#include "custommodel.h"

CustomModel::CustomModel(QObject* parent) : QAbstractItemModel(parent)
{
    // 初始化数据
    ListItem item1;
    item1.text = "Item 1";

    ListItem item2;
    item2.text = "Item 2";

    ListItem child1;
    child1.text = "Child 1 of Item 2";
    item2.children.append(child1);
    item1.children.append(child1);
    topLevelItems.append(item1);
    topLevelItems.append(item2);
}

CustomModel::~CustomModel()
{
    // 清理数据
    topLevelItems.clear();
}

QModelIndex CustomModel::index(int row, int column, const QModelIndex& parent) const
{
    if (!hasIndex(row, column, parent))
        return QModelIndex();

    if (!parent.isValid())
    {
        // 一级列表项
        if (row < topLevelItems.size())
            return createIndex(row, column, &topLevelItems[row]);
    }
    else
    {
        // 二级列表项
        ListItem* parentItem = static_cast<ListItem*>(parent.internalPointer());
        if (row < parentItem->children.size())
            return createIndex(row, column, &parentItem->children[row]);
    }

    return QModelIndex();
}

QModelIndex CustomModel::parent(const QModelIndex& child) const
{
    if (!child.isValid())
        return QModelIndex();

    ListItem* childItem = static_cast<ListItem*>(child.internalPointer());
    if (!childItem)
        return QModelIndex();

    ListItem* parentItem = nullptr;

    if (childItem != &topLevelItems[0])
    {
        for (const ListItem& item : topLevelItems)
        {
            if (item.children.contains(*childItem))
            {
                parentItem = const_cast<ListItem*>(&item);
                break;
            }
        }
    }

    if (parentItem)
    {
        int row = topLevelItems.indexOf(*parentItem);
        return createIndex(row, 0, parentItem);
    }

    return QModelIndex();
}

int CustomModel::rowCount(const QModelIndex& parent) const
{
    if (parent.column() > 0)
        return 0;

    if (!parent.isValid())
    {
        // 一级列表的行数
        return topLevelItems.size();
    }
    else
    {
        // 二级列表的行数
        ListItem* parentItem = static_cast<ListItem*>(parent.internalPointer());
        if (parentItem)
            return parentItem->children.size();
    }

    return 0;
}

int CustomModel::columnCount(const QModelIndex& parent) const
{
    Q_UNUSED(parent);
    // 列数为1
    return 1;
}

QVariant CustomModel::data(const QModelIndex& index, int role) const
{
    if (!index.isValid())
        return QVariant();

    if (role == Qt::DisplayRole)
    {
        ListItem* item = static_cast<ListItem*>(index.internalPointer());
        if (item)
            return item->text;
    }

    return QVariant();
}

bool CustomModel::setData(const QModelIndex& index, const QVariant& value, int role)
{
    if (!index.isValid())
        return false;

    if (role == Qt::EditRole)
    {
        ListItem* item = static_cast<ListItem*>(index.internalPointer());
        if (item)
        {
            item->text = value.toString();
            emit dataChanged(index, index);
            return true;
        }
    }

    return false;
}

bool CustomModel::insertTopLevelItem(int row, const ListItem& item)
{
    if (row < 0 || row > topLevelItems.size())
        return false;
    beginInsertRows(QModelIndex(), row, row);
    topLevelItems.insert(row, item);
    endInsertRows();
    return true;

}

bool CustomModel::insertChildItem(const QModelIndex& parent, int row, const ListItem& item)
{
    if (!parent.isValid() || row < 0 || row > rowCount(parent))
        return false;
    ListItem* parentItem = static_cast<ListItem*>(parent.internalPointer());
    if (!parentItem)
        return false;

    beginInsertRows(parent, row, row);
    parentItem->children.insert(row, item);
    endInsertRows();
    return true;
}

bool CustomModel::removeTopLevelItem(int row)
{
    if (row < 0 || row >= topLevelItems.size())
        return false;
    beginRemoveRows(QModelIndex(), row, row);
    topLevelItems.removeAt(row);
    endRemoveRows();
    return true;
}

bool CustomModel::removeChildItem(const QModelIndex& parent, int row)
{
    if (!parent.isValid() || row < 0 || row >= rowCount(parent))
        return false;
    ListItem* parentItem = static_cast<ListItem*>(parent.internalPointer());
    if (!parentItem)
        return false;

    beginRemoveRows(parent, row, row);
    parentItem->children.removeAt(row);
    endRemoveRows();
    return true;
}

ListItem CustomModel::getItem(const QModelIndex& index) const
{
    if (index.isValid())
    {
        ListItem* item = static_cast<ListItem*>(index.internalPointer());
        if (item)
            return *item;
    }
    return ListItem();
}

Qt::ItemFlags CustomModel::flags(const QModelIndex& index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;

    Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;
    if (index.column() == 0)
        flags |= Qt::ItemIsUserCheckable;

    return flags;
}