/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */

/*
    Rosegarden
    A MIDI and audio sequencer and musical notation editor.
    Copyright 2000-2023 the Rosegarden development team.

    Other copyrights also apply to some parts of this work.  Please
    see the AUTHORS file and individual file headers for details.

    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; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#define RG_MODULE_STRING "[LoopRuler]"
#define RG_NO_DEBUG_PRINT

#include "LoopRuler.h"

#include "misc/Debug.h"
#include "base/RulerScale.h"
#include "gui/general/GUIPalette.h"
#include "gui/general/AutoScroller.h"
#include "document/RosegardenDocument.h"
#include "misc/Preferences.h"

#include <QPainter>
#include <QRect>
#include <QPaintEvent>
#include <QMouseEvent>
#include <QBrush>

#include <utility>  // std::swap()


namespace Rosegarden
{


LoopRuler::LoopRuler(RosegardenDocument *doc,
                     RulerScale *rulerScale,
                     int height,
                     bool invert,
                     bool displayQuickMarker,
                     QWidget *parent) :
    QWidget(parent),
    m_doc(doc),
    m_displayQuickMarker(displayQuickMarker),
    m_quickMarkerPen(QPen(GUIPalette::getColour(GUIPalette::QuickMarker), 4)),
    m_width( -1),
    m_height(height),
    m_invert(invert),
    m_currentXOffset(0),
    m_lastMouseXPos(0.0),
    m_rulerScale(rulerScale),
    m_defaultGrid(rulerScale),
    m_loopGrid(new SnapGrid(rulerScale)),
    m_grid(&m_defaultGrid)
{
    // Always snap loop extents to beats; by default apply no snap to
    // pointer position
    //
    m_defaultGrid.setSnapTime(SnapGrid::NoSnap);
    m_loopGrid->setSnapTime(SnapGrid::SnapToBeat);

    // ??? This will get out of sync if they change modes.  But loading
    //     a new file will fix it.
    if (Preferences::getAdvancedLooping())
        setToolTip(tr("<qt><p>Click and drag to move the playback pointer.</p><p>Right-click and drag to set a range for looping or editing.</p><p>Right-click to switch between loop range and loop all.</p><p>Ctrl-click and drag to move the playback pointer with snap to beat.</p><p>Double-click to start playback.</p></qt>"));
    else
        setToolTip(tr("<qt><p>Click and drag to move the playback pointer.</p><p>Right-click and drag to set a range for looping or editing.</p><p>Right-click to toggle the range.</p><p>Ctrl-click and drag to move the playback pointer with snap to beat.</p><p>Double-click to start playback.</p></qt>"));

    connect(m_doc, &RosegardenDocument::loopChanged,
            this, &LoopRuler::slotLoopChanged);
}

LoopRuler::~LoopRuler()
{
    delete m_loopGrid;
}

void
LoopRuler::setSnapGrid(const SnapGrid *grid)
{
    delete m_loopGrid;
    if (grid == nullptr) {
        m_grid = &m_defaultGrid;
        m_loopGrid = new SnapGrid(m_defaultGrid);
    } else {
        m_grid = grid;
        m_loopGrid = new SnapGrid(*grid);
    }
    m_loopGrid->setSnapTime(SnapGrid::SnapToBeat);
}

void LoopRuler::scrollHoriz(int x)
{
    m_currentXOffset = -x;
    update();
}

QSize LoopRuler::sizeHint() const
{
    double width =
        m_rulerScale->getBarPosition(m_rulerScale->getLastVisibleBar()) +
        m_rulerScale->getBarWidth(m_rulerScale->getLastVisibleBar());

    QSize res(std::max(int(width), m_width), m_height);

    return res;
}

QSize LoopRuler::minimumSizeHint() const
{
    double firstBarWidth = m_rulerScale->getBarWidth(0);

    QSize res = QSize(int(firstBarWidth), m_height);

    return res;
}

void LoopRuler::paintEvent(QPaintEvent* e)
{
    const Composition &composition = m_doc->getComposition();

