// SPDX-License-Identifier: GPL-3.0-only
/*
 *  Prism Launcher - Minecraft Launcher
 *  Copyright (c) 2022 Jamie Mansfield <jmansfield@cadixdev.org>
 *  Copyright (C) 2022 Sefa Eyeoglu <contact@scrumplex.net>
 *  Copyright (C) 2022 TheKodeToad <TheKodeToad@proton.me>
 *  Copyright (c) 2023 Trial97 <alexandru.tripon97@gmail.com>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, version 3.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * This file incorporates work covered by the following copyright and
 * permission notice:
 *
 *      Copyright 2013-2021 MultiMC Contributors
 *
 *      Licensed under the Apache License, Version 2.0 (the "License");
 *      you may not use this file except in compliance with the License.
 *      You may obtain a copy of the License at
 *
 *          http://www.apache.org/licenses/LICENSE-2.0
 *
 *      Unless required by applicable law or agreed to in writing, software
 *      distributed under the License is distributed on an "AS IS" BASIS,
 *      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *      See the License for the specific language governing permissions and
 *      limitations under the License.
 */

#include "ModFolderPage.h"
#include "minecraft/mod/Resource.h"
#include "ui/dialogs/ExportToModListDialog.h"
#include "ui/dialogs/InstallLoaderDialog.h"
#include "ui_ExternalResourcesPage.h"

#include <QAbstractItemModel>
#include <QAction>
#include <QEvent>
#include <QKeyEvent>
#include <QMouseEvent>
#include <QHideEvent>
#include <QMenu>
#include <QShowEvent>
#include <QMessageBox>
#include <QSortFilterProxyModel>
#include <QInputDialog>
#include <QBoxLayout>
#include <QGridLayout>
#include <algorithm>
#include <memory>

#include "Application.h"

#include "ui/dialogs/CustomMessageBox.h"
#include "ui/dialogs/ResourceDownloadDialog.h"
#include "ui/dialogs/ResourceUpdateDialog.h"

#include "minecraft/PackProfile.h"
#include "minecraft/VersionFilterData.h"
#include "minecraft/mod/Mod.h"
#include "minecraft/mod/ModFolderModel.h"

#include "tasks/ConcurrentTask.h"
#include "tasks/Task.h"
#include "ui/dialogs/ProgressDialog.h"

ModFolderPage::~ModFolderPage()
{
    m_destructorStarted = true;

    if (m_filterWindow) {
        m_filterWindow->removeEventFilter(this);
    }
    if (ui && ui->treeView && ui->treeView->viewport()) {
        ui->treeView->viewport()->removeEventFilter(this);
    }
}

ModFolderPage::ModFolderPage(BaseInstance* inst, ModFolderModel* model, QWidget* parent)
    : ExternalResourcesPage(inst, model, parent), m_model(model)
{
    m_profileTabBar = new QTabBar(this);
    m_profileTabBar->setExpanding(false);
    m_profileTabBar->setDrawBase(false);         // no underline bar — matches Settings tab style
    m_profileTabBar->setDocumentMode(false);
    m_profileTabBar->setUsesScrollButtons(m_profileTabBar->count() > 1);
    m_profileTabBar->setElideMode(Qt::ElideRight);
    m_profileTabBar->setContextMenuPolicy(Qt::CustomContextMenu);
    // Palette-based stylesheet: selected tab uses palette(base) to match the
    // treeView background; unselected tabs use the standard button tone.
    m_profileTabBar->setStyleSheet(
        "QTabBar::tab {"
        "  padding: 4px 12px;"
        "  border: none;"
        "  background: palette(button);"
        "  color: palette(button-text);"
        "  margin-right: 1px;"
        "}"
        "QTabBar::tab:selected {"
        "  background: palette(base);"
        "  color: palette(text);"
        "}"
        "QTabBar::tab:hover:!selected {"
        "  background: palette(mid);"
        "  color: palette(button-text);"
        "}");

    // Chrome-style "+" button that sits immediately after the last tab
    m_newTabButton = new QToolButton(this);
    m_newTabButton->setText(QStringLiteral("+"));
    m_newTabButton->setToolTip(tr("New Tab"));
    m_newTabButton->setAutoRaise(true);
    m_newTabButton->setFixedSize(24, 24);

    if (ui->treeView->parentWidget() && ui->treeView->parentWidget()->layout()) {
        QLayout* layout = ui->treeView->parentWidget()->layout();
        if (auto grid = qobject_cast<QGridLayout*>(layout)) {
            // Container keeps the tab bar + "+" button left-aligned while
            // remaining flush with treeView (row=1, col=1, colSpan=2).
            QWidget* tabRowContainer = new QWidget(this);
            auto* tabRowLayout = new QHBoxLayout(tabRowContainer);
            tabRowLayout->setContentsMargins(0, 0, 0, 0);
            tabRowLayout->setSpacing(0);
            tabRowLayout->addWidget(m_profileTabBar, 0);  // natural tab-bar width
            tabRowLayout->addWidget(m_newTabButton,  0);  // fixed right of last tab
            tabRowLayout->addStretch(1);                  // remaining space left empty
            grid->addWidget(tabRowContainer, 0, 1, 1, 2);
        }
    }

