// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#include "generalsettings.h"
#include "coreconstants.h"
#include "coreplugintr.h"
#include "dialogs/ioptionspage.h"
#include "editormanager/editormanager_p.h"
#include "icore.h"
#include "themechooser.h"

#include <extensionsystem/pluginmanager.h>

#include <utils/algorithm.h>
#include <utils/checkablemessagebox.h>
#include <utils/hostosinfo.h>
#include <utils/infobar.h>
#include <utils/layoutbuilder.h>
#include <utils/qtcolorbutton.h>
#include <utils/stylehelper.h>
#include <utils/textcodec.h>

#include <QApplication>
#include <QCheckBox>
#include <QComboBox>
#include <QCoreApplication>
#include <QDir>
#include <QGuiApplication>
#include <QLibraryInfo>
#include <QMessageBox>
#include <QPushButton>
#include <QSettings>
#include <QStyleHints>

using namespace Utils;
using namespace Layouting;

namespace Core::Internal {

const char settingsKeyDpiPolicy[] = "Core/HighDpiScaleFactorRoundingPolicy";
const char settingsKeyCodecForLocale[] = "General/OverrideCodecForLocale";
const char settingsKeyToolbarStyle[] = "General/ToolbarStyle";

static bool defaultShowShortcutsInContextMenu()
{
    return QGuiApplication::styleHints()->showShortcutsInContextMenus();
}

GeneralSettings &generalSettings()
{
    static GeneralSettings theSettings;
    return theSettings;
}

GeneralSettings::GeneralSettings()
{
    setAutoApply(false);

    showShortcutsInContextMenus.setSettingsKey("General/ShowShortcutsInContextMenu");
    showShortcutsInContextMenus.setDefaultValue(defaultShowShortcutsInContextMenu());
    showShortcutsInContextMenus.setLabelText(
        Tr::tr("Show keyboard shortcuts in context menus (default: %1)")
            .arg(defaultShowShortcutsInContextMenu() ? Tr::tr("on") : Tr::tr("off")));
    showShortcutsInContextMenus.addOnChanged(this, [this] {
        QCoreApplication::setAttribute(Qt::AA_DontShowShortcutsInContextMenus,
                                       !showShortcutsInContextMenus());
    });

    provideSplitterCursors.setSettingsKey("General/OverrideSplitterCursors");
    provideSplitterCursors.setDefaultValue(false);
    provideSplitterCursors.setLabelText(Tr::tr("Override cursors for views"));
    provideSplitterCursors.setToolTip(
        Tr::tr("Provide cursors for resizing views.\nIf the system cursors for resizing views are "
               "not displayed properly, you can use the cursors provided by %1.")
            .arg(QGuiApplication::applicationDisplayName()));

    preferInfoBarOverPopup.setSettingsKey("General/PreferInfoBarOverPopup");
    preferInfoBarOverPopup.setDefaultValue(false);
    preferInfoBarOverPopup.setLabelText(Tr::tr("Prefer banner style info bars over pop-ups"));

    useTabsInEditorViews.setSettingsKey("General/UseTabsInEditorViews");
    useTabsInEditorViews.setDefaultValue(false);
    useTabsInEditorViews.setLabelText(Tr::tr("Use tabbed editors"));
    useTabsInEditorViews.addOnChanged(EditorManagerPrivate::instance(), [this] {
        EditorManagerPrivate::setShowingTabs(useTabsInEditorViews.value());
    });

    showOkAndCancelInSettingsMode.setSettingsKey("General/ShowOkAndCancelInSettingsMode");
    showOkAndCancelInSettingsMode.setDefaultValue(false);
    showOkAndCancelInSettingsMode.setLabelText(Tr::tr("Show OK and Cancel buttons in Preferences mode"));

    readSettings();
}

class GeneralSettingsWidget final : public IOptionsPageWidget
{
public:
    GeneralSettingsWidget();

    void apply() final;
    bool isDirty() const final;

    void resetInterfaceColor();
    void resetWarnings();
    void resetLanguage();

    static bool canResetWarnings();
    void fillLanguageBox() const;
    static QString language();
    static void setLanguage(const QString&);
    void fillCodecBox() const;
    static QByteArray codecForLocale();
    static void setCodecForLocale(const QByteArray&);
    void fillToolbarStyleBox() const;
    static void setDpiPolicy(Qt::HighDpiScaleFactorRoundingPolicy policy);

