/* This file is part of the KDE libraries
    Copyright (C) 2005, 2006 Ian Reinhart Geiser <geiseri@kde.org>
    Copyright (C) 2005, 2006 Matt Broadstone <mbroadst@gmail.com>
    Copyright (C) 2005, 2006 Richard J. Moore <rich@kde.org>
    Copyright (C) 2005, 2006 Erik L. Bunce <kde@bunce.us>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "numberedtextview.h"

#include <QTextDocument>
#include <QTextBlock>
#include <QTextEdit>
#include <QBoxLayout>
#include <QScrollBar>
#include <QPainter>
#include <QTextObjectInterface>
#include <QToolTip>
#include <QDebug>

NumberBar::NumberBar(QWidget *parent)
    : QWidget(parent), edit(nullptr), m_stopLine(-1), m_currentLine(-1), m_bugLine(-1)
{
    stopMarker = QPixmap(":/images/no.png");
    currentMarker = QPixmap(":/images/next.png");
    bugMarker = QPixmap(":/images/bug.png");
    setFixedWidth(fontMetrics().width(QStringLiteral("0000")) + bugMarker.width() + stopMarker.width() + currentMarker.width());
}

NumberBar::~NumberBar()
{
}

void NumberBar::setCurrentLine(int lineno)
{
    m_currentLine = lineno;
}

void NumberBar::setStopLine(int lineno)
{
    m_stopLine = lineno;
}

void NumberBar::setBugLine(int lineno)
{
    m_bugLine = lineno;
}

int NumberBar::currentLine() const
{
    return m_currentLine;
}

int NumberBar::stopLine() const
{
    return m_stopLine;
}

int NumberBar::bugLine() const
{
    return m_bugLine;
}

void NumberBar::setTextEdit(QTextEdit *edit)
{
    this->edit = edit;
    connect(edit->document()->documentLayout(), SIGNAL(update(QRectF)),
            this, SLOT(update()));
    connect(edit->verticalScrollBar(), SIGNAL(valueChanged(int)),
            this, SLOT(update()));
}

void NumberBar::paintEvent(QPaintEvent *)
{
    QAbstractTextDocumentLayout *layout = edit->document()->documentLayout();
    int contentsY = edit->verticalScrollBar()->value();
    qreal pageBottom = contentsY + edit->viewport()->height();
    const QFontMetrics fm = fontMetrics();
    const int ascent = fontMetrics().ascent() + 1; // height = ascent + descent + 1
    int lineCount = 1;

    QPainter p(this);

    bugRect = QRect();
    stopRect = QRect();
    currentRect = QRect();

    for (QTextBlock block = edit->document()->begin();
            block.isValid(); block = block.next(), ++lineCount) {

        const QRectF boundingRect = layout->blockBoundingRect(block);

        QPointF position = boundingRect.topLeft();
        if (position.y() + boundingRect.height() < contentsY) {
            continue;
        }
        if (position.y() > pageBottom) {
            break;
        }

        const QString txt = QString::number(lineCount);
        p.drawText(width() - fm.width(txt), qRound(position.y()) - contentsY + ascent, txt);

        // Bug marker
        if (m_bugLine == lineCount) {
            p.drawPixmap(1, qRound(position.y()) - contentsY, bugMarker);
            bugRect = QRect(1, qRound(position.y()) - contentsY, bugMarker.width(), bugMarker.height());
        }

        // Stop marker
        if (m_stopLine == lineCount) {
            p.drawPixmap(1, qRound(position.y()) - contentsY, stopMarker);
            stopRect = QRect(1, qRound(position.y()) - contentsY, stopMarker.width(), stopMarker.height());
        }