    // Install viewport filter so clicking blank space in the list clears selection.
    ui->treeView->viewport()->installEventFilter(this);

    connect(m_profileTabBar, &QTabBar::currentChanged, this, [this](int index) {
        ++m_profileSwitchGeneration;
        applyProfileSwitch(index, m_profileSwitchGeneration);
    });
    connect(m_profileTabBar, &QTabBar::customContextMenuRequested,
            this, &ModFolderPage::onTabContextMenuRequested);
    connect(m_newTabButton, &QToolButton::clicked, this, [this] {
        onTabNewToRight(m_profileTabBar->count() - 1);
    });

    ui->actionDownloadItem->setText(tr("Download Mods"));
    ui->actionDownloadItem->setToolTip(tr("Download mods from online mod platforms"));
    ui->actionDownloadItem->setEnabled(true);
    ui->actionsToolbar->insertActionBefore(ui->actionAddItem, ui->actionDownloadItem);

    connect(ui->actionDownloadItem, &QAction::triggered, this, &ModFolderPage::downloadMods);

    ui->actionUpdateItem->setToolTip(tr("Try to check or update all selected mods (all mods if none are selected)"));
    connect(ui->actionUpdateItem, &QAction::triggered, this, &ModFolderPage::updateMods);
    ui->actionsToolbar->insertActionBefore(ui->actionAddItem, ui->actionUpdateItem);

    auto* updateMenu = new QMenu(this);

    auto* update = updateMenu->addAction(tr("Check for Updates"));
    connect(update, &QAction::triggered, this, &ModFolderPage::updateMods);

    updateMenu->addAction(ui->actionVerifyItemDependencies);
    connect(ui->actionVerifyItemDependencies, &QAction::triggered, this, [this] { updateMods(true); });

    auto depsDisabled = APPLICATION->settings()->getSetting("ModDependenciesDisabled");
    ui->actionVerifyItemDependencies->setVisible(!depsDisabled->get().toBool());
    connect(depsDisabled.get(), &Setting::SettingChanged, this,
            [this](const Setting&, const QVariant& value) { ui->actionVerifyItemDependencies->setVisible(!value.toBool()); });

    updateMenu->addAction(ui->actionResetItemMetadata);
    connect(ui->actionResetItemMetadata, &QAction::triggered, this, &ModFolderPage::deleteModMetadata);

    ui->actionUpdateItem->setMenu(updateMenu);

    ui->actionChangeVersion->setToolTip(tr("Change a mod's version."));
    connect(ui->actionChangeVersion, &QAction::triggered, this, &ModFolderPage::changeModVersion);
    ui->actionsToolbar->insertActionAfter(ui->actionUpdateItem, ui->actionChangeVersion);

    ui->actionViewHomepage->setToolTip(tr("View the homepages of all selected mods."));

    ui->actionExportMetadata->setToolTip(tr("Export mod's metadata to text."));
    connect(ui->actionExportMetadata, &QAction::triggered, this, &ModFolderPage::exportModMetadata);
    ui->actionsToolbar->insertActionAfter(ui->actionViewHomepage, ui->actionExportMetadata);

    ui->actionsToolbar->insertActionAfter(ui->actionViewFolder, ui->actionViewConfigs);

    // Derive the settings key prefix from the model's directory name so that
    // each page type ("mods", "coremods", "nilmods") stores profiles independently.
    m_settingsPrefix = m_model->dir().dirName();

    m_instance->settings()->getOrRegisterSetting(profileListKey(), QStringList() << "All Mods");
    QStringList profileList = m_instance->settings()->get(profileListKey()).toStringList();
    m_profileTabBar->blockSignals(true);
    for (const QString& name : profileList) {
        m_profileTabBar->addTab(name);

        QString key = profileKey(name);
        m_instance->settings()->getOrRegisterSetting(key, QStringList());
        QStringList saved = m_instance->settings()->get(key).toStringList();
        m_profileStates[name] = QSet<QString>(saved.begin(), saved.end());
    }
    m_profileTabBar->blockSignals(false);
    m_profileTabBar->setUsesScrollButtons(m_profileTabBar->count() > 1);

    m_instance->settings()->getOrRegisterSetting(lastActiveIndexKey(), 0);
    int savedIndex = m_instance->settings()->get(lastActiveIndexKey()).toInt();
    if (savedIndex < 0 || savedIndex >= m_profileTabBar->count()) {
        savedIndex = 0;
    }
    m_profileTabBar->setCurrentIndex(savedIndex);
    applyProfileSwitch(m_profileTabBar->currentIndex(), m_profileSwitchGeneration);

