///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
// written by Christian Daniel                                                   //
//                                                                               //
// This program is free software; you can redistribute it and/or modify          //
// it under the terms of the GNU General Public License as published by          //
// the Free Software Foundation as version 3 of the License, or                  //
// (at your option) any later version.                                           //
//                                                                               //
// This program 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 General Public License V3 for more details.                               //
//                                                                               //
// You should have received a copy of the GNU General Public License             //
// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
///////////////////////////////////////////////////////////////////////////////////

#include <QKeyEvent>
#include <QLocale>
#include <QMouseEvent>
#include <QPainter>
#include <QWheelEvent>

#include "gui/valuedial.h"

ValueDial::ValueDial(QWidget *parent, ColorMapper colorMapper) :
    QWidget(parent),
    m_animationState(0),
    m_colorMapper(colorMapper)
{
    setAutoFillBackground(false);
    setAttribute(Qt::WA_OpaquePaintEvent, true);
    setAttribute(Qt::WA_NoSystemBackground, true);
    setMouseTracking(true);
    setFocusPolicy(Qt::StrongFocus);

    m_background.setStart(0, 0);
    m_background.setFinalStop(0, 1);
    m_background.setCoordinateMode(QGradient::ObjectBoundingMode);

    ColorMapper::colormap::const_iterator cmit = m_colorMapper.getDialBackgroundColorMap().begin();
    ColorMapper::colormap::const_iterator cmitEnd = m_colorMapper.getDialBackgroundColorMap().end();

    for (; cmit != cmitEnd; ++cmit) {
        m_background.setColorAt(cmit->first, cmit->second);
    }

    m_value = 0;
    m_valueNew = 0;
    m_valueMin = 0;
    m_valueMax = 2200000;
    m_numDigits = 7;
    m_numDecimalPoints = m_numDigits / 3;
    m_cursor = -1;
    m_digitWidth = 0;
    m_digitHeight = 0;

    m_hightlightedDigit = -1;
    m_text = formatText(m_value);
    m_cursorState = false;

    const QLocale &cLocale = QLocale::c();
    m_groupSeparator = cLocale.groupSeparator();

    connect(&m_animationTimer, SIGNAL(timeout()), this, SLOT(animate()));
    connect(&m_blinkTimer, SIGNAL(timeout()), this, SLOT(blink()));
}

void ValueDial::setFont(const QFont &font)
{
    QWidget::setFont(font);

    QFontMetrics fm(font);
    m_digitWidth = fm.width('0');
    m_digitHeight = fm.ascent();
    if (m_digitWidth < m_digitHeight) {
        m_digitWidth = m_digitHeight;
    }
    setFixedWidth((m_numDigits + m_numDecimalPoints) * m_digitWidth + 2);
    setFixedHeight(m_digitHeight * 2 + 2);
}

void ValueDial::setBold(bool bold)
{
    QFont f = font();
    f.setBold(bold);
    setFont(f);
}

void ValueDial::setColorMapper(ColorMapper colorMapper)
{
    m_colorMapper = colorMapper;

    ColorMapper::colormap::const_iterator cmit = m_colorMapper.getDialBackgroundColorMap().begin();
    ColorMapper::colormap::const_iterator cmitEnd = m_colorMapper.getDialBackgroundColorMap().end();

    for (; cmit != cmitEnd; ++cmit) {
        m_background.setColorAt(cmit->first, cmit->second);
    }
}

void ValueDial::setValue(quint64 value)
{
    m_valueNew = value;

    if (m_valueNew < m_valueMin) {
        m_valueNew = m_valueMin;
    } else if (m_valueNew > m_valueMax) {
        m_valueNew = m_valueMax;
    }

    if (m_valueNew < m_value) {
        m_animationState = 1;
    } else if (m_valueNew > m_value) {
        m_animationState = -1;
    } else {
        return;
    }

    m_animationTimer.start(20);
    m_textNew = formatText(m_valueNew);
}

void ValueDial::setValueRange(uint numDigits, quint64 min, quint64 max)
{
    m_numDigits = numDigits;
    m_numDecimalPoints = m_numDigits < 3 ? 0 : (m_numDigits % 3) == 0 ? (m_numDigits / 3) - 1 : m_numDigits / 3;
    m_valueMin = min;
    m_valueMax = max;

    m_text = formatText(m_value);

    if (m_value < min) {
        setValue(min);
    } else if (m_value > max) {
        setValue(max);
    }

    setFixedWidth((m_numDigits + m_numDecimalPoints) * m_digitWidth + 2);
}

quint64 ValueDial::findExponent(int digit)
{
    quint64 e = 1;
    int d = (m_numDigits + m_numDecimalPoints) - digit;
    d = d - (d / 4) - 1;

    for (int i = 0; i < d; i++) {
        e *= 10;
    }

    return e;
}

QChar ValueDial::digitNeigh(QChar c, bool dir)
{
    if (dir)
    {
        if (c == QChar('0')) {
            return QChar('9');
        } else {
            return QChar::fromLatin1(c.toLatin1() - 1);
        }
    }
    else
    {
        if (c == QChar('9')) {
            return QChar('0');
        } else {
            return QChar::fromLatin1(c.toLatin1() + 1);
        }
    }
}

