m_pluginLayout->setContentsMargins(0, 0, 0, 0);
    m_trayAreaLayout->setMargin(0);
    m_trayAreaLayout->setContentsMargins(0, 0, 0, 0);
    m_appAreaSonLayout->setMargin(0);
    m_appAreaSonLayout->setContentsMargins(0, 0, 0, 0);
    m_mainPanelLayout->addWidget(m_fixedAreaWidget);
    m_fixedAreaWidget->setLayout(m_fixedAreaLayout);
    m_mainPanelLayout->addWidget(m_appAreaWidget);
    m_mainPanelLayout->addWidget(m_trayAreaWidget);
    m_trayAreaWidget->setLayout(m_trayAreaLayout);
    m_mainPanelLayout->addWidget(m_pluginAreaWidget);
    m_pluginAreaWidget->setLayout(m_pluginLayout);
    m_appAreaSonWidget->setLayout(m_appAreaSonLayout);
    m_fixedAreaLayout->setSpacing(0);
    m_appAreaSonLayout->setSpacing(0);
    m_trayAreaLayout->setSpacing(0);
    m_pluginLayout->setSpacing(0);
}

void MainPanelControl::updateDisplayMode(DisplayMode m_displayMode)
{
    DAnchorsBase::clearAnchors(m_appAreaSonWidget);
    DAnchors<QWidget> anchors(m_appAreaSonWidget);
    if (m_displayMode == Dock::DisplayMode::Fashion) {
        anchors.setAnchor(Qt::AnchorHorizontalCenter, this, Qt::AnchorHorizontalCenter);
    } else {
        anchors.setAnchor(Qt::AnchorLeft, m_appAreaWidget, Qt::AnchorLeft);
    }
}

void MainPanelControl::updateMainPanelLayout()
{
    switch (m_position) {
    case Qt::TopEdge:
    case Qt::BottomEdge:
        m_fixedAreaWidget->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Expanding);
        m_appAreaWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
        m_pluginAreaWidget->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Expanding);
        m_trayAreaWidget->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Expanding);
        m_mainPanelLayout->setDirection(QBoxLayout::LeftToRight);
        m_fixedAreaLayout->setDirection(QBoxLayout::LeftToRight);
        m_pluginLayout->setDirection(QBoxLayout::LeftToRight);
        m_trayAreaLayout->setDirection(QBoxLayout::LeftToRight);
        m_appAreaSonLayout->setDirection(QBoxLayout::LeftToRight);
        break;
    case Qt::RightEdge:
    case Qt::LeftEdge:
        m_fixedAreaWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
        m_appAreaWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
        m_pluginAreaWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
        m_trayAreaWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
        m_mainPanelLayout->setDirection(QBoxLayout::TopToBottom);
        m_fixedAreaLayout->setDirection(QBoxLayout::TopToBottom);
        m_pluginLayout->setDirection(QBoxLayout::TopToBottom);
        m_trayAreaLayout->setDirection(QBoxLayout::TopToBottom);
        m_appAreaSonLayout->setDirection(QBoxLayout::TopToBottom);
        break;
    default:
        break;
    }

    QTimer::singleShot(0, this, &MainPanelControl::updateAppAreaSonWidgetSize);
}

void MainPanelControl::addFixedAreaItem(const int index, QWidget *wdg)
{
    m_fixedAreaLayout->insertWidget(index, wdg, 0, Qt::AlignCenter);
}

void MainPanelControl::addAppAreaItem(const int index, QWidget *wdg)
{
    m_appAreaSonLayout->insertWidget(index, wdg, 0, Qt::AlignCenter);
}

void MainPanelControl::addTrayAreaItem(const int index, QWidget *wdg)
{
    m_trayAreaLayout->insertWidget(index, wdg, 0, Qt::AlignCenter);
}

void MainPanelControl::addPluginAreaItem(const int index, QWidget *wdg)
{
    m_pluginLayout->insertWidget(index, wdg, 0, Qt::AlignCenter);
}

void MainPanelControl::removeFixedAreaItem(QWidget *wdg)
{
    m_fixedAreaLayout->removeWidget(wdg);
}

void MainPanelControl::removeAppAreaItem(QWidget *wdg)
{
    m_appAreaSonLayout->removeWidget(wdg);
}

void MainPanelControl::removeTrayAreaItem(QWidget *wdg)
{
    m_trayAreaLayout->removeWidget(wdg);
}

void MainPanelControl::removePluginAreaItem(QWidget *wdg)
{
    m_pluginLayout->removeWidget(wdg);
}

void MainPanelControl::resizeEvent(QResizeEvent *event)
{
    updateAppAreaSonWidgetSize();

    return QWidget::resizeEvent(event);
}

void MainPanelControl::updateAppAreaSonWidgetSize()
{
    for (int i = 0; i < m_appAreaSonLayout->count(); ++i) {
        QWidget *w = m_appAreaSonLayout->itemAt(i)->widget();
        if (w) {
            if ((m_position == Qt::TopEdge) || (m_position == Qt::BottomEdge)) {
                w->setMaximumSize(height(), height());
            } else {
                w->setMaximumSize(width(), width());
            }
        }
    }