    QComboBox *m_languageBox;
    QComboBox *m_codecBox;
    QtColorButton *m_colorButton;
    ThemeChooser *m_themeChooser;
    QPushButton *m_resetWarningsButton;
    QComboBox *m_toolbarStyleBox;
    QComboBox *m_policyComboBox = nullptr;
};

GeneralSettingsWidget::GeneralSettingsWidget()
    : m_languageBox(new QComboBox)
    , m_codecBox(new QComboBox)
    , m_colorButton(new QtColorButton)
    , m_themeChooser(new ThemeChooser)
    , m_resetWarningsButton(new QPushButton)
    , m_toolbarStyleBox(new QComboBox)
{
    m_languageBox->setObjectName("languageBox");
    m_languageBox->setSizeAdjustPolicy(QComboBox::AdjustToMinimumContentsLengthWithIcon);
    m_languageBox->setMinimumContentsLength(20);

    m_codecBox->setSizeAdjustPolicy(QComboBox::AdjustToMinimumContentsLengthWithIcon);
    m_codecBox->setMinimumContentsLength(20);

    m_colorButton->setMinimumSize(QSize(64, 0));
    m_colorButton->setProperty("alphaAllowed", QVariant(false));

    m_resetWarningsButton->setText(Tr::tr("Reset Warnings", "Button text"));
    m_resetWarningsButton->setToolTip(
        Tr::tr("Re-enable warnings that were suppressed by selecting \"Do Not "
           "Show Again\" (for example, missing highlighter).",
           nullptr));

    m_toolbarStyleBox->setSizeAdjustPolicy(QComboBox::AdjustToContents);

    auto resetColorButton = new QPushButton(Tr::tr("Reset"));
    resetColorButton->setToolTip(Tr::tr("Reset to default.", "Color"));

    Form form;
    form.addRow({Tr::tr("Color:"), m_colorButton, resetColorButton, st});
    form.addRow({Tr::tr("Theme:"), m_themeChooser});
    form.addRow({Tr::tr("Toolbar style:"), m_toolbarStyleBox, st});
    form.addRow({Tr::tr("Language:"), m_languageBox, st});

    if (StyleHelper::defaultHighDpiScaleFactorRoundingPolicy()
        != Qt::HighDpiScaleFactorRoundingPolicy::Unset) {
        using Policy = Qt::HighDpiScaleFactorRoundingPolicy;
        m_policyComboBox = new QComboBox;
        m_policyComboBox->addItem(Tr::tr("Round Up for .5 and Above"), int(Policy::Round));
        m_policyComboBox->addItem(Tr::tr("Always Round Up"), int(Policy::Ceil));
        m_policyComboBox->addItem(Tr::tr("Always Round Down"), int(Policy::Floor));
        m_policyComboBox->addItem(Tr::tr("Round Up for .75 and Above"),
                                  int(Policy::RoundPreferFloor));
        m_policyComboBox->addItem(Tr::tr("Don't Round"), int(Policy::PassThrough));
        m_policyComboBox->setSizeAdjustPolicy(QComboBox::AdjustToContents);
        m_policyComboBox->setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Preferred);

        const Policy userPolicy =
            ICore::settings()->value(settingsKeyDpiPolicy,
                                     int(StyleHelper::defaultHighDpiScaleFactorRoundingPolicy()))
                                      .value<Policy>();
        m_policyComboBox->setCurrentIndex(m_policyComboBox->findData(int(userPolicy)));

        form.addRow({Tr::tr("DPI rounding policy:"), m_policyComboBox});
        static const char *envVars[] = {
            StyleHelper::C_QT_SCALE_FACTOR_ROUNDING_POLICY, "QT_ENABLE_HIGHDPI_SCALING",
            "QT_FONT_DPI", "QT_SCALE_FACTOR", "QT_SCREEN_SCALE_FACTORS", "QT_USE_PHYSICAL_DPI",
        };
        if (anyOf(envVars, qEnvironmentVariableIsSet)) {
            QString toolTip = Tr::tr("The following environment variables are set and can "
                                     "influence the UI scaling behavior of %1:")
                                  .arg(QGuiApplication::applicationDisplayName()) + "\n";
            for (auto var : envVars) {
                if (qEnvironmentVariableIsSet(var))
                    toolTip.append(QLatin1String("\n") + var + "=" + qEnvironmentVariable(var));
            }
            auto envVarInfo = new InfoLabel(Tr::tr("Environment influences UI scaling behavior."));
            envVarInfo->setAdditionalToolTip(toolTip);
            form.addItem(envVarInfo);
        } else {
            form.addItem(st);
        }
    }