    connect(m_model, &QAbstractItemModel::dataChanged, this, [this]() {
        if (!m_applyingProfile) {
            saveCurrentProfileState();
        }
    });
}

bool ModFolderPage::shouldDisplay() const
{
    return true;
}

void ModFolderPage::updateFrame(const QModelIndex& current, [[maybe_unused]] const QModelIndex& previous)
{
    auto sourceCurrent = m_filterModel->mapToSource(current);
    int row = sourceCurrent.row();
    const Mod& mod = m_model->at(row);
    ui->frame->updateWithMod(mod);
}

void ModFolderPage::removeItems(const QItemSelection& selection)
{
    if (m_instance != nullptr && m_instance->isRunning()) {
        auto response = CustomMessageBox::selectable(this, tr("Confirm Delete"),
                                                     tr("If you remove mods while the game is running it may crash your game.\n"
                                                        "Are you sure you want to do this?"),
                                                     QMessageBox::Warning, QMessageBox::Yes | QMessageBox::No, QMessageBox::No)
                            ->exec();

        if (response != QMessageBox::Yes) {
            return;
        }
    }

    auto indexes = selection.indexes();
    auto affected = m_model->getAffectedMods(indexes, EnableAction::DISABLE);
    if (!affected.isEmpty()) {
        auto response = CustomMessageBox::selectable(this, tr("Confirm Disable"),
                                                     tr("The mods you are trying to delete are required by %1 mods.\n"
                                                        "Do you want to disable them?")
                                                         .arg(affected.length()),
                                                     QMessageBox::Warning, QMessageBox::Yes | QMessageBox::No | QMessageBox::Cancel,
                                                     QMessageBox::Cancel)
                            ->exec();

        if (response == QMessageBox::Cancel) {
            return;
        }
        if (response == QMessageBox::Yes) {
            m_model->setResourceEnabled(affected, EnableAction::DISABLE);
        }
    }
    m_model->deleteResources(indexes);
}

void ModFolderPage::downloadMods()
{
    if (m_instance->typeName() != "Minecraft") {
        return;  // this is a null instance or a legacy instance
    }

    auto* profile = static_cast<MinecraftInstance*>(m_instance)->getPackProfile();
    if (!profile->getModLoaders().has_value()) {
        if (handleNoModLoader()) {
            return;
        }
    }

    m_downloadDialog = new ResourceDownload::ModDownloadDialog(this, m_model, m_instance);
    connect(this, &QObject::destroyed, m_downloadDialog, &QDialog::close);
    connect(m_downloadDialog, &QDialog::finished, this, &ModFolderPage::downloadDialogFinished);

    m_downloadDialog->open();
}

void ModFolderPage::downloadDialogFinished(int result)
{
    if (m_downloadFlowActive) {
        return;
    }
    m_downloadFlowActive = true;

    auto dialog = m_downloadDialog;
    m_downloadDialog.clear();

    if (result != 0) {
        auto* tasks = new ConcurrentTask(tr("Download Mods"), APPLICATION->settings()->get("NumberOfConcurrentDownloads").toInt());
        auto terminalHandled = std::make_shared<bool>(false);
        connect(tasks, &Task::failed, [this, tasks, terminalHandled](const QString& reason) {
            if (*terminalHandled) {
                return;
            }
            *terminalHandled = true;
            CustomMessageBox::selectable(this, tr("Error"), reason, QMessageBox::Critical)->show();
            tasks->deleteLater();
        });
        connect(tasks, &Task::aborted, [this, tasks, terminalHandled]() {
            if (*terminalHandled) {
                return;
            }
            *terminalHandled = true;
            CustomMessageBox::selectable(this, tr("Aborted"), tr("Download stopped by user."), QMessageBox::Information)->show();
            tasks->deleteLater();
        });
        connect(tasks, &Task::succeeded, [this, tasks, terminalHandled]() {
            if (*terminalHandled) {
                return;
            }
            *terminalHandled = true;
            QStringList warnings = tasks->warnings();
            if (warnings.count()) {
                CustomMessageBox::selectable(this, tr("Warnings"), warnings.join('\n'), QMessageBox::Warning)->show();
            }

            tasks->deleteLater();
        });

        if (dialog) {
            for (auto& task : dialog->getTasks()) {
                tasks->addTask(task);
            }
        } else {
            qWarning() << "ResourceDownloadDialog vanished before we could collect tasks!";
        }

