// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#include "clangformatconfigwidget.h"

// the file below was generated by scripts/generateClangFormatChecksLayout.py
#include "clangformatchecks.h"
#include "clangformatconstants.h"
#include "clangformatfile.h"
#include "clangformatindenter.h"
#include "clangformattr.h"
#include "clangformatutils.h"

#include <coreplugin/icore.h>

#include <cppeditor/cppcodestylepreferences.h>
#include <cppeditor/cppcodestylesettings.h>
#include <cppeditor/cppcodestylesettingspage.h>
#include <cppeditor/cppcodestylesnippets.h>
#include <cppeditor/cpphighlighter.h>
#include <cppeditor/cpptoolssettings.h>

#include <projectexplorer/editorconfiguration.h>
#include <projectexplorer/project.h>

#include <texteditor/displaysettings.h>
#include <texteditor/icodestylepreferences.h>
#include <texteditor/snippets/snippeteditor.h>
#include <texteditor/textdocument.h>
#include <texteditor/texteditorsettings.h>

#include <utils/guard.h>
#include <utils/layoutbuilder.h>
#include <utils/qtcassert.h>
#include <utils/utilsicons.h>

#include <QComboBox>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
#include <QScrollArea>
#include <QVBoxLayout>

#include <memory>
#include <sstream>

using namespace ProjectExplorer;
using namespace Utils;

namespace ClangFormat {

class ClangFormatConfigWidget final : public CppEditor::CppCodeStyleWidget
{
public:
    ClangFormatConfigWidget(TextEditor::ICodeStylePreferences *codeStyle,
                            Project *project,
                            QWidget *parent);
    void apply() final;
    void finish() final;
    void setCodeStyleSettings(const CppEditor::CppCodeStyleSettings &settings) final;
    void setTabSettings(const TextEditor::TabSettings &settings) final;
    void synchronize() final;

private:
    bool eventFilter(QObject *object, QEvent *event) final;

    FilePath globalPath();
    FilePath projectPath();
    void createStyleFileIfNeeded(bool isGlobal);
    void showOrHideWidgets();
    void initChecksAndPreview();
    void connectChecks();

    void fillTable();
    std::string readFile(const QString &path);
    void saveChanges(QObject *sender);

    void updatePreview();
    void slotCodeStyleChanged(TextEditor::ICodeStylePreferences *currentPreferences);

    ProjectExplorer::Project *m_project = nullptr;
    QWidget *m_checksWidget = nullptr;
    QScrollArea *m_checksScrollArea = nullptr;
    TextEditor::SnippetEditorWidget *m_preview = nullptr;
    std::unique_ptr<ClangFormatFile> m_config;
    clang::format::FormatStyle m_style;
    Guard m_ignoreChanges;
    QLabel *m_fallbackConfig;
    QLabel *m_clangVersion;
    QLabel *m_clangWarningText;
    QLabel *m_clangWarningIcon;
};

bool ClangFormatConfigWidget::eventFilter(QObject *object, QEvent *event)
{
    if (event->type() == QEvent::Wheel && qobject_cast<QComboBox *>(object)) {
        event->ignore();
        return true;
    }
    return QWidget::eventFilter(object, event);
}

ClangFormatConfigWidget::ClangFormatConfigWidget(TextEditor::ICodeStylePreferences *codeStyle,
                                                 Project *project,
                                                 QWidget *parent)
    : CppCodeStyleWidget(parent)
{
    m_project = project;
    m_config = std::make_unique<ClangFormatFile>(codeStyle->currentPreferences());

    m_fallbackConfig = new QLabel(Tr::tr("Clang-Format Style"));
    m_checksScrollArea = new QScrollArea();
    m_checksWidget = new ClangFormatChecks();

    m_checksScrollArea->setWidget(m_checksWidget);
    m_checksScrollArea->setWidgetResizable(true);
    m_checksWidget->setEnabled(!codeStyle->isReadOnly() && !codeStyle->isTemporarilyReadOnly()
                                && !codeStyle->isAdditionalTabDisabled());


    static const int expectedMajorVersion = 17;
    m_clangVersion = new QLabel(Tr::tr("Current ClangFormat version: %1.").arg(LLVM_VERSION_STRING),
                                 this);
    m_clangWarningText
        = new QLabel(Tr::tr("The widget was generated for ClangFormat %1. "
                            "If you use a different version, the widget may work incorrectly.")
                         .arg(expectedMajorVersion),
                     this);