QString ValueDial::formatText(quint64 value)
{
    QString str = QString("%1").arg(value, m_numDigits, 10, QChar('0'));

    for (int i = 0; i < m_numDecimalPoints; i++)
    {
        int ipoint = m_numDigits - 3 - 3 * i;

        if (ipoint != 0)
        { // do not insert leading point
            const QLocale &cLocale = QLocale::c();
            str.insert(ipoint, cLocale.groupSeparator());
        }
    }

    return str;
}

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

    painter.setPen(Qt::black);
    painter.setBrush(m_background);

    painter.drawRect(0, 0, width() - 1, height() - 1);

    painter.setPen(m_colorMapper.getBoundaryColor());
    painter.setBrush(Qt::NoBrush);

    for (int i = 1; i < m_numDigits + m_numDecimalPoints; i++)
    {
        painter.setPen(m_colorMapper.getBoundaryColor());
        painter.drawLine(1 + i * m_digitWidth, 1, 1 + i * m_digitWidth, height() - 1);
        painter.setPen(m_colorMapper.getBoundaryAlphaColor());
        painter.drawLine(0 + i * m_digitWidth, 1, 0 + i * m_digitWidth, height() - 1);
        painter.drawLine(2 + i * m_digitWidth, 1, 2 + i * m_digitWidth, height() - 1);
    }

    painter.setPen(m_colorMapper.getBoundaryAlphaColor());
    painter.drawLine(1, 1, 1, height() - 1);
    painter.drawLine(width() - 2, 1, width() - 2, height() - 1);

    // dial borders
    painter.setPen(m_colorMapper.getDarkBorderColor());
    painter.drawLine(0, 0, width() - 2, 0);
    painter.drawLine(0, height() - 1, 0, 0);
    painter.setPen(m_colorMapper.getLightBorderColor());
    painter.drawLine(1, height() - 1, width() - 1, height() - 1);
    painter.drawLine(width() - 1, height() - 1, width() - 1, 0);

    if (m_hightlightedDigit >= 0)
    {
        painter.setPen(Qt::NoPen);
        painter.setBrush(m_colorMapper.getHighlightColor());
        painter.drawRect(2 + m_hightlightedDigit * m_digitWidth, 1, m_digitWidth - 1, height() - 1);
    }

    if (m_animationState == 0)
    {
        for (int i = 0; i < m_text.length(); i++)
        {
            painter.setClipRect(1 + i * m_digitWidth, 1, m_digitWidth, m_digitHeight * 2);
            painter.setPen(m_colorMapper.getSecondaryForegroundColor());
            painter.drawText(QRect(1 + i * m_digitWidth, m_digitHeight * 0.6, m_digitWidth, m_digitHeight), Qt::AlignCenter, m_text.mid(i, 1));

            if (m_text[i] != m_groupSeparator)
            {
                painter.setPen(m_colorMapper.getForegroundColor());
                painter.drawText(QRect(1 + i * m_digitWidth, m_digitHeight * -0.7, m_digitWidth, m_digitHeight), Qt::AlignCenter, digitNeigh(m_text[i], true));
                painter.drawText(QRect(1 + i * m_digitWidth, m_digitHeight * 1.9, m_digitWidth, m_digitHeight), Qt::AlignCenter, digitNeigh(m_text[i], false));
            }
        }

        painter.setClipping(false);

        if ((m_cursor >= 0) && (m_cursorState))
        {
            painter.setPen(Qt::NoPen);
            painter.setBrush(m_colorMapper.getSecondaryForegroundColor());
            painter.drawRect(4 + m_cursor * m_digitWidth, 1 + m_digitHeight * 1.5, m_digitWidth - 5, m_digitHeight / 6);
        }
    }
    else
    {
        for (int i = 0; i < m_text.length(); i++)
        {
            if (m_text[i] == m_textNew[i])
            {
                painter.setClipRect(1 + i * m_digitWidth, 1, m_digitWidth, m_digitHeight * 2);
                painter.setPen(m_colorMapper.getSecondaryForegroundColor());
                painter.drawText(QRect(1 + i * m_digitWidth, m_digitHeight * 0.6, m_digitWidth, m_digitHeight), Qt::AlignCenter, m_text.mid(i, 1));