        ProgressDialog loadDialog(this);
        loadDialog.setSkipButton(true, tr("Abort"));
        loadDialog.execWithTask(tasks);

        m_model->update();
    }
    if (dialog) {
        dialog->deleteLater();
    }
    m_downloadFlowActive = false;
}

void ModFolderPage::updateMods(bool includeDeps)
{
    if (m_instance->typeName() != "Minecraft") {
        return;  // this is a null instance or a legacy instance
    }

    auto* profile = static_cast<MinecraftInstance*>(m_instance)->getPackProfile();
    if (!profile->getModLoaders().has_value()) {
        if (handleNoModLoader()) {
            return;
        }
    }
    if (APPLICATION->settings()->get("ModMetadataDisabled").toBool()) {
        QMessageBox::critical(this, tr("Error"), tr("Mod updates are unavailable when metadata is disabled!"));
        return;
    }
    if (m_instance != nullptr && m_instance->isRunning()) {
        auto response =
            CustomMessageBox::selectable(this, tr("Confirm Update"),
                                         tr("Updating mods while the game is running may cause mod duplication and game crashes.\n"
                                            "The old files may not be deleted as they are in use.\n"
                                            "Are you sure you want to do this?"),
                                         QMessageBox::Warning, QMessageBox::Yes | QMessageBox::No, QMessageBox::No)
                ->exec();

        if (response != QMessageBox::Yes) {
            return;
        }
    }
    auto selection = m_filterModel->mapSelectionToSource(ui->treeView->selectionModel()->selection()).indexes();

    auto modsList = m_model->selectedResources(selection);
    bool useAll = modsList.empty();
    if (useAll) {
        modsList = m_model->allResources();
    }

    ResourceUpdateDialog updateDialog(this, m_instance, m_model, modsList, includeDeps, profile->getModLoadersList());
    updateDialog.checkCandidates();

    if (updateDialog.aborted()) {
        CustomMessageBox::selectable(this, tr("Aborted"), tr("The mod updater was aborted!"), QMessageBox::Warning)->show();
        return;
    }
    if (updateDialog.noUpdates()) {
        QString message{ tr("'%1' is up-to-date! :)").arg(modsList.front()->name()) };
        if (modsList.size() > 1) {
            if (useAll) {
                message = tr("All mods are up-to-date! :)");
            } else {
                message = tr("All selected mods are up-to-date! :)");
            }
        }
        CustomMessageBox::selectable(this, tr("Update checker"), message)->exec();
        return;
    }

    if (updateDialog.exec() != 0) {
        auto* tasks = new ConcurrentTask("Download Mods", APPLICATION->settings()->get("NumberOfConcurrentDownloads").toInt());
        auto terminalHandled = std::make_shared<bool>(false);
        connect(tasks, &Task::failed, [this, tasks, terminalHandled](const QString& reason) {
            if (*terminalHandled) {
                return;
            }
            *terminalHandled = true;
            CustomMessageBox::selectable(this, tr("Error"), reason, QMessageBox::Critical)->show();
            tasks->deleteLater();
        });
        connect(tasks, &Task::aborted, [this, tasks, terminalHandled]() {
            if (*terminalHandled) {
                return;
            }
            *terminalHandled = true;
            CustomMessageBox::selectable(this, tr("Aborted"), tr("Download stopped by user."), QMessageBox::Information)->show();
            tasks->deleteLater();
        });
        connect(tasks, &Task::succeeded, [this, tasks, terminalHandled]() {
            if (*terminalHandled) {
                return;
            }
            *terminalHandled = true;
            QStringList warnings = tasks->warnings();
            if (warnings.count()) {
                CustomMessageBox::selectable(this, tr("Warnings"), warnings.join('\n'), QMessageBox::Warning)->show();
            }
            tasks->deleteLater();
        });

        for (const auto& task : updateDialog.getTasks()) {
            tasks->addTask(task);
        }

        ProgressDialog loadDialog(this);
        loadDialog.setSkipButton(true, tr("Abort"));
        loadDialog.execWithTask(tasks);

        m_model->update();
    }
}

void ModFolderPage::deleteModMetadata()
{
    auto selection = m_filterModel->mapSelectionToSource(ui->treeView->selectionModel()->selection()).indexes();
    auto selectionCount = m_model->selectedMods(selection).length();
    if (selectionCount == 0) {
        return;
    }
    if (selectionCount > 1) {
        auto response = CustomMessageBox::selectable(this, tr("Confirm Removal"),
                                                     tr("You are about to remove the metadata for %1 mods.\n"
                                                        "Are you sure?")
                                                         .arg(selectionCount),
                                                     QMessageBox::Warning, QMessageBox::Yes | QMessageBox::No, QMessageBox::No)
                            ->exec();

        if (response != QMessageBox::Yes) {
            return;
        }
    }

    m_model->deleteMetadata(selection);
}

void ModFolderPage::changeModVersion()
{
    if (m_instance->typeName() != "Minecraft") {
        return;  // this is a null instance or a legacy instance
    }