    QPalette palette = m_clangWarningText->palette();
    palette.setColor(QPalette::WindowText, Qt::red);
    m_clangWarningText->setPalette(palette);

    m_clangWarningIcon = new QLabel(this);
    m_clangWarningIcon->setPixmap(Icons::WARNING.icon().pixmap(16, 16));

    if (LLVM_VERSION_MAJOR == expectedMajorVersion) {
        m_clangWarningText->hide();
        m_clangWarningIcon->hide();
    }

    FilePath fileName;
    if (m_project)
        fileName = m_project->projectFilePath().pathAppended("snippet.cpp");
    else
        fileName = Core::ICore::userResourcePath("snippet.cpp");

    m_preview = new TextEditor::SnippetEditorWidget(this);
    TextEditor::DisplaySettings displaySettings = m_preview->displaySettings();
    displaySettings.m_visualizeWhitespace = true;
    m_preview->setDisplaySettings(displaySettings);
    m_preview->setPlainText(QLatin1String(CppEditor::Constants::DEFAULT_CODE_STYLE_SNIPPETS[0]));
    auto *indenter = new ClangFormatIndenter(m_preview->document());
    indenter->setOverriddenPreferences(codeStyle);
    m_preview->textDocument()->setIndenter(indenter);
    m_preview->textDocument()->setFontSettings(TextEditor::TextEditorSettings::fontSettings());
    m_preview->textDocument()->resetSyntaxHighlighter(
        [] { return new CppEditor::CppHighlighter(); });
    m_preview->textDocument()->indenter()->setFileName(fileName);

    using namespace Layouting;

    Column {
        m_fallbackConfig,
        Row {m_clangWarningIcon, m_clangWarningText, st},
        m_clangVersion,
        Row { m_checksScrollArea, m_preview },
    }.attachTo(this);

    connect(codeStyle, &TextEditor::ICodeStylePreferences::currentPreferencesChanged,
            this, &ClangFormatConfigWidget::slotCodeStyleChanged);

    slotCodeStyleChanged(codeStyle->currentPreferences());

    showOrHideWidgets();
    fillTable();
    updatePreview();

    connectChecks();
}

void ClangFormatConfigWidget::slotCodeStyleChanged(
    TextEditor::ICodeStylePreferences *codeStyle)
{
    if (!codeStyle)
        return;
    m_config.reset(new ClangFormatFile(codeStyle));
    m_config->setIsReadOnly(codeStyle->isReadOnly());
    m_style = m_config->style();

    m_checksWidget->setEnabled(!codeStyle->isReadOnly() && !codeStyle->isTemporarilyReadOnly()
                                && !codeStyle->isAdditionalTabDisabled());

    fillTable();
    updatePreview();
}

void ClangFormatConfigWidget::connectChecks()
{
    auto doSaveChanges = [this](QObject *sender) {
        if (!m_ignoreChanges.isLocked())
            saveChanges(sender);
    };

    for (QObject *child : m_checksWidget->children()) {
        auto comboBox = qobject_cast<QComboBox *>(child);
        if (comboBox != nullptr) {
            connect(comboBox, &QComboBox::currentIndexChanged,
                    this, std::bind(doSaveChanges, comboBox));
            comboBox->installEventFilter(this);
            continue;
        }

        const auto button = qobject_cast<QPushButton *>(child);
        if (button != nullptr)
            connect(button, &QPushButton::clicked, this, std::bind(doSaveChanges, button));
    }
}

static clang::format::FormatStyle constructStyle(const QByteArray &baseStyle = QByteArray())
{
    if (!baseStyle.isEmpty()) {
        // Try to get the style for this base style.
        llvm::Expected<clang::format::FormatStyle> style
            = clang::format::getStyle(baseStyle.toStdString(), "dummy.cpp", baseStyle.toStdString());
        if (style)
            return *style;

        handleAllErrors(style.takeError(), [](const llvm::ErrorInfoBase &) {
            // do nothing
        });
        // Fallthrough to the default style.
    }
    return qtcStyle();
}

FilePath ClangFormatConfigWidget::globalPath()
{
    return Core::ICore::userResourcePath();
}