                if (m_text[i] != m_groupSeparator)
                {
                    painter.setPen(m_colorMapper.getForegroundColor());
                    painter.drawText(QRect(1 + i * m_digitWidth, m_digitHeight * -0.7, m_digitWidth, m_digitHeight), Qt::AlignCenter, digitNeigh(m_text[i], true));
                    painter.drawText(QRect(1 + i * m_digitWidth, m_digitHeight * 1.9, m_digitWidth, m_digitHeight), Qt::AlignCenter, digitNeigh(m_text[i], false));
                }
            }
            else
            {
                int h = m_digitHeight * 0.6 + m_digitHeight * m_animationState / 2.0;
                painter.setClipRect(1 + i * m_digitWidth, 1, m_digitWidth, m_digitHeight * 2);
                painter.setPen(m_colorMapper.getSecondaryForegroundColor());
                painter.drawText(QRect(1 + i * m_digitWidth, h, m_digitWidth, m_digitHeight), Qt::AlignCenter, m_text.mid(i, 1));

                if (m_text[i] != m_groupSeparator)
                {
                    painter.setPen(m_colorMapper.getForegroundColor());
                    painter.drawText(QRect(1 + i * m_digitWidth, h + m_digitHeight * -0.7, m_digitWidth, m_digitHeight), Qt::AlignCenter, digitNeigh(m_text[i], true));
                    painter.drawText(QRect(1 + i * m_digitWidth, h + m_digitHeight * 1.9, m_digitWidth, m_digitHeight), Qt::AlignCenter, digitNeigh(m_text[i], false));
                }
            }
        }
    }
}

void ValueDial::mousePressEvent(QMouseEvent *event)
{
    int i;

    i = (event->x() - 1) / m_digitWidth;

    if (m_text[i] == m_groupSeparator)
    {
        i++;

        if (i > m_numDigits + m_numDecimalPoints) {
            return;
        }
    }

    Qt::MouseButton mouseButton = event->button();

    if (mouseButton == Qt::RightButton) // ceil value at current digit
    {
        if (m_cursor >= 0)
        {
            m_cursor = -1;
            m_blinkTimer.stop();
            update();
        }

        quint64 e = findExponent(i);
        m_valueNew = (m_value / e) * e;
        setValue(m_valueNew);
        emit changed(m_valueNew);
        //qDebug("ValueDial::mousePressEvent: Qt::RightButton: i: %d e: %llu new: %llu", i, e, valueNew);
    }
    else if (mouseButton == Qt::LeftButton) // set cursor at current digit
    {
        m_cursor = i;
        m_cursorState = true;
        m_blinkTimer.start(400);

        update();
    }
}

void ValueDial::mouseMoveEvent(QMouseEvent *event)
{
    int i;
    i = (event->x() - 1) / m_digitWidth;

    if (m_text[i] == m_groupSeparator) {
        i = -1;
    }

    if (i != m_hightlightedDigit)
    {
        m_hightlightedDigit = i;
        update();
    }
}

void ValueDial::wheelEvent(QWheelEvent *event)
{
    int i;
    i = (event->x() - 1) / m_digitWidth;

    if (m_text[i] != m_groupSeparator) {
        m_hightlightedDigit = i;
    } else {
        return;
    }

    if (m_cursor >= 0)
    {
        m_cursor = -1;
        m_blinkTimer.stop();
        update();
    }

    quint64 e = findExponent(m_hightlightedDigit);

    if (m_animationState == 0)
    {
        if (event->delta() < 0)
        {
            if (event->modifiers() & Qt::ShiftModifier) {
                e *= 5;
            } else if (event->modifiers() & Qt::ControlModifier) {
                e *= 2;
            }

            if (m_value < e) {
                m_valueNew = m_valueMin;
            } else {
                m_valueNew = m_value - e;
            }
        }
        else
        {
            if (event->modifiers() & Qt::ShiftModifier) {
                e *= 5;
            } else if (event->modifiers() & Qt::ControlModifier) {
                e *= 2;
            }

            if (m_valueMax - m_value < e) {
                m_valueNew = m_valueMax;
            } else {
                m_valueNew = m_value + e;
            }
        }

        setValue(m_valueNew);
        emit changed(m_valueNew);
        event->accept();
    }
}

void ValueDial::leaveEvent(QEvent *)
{
    if (m_hightlightedDigit != -1)
    {
        m_hightlightedDigit = -1;
        update();
    }
}