    auto* profile = static_cast<MinecraftInstance*>(m_instance)->getPackProfile();
    if (!profile->getModLoaders().has_value()) {
        if (handleNoModLoader()) {
            return;
        }
    }
    if (APPLICATION->settings()->get("ModMetadataDisabled").toBool()) {
        QMessageBox::critical(this, tr("Error"), tr("Mod updates are unavailable when metadata is disabled!"));
        return;
    }
    auto selection = m_filterModel->mapSelectionToSource(ui->treeView->selectionModel()->selection()).indexes();
    auto modsList = m_model->selectedMods(selection);
    if (modsList.length() != 1 || modsList[0]->metadata() == nullptr) {
        return;
    }

    m_downloadDialog = new ResourceDownload::ModDownloadDialog(this, m_model, m_instance, true);
    connect(this, &QObject::destroyed, m_downloadDialog, &QDialog::close);
    connect(m_downloadDialog, &QDialog::finished, this, &ModFolderPage::downloadDialogFinished);

    m_downloadDialog->setResourceMetadata((*modsList.begin())->metadata());
    m_downloadDialog->open();
}

void ModFolderPage::exportModMetadata()
{
    auto selection = m_filterModel->mapSelectionToSource(ui->treeView->selectionModel()->selection()).indexes();
    auto selectedMods = m_model->selectedMods(selection);
    if (selectedMods.length() == 0) {
        // Scope to the mods currently enabled by the active profile tab only.
        for (auto* mod : m_model->allMods()) {
            if (mod->enabled()) {
                selectedMods.append(mod);
            }
        }
    }

    std::ranges::sort(selectedMods, [](const Mod* a, const Mod* b) { return a->name() < b->name(); });
    ExportToModListDialog dlg(m_instance->name(), selectedMods, this);
    dlg.exec();
}


CoreModFolderPage::CoreModFolderPage(BaseInstance* inst, ModFolderModel* mods, QWidget* parent) : ModFolderPage(inst, mods, parent)
{
    auto* mcInst = dynamic_cast<MinecraftInstance*>(m_instance);
    if (mcInst) {
        auto* version = mcInst->getPackProfile();
        if ((version != nullptr) && version->getComponent("net.minecraftforge") && version->getComponent("net.minecraft")) {
            auto minecraftCmp = version->getComponent("net.minecraft");
            if (!minecraftCmp->m_loaded) {
                version->reload(Net::Mode::Offline);

                auto update = version->getCurrentTask();
                if (update && update->isRunning()) {
                    connect(update.get(), &Task::finished, this, [this] {
                        if (m_container) {
                            m_container->refreshContainer();
                        }
                    });
                } else if (m_container) {
                    m_container->refreshContainer();
                }
            }
        }
    }
}

bool CoreModFolderPage::shouldDisplay() const
{
    if (ModFolderPage::shouldDisplay()) {
        auto* inst = dynamic_cast<MinecraftInstance*>(m_instance);
        if (!inst) {
            return true;
        }

        auto* version = inst->getPackProfile();
        if ((version == nullptr) || !version->getComponent("net.minecraftforge") || !version->getComponent("net.minecraft")) {
            return false;
        }
        auto minecraftCmp = version->getComponent("net.minecraft");
        return minecraftCmp->m_loaded && minecraftCmp->getReleaseDateTime() < g_VersionFilterData.legacyCutoffDate;
    }
    return false;
}

NilModFolderPage::NilModFolderPage(BaseInstance* inst, ModFolderModel* mods, QWidget* parent) : ModFolderPage(inst, mods, parent) {}

bool NilModFolderPage::shouldDisplay() const
{
    return m_model->dir().exists();
}

// Helper function so this doesn't need to be duplicated 3 times
inline bool ModFolderPage::handleNoModLoader()
{
    int resp = QMessageBox::question(
        this, ModFolderPage::tr("Missing Mod Loader"),
        ModFolderPage::tr("You need to install a compatible mod loader before installing mods. Would you like to do so?"),
        QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
    if (resp == QMessageBox::Yes) {
        // Should be safe
        auto* profile = static_cast<MinecraftInstance*>(this->m_instance)->getPackProfile();
        InstallLoaderDialog dialog(profile, QString(), this);
        bool ret = dialog.exec() != 0;
        this->m_container->refreshContainer();

        // returning negation of dialog.exec which'll be true if the install loader dialog got canceled/closed
        // and false if the user went through and installed a loader
        return !ret;
    }
    // Nothing happens the dialog is already closing
    // returning true so the caller doesn't go and continue with opening it's dialog without a mod loader
    return true;
}

void ModFolderPage::saveCurrentProfileState()
{
    if (m_currentProfile.isEmpty()) {
        return;
    }
    bool stillExists = false;
    for (int i = 0; i < m_profileTabBar->count(); ++i) {
        if (m_profileTabBar->tabText(i) == m_currentProfile) {
            stillExists = true;
            break;
        }
    }
    if (!stillExists) {
        return;
    }
    QSet<QString> enabledMods;
    for (int i = 0; i < m_model->rowCount(); ++i) {
        const Resource& res = m_model->at(i);
        if (res.enabled()) {
            enabledMods.insert(res.getOriginalFileName());
        }
    }
    m_profileStates[m_currentProfile] = enabledMods;
    QString key = profileKey(m_currentProfile);