    for (int i = 0; i < m_fixedAreaLayout->count(); ++i) {
        QWidget *w = m_fixedAreaLayout->itemAt(i)->widget();
        if (w) {
            if ((m_position == Qt::TopEdge) || (m_position == Qt::BottomEdge)) {
                w->setMaximumSize(height(), height());
            } else {
                w->setMaximumSize(width(), width());
            }
        }
    }

    if ((m_position == Qt::TopEdge) || (m_position == Qt::BottomEdge)) {
        m_appAreaSonWidget->setMaximumWidth(qMin((m_appAreaWidget->geometry().right() - width() / 2) * 2, m_appAreaWidget->width()));
    } else {
        m_appAreaSonWidget->setMaximumHeight(qMin((m_appAreaWidget->geometry().bottom() - height() / 2) * 2, m_appAreaWidget->height()));
    }

    m_appAreaSonWidget->adjustSize();
}

void MainPanelControl::setPositonValue(const Qt::Edge val)
{
    m_position = val;
}

void MainPanelControl::insertItem(const int index, DockItem *item)
{
    item->installEventFilter(this);

    switch (item->itemType()) {
    case DockItem::Launcher:
        addFixedAreaItem(index, item);
        break;
    case DockItem::App:
        addAppAreaItem(index, item);
        break;
    case DockItem::TrayPlugin:
        addTrayAreaItem(index, item);
        break;
    case DockItem::Plugins:
        addPluginAreaItem(index, item);
        break;
    default:
        break;
    }

    updateAppAreaSonWidgetSize();
}

void MainPanelControl::removeItem(DockItem *item)
{
    switch (item->itemType()) {
    case DockItem::Launcher:
        removeFixedAreaItem(item);
        break;
    case DockItem::App:
        removeAppAreaItem(item);
        break;
    case DockItem::TrayPlugin:
        removeTrayAreaItem(item);
        break;
    case DockItem::Plugins:
        removePluginAreaItem(item);
        break;
    default:
        break;
    }

    updateAppAreaSonWidgetSize();
}

void MainPanelControl::moveItem(DockItem *sourceItem, DockItem *targetItem)
{
    // get target index
    int idx = -1;
    if (targetItem->itemType() == DockItem::App)
        idx = m_appAreaSonLayout->indexOf(targetItem);
    else if (targetItem->itemType() == DockItem::Plugins)
        idx = m_pluginLayout->indexOf(targetItem);
    else
        return;

    // remove old item
    removeItem(sourceItem);

    // insert new position
    insertItem(idx, sourceItem);
}

void MainPanelControl::dragEnterEvent(QDragEnterEvent *e)
{
    e->accept();
}

void MainPanelControl::dragMoveEvent(QDragMoveEvent *e)
{
    DockItem *sourceItem = qobject_cast<DockItem *>(e->source());
    if (!sourceItem) {
        e->ignore();
        return;
    }

    DockItem *targetItem = dropTargetItem(sourceItem, e->pos());
    if (!targetItem) {
        e->ignore();
        return;
    }

    e->accept();

    if (targetItem == sourceItem)
        return;

    moveItem(sourceItem, targetItem);
    emit itemMoved(sourceItem, targetItem);
}

bool MainPanelControl::eventFilter(QObject *watched, QEvent *event)
{
    if (event->type() != QEvent::MouseMove)
        return false;

    QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
    if (!mouseEvent || mouseEvent->buttons() != Qt::LeftButton)
        return false;

    DockItem *item = qobject_cast<DockItem *>(watched);
    if (!item)
        return false;

    if (item->itemType() != DockItem::App && item->itemType() != DockItem::Plugins)
        return false;

    startDrag(item);

    return true;
}

void MainPanelControl::startDrag(DockItem *item)
{
    const QPixmap pixmap = item->grab();

    item->setDraging(true);
    item->update();

    QDrag *drag = new QDrag(item);
    drag->setPixmap(pixmap);
    drag->setHotSpot(pixmap.rect().center() / pixmap.devicePixelRatioF());
    drag->setMimeData(new QMimeData);
    drag->exec(Qt::MoveAction);

    item->setDraging(false);
    item->update();
}

DockItem *MainPanelControl::dropTargetItem(DockItem *sourceItem, QPoint point)
{
    QWidget *parentWidget = nullptr;

    switch (sourceItem->itemType()) {
    case DockItem::App:
        parentWidget = m_appAreaSonWidget;
        break;
    case DockItem::Plugins:
        parentWidget = m_pluginAreaWidget;
        break;
    default:
        break;
    }

    if (!parentWidget)
        return nullptr;

    point = parentWidget->mapFromParent(point);
    QLayout *parentLayout = parentWidget->layout();

    DockItem *targetItem = nullptr;

    for (int i = 0 ; i < parentLayout->count(); ++i) {
        QLayoutItem *layoutItem = parentLayout->itemAt(i);
        DockItem *dockItem = qobject_cast<DockItem *>(layoutItem->widget());
        if (!dockItem)
            continue;

        QRect rect;
        rect.setTopLeft(dockItem->pos());
        rect.setSize(dockItem->size());

        if (rect.contains(point)) {
            targetItem = dockItem;
            break;
        }
    }

    return targetItem;
}