#include "mappingtablepage.h"
#include "utils/Constants.h"
#include "src/utils/logmanager.h"
#include "src/utils/custjsonio.h"

#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QHeaderView>
#include <QMessageBox>
#include <QFile>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonParseError>
#include <QStandardItem>
#include <QLabel>
#include <algorithm>
#include "ElaPushButton.h"
#include "ElaLineEdit.h"
#include "ElaTableView.h"
#include "ElaTheme.h"

// 数据映射三页（表替换/函数替换/不转码功能函数）的公共基类:
// 收编 UI 骨架/删除/编辑置脏/保存保序写/外部修改重载/主题联动等同构样板;
// 数据结构与校验差异由子类通过 populateModel/collectMappingData/onAddRow 实现
MappingTablePage::MappingTablePage(int columnCount,
                                   const QStringList &headers,
                                   const QString &searchPlaceholder,
                                   const QString &tipText,
                                   QWidget *parent)
    : QWidget(parent)
    , m_isLoading(false)
    , m_dirty(false)
{
    initUI(columnCount, headers, searchPlaceholder, tipText);
}

MappingTablePage::~MappingTablePage()
{
}

void MappingTablePage::initUI(int columnCount, const QStringList &headers,
                              const QString &searchPlaceholder, const QString &tipText)
{
    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->setContentsMargins(20, 20, 20, 20);
    mainLayout->setSpacing(10);

    // 搜索框
    QHBoxLayout *searchLayout = new QHBoxLayout;
    m_searchEdit = new ElaLineEdit(this);
    m_searchEdit->setPlaceholderText(searchPlaceholder);
    m_searchEdit->setClearButtonEnabled(true);
    connect(m_searchEdit, &ElaLineEdit::textChanged,
            this, &MappingTablePage::onSearchTextChanged);
    searchLayout->addWidget(m_searchEdit);
    mainLayout->addLayout(searchLayout);

    m_model = new QStandardItemModel(this);
    m_model->setColumnCount(columnCount);
    m_model->setHorizontalHeaderLabels(headers);
    connect(m_model, &QStandardItemModel::itemChanged,
            this, &MappingTablePage::onModelItemChanged);

    m_proxyModel = new MappingFilterProxyModel(columnCount, this);
    m_proxyModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
    m_proxyModel->setSourceModel(m_model);

    m_tableView = new ElaTableView;
    m_tableView->setModel(m_proxyModel);
    m_tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    m_tableView->setSelectionMode(QAbstractItemView::ExtendedSelection);
    m_tableView->setEditTriggers(QAbstractItemView::DoubleClicked | QAbstractItemView::EditKeyPressed);
    m_tableView->verticalHeader()->setVisible(false);
    for (int c = 0; c < columnCount; ++c)
        m_tableView->horizontalHeader()->setSectionResizeMode(c, QHeaderView::Stretch);
    mainLayout->addWidget(m_tableView);

    QHBoxLayout *btnLayout = new QHBoxLayout;
    ElaPushButton *addBtn = new ElaPushButton("添加", this);
    ElaPushButton *delBtn = new ElaPushButton("删除选中", this);
    ElaPushButton *saveBtn = new ElaPushButton("保存", this);

    // 虚函数经 this 指针调用, 运行时正确分派到子类实现
    connect(addBtn, &ElaPushButton::clicked, this, &MappingTablePage::onAddRow);
    connect(delBtn, &ElaPushButton::clicked, this, &MappingTablePage::onDeleteRow);
    connect(saveBtn, &ElaPushButton::clicked, this, &MappingTablePage::onSave);

    btnLayout->addWidget(addBtn);
    btnLayout->addWidget(delBtn);
    btnLayout->addStretch();
    btnLayout->addWidget(saveBtn);
    mainLayout->addLayout(btnLayout);

    QHBoxLayout *tipLayout = new QHBoxLayout;
    m_tipLabel = new QLabel(tipText);
    tipLayout->addWidget(m_tipLabel);
    tipLayout->addStretch();
    mainLayout->addLayout(tipLayout);

    // 外部修改监控: 双监控+防抖+mtime 回环过滤+保存窗口统一由 JsonFileMonitor 处理
    m_monitor = new JsonFileMonitor(this);
    connect(m_monitor, &JsonFileMonitor::reloadRequested,
            this, &MappingTablePage::onReloadRequested);

    // tip 标签为主题感知: 跟随 Ela 主题切换, 并按当前主题初始化
    connect(ElaTheme::getInstance(), &ElaTheme::themeModeChanged,
            this, &MappingTablePage::updateTipStyle);
    updateTipStyle();
}

