#include "mainwindow.h"
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QInputDialog>
#include <QMessageBox>
#include <QHeaderView>
#include <QMenu>
#include <QMenuBar>
#include <QFile>
#include <QTextStream>
#include <QFileDialog>
#include <QFileInfo>
#include <QToolBar>
#include <QToolButton>

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    setupUI();
    setWindowTitle("学生信息管理系统");
}

MainWindow::~MainWindow() {}

void MainWindow::setupUI()
{
    QWidget *central = new QWidget(this);
    setCentralWidget(central);

    // Action 定义
    QAction *actImport  = new QAction("导入", this);
    QAction *actSave    = new QAction("保存", this);

    QAction *actAddCls  = new QAction("新增班级", this);
    QAction *actDelCls  = new QAction("删除班级", this);
    QAction *actRenCls  = new QAction("重命名班级", this);

    // 工具栏（唯一一行）
    QToolBar *toolBar = addToolBar("主工具栏");
    toolBar->setMovable(false);
    toolBar->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);

    // 默认显示“文件”相关
    toolBar->addAction(actImport);
    toolBar->addAction(actSave);

    // 伪菜单栏按钮
    QToolButton *fileBtn = new QToolButton(this);
    fileBtn->setText("文件");
    fileBtn->setToolButtonStyle(Qt::ToolButtonTextOnly);
    fileBtn->setAutoRaise(true);   // 看起来像菜单

    QToolButton *editBtn = new QToolButton(this);
    editBtn->setText("编辑");
    editBtn->setToolButtonStyle(Qt::ToolButtonTextOnly);
    editBtn->setAutoRaise(true);

    // 放到菜单栏位置
    QWidget *menuWidget = new QWidget(this);
    QHBoxLayout *menuLayout = new QHBoxLayout(menuWidget);
    menuLayout->setContentsMargins(6, 0, 0, 0);
    menuLayout->setSpacing(10);

    menuLayout->addWidget(fileBtn);
    menuLayout->addWidget(editBtn);
    menuLayout->addStretch();

    menuBar()->setCornerWidget(menuWidget, Qt::TopLeftCorner);

    // 按钮点击 → 切换工具栏
    connect(fileBtn, &QToolButton::clicked, this, [=]() {
        toolBar->clear();
        toolBar->addAction(actImport);
        toolBar->addAction(actSave);
    });

    connect(editBtn, &QToolButton::clicked, this, [=]() {
        toolBar->clear();
        toolBar->addAction(actAddCls);
        toolBar->addAction(actDelCls);
        toolBar->addAction(actRenCls);
    });

    // 核心控件初始化
    tree = new QTreeWidget;
    tree->setHeaderLabel("班级列表");

    table = new QTableWidget(0, 5);
    table->setHorizontalHeaderLabels({"姓名", "性别", "年龄", "学号", "电话"});
    table->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
    table->setSelectionBehavior(QAbstractItemView::SelectRows);

    // 右侧编辑面板
    nameEdit = new QLineEdit;
    genderEdit = new QLineEdit;
    ageEdit = new QLineEdit;
    idEdit = new QLineEdit;
    phoneEdit = new QLineEdit;

    addBtn = new QPushButton("新增");
    delBtn = new QPushButton("删除");
    updateBtn = new QPushButton("修改");
    searchBtn = new QPushButton("查询");
    refreshBtn = new QPushButton("刷新/清空查询");

    QVBoxLayout *rightLayout = new QVBoxLayout;
    rightLayout->addWidget(new QLabel("姓名:"));
    rightLayout->addWidget(nameEdit);
    rightLayout->addWidget(new QLabel("性别:"));
    rightLayout->addWidget(genderEdit);
    rightLayout->addWidget(new QLabel("年龄:"));
    rightLayout->addWidget(ageEdit);
    rightLayout->addWidget(new QLabel("学号:"));
    rightLayout->addWidget(idEdit);
    rightLayout->addWidget(new QLabel("电话:"));
    rightLayout->addWidget(phoneEdit);
    rightLayout->addWidget(addBtn);
    rightLayout->addWidget(updateBtn);
    rightLayout->addWidget(delBtn);
    rightLayout->addWidget(searchBtn);
    rightLayout->addWidget(refreshBtn);
    rightLayout->addStretch();

    // 分页控件
    btnPrev = new QPushButton("上一页");
    btnNext = new QPushButton("下一页");
    pageLabel = new QLabel("第 1/1 页");
    QHBoxLayout *pageLayout = new QHBoxLayout;
    pageLayout->addStretch();
    pageLayout->addWidget(btnPrev);
    pageLayout->addWidget(pageLabel);
    pageLayout->addWidget(btnNext);
    pageLayout->addStretch();

