#include "ScriptSideWidget.hpp"

// Qt Headers
#include <QPainter>
#include <QApplication>
#include <QStyleOption>
#include <QPixmapCache>

// Roblox Studio Headers
#include "RobloxScriptDoc.hpp"
#include "ScriptTextEditor.hpp"
#include "AuthoringSettings.hpp"
#include "QtUtilities.hpp"

FASTFLAG(LuaDebugger)

ScriptSideWidget::ScriptSideWidget(ScriptTextEditor* editor)
    : QWidget(editor)
    , m_pScriptEditor(editor)
    , m_foldArea(QtUtilities::BranchIndicatorSize)
    , m_debugArea(0)
{
}

ScriptSideWidget::~ScriptSideWidget() {}

void ScriptSideWidget::updateArea()
{
    int digits = 1;
    int max = qMax(1, m_pScriptEditor->blockCount());

    while (max >= 10)
    {
        max /= 10;
        ++digits;
    }

    QFontMetrics fm(m_font);
    int newWidth = fm.horizontalAdvance(QLatin1Char('9')) * digits + 10 + (FFlag::LuaDebugger ? (m_debugArea + m_foldArea) : m_foldArea);
    ;
    if (width() != newWidth)
    {
        setFixedWidth(newWidth);
        m_pScriptEditor->setViewportMargins(newWidth, 0, 0, 0);
    }
    update();
}

void ScriptSideWidget::updateDebugArea()
{
    // first remove saved pixmap
    QPixmapCache::remove(QString("BreakpointState1"));
    QPixmapCache::remove(QString("BreakpointState2"));
    // update debug area
    m_debugArea = m_pScriptEditor->fontMetrics().height();
}

void ScriptSideWidget::toggleFold(int lineNumber, bool updateView)
{
    if (isFolded(lineNumber))
        unfold(lineNumber, updateView);
    else
        fold(lineNumber, updateView);
}

void ScriptSideWidget::fold(int lineNumber, bool updateView)
{
    QTextBlock startBlock = m_pScriptEditor->document()->findBlockByNumber(lineNumber - 1);

    if (!isFoldable(startBlock) || isFolded(lineNumber))
        return;

    QTextBlock endBlock = ScriptEditorUtils::findFoldBoundary(startBlock, false);

    QTextBlock block = startBlock.next();
    while (block.isValid() && (block.blockNumber() <= endBlock.blockNumber()))
    {
        block.setVisible(false);
        block.setLineCount(0);
        block = block.next();
    }

    m_FoldedBlocks << startBlock.blockNumber();

    QTextBlock closingBlock = endBlock;
    if (endBlock != m_pScriptEditor->document()->lastBlock())
        closingBlock = endBlock.next();

    QTextCursor cursor = m_pScriptEditor->textCursor();
    int blockNumber = cursor.block().blockNumber();
    if (blockNumber > startBlock.blockNumber() && blockNumber <= endBlock.blockNumber())
    {
        cursor.setPosition(endBlock.position() + endBlock.length(), QTextCursor::MoveAnchor);
        m_pScriptEditor->setTextCursor(cursor);
    }

    if (updateView)
    {
        m_pScriptEditor->document()->markContentsDirty(startBlock.position(), closingBlock.position() + closingBlock.length());
        m_pScriptEditor->updateFolds();
        m_pScriptEditor->viewport()->resize(m_pScriptEditor->viewport()->sizeHint());
        update();
    }
}

void ScriptSideWidget::unfold(int lineNumber, bool updateView)
{
    QTextBlock startBlock = m_pScriptEditor->document()->findBlockByNumber(lineNumber - 1);

    if (!isFoldable(startBlock))
        return;

    QTextBlock endBlock = ScriptEditorUtils::findFoldBoundary(startBlock, false);