FilePath ClangFormatConfigWidget::projectPath()
{
    if (m_project)
        return globalPath().pathAppended("clang-format/" + projectUniqueId(m_project));

    return {};
}

void ClangFormatConfigWidget::createStyleFileIfNeeded(bool isGlobal)
{
    const FilePath path = isGlobal ? globalPath() : projectPath();
    const FilePath configFile = path / Constants::SETTINGS_FILE_NAME;

    if (configFile.exists())
        return;

    path.ensureWritableDir();
    if (!isGlobal) {
        FilePath possibleProjectConfig = m_project->rootProjectDirectory()
                                         / Constants::SETTINGS_FILE_NAME;
        if (possibleProjectConfig.exists()) {
            // Just copy th .clang-format if current project has one.
            possibleProjectConfig.copyFile(configFile);
            return;
        }
    }

    const std::string config = clang::format::configurationAsText(constructStyle());
    configFile.writeFileContents(QByteArray::fromStdString(config));
}

void ClangFormatConfigWidget::showOrHideWidgets()
{
    auto verticalLayout = qobject_cast<QVBoxLayout *>(layout());
    QTC_ASSERT(verticalLayout, return);

    QLayoutItem *lastItem = verticalLayout->itemAt(verticalLayout->count() - 1);
    if (lastItem->spacerItem())
        verticalLayout->removeItem(lastItem);

    createStyleFileIfNeeded(!m_project);
    m_fallbackConfig->show();
    m_checksScrollArea->show();
    m_preview->show();
}

void ClangFormatConfigWidget::updatePreview()
{
    QTextCursor cursor(m_preview->document());
    cursor.setPosition(0);
    cursor.movePosition(QTextCursor::End, QTextCursor::KeepAnchor);
    m_preview->textDocument()->autoFormatOrIndent(cursor);
}

std::string ClangFormatConfigWidget::readFile(const QString &path)
{
    const std::string defaultStyle = clang::format::configurationAsText(qtcStyle());

    QFile file(path);
    if (!file.open(QFile::ReadOnly))
        return defaultStyle;

    const std::string content = file.readAll().toStdString();
    file.close();

    clang::format::FormatStyle style;
    style.Language = clang::format::FormatStyle::LK_Cpp;
    const std::error_code error = clang::format::parseConfiguration(content, &style);
    QTC_ASSERT(error.value() == static_cast<int>(clang::format::ParseError::Success),
               return defaultStyle);

    addQtcStatementMacros(style);
    std::string settings = clang::format::configurationAsText(style);

    // Needed workaround because parseConfiguration remove BasedOnStyle field
    // ToDo: standardize this behavior for future
    const size_t index = content.find("BasedOnStyle");
    if (index != std::string::npos) {
        const size_t size = content.find("\n", index) - index;
        const size_t insert_index = settings.find("\n");
        settings.insert(insert_index, "\n" + content.substr(index, size));
    }

    return settings;
}

static std::map<QString, QString> getMapFromString(const QString &text)
{
    std::map<QString, QString> objectNameMap;

    QString parentName;
    for (QString line : text.split('\n')) {
        if (line.isEmpty())
            continue;

        QStringList list = line.split(':');
        QString key = !list.isEmpty() ? list[0] : "";
        QString value = line.mid(key.size() + 1).trimmed();

        if (line.contains(':') && value.isEmpty()) {
            parentName = key;
            continue;
        }

        if (!value.isEmpty() && !line.startsWith("  "))
            parentName = "";

        if (line.startsWith("  - ") || line.startsWith("    ")) {
            line.remove(0, 2);
            if (objectNameMap.find(parentName) == objectNameMap.end())
                objectNameMap[parentName] = line + "\n";
            else
                objectNameMap[parentName] += line + "\n";
            continue;
        }

        if (line.startsWith("  ")) {
            key.remove(0, 2);
            key = parentName + key;
            objectNameMap.insert(std::make_pair(key, value));
            continue;
        }

        objectNameMap.insert(std::make_pair(key, value));
    }

    return objectNameMap;
}

void ClangFormatConfigWidget::fillTable()
{
    GuardLocker locker(m_ignoreChanges);

    const QString configText = QString::fromStdString(readFile(m_config->filePath().path()));
    std::map<QString, QString> objectNameMap = getMapFromString(configText);

    for (QObject *child : m_checksWidget->children()) {
        if (!qobject_cast<QComboBox *>(child) && !qobject_cast<QLineEdit *>(child)
            && !qobject_cast<QPlainTextEdit *>(child)) {
            continue;
        }

        if (objectNameMap.find(child->objectName()) == objectNameMap.end())
            continue;