    form.flush();
    form.addRow({Tr::tr("Text codec for tools:"), m_codecBox, st});
    form.addRow({empty, generalSettings().showShortcutsInContextMenus});
    form.addRow({empty, generalSettings().provideSplitterCursors});
    form.addRow({empty, generalSettings().preferInfoBarOverPopup});
    form.addRow({empty, generalSettings().useTabsInEditorViews});
    form.addRow({empty, generalSettings().showOkAndCancelInSettingsMode});
    form.addRow({Row{m_resetWarningsButton, st}});

    Column {
        Group {
            title(Tr::tr("User Interface")),
            form
        }
    }.attachTo(this);

    fillLanguageBox();
    fillCodecBox();
    fillToolbarStyleBox();

    m_colorButton->setColor(StyleHelper::requestedBaseColor());
    m_resetWarningsButton->setEnabled(canResetWarnings());

    connect(resetColorButton,
            &QAbstractButton::clicked,
            this,
            &GeneralSettingsWidget::resetInterfaceColor);
    connect(m_resetWarningsButton,
            &QAbstractButton::clicked,
            this,
            &GeneralSettingsWidget::resetWarnings);

    setOnCancel([] { generalSettings().cancel(); });

    installCheckSettingsDirtyTrigger(m_languageBox);
    installCheckSettingsDirtyTrigger(m_codecBox);
    installCheckSettingsDirtyTrigger(m_colorButton);
    installCheckSettingsDirtyTrigger(m_themeChooser->themeComboBox());
    installCheckSettingsDirtyTrigger(m_toolbarStyleBox);
    installCheckSettingsDirtyTrigger(m_policyComboBox);

    connect(&generalSettings(), &AspectContainer::volatileValueChanged, &checkSettingsDirty);
}

static bool hasQmFilesForLocale(const QString &locale, const QString &creatorTrPath)
{
    static const QString qtTrPath = QLibraryInfo::path(QLibraryInfo::TranslationsPath);

    const QString trFile = QLatin1String("/qt_") + locale + QLatin1String(".qm");
    return QFileInfo::exists(qtTrPath + trFile) || QFileInfo::exists(creatorTrPath + trFile);
}

void GeneralSettingsWidget::fillLanguageBox() const
{
    const QString currentLocale = language();

    m_languageBox->addItem(Tr::tr("<System Language>"), QString());

    struct Item
    {
        QString display;
        QString locale;
        QString comparisonId;
    };

    QList<Item> items;
    // need to add this explicitly, since there is no qm file for English
    const QString english = QLocale::languageToString(QLocale::English);
    items.append({english, QString("en"), english});

    const FilePath creatorTrPath = ICore::resourcePath("translations");
    const FilePaths languageFiles = creatorTrPath.dirEntries(
        QStringList(QLatin1String("qtcreator*.qm")));
    for (const FilePath &languageFile : languageFiles) {
        const QString name = languageFile.fileName();
        // Ignore english ts file that is for temporary spelling fixes only.
        // We have the "English" item that is explicitly added at the top.
        if (name == "qtcreator_en.qm")
            continue;
        int start = name.indexOf('_') + 1;
        int end = name.lastIndexOf('.');
        const QString locale = name.mid(start, end - start);
        // no need to show a language that creator will not load anyway
        if (hasQmFilesForLocale(locale, creatorTrPath.toUrlishString())) {
            QLocale tmpLocale(locale);
            const auto languageItem = QString("%1 (%2) - %3 (%4)")
                                          .arg(
                                              tmpLocale.nativeLanguageName(),
                                              tmpLocale.nativeTerritoryName(),
                                              QLocale::languageToString(tmpLocale.language()),
                                              QLocale::territoryToString(tmpLocale.territory()));
            // Create a fancy comparison string.
            // We cannot use a "locale aware comparison" because we are comparing different locales.
            // The probably "optimal solution" would be to compare by "latinized native name",
            // but that's hard. Instead
            // - for non-Latin-script locales use the english name, otherwise the native name
            // - get rid of fancy characters like 'č' by decomposing them (e.g. to 'c')
            QString comparisonId = tmpLocale.script() == QLocale::LatinScript
                                       ? (tmpLocale.nativeLanguageName() + " "
                                          + tmpLocale.nativeTerritoryName())
                                       : (QLocale::languageToString(tmpLocale.language()) + " "
                                          + QLocale::territoryToString(tmpLocale.territory()));
            for (int i = 0; i < comparisonId.size(); ++i) {
                QChar &c = comparisonId[i];
                if (c.decomposition().isEmpty())
                    continue;
                c = c.decomposition().at(0);
            }
            items.append({languageItem, locale, comparisonId});
        }
    }

