#include "tableEditModel.h"

TableEditModel::TableEditModel(QObject *parent, const QSqlDatabase &db, const QStringList &visibleColumns)
    : QSqlTableModel(parent, db), m_visibleColumns(visibleColumns)
{
    setEditStrategy(QSqlTableModel::OnManualSubmit); //对编辑数据手动进行提交

    m_pageSize = 100;
    m_currentPage = 1;
    m_totalRecords = 0;
}

TableEditModel::~TableEditModel()
{}

//重写生成查询的方法
QString TableEditModel::selectStatement() const
{
    QString originalQuery = QSqlTableModel::selectStatement();
    QString newQuery;
    if(m_visibleColumns.isEmpty())
        newQuery = originalQuery;
    else
    {
        int fromInex = originalQuery.indexOf(" FROM ");
        QString selectPart = "SELECT " + m_visibleColumns.join(", ");
        newQuery = selectPart + originalQuery + selectPart.mid(fromInex);
    }
    newQuery = newQuery + QString(" LIMIT %1 OFFSET %2").arg(m_pageSize, (m_currentPage - 1) * m_pageSize);

    return newQuery;
}

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

    if(index.column() == 0) //第一列显示行号
    {
        int golbalRow = (m_currentPage - 1) * m_pageSize + index.row();
        switch (role)
        {
            case Qt::DisplayRole:
            {
                QString displayRow = QString::number(golbalRow + 1);
                if(m_editCache.keys().contains(index.row()))
                    displayRow = "*" + displayRow;
                return displayRow;
            }
            case Qt::DecorationRole:
                return QVariant();
            case Qt::TextAlignmentRole: //行号居中展示
                return Qt::AlignCenter;
            default:
                return QVariant();
        }
    }
    else if(role == Qt::UserRole + 100) //先以100来标识数据是否被编辑,在相关代理Delegate类实现中同步进行处理（文字加粗等效果）
            return isDirty(index);
    else
        return QSqlTableModel::data(createIndex(index.row(), index.column() - 1), role); //因为第一列显示行号，所以其它数据列要错位展示
}

bool TableEditModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    if (!index.isValid() || index.column() == 0 || role != Qt::EditRole) //忽略行号列
        return false;

    // if(index.column() == 0) //忽略行号列
    //     return QSqlTableModel::setData(createIndex(index.row(), index.column()-1), value, role);

    int row = index.row();
    if (row < 0 || row >= rowCount())
        return false;

    //记录修改到缓存
    if(!m_editCache.contains(row))
    {
        EditRecord record;
        record.original = QSqlTableModel::record(row);
        m_editCache[row] = record;
    }
    m_editCache[row].modified.setValue(index.column() - 1, value);

    emit dataChanged(index, index, {role});
    return true;
}

int TableEditModel::columnCount(const QModelIndex &parent) const
{
    return QSqlTableModel::columnCount(parent) + 1; // 原始列数 + 行号列
}

Qt::ItemFlags TableEditModel::flags(const QModelIndex &index) const
{
    if(index.column() == 0) //行号列不可编辑
        return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
    else return QSqlTableModel::flags(this->index(index.row(), index.column() - 1));
}