    m_instance->settings()->getOrRegisterSetting(key, QStringList());
    m_instance->settings()->set(key, QStringList(enabledMods.begin(), enabledMods.end()));
}

void ModFolderPage::applyProfileSwitch(int index, int generation) {
    if (m_currentProfile.isEmpty()) {
        QVariant val = m_profileTabBar->property("currentProfileName");
        m_currentProfile = val.isValid() ? val.toString() : QString();
    }

    saveCurrentProfileState();

    if (index >= 0 && index < m_profileTabBar->count()) {
        QString tabName = m_profileTabBar->tabText(index);
        m_currentProfile = tabName;
        m_profileTabBar->setProperty("currentProfileName", tabName);
        m_instance->settings()->set(lastActiveIndexKey(), index);

        QSet<QString> enabledMods;
        if (m_profileStates.contains(tabName)) {
            enabledMods = m_profileStates[tabName];
        } else {
            QString key = profileKey(tabName);
            m_instance->settings()->getOrRegisterSetting(key, QStringList());
            QStringList saved = m_instance->settings()->get(key).toStringList();
            enabledMods = QSet<QString>(saved.begin(), saved.end());
            m_profileStates[tabName] = enabledMods;
        }

        QModelIndexList toEnable;
        QModelIndexList toDisable;
        for (int i = 0; i < m_model->rowCount(); ++i) {
            const Resource& res = m_model->at(i);
            QModelIndex idx = m_model->index(i, 0);
            if (enabledMods.contains(res.getOriginalFileName())) {
                if (!res.enabled()) {
                    toEnable.append(idx);
                }
            } else {
                if (res.enabled()) {
                    toDisable.append(idx);
                }
            }
        }
        m_applyingProfile = true;
        if (!toEnable.isEmpty()) {
            m_model->setResourceEnabled(toEnable, EnableAction::ENABLE);
        }
        if (!toDisable.isEmpty()) {
            m_model->setResourceEnabled(toDisable, EnableAction::DISABLE);
        }

        // Capture generation token. If tab changes again before this update
        // completes, the token will be stale and we discard the result.
        int capturedGeneration = generation;
        connect(m_model, &ResourceFolderModel::updateFinished, this,
            [this, capturedGeneration] {
                if (capturedGeneration == m_profileSwitchGeneration) {
                    saveCurrentProfileState();
                }
                m_applyingProfile = false;
            },
            Qt::SingleShotConnection);

        m_model->update();

    } else {
        m_currentProfile = QString();
        m_profileTabBar->setProperty("currentProfileName", QString());
        m_applyingProfile = false;
    }
}


void ModFolderPage::onAddProfileClicked() {
    bool ok;
    QString name = QInputDialog::getText(this, tr("Add Profile"), tr("Profile Name:"),
                                         QLineEdit::Normal, QString(), &ok);
    if (ok && !name.isEmpty()) {
        // Always create a blank-slate profile — no state bleeding from the current profile.
        createProfile(name, QSet<QString>{});
    }
}

void ModFolderPage::onRemoveProfileClicked() {
    int index = m_profileTabBar->currentIndex();
    // Guard: index 0 is the base profile and must never be removed.
    if (index > 0) {
        onTabRemove(index);
    }
}

// ---------------------------------------------------------------------------
// Profile creation helpers
// ---------------------------------------------------------------------------

void ModFolderPage::createProfile(const QString& name, const QSet<QString>& initialState,
                                   int insertAfterIndex)
{
    // Guard: duplicate name
    for (int i = 0; i < m_profileTabBar->count(); ++i) {
        if (m_profileTabBar->tabText(i) == name) {
            QMessageBox::warning(this, tr("Warning"),
                                 tr("A profile with this name already exists."));
            return;
        }
    }

    // Persist state to memory and settings
    m_profileStates[name] = initialState;
    QString key = profileKey(name);

    m_instance->settings()->getOrRegisterSetting(key, QStringList());
    m_instance->settings()->set(key, QStringList(initialState.begin(), initialState.end()));

    // Insert tab at the correct position
    if (insertAfterIndex >= 0 && insertAfterIndex < m_profileTabBar->count()) {
        m_profileTabBar->insertTab(insertAfterIndex + 1, name);
    } else {
        m_profileTabBar->addTab(name);
    }
    m_profileTabBar->setUsesScrollButtons(m_profileTabBar->count() > 1);

    saveProfileList();
}

void ModFolderPage::saveProfileList()
{
    QStringList profileList;
    for (int i = 0; i < m_profileTabBar->count(); ++i) {
        profileList.append(m_profileTabBar->tabText(i));
    }
    m_instance->settings()->set(profileListKey(), profileList);
}