    Utils::sort(items, [](const Item &a, const Item &b) {
        return a.comparisonId.compare(b.comparisonId, Qt::CaseInsensitive) < 0;
    });
    for (const Item &i : std::as_const(items)) {
        m_languageBox->addItem(i.display, i.locale);
        if (i.locale == currentLocale)
            m_languageBox->setCurrentIndex(m_languageBox->count() - 1);
    }
}

void GeneralSettingsWidget::apply()
{
    generalSettings().apply();
    generalSettings().writeSettings();

    int currentIndex = m_languageBox->currentIndex();
    setLanguage(m_languageBox->itemData(currentIndex, Qt::UserRole).toString());
    if (m_policyComboBox) {
        const Qt::HighDpiScaleFactorRoundingPolicy selectedPolicy =
            m_policyComboBox->currentData().value<Qt::HighDpiScaleFactorRoundingPolicy>();
        setDpiPolicy(selectedPolicy);
    }
    currentIndex = m_codecBox->currentIndex();
    if (currentIndex != -1)
        setCodecForLocale(m_codecBox->itemText(currentIndex).toLocal8Bit());
    // Apply the new base color if accepted
    StyleHelper::setBaseColor(m_colorButton->color());
    m_themeChooser->apply();
    if (const auto newStyle = m_toolbarStyleBox->currentData().value<StyleHelper::ToolbarStyle>();
        newStyle != StyleHelper::toolbarStyle()) {
        ICore::settings()->setValueWithDefault(settingsKeyToolbarStyle, int(newStyle),
                                               int(StyleHelper::defaultToolbarStyle()));
        StyleHelper::setToolbarStyle(newStyle);
        QStyle *applicationStyle = QApplication::style();
        for (QWidget *widget : QApplication::allWidgets())
            applicationStyle->polish(widget);
    }
}

bool GeneralSettingsWidget::isDirty() const
{
    if (generalSettings().isDirty())
        return true;

    QtcSettings *settings = ICore::settings();

    int currentIndex = m_languageBox->currentIndex();
    QString selecetedLanguange = m_languageBox->itemData(currentIndex, Qt::UserRole).toString();
    if (settings->value("General/OverrideLanguage").toString() != selecetedLanguange)
        return true;

    if (m_policyComboBox) {
        const Qt::HighDpiScaleFactorRoundingPolicy selectedPolicy =
            m_policyComboBox->currentData().value<Qt::HighDpiScaleFactorRoundingPolicy>();
        using Policy = Qt::HighDpiScaleFactorRoundingPolicy;
        const Policy previousPolicy = settings->value(
                    settingsKeyDpiPolicy,
                    int(StyleHelper::defaultHighDpiScaleFactorRoundingPolicy())).value<Policy>();
        if (selectedPolicy != previousPolicy)
            return true;
    }

    currentIndex = m_codecBox->currentIndex();
    if (currentIndex != -1) {
        QByteArray selectedCodec = m_codecBox->itemText(currentIndex).toLocal8Bit();
        if (selectedCodec != settings->value(settingsKeyCodecForLocale).toByteArray())
            return true;
    }

    if (m_colorButton->color() != StyleHelper::requestedBaseColor())
        return true;

    if (m_themeChooser->isDirty())
        return true;

    if (const auto newStyle = m_toolbarStyleBox->currentData().value<StyleHelper::ToolbarStyle>();
            newStyle != StyleHelper::toolbarStyle()) {
        return true;
    }

    return false;
}

void GeneralSettingsWidget::resetInterfaceColor()
{
    m_colorButton->setColor(StyleHelper::DEFAULT_BASE_COLOR);
    checkSettingsDirty();
}

void GeneralSettingsWidget::resetWarnings()
{
    InfoBar::clearGloballySuppressed();
    CheckableMessageBox::resetAllDoNotAskAgainQuestions();
    m_resetWarningsButton->setEnabled(false);
}

bool GeneralSettingsWidget::canResetWarnings()
{
    return InfoBar::anyGloballySuppressed() || CheckableMessageBox::hasSuppressedQuestions();
}

void GeneralSettingsWidget::resetLanguage()
{
    // system language is default
    m_languageBox->setCurrentIndex(0);
}