    QTextBlock block = startBlock.next();
    while (block.isValid() && (block.blockNumber() <= endBlock.blockNumber()))
    {
        block.setVisible(true);
        block.setLineCount(block.layout()->lineCount());

        if (m_FoldedBlocks.contains(block.blockNumber()))
            block = ScriptEditorUtils::findFoldBoundary(block, false);

        block = block.next();
    }

    m_FoldedBlocks.removeOne(startBlock.blockNumber());

    if (updateView)
    {
        QTextBlock closingBlock = endBlock;
        if (endBlock != m_pScriptEditor->document()->lastBlock())
            closingBlock = endBlock.next();

        m_pScriptEditor->document()->markContentsDirty(startBlock.position(), closingBlock.position() + closingBlock.length());
        m_pScriptEditor->updateFolds();
        m_pScriptEditor->viewport()->resize(m_pScriptEditor->viewport()->sizeHint());
        update();
    }
}

bool ScriptSideWidget::isFolded(int lineNumber)
{
    QTextBlock block = m_pScriptEditor->document()->findBlockByNumber(lineNumber);

    if (!block.isValid())
        return false;
    return !block.isVisible();
}

bool ScriptSideWidget::isFolded(const QTextBlock& block)
{
    if (block.isValid() && m_FoldedBlocks.contains(block.blockNumber()))
        return true;
    return false;
}

bool ScriptSideWidget::isFoldable(QTextBlock& block)
{
    if (!block.isValid())
        return false;

    bool bFold = false;
    RBXTextUserData* pUserData = dynamic_cast<RBXTextUserData*>(block.userData());
    if (pUserData)
        bFold = (pUserData->getFoldState() > 0);

    return bFold;
}

void ScriptSideWidget::toggleAllFolds(bool expand)
{
    QTextBlock currentBlock = expand ? m_pScriptEditor->document()->begin() : m_pScriptEditor->document()->end().previous();
    while (currentBlock.isValid())
    {
        if (isFoldable(currentBlock))
            expand ? unfold(currentBlock.blockNumber() + 1) : fold(currentBlock.blockNumber() + 1);
        currentBlock = expand ? currentBlock.next() : currentBlock.previous();
    }
}

void ScriptSideWidget::paintEvent(QPaintEvent* evt)
{
    QPainter painter(this);

    painter.fillRect(rect(), QColor(Qt::lightGray).lighter(115));
    painter.setFont(m_font);

    const QFontMetrics fm(m_font);

    const int pageBottom = m_pScriptEditor->viewport()->height();
    const QTextBlock currentBlock = m_pScriptEditor->document()->findBlock(m_pScriptEditor->textCursor().position());
    const QPointF viewportOffset = m_pScriptEditor->contentOffset();
    const int xofs = width() - m_foldArea;

    QTextBlock block = m_pScriptEditor->firstVisibleBlock();
    int lineCount = block.blockNumber();

    while (block.isValid())
    {
        lineCount += 1;

        // The top left position of the block in the document
        QPointF position = m_pScriptEditor->blockBoundingGeometry(block).topLeft() + viewportOffset;

        // Check if the position of the block is outside of the visible area
        if (position.y() > pageBottom)
            break;

        // We want the line number for the selected line to be bold.
        bool isBold = false;
        if (block == currentBlock)
        {
            isBold = true;
            QFont font = painter.font();
            font.setBold(true);
            painter.setFont(font);
        }

        // Draw the line number right justified at the y position of the
        // line. 3 is a magic padding number. drawText(x, y, text).
        if (block.isVisible())
        {
            const QString strNumber = QString::number(lineCount);
            const int x = width() - (FFlag::LuaDebugger ? (m_debugArea + m_foldArea) : m_foldArea) - fm.horizontalAdvance(strNumber) - 3;
            const int y = position.y() + fm.ascent();
            painter.drawText(x, y, strNumber);
        }

        // Remove the bold style if it was set previously.
        if (isBold)
        {
            QFont font = painter.font();
            font.setBold(false);
            painter.setFont(font);
        }

        block = block.next();
    }

    // Breakpoints region
    int xofsB = width() - (m_debugArea + m_foldArea);
    if (FFlag::LuaDebugger)
        painter.fillRect(xofsB, 0, m_debugArea, height(), QColor(Qt::lightGray).lighter(120));