    // 布局组合
    QVBoxLayout *centerLayout = new QVBoxLayout;
    centerLayout->addWidget(table);
    centerLayout->addLayout(pageLayout);

    QHBoxLayout *mainLayout = new QHBoxLayout(central);
    mainLayout->addWidget(tree, 1);
    mainLayout->addLayout(centerLayout, 3);
    mainLayout->addLayout(rightLayout, 1);

    // 信号槽连接
    connect(actAddCls, &QAction::triggered, this, &MainWindow::addClass);
    connect(actDelCls, &QAction::triggered, this, &MainWindow::deleteClass);
    connect(actRenCls, &QAction::triggered, this, &MainWindow::renameClass);
    connect(actImport, &QAction::triggered, this, &MainWindow::importData);
    connect(actSave, &QAction::triggered, this, &MainWindow::saveData);

    connect(tree, &QTreeWidget::itemClicked, this, &MainWindow::onClassClicked);
    connect(addBtn, &QPushButton::clicked, this, &MainWindow::addStudent);
    connect(delBtn, &QPushButton::clicked, this, &MainWindow::deleteStudent);
    connect(updateBtn, &QPushButton::clicked, this, &MainWindow::updateStudent);
    connect(searchBtn, &QPushButton::clicked, this, &MainWindow::searchStudent);
    connect(refreshBtn, &QPushButton::clicked, this, &MainWindow::refreshAll);
    connect(table, &QTableWidget::cellClicked, this, &MainWindow::tableItemClicked);
    connect(btnPrev, &QPushButton::clicked, this, &MainWindow::prevPage);
    connect(btnNext, &QPushButton::clicked, this, &MainWindow::nextPage);

    resize(1000, 600);
}

// 业务逻辑实现

QString MainWindow::currentClass() const
{
    auto item = tree->currentItem();
    return item ? item->text(0) : "";
}

void MainWindow::refreshTable()
{
    table->setRowCount(0);
    int total = displayList.size();
    int maxPage = qMax(1, (total + pageSize - 1) / pageSize);
    if (currentPage > maxPage)
        currentPage = maxPage;

    pageLabel->setText(QString("第 %1/%2 页").arg(currentPage).arg(maxPage));

    int start = (currentPage - 1) * pageSize;
    int end = qMin(start + pageSize, total);

    for (int i = start; i < end; ++i)
    {
        int r = table->rowCount();
        table->insertRow(r);
        table->setItem(r, 0, new QTableWidgetItem(displayList[i].name));
        table->setItem(r, 1, new QTableWidgetItem(displayList[i].gender));
        table->setItem(r, 2, new QTableWidgetItem(QString::number(displayList[i].age)));
        table->setItem(r, 3, new QTableWidgetItem(displayList[i].id));
        table->setItem(r, 4, new QTableWidgetItem(displayList[i].phone));
    }
}

void MainWindow::onClassClicked(QTreeWidgetItem *item)
{
    displayList = classData[item->text(0)];
    currentPage = 1;
    refreshTable();
}

void MainWindow::addStudent()
{
    QString cls = currentClass();
    if (cls.isEmpty())
        return;

    Student s{nameEdit->text(), genderEdit->text(), ageEdit->text().toInt(), idEdit->text(), phoneEdit->text()};
    if (s.name.isEmpty() || s.id.isEmpty())
    {
        QMessageBox::warning(this, "错误", "姓名和学号不能为空"); //
        return;
    }

    // 查重
    for (const auto &st : classData[cls])
    {
        if (st.id == s.id)
        {
            QMessageBox::warning(this, "错误", "学号重复");
            return;
        }
    }

    classData[cls].append(s);
    saveClassToFile(cls); // 自动保存

    // 刷新输入框内容
    nameEdit->clear();
    genderEdit->clear();
    ageEdit->clear();
    idEdit->clear();
    phoneEdit->clear();

    refreshAll();
}

void MainWindow::updateStudent()
{
    QString cls = currentClass();
    int row = table->currentRow();
    if (cls.isEmpty() || row < 0)
        return;

    int realIdx = (currentPage - 1) * pageSize + row;
    Student &s = classData[cls][realIdx];
    s.name = nameEdit->text();
    s.gender = genderEdit->text();
    s.age = ageEdit->text().toInt();
    s.phone = phoneEdit->text();

    saveClassToFile(cls);
    refreshAll();
}

void MainWindow::deleteStudent()
{
    QString cls = currentClass();
    int row = table->currentRow();
    if (row < 0 || QMessageBox::question(this, "确认", "确定删除？") != QMessageBox::Yes)
        return;

    int realIdx = (currentPage - 1) * pageSize + row;
    classData[cls].removeAt(realIdx);
    saveClassToFile(cls);
    refreshAll();
}

void MainWindow::searchStudent()
{
    QString cls = currentClass();
    if (cls.isEmpty())
    {
        QMessageBox::warning(this, "提示", "请先在左侧选择一个班级再进行查询");
        return;
    }

