#include "ElaTreeViewStyle.h"

#include <QDebug>
#include <QPainter>
#include <QPainterPath>
#include <QStyleOption>

#include "ElaTheme.h"
ElaTreeViewStyle::ElaTreeViewStyle(QStyle *style) {
    _pItemHeight   = 35;
    _pHeaderMargin = 5;
    _themeMode     = eTheme->getThemeMode();
    connect(eTheme, &ElaTheme::themeModeChanged, this, [=](ElaThemeType::ThemeMode themeMode) { _themeMode = themeMode; });
}

ElaTreeViewStyle::~ElaTreeViewStyle() {}

void ElaTreeViewStyle::drawPrimitive(PrimitiveElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget) const {
    switch (element) {
    case QStyle::PE_PanelItemViewItem: {
        // Item背景
        if (const QStyleOptionViewItem *vopt = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
            painter->save();
            painter->setRenderHint(QPainter::Antialiasing);
            QRect itemRect = vopt->rect;
            itemRect.adjust(0, 2, 0, -2);
            QPainterPath path;
            path.addRoundedRect(itemRect, 4, 4);
            if (vopt->state & QStyle::State_Selected) {
                if (vopt->state & QStyle::State_MouseOver) {
                    // 选中时覆盖
                    painter->fillPath(path, ElaThemeColor(_themeMode, BasicSelectedHoverAlpha));
                } else {
                    // 选中
                    painter->fillPath(path, ElaThemeColor(_themeMode, BasicSelectedAlpha));
                }
            } else {
                if (vopt->state & QStyle::State_MouseOver) {
                    // 覆盖时颜色
                    painter->fillPath(path, ElaThemeColor(_themeMode, BasicHoverAlpha));
                }
            }
            painter->restore();
        }
        return;
    }
    case QStyle::PE_IndicatorBranch: {
        // 展开图标绘制
        if (const QStyleOptionViewItem *vopt = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
            if (vopt->state.testFlag(QStyle::State_Children)) {
                painter->save();
                QRect indicatorRect = option->rect;
                indicatorRect.adjust(0, 0, -2, 0);
                QFont iconFont = QFont("ElaAwesome");
                iconFont.setPixelSize(17);
                painter->setFont(iconFont);
                painter->setPen(ElaThemeColor(_themeMode, BasicText));
                painter->drawText(indicatorRect, Qt::AlignVCenter | Qt::AlignRight,
                                  vopt->state.testFlag(QStyle::State_Open) ? QChar((unsigned short)ElaIconType::AngleDown)
                                                                           : QChar((unsigned short)ElaIconType::AngleRight));
                painter->restore();
            }
        }
        return;
    }
    case QStyle::PE_PanelItemViewRow: {
        return;
    }
    case QStyle::PE_Widget: {
        return;
    }
    case QStyle::PE_Frame: {
        return;
    }
    default: {
        break;
    }
    }
    QProxyStyle::drawPrimitive(element, option, painter, widget);
}

void ElaTreeViewStyle::drawControl(ControlElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget) const {
    switch (element) {
    case QStyle::CE_ShapedFrame: {
        // viewport视口外的其他区域背景
        QRect frameRect = option->rect;
        frameRect.adjust(1, 1, -1, -1);
        painter->save();
        painter->setRenderHints(QPainter::Antialiasing);
        painter->setPen(ElaThemeColor(_themeMode, PopupBorder));
        painter->setBrush(ElaThemeColor(_themeMode, BasicBaseAlpha));
        painter->drawRoundedRect(frameRect, 3, 3);
        painter->restore();
        return;
    }
    case QStyle::CE_HeaderLabel: {
        // 表头文字绘制
        if (const QStyleOptionHeader *hopt = qstyleoption_cast<const QStyleOptionHeader *>(option)) {
            QRect headerRect = option->rect;
            painter->save();
            painter->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::TextAntialiasing);
            if (!hopt->text.isEmpty()) {
                painter->setPen(ElaThemeColor(_themeMode, BasicText));
                painter->drawText(headerRect, hopt->textAlignment, hopt->text);
            }
            painter->restore();
        }
        return;
    }
    case QStyle::CE_HeaderSection: {
        // 表头背景绘制
        painter->save();
        painter->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::TextAntialiasing);
        painter->setPen(Qt::NoPen);
        painter->setBrush(ElaThemeColor(_themeMode, BasicBaseDeepAlpha));
        painter->drawRect(option->rect);
        painter->restore();
        return;
    }
    case QStyle::CE_ItemViewItem: {
        if (const QStyleOptionViewItem *vopt = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
            // 背景绘制
            this->drawPrimitive(QStyle::PE_PanelItemViewItem, option, painter, widget);