// ---------------------------------------------------------------------------
// Tab context-menu
// ---------------------------------------------------------------------------

void ModFolderPage::onTabContextMenuRequested(const QPoint& pos)
{
    int tabIndex = m_profileTabBar->tabAt(pos);

    QMenu menu(this);

    // ── Management group ────────────────────────────────────────────────────
    auto* newToRight = menu.addAction(tr("New Tab to Right"));
    int insertAfter = tabIndex >= 0 ? tabIndex : m_profileTabBar->count() - 1;
    connect(newToRight, &QAction::triggered, this, [this, insertAfter] {
        onTabNewToRight(insertAfter);
    });

    if (tabIndex >= 0) {
        auto* duplicate = menu.addAction(tr("Duplicate"));
        connect(duplicate, &QAction::triggered, this, [this, tabIndex] {
            onTabDuplicate(tabIndex);
        });

        // Rename and Remove are permanently blocked for the base profile (index 0).
        if (tabIndex != 0) {
            auto* rename = menu.addAction(tr("Rename"));
            connect(rename, &QAction::triggered, this, [this, tabIndex] {
                onTabRename(tabIndex);
            });

            auto* remove = menu.addAction(tr("Remove"));
            connect(remove, &QAction::triggered, this, [this, tabIndex] {
                onTabRemove(tabIndex);
            });
        }

        // ── Selection / bulk-action group ────────────────────────────────────
        menu.addSeparator();

        auto* enableAll = menu.addAction(tr("Enable All"));
        connect(enableAll, &QAction::triggered, this, [this, tabIndex] {
            onTabEnableAll(tabIndex);
        });

        auto* disableAll = menu.addAction(tr("Disable All"));
        connect(disableAll, &QAction::triggered, this, [this, tabIndex] {
            onTabDisableAll(tabIndex);
        });
    }

    menu.exec(m_profileTabBar->mapToGlobal(pos));
}

void ModFolderPage::onTabNewToRight(int sourceIndex)
{
    bool ok;
    QString name = QInputDialog::getText(this, tr("New Profile"), tr("Profile Name:"),
                                         QLineEdit::Normal, QString(), &ok);
    if (ok && !name.isEmpty()) {
        createProfile(name, QSet<QString>{}, sourceIndex);
    }
}

void ModFolderPage::onTabDuplicate(int sourceIndex)
{
    // Flush the live state of the currently active profile before reading source.
    if (!m_currentProfile.isEmpty()) {
        QSet<QString> enabledMods;
        for (int i = 0; i < m_model->rowCount(); ++i) {
            const Resource& res = m_model->at(i);
            if (res.enabled()) {
                enabledMods.insert(res.getOriginalFileName());
            }
        }
        m_profileStates[m_currentProfile] = enabledMods;
    }

    QString sourceName = m_profileTabBar->tabText(sourceIndex);
    QSet<QString> sourceState = m_profileStates.value(sourceName);

    bool ok;
    QString name = QInputDialog::getText(this, tr("Duplicate Profile"),
                                          tr("New Profile Name:"), QLineEdit::Normal,
                                          tr("Copy of %1").arg(sourceName), &ok);
    if (ok && !name.isEmpty()) {
        createProfile(name, sourceState, sourceIndex);
    }
}

void ModFolderPage::onTabRename(int tabIndex)
{
    if (tabIndex == 0) return;  // Guard: base profile cannot be renamed

    QString oldName = m_profileTabBar->tabText(tabIndex);

    bool ok;
    QString newName = QInputDialog::getText(this, tr("Rename Profile"),
                                             tr("New Profile Name:"), QLineEdit::Normal,
                                             oldName, &ok);

    if (!ok || newName.isEmpty() || newName == oldName) return;

    // Validate: no duplicate names
    for (int i = 0; i < m_profileTabBar->count(); ++i) {
        if (m_profileTabBar->tabText(i) == newName) {
            QMessageBox::warning(this, tr("Warning"),
                                 tr("A profile named \"%1\" already exists.").arg(newName));
            return;
        }
    }

    // Migrate in-memory state to the new key
    if (m_profileStates.contains(oldName)) {
        m_profileStates[newName] = m_profileStates.take(oldName);
    }

    // Migrate settings: read → reset old key → write under new key
    QString oldKey = profileKey(oldName);
    QString newKey = profileKey(newName);
    QStringList stateData = m_instance->settings()->get(oldKey).toStringList();
    m_instance->settings()->reset(oldKey);
    m_instance->settings()->getOrRegisterSetting(newKey, QStringList());
    m_instance->settings()->set(newKey, stateData);

    // Update the visible tab label
    m_profileTabBar->setTabText(tabIndex, newName);