QString GeneralSettingsWidget::language()
{
    QtcSettings *settings = ICore::settings();
    return settings->value("General/OverrideLanguage").toString();
}

void GeneralSettingsWidget::setLanguage(const QString &locale)
{
    QtcSettings *settings = ICore::settings();
    if (settings->value("General/OverrideLanguage").toString() != locale)
        ICore::askForRestart(Tr::tr("The language change will take effect after restart."));

    settings->setValueWithDefault("General/OverrideLanguage", locale, {});
}

void GeneralSettingsWidget::fillCodecBox() const
{
    const QByteArray currentCodec = codecForLocale();

    for (const TextEncoding &encoding : TextEncoding::availableEncodings()) {
        m_codecBox->addItem(encoding.displayName());
        if (encoding.name() == currentCodec)
            m_codecBox->setCurrentIndex(m_codecBox->count() - 1);
    }
}

QByteArray GeneralSettingsWidget::codecForLocale()
{
    QtcSettings *settings = ICore::settings();
    QByteArray codec = settings->value(settingsKeyCodecForLocale).toByteArray();
    if (codec.isEmpty())
        codec = TextEncoding::encodingForLocale().name();
    return codec;
}

void GeneralSettingsWidget::setCodecForLocale(const QByteArray &codec)
{
    QtcSettings *settings = ICore::settings();
    settings->setValueWithDefault(settingsKeyCodecForLocale, codec, {});
    TextEncoding::setEncodingForLocale(codec);
}

StyleHelper::ToolbarStyle toolbarStylefromSettings()
{
    if (!ExtensionSystem::PluginManager::instance()) // May happen in tests
        return StyleHelper::defaultToolbarStyle();

    return StyleHelper::ToolbarStyle(
                ICore::settings()->value(settingsKeyToolbarStyle,
                                         int(StyleHelper::defaultToolbarStyle())).toInt());
}

void GeneralSettingsWidget::fillToolbarStyleBox() const
{
    m_toolbarStyleBox->addItem(Tr::tr("Compact"),
                               QVariant::fromValue(StyleHelper::ToolbarStyle::Compact));
    m_toolbarStyleBox->addItem(Tr::tr("Relaxed"),
                               QVariant::fromValue(StyleHelper::ToolbarStyle::Relaxed));
    const int curId = m_toolbarStyleBox->findData(QVariant::fromValue(toolbarStylefromSettings()));
    m_toolbarStyleBox->setCurrentIndex(curId);
}

void GeneralSettingsWidget::setDpiPolicy(Qt::HighDpiScaleFactorRoundingPolicy policy)
{
    QtcSettings *settings = ICore::settings();
    using Policy = Qt::HighDpiScaleFactorRoundingPolicy;
    const Policy previousPolicy = settings->value(
                settingsKeyDpiPolicy,
                int(StyleHelper::defaultHighDpiScaleFactorRoundingPolicy())).value<Policy>();
    if (policy != previousPolicy) {
        ICore::askForRestart(
            Tr::tr("The DPI rounding policy change will take effect after restart."));
    }
    settings->setValueWithDefault(settingsKeyDpiPolicy, int(policy),
                                  int(StyleHelper::defaultHighDpiScaleFactorRoundingPolicy()));
}

void GeneralSettings::applyToolbarStyleFromSettings()
{
    StyleHelper::setToolbarStyle(toolbarStylefromSettings());
}

// GeneralSettingsPage

class GeneralSettingsPage final : public IOptionsPage
{
public:
    GeneralSettingsPage()
    {
        setId(Constants::SETTINGS_ID_INTERFACE);
        setDisplayName(Tr::tr("Interface"));
        setCategory(Constants::SETTINGS_CATEGORY_CORE);
        setWidgetCreator([] { return new GeneralSettingsWidget; });
    }
};

const GeneralSettingsPage settingsPage;

} // Core::Internal