            // 内容绘制
            QRect itemRect = option->rect;
            painter->save();
            painter->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::TextAntialiasing);
            QRect checkRect = proxy()->subElementRect(SE_ItemViewItemCheckIndicator, vopt, widget);
            QRect iconRect  = proxy()->subElementRect(SE_ItemViewItemDecoration, vopt, widget);
            QRect textRect  = proxy()->subElementRect(SE_ItemViewItemText, vopt, widget);
            // 复选框绘制
            if (checkRect.isValid()) {
                painter->save();
                // 图标绘制
                if (vopt->checkState == Qt::Checked) {
                    painter->setPen(Qt::NoPen);
                    painter->setBrush(ElaThemeColor(_themeMode, PrimaryNormal));
                    painter->drawRoundedRect(checkRect, 2, 2);
                    QFont iconFont = QFont("ElaAwesome");
                    iconFont.setPixelSize(checkRect.width() * 0.85);
                    painter->setFont(iconFont);
                    painter->setPen(ElaThemeColor(ElaThemeType::Dark, BasicText));
                    painter->drawText(checkRect, Qt::AlignCenter, QChar((unsigned short)ElaIconType::Check));
                } else if (vopt->checkState == Qt::PartiallyChecked) {
                    painter->setPen(Qt::NoPen);
                    painter->setBrush(ElaThemeColor(_themeMode, PrimaryNormal));
                    painter->drawRoundedRect(checkRect, 2, 2);
                    painter->setPen(ElaThemeColor(ElaThemeType::Dark, BasicText));
                    QLine checkLine(checkRect.x() + 3, checkRect.center().y(), checkRect.right() - 3, checkRect.center().y());
                    painter->drawLine(checkLine);
                } else {
                    painter->setPen(QPen(ElaThemeColor(_themeMode, BasicBorderDeep), 1.2));
                    painter->setBrush(Qt::transparent);
                    painter->drawRoundedRect(checkRect, 2, 2);
                }
                painter->restore();
            }
            // 图标绘制
            if (!vopt->icon.isNull()) {
                QIcon::Mode  mode  = QIcon::Normal;
                QIcon::State state = vopt->state & QStyle::State_Open ? QIcon::On : QIcon::Off;
                vopt->icon.paint(painter, iconRect, vopt->decorationAlignment, mode, state);
            }
            // 文字绘制
            if (!vopt->text.isEmpty()) {
                painter->setPen(ElaThemeColor(_themeMode, BasicText));
                painter->drawText(textRect, vopt->displayAlignment, vopt->text);
            }
            // 选中特效
            int heightOffset = itemRect.height() / 4;
            painter->setPen(Qt::NoPen);
            painter->setBrush(ElaThemeColor(_themeMode, PrimaryNormal));
            if (vopt->state.testFlag(QStyle::State_Selected) &&
                (vopt->viewItemPosition == QStyleOptionViewItem::Beginning || vopt->viewItemPosition == QStyleOptionViewItem::OnlyOne)) {
                painter->drawRoundedRect(QRectF(itemRect.x() + 3, itemRect.y() + heightOffset, 3, itemRect.height() - 2 * heightOffset), 3, 3);
            }
            painter->restore();
        }
        return;
    }
    default: {
        break;
    }
    }
    QProxyStyle::drawControl(element, option, painter, widget);
}

QSize ElaTreeViewStyle::sizeFromContents(ContentsType type, const QStyleOption *option, const QSize &size, const QWidget *widget) const {
    switch (type) {
    case QStyle::CT_ItemViewItem: {
        QSize itemSize = QProxyStyle::sizeFromContents(type, option, size, widget);
        itemSize.setHeight(_pItemHeight);
        return itemSize;
    }
    default: {
        break;
    }
    }
    return QProxyStyle::sizeFromContents(type, option, size, widget);
}

int ElaTreeViewStyle::pixelMetric(PixelMetric metric, const QStyleOption *option, const QWidget *widget) const {
    switch (metric) {
    case QStyle::PM_HeaderMargin: {
        return _pHeaderMargin;
    }
    default: {
        break;
    }
    }
    return QProxyStyle::pixelMetric(metric, option, widget);
}

QRect ElaTreeViewStyle::subElementRect(SubElement element, const QStyleOption *option, const QWidget *widget) const {
    switch (element) {
    case QStyle::SE_ItemViewItemCheckIndicator: {
        if (const QStyleOptionViewItem *vopt = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
            if (vopt->viewItemPosition != QStyleOptionViewItem::Middle && vopt->viewItemPosition != QStyleOptionViewItem::End) {
                QRect indicatorRect = QProxyStyle::subElementRect(element, option, widget);
                indicatorRect.adjust(_leftPadding, 0, _leftPadding, 0);
                return indicatorRect;
            }
        }
        break;
    }
    case QStyle::SE_ItemViewItemDecoration: {
        if (const QStyleOptionViewItem *vopt = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
            if (vopt->viewItemPosition != QStyleOptionViewItem::Middle && vopt->viewItemPosition != QStyleOptionViewItem::End) {
                QRect iconRect = QProxyStyle::subElementRect(element, option, widget);
                iconRect.adjust(_leftPadding + 5, 0, _leftPadding + 5, 0);
                return iconRect;
            }
        }
        break;
    }
    case QStyle::SE_ItemViewItemText: {
        if (const QStyleOptionViewItem *vopt = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
            if (vopt->viewItemPosition != QStyleOptionViewItem::Middle && vopt->viewItemPosition != QStyleOptionViewItem::End) {
                QRect textRect = QProxyStyle::subElementRect(element, option, widget);
                textRect.adjust(_leftPadding + 10, 0, 0, 0);
                return textRect;
            }
        }
        break;
    }
    default: {
        break;
    }
    }
    return QProxyStyle::subElementRect(element, option, widget);
}