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

#include "clangformatconfigwidget.h"

#include "clangformatconstants.h"
#include "clangformatindenter.h"
#include "clangformatfile.h"
#include "clangformatsettings.h"
#include "clangformatutils.h"

// the file was generated by scripts/generateClangFormatChecksLayout.py
#include "clangformatchecks.h"

#include <clang/Format/Format.h>

#include <coreplugin/icore.h>

#include <cppeditor/cppcodestylepreferences.h>
#include <cppeditor/cppcodestylesettings.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/layoutbuilder.h>
#include <utils/qtcassert.h>

#include <QComboBox>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
#include <QSharedPointer>
#include <QVBoxLayout>
#include <QWeakPointer>
#include <QWidget>

#include <sstream>

using namespace ProjectExplorer;
using namespace Utils;

namespace ClangFormat {

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

    resize(489, 305);
    m_fallbackConfig = new QLabel(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());

    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]));
    m_preview->textDocument()->setIndenter(new ClangFormatIndenter(m_preview->document()));
    m_preview->textDocument()->setFontSettings(TextEditor::TextEditorSettings::fontSettings());
    m_preview->textDocument()->setSyntaxHighlighter(new CppEditor::CppHighlighter);
    m_preview->textDocument()->indenter()->setFileName(fileName);

    using namespace Layouting;

    Column {
        m_fallbackConfig,
        Row { m_checksScrollArea, m_preview },
    }.attachTo(this);

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

    slotCodeStyleChanged(codeStyle->currentPreferences());

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

    connectChecks();
}

ClangFormatConfigWidget::~ClangFormatConfigWidget() = default;

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

    m_checksWidget->setEnabled(!codeStyle->isReadOnly());

    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));
    }
}

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()->autoIndent(cursor);
}

static inline void ltrim(std::string &s)
{
    s.erase(s.begin(), std::find_if(s.begin(), s.end(), [](int ch) { return !std::isspace(ch); }));
}

static inline void rtrim(std::string &s)
{
    s.erase(std::find_if(s.rbegin(), s.rend(), [](int ch) { return !std::isspace(ch); }).base(),
            s.end());
}

static inline void trim(std::string &s)
{
    ltrim(s);
    rtrim(s);
}

static void fillPlainText(QPlainTextEdit *plainText, const std::string &text, size_t index)
{
    if (index == std::string::npos) {
        plainText->setPlainText("");
        return;
    }
    size_t valueStart = text.find('\n', index + 1);
    size_t valueEnd;
    std::string value;
    QTC_ASSERT(valueStart != std::string::npos, return;);
    do {
        valueEnd = text.find('\n', valueStart + 1);
        if (valueEnd == std::string::npos)
            break;
        // Skip also 2 spaces - start with valueStart + 1 + 2.
        std::string line = text.substr(valueStart + 3, valueEnd - valueStart - 3);
        rtrim(line);
        value += value.empty() ? line : '\n' + line;
        valueStart = valueEnd;
    } while (valueEnd < text.size() - 1 && text.at(valueEnd + 1) == ' ');
    plainText->setPlainText(QString::fromStdString(value));
}

static void fillComboBoxOrLineEdit(QObject *object, const std::string &text, size_t index)
{
    auto *comboBox = qobject_cast<QComboBox *>(object);
    auto *lineEdit = qobject_cast<QLineEdit *>(object);
    if (index == std::string::npos) {
        if (comboBox)
            comboBox->setCurrentIndex(0);
        else
            lineEdit->setText("");
        return;
    }

    const size_t valueStart = text.find(':', index + 1);
    QTC_ASSERT(valueStart != std::string::npos, return;);
    const size_t valueEnd = text.find('\n', valueStart + 1);
    QTC_ASSERT(valueEnd != std::string::npos, return;);
    std::string value = text.substr(valueStart + 1, valueEnd - valueStart - 1);
    trim(value);

    if (comboBox) {
        if (comboBox->findText(QString::fromStdString(value)) == -1) {
            comboBox->setCurrentIndex(0);
            return;
        }
        comboBox->setCurrentText(QString::fromStdString(value));
        return;
    }

    lineEdit->setText(QString::fromStdString(value));
}

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

    const std::string configText = readFile(m_config->filePath().path());

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

        size_t index = configText.find('\n' + child->objectName().toStdString());
        if (index == std::string::npos)
            index = configText.find("\n  " + child->objectName().toStdString());

        if (qobject_cast<QPlainTextEdit *>(child))
            fillPlainText(qobject_cast<QPlainTextEdit *>(child), configText, index);
        else
            fillComboBoxOrLineEdit(child, configText, index);
    }
}

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;

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

            QWidget *valueWidget = m_checksWidget->findChild<QWidget *>(label->text().trimmed());
            if (!valueWidget) {
                // Currently BraceWrapping only.
                fields.append({label->text(), ""});
                continue;
            }

            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);
}

} // namespace ClangFormat