    // 1. 获取所有输入框的关键字，并去掉首尾空格
    QString nameKw = nameEdit->text().trimmed();
    QString genderKw = genderEdit->text().trimmed();
    QString ageKw = ageEdit->text().trimmed();
    QString idKw = idEdit->text().trimmed();
    QString phoneKw = phoneEdit->text().trimmed();

    displayList.clear();

    // 2. 遍历当前班级的所有学生
    for (const auto &s : classData[cls])
    {
        // 初始假设该学生符合条件
        bool isMatch = true;

        // 3. 逐个字段进行条件校验（逻辑：如果输入框不为空，则必须匹配该条件）

        // 校验姓名
        if (!nameKw.isEmpty() && !s.name.contains(nameKw, Qt::CaseInsensitive))
        {
            isMatch = false;
        }
        // 校验性别
        if (isMatch && !genderKw.isEmpty() && !s.gender.contains(genderKw, Qt::CaseInsensitive))
        {
            isMatch = false;
        }
        // 校验年龄
        if (isMatch && !ageKw.isEmpty() && !QString::number(s.age).contains(ageKw))
        {
            isMatch = false;
        }
        // 校验学号
        if (isMatch && !idKw.isEmpty() && !s.id.contains(idKw, Qt::CaseInsensitive))
        {
            isMatch = false;
        }
        // 校验电话
        if (isMatch && !phoneKw.isEmpty() && !s.phone.contains(phoneKw, Qt::CaseInsensitive))
        {
            isMatch = false;
        }

        // 4. 如果所有非空条件都通过，则加入显示列表
        if (isMatch)
        {
            displayList.append(s);
        }
    }

    currentPage = 1; // 重置到第一页
    refreshTable();  // 刷新表格显示
}

void MainWindow::refreshAll()
{
    QString cls = currentClass();
    if (!cls.isEmpty())
        displayList = classData[cls]; // 恢复初始状态
    currentPage = 1;

    // 刷新输入框内容
    nameEdit->clear();
    genderEdit->clear();
    ageEdit->clear();
    idEdit->clear();
    phoneEdit->clear();

    refreshTable();
}

// --- 文件与分页 ---

void MainWindow::saveClassToFile(const QString &className)
{
    QFile file(className + ".txt"); // 按班级名保存
    if (file.open(QIODevice::WriteOnly | QIODevice::Text))
    {
        QTextStream out(&file);
        for (const auto &s : classData[className])
        {
            out << s.name << "," << s.gender << "," << s.age << "," << s.id << "," << s.phone << "\n";
        }
    }
}

void MainWindow::saveData()
{
    for (auto it = classData.begin(); it != classData.end(); ++it)
        saveClassToFile(it.key());
    QMessageBox::information(this, "提示", "所有班级已保存");
}

void MainWindow::importData()
{
    // 1. 直接弹出文件选择框，不需要预先选中班级
    QString path = QFileDialog::getOpenFileName(this, "导入班级文件", "", "文本文件 (*.txt);;所有文件 (*.*)");
    if (path.isEmpty())
        return;

    // 2. 提取文件名作为班级名
    QFileInfo fileInfo(path);
    QString className = fileInfo.baseName(); // 例如 "高三二班"

    // 3. 检查班级是否已存在，不存在则新建
    if (!classData.contains(className))
    {
        classData[className] = QList<Student>();
        QTreeWidgetItem *newItem = new QTreeWidgetItem({className});
        tree->addTopLevelItem(newItem);
        tree->setCurrentItem(newItem); // 自动选中这个新创建的班级
    }
    else
    {
        // 如果班级已存在，询问是追加还是清空
        QMessageBox::StandardButton reply;
        reply = QMessageBox::question(this, "班级已存在",
                                      QString("班级 '%1' 已存在，是否追加数据？\n(选“否”将清空原数据并覆盖)").arg(className),
                                      QMessageBox::Yes | QMessageBox::No | QMessageBox::Cancel);

        if (reply == QMessageBox::Cancel)
            return;
        if (reply == QMessageBox::No)
        {
            classData[className].clear(); // 清空原数据实现“覆盖”
        }

        // 选中已有的班级节点
        QList<QTreeWidgetItem *> items = tree->findItems(className, Qt::MatchExactly);
        if (!items.isEmpty())
            tree->setCurrentItem(items[0]);
    }

    // 4. 读取文件内容
    QFile file(path);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        QMessageBox::critical(this, "错误", "无法打开文件");
        return;
    }