        if (QPlainTextEdit *plainText = qobject_cast<QPlainTextEdit *>(child)) {
            plainText->setPlainText(objectNameMap[child->objectName()]);
            continue;
        }

        if (QComboBox *comboBox = qobject_cast<QComboBox *>(child)) {
            if (comboBox->findText(objectNameMap[child->objectName()]) == -1) {
                comboBox->setCurrentIndex(0);
            } else {
                comboBox->setCurrentText(objectNameMap[child->objectName()]);
            }
            continue;
        }

        if (QLineEdit *lineEdit = qobject_cast<QLineEdit *>(child)) {
            lineEdit->setText(objectNameMap[child->objectName()]);
            continue;
        }
    }
}

void ClangFormatConfigWidget::saveChanges(QObject *sender)
{
    if (sender->objectName() == "BasedOnStyle") {
        const auto *basedOnStyle = m_checksWidget->findChild<QComboBox *>("BasedOnStyle");
        m_config->setBasedOnStyle(basedOnStyle->currentText());
    } else {
        QList<ClangFormatFile::Field> fields;
        QString parentName;

        for (QObject *child : m_checksWidget->children()) {
            if (child->objectName() == "BasedOnStyle")
                continue;
            auto *label = qobject_cast<QLabel *>(child);
            if (!label)
                continue;

            // reset parent name if label starts without "  "
            if (!label->text().startsWith("  "))
                parentName = "";

            QList<QWidget *> valueWidgets = m_checksWidget->findChildren<QWidget *>(
                parentName + label->text().trimmed());

            if (valueWidgets.empty()) {
                // Currently BraceWrapping only.
                fields.append({label->text(), ""});
                // save parent name
                parentName = label->text().trimmed();
                continue;
            }

            QWidget *valueWidget = valueWidgets.first();
            if (valueWidgets.size() > 1) {
                for (QWidget *w : valueWidgets) {
                    if (w->objectName() == parentName + label->text().trimmed()) {
                        valueWidget = w;
                        break;
                    }
                }
            }

            if (!qobject_cast<QComboBox *>(valueWidget) && !qobject_cast<QLineEdit *>(valueWidget)
                && !qobject_cast<QPlainTextEdit *>(valueWidget)) {
                continue;
            }

            auto *plainText = qobject_cast<QPlainTextEdit *>(valueWidget);
            if (plainText) {
                if (plainText->toPlainText().trimmed().isEmpty())
                    continue;

                std::stringstream content;
                QStringList list = plainText->toPlainText().split('\n');
                for (const QString &line : list)
                    content << "\n  " << line.toStdString();

                fields.append({label->text(), QString::fromStdString(content.str())});
            } else {
                QString text;
                if (auto *comboBox = qobject_cast<QComboBox *>(valueWidget)) {
                    text = comboBox->currentText();
                } else {
                    auto *lineEdit = qobject_cast<QLineEdit *>(valueWidget);
                    QTC_ASSERT(lineEdit, continue;);
                    text = lineEdit->text();
                }

                if (!text.isEmpty() && text != "Default")
                    fields.append({label->text(), text});
            }
        }
        m_config->changeFields(fields);
    }

    fillTable();
    updatePreview();
    synchronize();
}

void ClangFormatConfigWidget::setCodeStyleSettings(const CppEditor::CppCodeStyleSettings &settings)
{
    m_config->fromCppCodeStyleSettings(settings);

    fillTable();
    updatePreview();
}

void ClangFormatConfigWidget::setTabSettings(const TextEditor::TabSettings &settings)
{
    m_config->fromTabSettings(settings);

    fillTable();
    updatePreview();
}

void ClangFormatConfigWidget::synchronize()
{
    emit codeStyleSettingsChanged(m_config->toCppCodeStyleSettings(m_project));
    emit tabSettingsChanged(m_config->toTabSettings(m_project));
}

void ClangFormatConfigWidget::apply()
{
    if (!m_checksWidget->isVisible() && !m_checksWidget->isEnabled())
        return;

    m_style = m_config->style();
}

void ClangFormatConfigWidget::finish()
{
    if (!m_checksWidget->isVisible() && !m_checksWidget->isEnabled())
        return;

    m_config->setStyle(m_style);
}

CppEditor::CppCodeStyleWidget *createClangFormatConfigWidget(
    TextEditor::ICodeStylePreferences *codeStyle,
    Project *project,
    QWidget *parent)
{
    return new ClangFormatConfigWidget(codeStyle, project, parent);
}

} // namespace ClangFormat