void ValueDial::keyPressEvent(QKeyEvent *value)
{
    if (m_cursor >= 0)
    {
        if ((value->key() == Qt::Key_Return) || (value->key() == Qt::Key_Enter) || (value->key() == Qt::Key_Escape))
        {
            m_cursor = -1;
            m_cursorState = false;
            m_blinkTimer.stop();
            update();
            return;
        }
    }

    if ((m_cursor < 0) && (m_hightlightedDigit >= 0))
    {
        m_cursor = m_hightlightedDigit;

        if (m_text[m_cursor] == m_groupSeparator) {
            m_cursor++;
        }

        if (m_cursor >= m_numDigits + m_numDecimalPoints) {
            return;
        }

        m_cursorState = true;
        m_blinkTimer.start(400);
        update();
    }

    if (m_cursor < 0) {
        return;
    }

    if ((value->key() == Qt::Key_Left) || (value->key() == Qt::Key_Backspace))
    {
        if (m_cursor > 0)
        {
            m_cursor--;

            if (m_text[m_cursor] == m_groupSeparator) {
                m_cursor--;
            }

            if (m_cursor < 0) {
                m_cursor++;
            }

            m_cursorState = true;
            update();
            return;
        }
    }
    else if (value->key() == Qt::Key_Right)
    {
        if (m_cursor < m_numDecimalPoints + m_numDigits)
        {
            m_cursor++;

            if (m_text[m_cursor] == m_groupSeparator) {
                m_cursor++;
            }

            if (m_cursor >= m_numDecimalPoints + m_numDigits) {
                m_cursor--;
            }

            m_cursorState = true;
            update();
            return;
        }
    }
    else if (value->key() == Qt::Key_Up)
    {
        quint64 e = findExponent(m_cursor);

        if (value->modifiers() & Qt::ShiftModifier) {
            e *= 5;
        } else if (value->modifiers() & Qt::ControlModifier) {
            e *= 2;
        }

        if (m_animationState != 0) {
            m_value = m_valueNew;
        }

        if (m_valueMax - m_value < e) {
            m_valueNew = m_valueMax;
        } else {
            m_valueNew = m_value + e;
        }

        setValue(m_valueNew);
        emit changed(m_valueNew);
    }
    else if (value->key() == Qt::Key_Down)
    {
        quint64 e = findExponent(m_cursor);

        if (value->modifiers() & Qt::ShiftModifier) {
            e *= 5;
        } else if (value->modifiers() & Qt::ControlModifier) {
            e *= 2;
        }

        if (m_animationState != 0) {
            m_value = m_valueNew;
        }

        if (m_value < e) {
            m_valueNew = m_valueMin;
        } else {
            m_valueNew = m_value - e;
        }

        setValue(m_valueNew);
        emit changed(m_valueNew);
    }

    if (value->text().length() != 1) {
        return;
    }

    QChar c = value->text()[0];

    if (c >= QChar('0') && (c <= QChar('9')))
    {
        int d = c.toLatin1() - '0';
        quint64 e = findExponent(m_cursor);
        quint64 v = (m_value / e) % 10;

        if (m_animationState != 0) {
            m_value = m_valueNew;
        }

        v = m_value - v * e;
        v += d * e;
        setValue(v);
        emit changed(m_valueNew);
        m_cursor++;

        if (m_text[m_cursor] == m_groupSeparator) {
            m_cursor++;
        }

        if (m_cursor >= m_numDigits + m_numDecimalPoints)
        {
            m_cursor = -1;
            m_blinkTimer.stop();
        }
        else
        {
            m_cursorState = true;
        }

        update();
    }
}

void ValueDial::focusInEvent(QFocusEvent *)
{
    if (m_cursor == -1)
    {
        m_cursor = 0;
        m_cursorState = true;
        m_blinkTimer.start(400);
        update();
    }
}

void ValueDial::focusOutEvent(QFocusEvent *)
{
    m_cursor = -1;
    m_blinkTimer.stop();
    update();
}

void ValueDial::animate()
{
    update();

    if (m_animationState > 0)
    {
        m_animationState++;
    }
    else if (m_animationState < 0) {
        m_animationState--;
    }
    else
    {
        m_animationTimer.stop();
        m_animationState = 0;
        return;
    }

    if (abs(m_animationState) >= 4)
    {
        m_animationState = 0;
        m_animationTimer.stop();
        m_value = m_valueNew;
        m_text = m_textNew;
    }
}

void ValueDial::blink()
{
    if (m_cursor >= 0)
    {
        m_cursorState = !m_cursorState;
        update();
    }
}