// 由子类构造体内调用(规避构造期虚函数绑定到基类版本): 先读后清空,
// 读取/解析失败时保留现有模型内容并不清脏, 避免用户随手保存把空表写回磁盘
void MappingTablePage::load()
{
    m_isLoading = true;

    bool readOk = false;
    QJsonObject custJson = readCustJson(&readOk).object();
    if (readOk) {
        // 批量重建期间抑制逐行重绘: 映射表可达数百~上千行, 三个子页共用此路径,
        // 基类统一加抑制子页同时受益(populateModel 为虚函数)
        m_tableView->setUpdatesEnabled(false);
        m_model->removeRows(0, m_model->rowCount());
    }

    if (readOk) {
        populateModel(custJson);
        m_tableView->setUpdatesEnabled(true);
    }

    m_isLoading = false;
    // 仅读取/解析成功时清脏: 失败时模型保留了旧内容(可能含未保存编辑),
    // 清脏会让外部变更保护失效, 且"保存"会把旧表写回损坏的文件
    if (readOk) {
        m_dirty = false;
    }

    // 设置监控并记录 mtime 基准, 供防抖回调过滤自身写入回环
    m_monitor->watch(getCustJsonPath());
}

QString MappingTablePage::getCustJsonPath() const
{
    return Constants::custJson();
}

QJsonDocument MappingTablePage::readCustJson(bool *ok)
{
    if (ok) *ok = false;
    const QString jsonPath = getCustJsonPath();
    QFile file(jsonPath);
    if (!file.open(QIODevice::ReadOnly)) {
        LogManager::instance()->logError("无法读取 cust.json: " + jsonPath);
        return QJsonDocument();
    }
    const QByteArray data = file.readAll();
    file.close();
    QJsonParseError error;
    QJsonDocument doc = QJsonDocument::fromJson(data, &error);
    if (error.error != QJsonParseError::NoError) {
        LogManager::instance()->logError(
            QString("cust.json 解析失败: %1 (行 %2)").arg(error.errorString()).arg(error.offset));
        return QJsonDocument();
    }
    if (ok) *ok = true;
    return doc;
}

void MappingTablePage::onDeleteRow()
{
    QModelIndexList selectedRows = m_tableView->selectionModel()->selectedRows();
    if (selectedRows.isEmpty()) {
        QMessageBox::warning(this, "提示", "请先选中要删除的行！");
        return;
    }

    QStringList keyNames;
    QList<int> sourceRows;
    for (const QModelIndex &idx : selectedRows) {
        QModelIndex srcIdx = m_proxyModel->mapToSource(idx);
        QStandardItem *keyItem = m_model->item(srcIdx.row(), 0);
        if (keyItem) keyNames.append(keyItem->text());
        sourceRows.append(srcIdx.row());
    }

    // 单选但键名 item 缺失(空单元格/排序中列被隐藏)时 keyNames 可能为空,
    // 退化为按数量确认, 避免 QList::first() 对空列表断言崩溃
    const QString confirmMsg = (selectedRows.size() == 1 && !keyNames.isEmpty())
        ? deleteConfirmSingle(keyNames.first())
        : deleteConfirmMulti(selectedRows.size());

    QMessageBox::StandardButton reply = QMessageBox::question(this, "确认删除",
        confirmMsg, QMessageBox::Yes | QMessageBox::No);
    if (reply != QMessageBox::Yes) return;

    // 从高行号到低行号删除，避免索引偏移问题
    std::sort(sourceRows.begin(), sourceRows.end(), std::greater<int>());
    for (int row : sourceRows) {
        m_model->removeRow(row);
    }
    m_dirty = true;   // 删除行同样视为未保存修改，纳入外部文件变更保护
}

void MappingTablePage::onModelItemChanged(QStandardItem *item)
{
    if (m_isLoading) return;
    m_dirty = true;   // 用户编辑了映射表，标记有未保存修改
    Q_UNUSED(item);
}

void MappingTablePage::onSave()
{
    QString errorMessage;
    const SaveResult result = saveToDisk(&errorMessage);
    if (result == SaveResult::Ok) {
        QMessageBox::information(this, "提示", "保存成功！");
    } else if (result == SaveResult::ValidationFailed) {
        QMessageBox::warning(this, "提示", errorMessage);
    } else {
        QMessageBox::critical(this, "错误", errorMessage);
    }
}