    // Code Folding
    painter.fillRect(xofs, 0, m_foldArea, height(), QColor(Qt::lightGray).lighter(130));
    block = m_pScriptEditor->firstVisibleBlock();
    while (block.isValid())
    {
        // Check if the position of the block is outside of the visible area
        const QPointF position = m_pScriptEditor->blockBoundingGeometry(block).topLeft() + viewportOffset;
        if (position.y() > pageBottom)
            break;

        QString blockText = block.text();
        if (block.isVisible())
        {
            if (FFlag::LuaDebugger)
            {
                RBXTextUserData* pUserData = dynamic_cast<RBXTextUserData*>(block.userData());
                if (pUserData)
                {
                    if (pUserData->getBreakpointState())
                        painter.drawPixmap(
                            xofsB + 1, qRound(position.y()) - 1, QtUtilities::getBreakpointPixmap(pUserData->getBreakpointState(), m_debugArea - 2));

                    if (!pUserData->getMarker().isEmpty())
                    {
                        QPixmap marker(pUserData->getMarker());
                        painter.drawPixmap(xofsB + 1, qRound(position.y()) - 2,
                            marker.scaled(m_debugArea - 2, m_debugArea - 2, Qt::KeepAspectRatio, Qt::SmoothTransformation));
                    }
                }
            }

            if (isFoldable(block))
            {
                if (m_FoldedBlocks.contains(block.blockNumber()))
                    painter.drawPixmap(xofs, qRound(position.y()), QtUtilities::getBranchIndicator(QStyle::State_Children));
                else
                    painter.drawPixmap(xofs, qRound(position.y()), QtUtilities::getBranchIndicator(QStyle::State_Children | QStyle::State_Open));
            }
        }

        block = block.next();
    }

    painter.end();

    QWidget::paintEvent(evt);
}

void ScriptSideWidget::mousePressEvent(QMouseEvent* evt)
{
    if (m_foldArea > 0)
    {
        QFontMetrics fm(m_font);

        const int xofs = FFlag::LuaDebugger ? 0 : (width() - m_foldArea);
        const int fh = fm.lineSpacing();
        const int ys = evt->pos().y();

        int lineNumber = 0;

        if (evt->pos().x() > xofs)
        {
            QTextBlock block = m_pScriptEditor->firstVisibleBlock();
            const QPointF viewportOffset = m_pScriptEditor->contentOffset();
            const int pageBottom = m_pScriptEditor->viewport()->height();

            while (block.isValid())
            {
                const QPointF position = m_pScriptEditor->blockBoundingGeometry(block).topLeft() + viewportOffset;
                if (position.y() > pageBottom)
                    break;

                if ((position.y() < ys) && ((position.y() + fh) > ys))
                {
                    int xofF = width() - m_foldArea;
                    if (FFlag::LuaDebugger && (evt->pos().x() > xofs) && (evt->pos().x() < xofF))
                    {
                        Q_EMIT toggleBreakpoint(block.blockNumber());
                        update();
                        break;
                    }
                    else if (isFoldable(block))
                    {
                        lineNumber = block.blockNumber() + 1;
                        break;
                    }
                }

                block = block.next();
            }
        }

        if (lineNumber > 0)
            toggleFold(lineNumber);
    }
}

void ScriptSideWidget::onPropertyChanged(const Aya::Reflection::PropertyDescriptor* pDescriptor)
{
    if (!pDescriptor || pDescriptor->category.str == sScriptCategoryName)
    {
        m_font = AuthoringSettings::singleton().editorFont;
        m_font.setFixedPitch(true);
        m_font.setStrikeOut(false);
        m_font.setUnderline(false);
        m_font.setBold(false);
        updateArea();
        if (FFlag::LuaDebugger)
            updateDebugArea();
    }
}