#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFile>
#include <QTextStream>
#include <QTableWidget>
#include <QFileDialog>
#include <QProgressDialog>
#include <QMessageBox>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    setAcceptDrops(true); // 允许窗口接受拖放事件

    connect(ui->actionOpen, &QAction::triggered, this, &MainWindow::onOpenButtonClicked);
    connect(ui->actionSave, &QAction::triggered, this, &MainWindow::onSaveButtonClicked);

    QIcon openIcon = QApplication::style()->standardIcon(QStyle::SP_DialogOpenButton);
    QIcon saveIcon = QApplication::style()->standardIcon(QStyle::SP_DialogSaveButton);

    ui->actionOpen->setIcon(openIcon);
    ui->actionSave->setIcon(saveIcon);

    ui->actionOpen->setShortcut(QKeySequence(Qt::CTRL + Qt::Key_N));
    ui->actionSave->setShortcut(QKeySequence(Qt::CTRL + Qt::Key_S));
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::loadTextFile(const QString& fileName)
{
    QFile file(fileName);

    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        // 文件打开失败，处理错误
        return;
    }

    QTextStream in(&file);

    // 获取文件大小并预分配内存
    qint64 fileSize = file.size();
    QString textData;
    textData.reserve(fileSize);

    int tableRow = 0;
    int tableCol = 0;
    while (!in.atEnd())
    {
        QString line = in.readLine();
        textData += line + "\n"; // 保存所有文本数据
        tableRow++;

        if (tableRow == 2)
        {
            tableCol = line.split("\t").count(); // 获取第二行的列数
        }
    }

    file.close();

    progressDialog = new QProgressDialog("Loading...", "Cancel", 0, 0, this);
    progressDialog->setWindowModality(Qt::WindowModal);
    progressDialog->setAutoClose(false);
    progressDialog->setAutoReset(false);
    progressDialog->setRange(0, tableRow);
    progressDialog->setValue(0);
    progressDialog->show();

    // 将数据显示在表格中
        QTableWidget* tableWidget = ui->tableWidget;

    // 设置表格的行数和列数
    tableWidget->setRowCount(tableRow);
    tableWidget->setColumnCount(tableCol);

    tableWidget->blockSignals(true); // 阻止信号发射

    QStringList rows = textData.split("\n");
    for (int i = 0; i < tableRow; ++i)
    {
        QStringList row = rows.at(i).split("\t");

        if (i == 1)
        {
            // 获取第二行的列名-设置表格的列标题
            tableWidget->setHorizontalHeaderLabels(row);
        }

        for (int j = 0; j < tableCol; ++j)
        {
            QTableWidgetItem* item = new QTableWidgetItem(row.at(j));
            tableWidget->setItem(i, j, item);
        }
        progressDialog->setValue(i);
        QApplication::processEvents(); // 处理界面事件，使进度条能够更新
        if (progressDialog->wasCanceled())
        {
            tableWidget->clear();
            break;
        }
    }
    progressDialog->setValue(tableRow);
    progressDialog->hide();
    tableWidget->blockSignals(false); // 恢复信号发射
}

void MainWindow::onOpenButtonClicked()
{
    QString fileName = QFileDialog::getOpenFileName(this, "Open Text File", "", "Text Files (*.txt)");
    if (!fileName.isEmpty())
    {
        loadTextFile(fileName);
    }
}

void MainWindow::onSaveButtonClicked()
{
    QString fileName = QFileDialog::getSaveFileName(this, "Save Text File", "", "Text Files (*.txt)");
    if (!fileName.isEmpty())
    {
        QFile file(fileName);
        if (file.open(QIODevice::WriteOnly))
        {
            // 写入UTF-16带有BOM的标记
            QByteArray bom;
            bom.append((char)0xFF);
            bom.append((char)0xFE);
            file.write(bom);

            QTextStream out(&file);
            out.setCodec("UTF-16LE");//Qt6 use: out.setEncoding(QStringConverter::Utf16LE);

            QTableWidget* tableWidget = ui->tableWidget;
            int rowCount = tableWidget->rowCount();
            int columnCount = tableWidget->columnCount();

            for (int i = 0; i < rowCount; ++i)
            {
                for (int j = 0; j < columnCount; ++j)
                {
                    QTableWidgetItem* item = tableWidget->item(i, j);
                    if (item != nullptr)
                    {
                        QString text = item->text();
                        out << text;
                    }

                    if (j != columnCount - 1)
                    {
                        out << "\t"; // 制表符分隔
                    }
                }

                out << "\r\n"; // 换行，注意使用\r\n表示换行符
            }

            file.close();
            QMessageBox::information(this, "保存完成", "文件已成功保存。");
        }
    }
}

void MainWindow::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasUrls())
    {
        event->acceptProposedAction();
    }
}

void MainWindow::dropEvent(QDropEvent *event)
{
    const QMimeData* mimeData = event->mimeData();
    if (mimeData->hasUrls())
    {
        QList<QUrl> urlList = mimeData->urls();
        if (urlList.length() == 1)
        {
            QString fileName = urlList.first().toLocalFile();
            if (!fileName.isEmpty())
            {
                loadTextFile(fileName);
            }
        }
    }
}