    QTextStream in(&file);
    int count = 0;
    while (!in.atEnd())
    {
        QString line = in.readLine();
        QStringList fields = line.split(",");
        if (fields.size() >= 5)
        {
            Student s;
            s.name = fields[0].trimmed();
            s.gender = fields[1].trimmed();
            s.age = fields[2].trimmed().toInt();
            s.id = fields[3].trimmed();
            s.phone = fields[4].trimmed();
            classData[className].append(s);
            count++;
        }
    }
    file.close();

    // 5. 更新显示
    displayList = classData[className];
    currentPage = 1;
    refreshTable();

    QMessageBox::information(this, "导入成功", QString("已成功创建/更新班级 '%1'，并导入 %2 条学生记录。").arg(className).arg(count));
}

void MainWindow::prevPage()
{
    if (currentPage > 1)
    {
        currentPage--;
        refreshTable();
    }
}
void MainWindow::nextPage()
{
    if (currentPage * pageSize < displayList.size())
    {
        currentPage++;
        refreshTable();
    }
}

void MainWindow::tableItemClicked(int row, int)
{
    int realIdx = (currentPage - 1) * pageSize + row;
    if (realIdx < displayList.size())
    {
        const auto &s = displayList[realIdx];
        nameEdit->setText(s.name);
        genderEdit->setText(s.gender);
        ageEdit->setText(QString::number(s.age));
        idEdit->setText(s.id);
        phoneEdit->setText(s.phone);
    }
}

// 班级管理槽函数（逻辑同前，移至菜单触发）
void MainWindow::addClass()
{
    while (true)
    {
        bool ok;
        // 弹出输入框
        QString name = QInputDialog::getText(this, "新建班级", "请输入班级名称:", QLineEdit::Normal, "", &ok);

        // 如果用户点击了“取消”或直接关闭窗口，则退出函数
        if (!ok)
            return;

        name = name.trimmed(); // 去除首尾空格

        // 逻辑判断 1：不能为空
        if (name.isEmpty())
        {
            QMessageBox::warning(this, "错误", "班级名称不能为空，请重新输入！");
            continue; // 跳回循环开始，重新弹出输入框
        }

        // 逻辑判断 2：检查是否已存在
        if (classData.contains(name))
        {
            QMessageBox::warning(this, "错误", QString("班级“%1”已存在，请换一个名称！").arg(name));
            continue; // 跳回循环开始，重新弹出输入框
        }

        // 校验通过：保存数据并更新界面
        classData[name] = QList<Student>();
        QTreeWidgetItem *newItem = new QTreeWidgetItem({name});
        tree->addTopLevelItem(newItem);
        tree->setCurrentItem(newItem); // 自动选中新创建的班级

        break; // 成功创建后跳出循环
    }
}

void MainWindow::deleteClass()
{
    auto item = tree->currentItem();
    if (!item)
    {
        QMessageBox::warning(this, "提示", "请先选择要删除的班级");
        return;
    }
    if (item && QMessageBox::question(this, "确认", "删除班级及其信息？") == QMessageBox::Yes)
    {
        classData.remove(item->text(0));
        delete item;
        displayList.clear();
        refreshTable();
    }
}

void MainWindow::renameClass()
{
    // 1. 获取当前选中的班级节点
    auto item = tree->currentItem();
    if (!item)
    {
        QMessageBox::warning(this, "提示", "请先选择要重命名的班级");
        return;
    }

    QString oldName = item->text(0);

    // 2. 使用循环处理重复或为空的情况
    while (true)
    {
        bool ok;
        // 弹出输入框，默认显示旧名称
        QString newName = QInputDialog::getText(this, "重命名班级", "请输入新的班级名称:",
                                                QLineEdit::Normal, oldName, &ok);

        // 如果用户点击了“取消”，则直接退出
        if (!ok)
            return;

        newName = newName.trimmed(); // 去除多余空格

        // 情况 A：名称没变，直接退出
        if (newName == oldName)
            return;

        // 情况 B：名称为空
        if (newName.isEmpty())
        {
            QMessageBox::warning(this, "错误", "班级名称不能为空，请重新输入！");
            continue; // 跳回循环开始，再次弹出对话框
        }

        // 情况 C：名称与现有其他班级重复
        if (classData.contains(newName))
        {
            QMessageBox::warning(this, "错误", QString("班级“%1”已存在，请换一个名称！").arg(newName));
            continue; // 跳回循环开始
        }

        // 3. 校验通过，更新底层数据结构 QMap
        // 使用 take() 移除旧键并返回对应的数据列表，再赋值给新键
        classData[newName] = classData.take(oldName);

        // 4. 更新界面显示的名称
        item->setText(0, newName);

        break; // 完成重命名，跳出循环
    }
}