    // Keep current-profile tracking in sync
    if (m_currentProfile == oldName) {
        m_currentProfile = newName;
        m_profileTabBar->setProperty("currentProfileName", newName);
    }

    saveProfileList();
}

void ModFolderPage::onTabRemove(int tabIndex)
{
    if (tabIndex == 0) return;  // Guard: base profile cannot be removed

    QString name = m_profileTabBar->tabText(tabIndex);

    auto response = CustomMessageBox::selectable(
                        this, tr("Remove Profile"),
                        tr("Are you sure you want to remove the profile \"%1\"?\n"
                           "This cannot be undone.").arg(name),
                        QMessageBox::Warning,
                        QMessageBox::Yes | QMessageBox::No, QMessageBox::No)->exec();

    if (response != QMessageBox::Yes) return;

    m_profileStates.remove(name);

    m_instance->settings()->reset(profileKey(name));

    m_profileTabBar->removeTab(tabIndex);
    m_profileTabBar->setUsesScrollButtons(m_profileTabBar->count() > 1);
    saveProfileList();
}

void ModFolderPage::onTabEnableAll(int tabIndex)
{
    if (m_profileTabBar->currentIndex() != tabIndex) {
        m_profileTabBar->setCurrentIndex(tabIndex);
    }
    applyProfileSwitch(tabIndex, m_profileSwitchGeneration);

    // Build the full index list and enable every mod in the active profile.
    QModelIndexList allIndices;
    allIndices.reserve(m_model->rowCount());
    for (int i = 0; i < m_model->rowCount(); ++i) {
        allIndices.append(m_model->index(i, 0));
    }
    if (!allIndices.isEmpty()) {
        m_model->setResourceEnabled(allIndices, EnableAction::ENABLE);
        m_model->update();
    }
}

void ModFolderPage::onTabDisableAll(int tabIndex)
{
    if (m_profileTabBar->currentIndex() != tabIndex) {
        m_profileTabBar->setCurrentIndex(tabIndex);
    }
    applyProfileSwitch(tabIndex, m_profileSwitchGeneration);

    // Build the full index list and disable every mod in the active profile.
    QModelIndexList allIndices;
    allIndices.reserve(m_model->rowCount());
    for (int i = 0; i < m_model->rowCount(); ++i) {
        allIndices.append(m_model->index(i, 0));
    }
    if (!allIndices.isEmpty()) {
        m_model->setResourceEnabled(allIndices, EnableAction::DISABLE);
        m_model->update();
    }
}

bool ModFolderPage::eventFilter(QObject* obj, QEvent* ev)
{
    // Safety guard: ensure the page, its UI, and tree view are fully valid
    if (!ui || !ui->treeView || !m_model) {
        return ExternalResourcesPage::eventFilter(obj, ev);
    }

    // When focus or clicks land outside this page (e.g. the instance sidebar), clear selection.
    if (ev->type() == QEvent::MouseButtonPress || ev->type() == QEvent::FocusIn) {
        if (this->isVisible()) {
            QWidget* widget = qobject_cast<QWidget*>(obj);
            if (widget) {
                if (!this->isAncestorOf(widget) && widget != this) {
                    ui->treeView->clearSelection();
                    ui->treeView->setCurrentIndex(QModelIndex());
                }
            }
        }
    }

    // Clear treeView selection when the user clicks on empty space below the
    // last row, so that Export List reverts to the full active-profile scope.
    if (obj == ui->treeView->viewport() && ev->type() == QEvent::MouseButtonPress) {
        auto* me = static_cast<QMouseEvent*>(ev);
        const QModelIndex idx = ui->treeView->indexAt(me->pos());
        if (!idx.isValid()) {
            ui->treeView->clearSelection();
            ui->treeView->setCurrentIndex(QModelIndex());
            return true;
        }
    }
    return ExternalResourcesPage::eventFilter(obj, ev);
}

void ModFolderPage::mousePressEvent(QMouseEvent* event)
{
    if (ui->treeView) {
        QPoint posInTreeView = ui->treeView->mapFrom(this, event->pos());
        if (!ui->treeView->rect().contains(posInTreeView)) {
            ui->treeView->clearSelection();
            ui->treeView->setCurrentIndex(QModelIndex());
        }
    }
    ExternalResourcesPage::mousePressEvent(event);
}

void ModFolderPage::showEvent(QShowEvent* event)
{
    ExternalResourcesPage::showEvent(event);
    QWidget* w = window();
    if (w && m_filterWindow != w) {
        if (m_filterWindow) {
            m_filterWindow->removeEventFilter(this);
        }
        m_filterWindow = w;
        w->installEventFilter(this);
    }
}

void ModFolderPage::hideEvent(QHideEvent* event)
{
    if (m_filterWindow) {
        m_filterWindow->removeEventFilter(this);
        m_filterWindow = nullptr;
    }
    ExternalResourcesPage::hideEvent(event);
}