        // Current line marker
        if (m_currentLine == lineCount) {
            p.drawPixmap(1, qRound(position.y()) - contentsY, currentMarker);
            currentRect = QRect(1, qRound(position.y()) - contentsY, currentMarker.width(), currentMarker.height());
        }
    }
}

bool NumberBar::event(QEvent *event)
{
    if (event->type() == QEvent::ToolTip) {
        QHelpEvent *helpEvent = static_cast<QHelpEvent *>(event);

        if (stopRect.contains(helpEvent->pos())) {
            QToolTip::showText(helpEvent->globalPos(), "Stop Here");
        } else if (currentRect.contains(helpEvent->pos())) {
            QToolTip::showText(helpEvent->globalPos(), "Current Line");
        } else if (bugRect.contains(helpEvent->pos())) {
            QToolTip::showText(helpEvent->globalPos(), "Error Line");
        }
    }

    return QWidget::event(event);
}

NumberedTextView::NumberedTextView(QWidget *parent)
    : QFrame(parent)
{
    setFrameStyle(QFrame::StyledPanel | QFrame::Sunken);
    setLineWidth(2);

    // Setup the main view
    view = new QTextEdit(this);
    view->setFontFamily("Monospace");
    view->setLineWrapMode(QTextEdit::NoWrap);
    view->setFrameStyle(QFrame::NoFrame);
    view->installEventFilter(this);

    connect(view->document(), SIGNAL(contentsChange(int,int,int)), this, SLOT(textChanged(int,int,int)));

    // Setup the line number pane
    numbers = new NumberBar(this);
    numbers->setTextEdit(view);
    // Testing...
    numbers->setStopLine(3);
    numbers->setBugLine(1);
    setCurrentLine(5);

    box = new QHBoxLayout(this);
    box->setSpacing(0);
    box->setContentsMargins(0, 0, 0, 0);
    box->addWidget(numbers);
    box->addWidget(view);
}

NumberedTextView::~NumberedTextView()
{
}

void NumberedTextView::setCurrentLine(int lineno)
{
    numbers->setCurrentLine(lineno);
    textChanged(0, 0, 1);
}

void NumberedTextView::setStopLine(int lineno)
{
    numbers->setStopLine(lineno);
}

void NumberedTextView::setBugLine(int lineno)
{
    numbers->setBugLine(lineno);
}

int NumberedTextView::currentLine() const
{
    return numbers->currentLine();
}

int NumberedTextView::stopLine() const
{
    return numbers->stopLine();
}

int NumberedTextView::bugLine() const
{
    return numbers->bugLine();
}

QString NumberedTextView::text() const
{
    return view->toPlainText();
}

void NumberedTextView::setText(const QString &text)
{
    view->setPlainText(text);
}

void NumberedTextView::textChanged(int pos, int removed, int added)
{
    Q_UNUSED(pos);

    if (removed == 0 && added == 0) {
        return;
    }

    QTextBlock block = highlight.block();
    QTextBlockFormat fmt = block.blockFormat();
    QColor bg = view->palette().base().color();
    fmt.setBackground(bg);
    highlight.setBlockFormat(fmt);

    int lineCount = 1;
    for (QTextBlock block = view->document()->begin();
            block.isValid(); block = block.next(), ++lineCount) {

        if (lineCount == numbers->currentLine()) {
            fmt = block.blockFormat();
            QColor bg = view->palette().color(QPalette::Highlight).lighter(175);
            fmt.setBackground(bg);

            highlight = QTextCursor(block);
            highlight.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
            highlight.setBlockFormat(fmt);

            break;
        }
    }
}

bool NumberedTextView::eventFilter(QObject *obj, QEvent *event)
{
    if (obj != view) {
        return QFrame::eventFilter(obj, event);
    }

    if (event->type() == QEvent::ToolTip) {
        QHelpEvent *helpEvent = static_cast<QHelpEvent *>(event);

        QTextCursor cursor = view->cursorForPosition(helpEvent->pos());
        cursor.movePosition(QTextCursor::StartOfWord, QTextCursor::MoveAnchor);
        cursor.movePosition(QTextCursor::EndOfWord, QTextCursor::KeepAnchor);

        QString word = cursor.selectedText();
        emit mouseHover(word);
        emit mouseHover(helpEvent->pos(), word);

        // QToolTip::showText( helpEvent->globalPos(), word ); // For testing
    }

    return false;
}