MappingTablePage::SaveResult MappingTablePage::saveToDisk(QString *errorMessage)
{
    if (errorMessage) errorMessage->clear();

    // 开启保存窗口: 窗口期内监控事件直接忽略
    m_monitor->beginSaveWindow();

    // 读取原始文件内容以保留顶层 key 顺序
    const QString jsonPath = getCustJsonPath();
    QFile file(jsonPath);
    if (!file.open(QIODevice::ReadOnly)) {
        m_monitor->endSave();   // 早退必须关闭窗口，否则监控被永久抑制
        if (errorMessage) *errorMessage = "无法读取 cust.json！";
        return SaveResult::Error;
    }
    const QString rawJson = QString::fromUtf8(file.readAll());
    file.close();

    QJsonParseError error;
    QJsonDocument doc = QJsonDocument::fromJson(rawJson.toUtf8(), &error);
    if (error.error != QJsonParseError::NoError) {
        m_monitor->endSave();
        if (errorMessage) *errorMessage = "cust.json 解析失败: " + error.errorString();
        return SaveResult::Error;
    }
    QJsonObject custJson = doc.object();

    // 提取原始 key 顺序
    const QStringList keyOrder = CustJsonIo::extractTopLevelKeyOrder(rawJson);

    // 子类校验并回填数据: 校验失败不落盘
    QString validateError;
    const QHash<QString, QString> overrideRaw = collectMappingData(custJson, validateError);
    if (!validateError.isEmpty()) {
        m_monitor->endSave();
        if (errorMessage) *errorMessage = validateError;
        return SaveResult::ValidationFailed;
    }

    // endSave 以保存后的新 mtime 为基准(writeCustJsonOrdered 同步写完才返回),
    // 成功/失败都要关闭窗口, 且必须先于模态弹窗:
    // 弹窗阻塞期间若发生外部修改, 迟到的 endSave 会把外部修改的 mtime
    // 当作自身保存基准, 导致外部变更被静默吞掉
    const bool writeOk = CustJsonIo::writeCustJsonOrdered(jsonPath, custJson, keyOrder, overrideRaw);
    m_monitor->endSave();
    if (writeOk) {
        m_dirty = false;   // 保存成功后与磁盘内容一致
        LogManager::instance()->logInfo(saveLogText(m_model->rowCount()));
        onSavedToDisk();   // 落盘成功钩子(表替换页覆写: 同步 table_mapping.json)
        return SaveResult::Ok;
    }
    if (errorMessage) *errorMessage = "保存到 cust.json 失败！";
    return SaveResult::Error;
}

void MappingTablePage::onSavedToDisk()
{
}

void MappingTablePage::onReloadRequested()
{
    // 有未保存编辑时询问，避免外部修改静默覆盖用户的编辑
    if (m_dirty) {
        QMessageBox::StandardButton reply = QMessageBox::question(this, "文件已变更",
            "cust.json 已被其他页面或外部程序修改，重新加载将丢失当前未保存的编辑。是否重新加载？",
            QMessageBox::Yes | QMessageBox::No);
        if (reply != QMessageBox::Yes) {
            return;   // 监控组件已记住本次版本，避免同一份内容反复弹窗询问
        }
    }

    LogManager::instance()->logInfo(reloadLogText());
    load();
}

void MappingTablePage::onSearchTextChanged(const QString &text)
{
    // setFilterFixedString 自动转义正则元字符, 按不区分大小写的包含匹配
    m_proxyModel->setFilterFixedString(text);
}

void MappingTablePage::updateTipStyle()
{
    if (!m_tipLabel) return;
    const ElaThemeType::ThemeMode mode = ElaTheme::getInstance()->getThemeMode();
    const QString textColor = ElaThemeColor(mode, BasicText).name();
    m_tipLabel->setStyleSheet(QString("color: %1; font-size: 13px;").arg(textColor));
}

// ---------------------------------------------------------------------------
// 默认文案虚点实现（子类按需覆写）
// ---------------------------------------------------------------------------
QString MappingTablePage::saveLogText(int rowCount) const
{
    Q_UNUSED(rowCount);
    return "配置已保存到 cust.json";
}

QString MappingTablePage::reloadLogText() const
{
    return "检测到 cust.json 外部修改，自动刷新数据";
}

QString MappingTablePage::deleteConfirmSingle(const QString &name) const
{
    return QString("确定要删除 \"%1\" 这条映射吗？").arg(name);
}

QString MappingTablePage::deleteConfirmMulti(int count) const
{
    return QString("确定要删除选中的 %1 条映射吗？").arg(count);
}