    QPainter paint(this);

    paint.setClipRegion(e->region());
    paint.setClipRect(e->rect().normalized());

    // Draw the background.
    if (composition.getLoopMode() == Composition::LoopAll) {
        // Something different to indicate LoopAll.
        QBrush bg = QBrush(QColor(64,64,128));
        paint.fillRect(e->rect(), bg);
    } else {
        // The usual dark gray.
        QBrush bg = QBrush(GUIPalette::getColour(GUIPalette::LoopRulerBackground));
        paint.fillRect(e->rect(), bg);
    }

    drawLoopMarker(&paint);

    paint.setBrush(palette().windowText());
    drawBarSections(&paint);

    if (m_displayQuickMarker) {
        timeT tQM = m_doc->getQuickMarkerTime();
        if (tQM >= 0) {
            // draw quick marker
            double xQM = m_rulerScale->getXForTime(tQM)
                       + m_currentXOffset;

            paint.setPen(m_quickMarkerPen);

            // looks necessary to compensate for shift in the CompositionView (cursor)
            paint.translate(1, 0);

            // draw red segment
            paint.drawLine(int(xQM), 1, int(xQM), m_height-1);
        }
    }
}

void LoopRuler::drawBarSections(QPainter* paint)
{
    QRect clipRect = paint->clipRegion().boundingRect();

    int firstBar = m_rulerScale->getBarForX(clipRect.x() -
                                            m_currentXOffset);
    int lastBar = m_rulerScale->getLastVisibleBar();
    if (firstBar < m_rulerScale->getFirstVisibleBar()) {
        firstBar = m_rulerScale->getFirstVisibleBar();
    }

    paint->setPen(GUIPalette::getColour(GUIPalette::LoopRulerForeground));

    for (int i = firstBar; i < lastBar; ++i) {

        double x = m_rulerScale->getBarPosition(i) + m_currentXOffset;
        if (x > clipRect.x() + clipRect.width())
            break;

        double width = m_rulerScale->getBarWidth(i);
        if (width == 0)
            continue;

        if (x + width < clipRect.x())
            continue;

        if (m_invert) {
            paint->drawLine(int(x), 0, int(x), 5*m_height / 7);
        } else {
            paint->drawLine(int(x), 2*m_height / 7, int(x), m_height);
        }

        double beatAccumulator = m_rulerScale->getBeatWidth(i);
        double inc = beatAccumulator;
        if (inc == 0)
            continue;

        for (; beatAccumulator < width; beatAccumulator += inc) {
            if (m_invert) {
                paint->drawLine(int(x + beatAccumulator), 0,
                                int(x + beatAccumulator), 2 * m_height / 7);
            } else {
                paint->drawLine(int(x + beatAccumulator), 5*m_height / 7,
                                int(x + beatAccumulator), m_height);
            }
        }
    }
}

void
LoopRuler::drawLoopMarker(QPainter *paint)
{
    const Composition &composition = m_doc->getComposition();

    int x1 = 0;
    int x2 = 0;

    // If we're dragging out a new loop...
    if (m_loopDrag) {
        // Go with the drag range.
        x1 = lround(m_rulerScale->getXForTime(m_startDrag)) +
                m_currentXOffset;
        x2 = lround(m_rulerScale->getXForTime(m_endDrag)) +
                m_currentXOffset;
    } else {
        // Go with the composition loop.
        const Composition::LoopMode loopMode = composition.getLoopMode();

        // In legacy mode, loop off draws nothing.
        if (!Preferences::getAdvancedLooping()  &&
            loopMode != Composition::LoopOn)
            return;

        x1 = lround(m_rulerScale->getXForTime(composition.getLoopStart())) +
                m_currentXOffset;
        x2 = lround(m_rulerScale->getXForTime(composition.getLoopEnd())) +
                m_currentXOffset;
    }

    // Draw the loop.

    paint->save();

    QColor color;

    // ??? Probably should use GUIPalette instead of hard-coding?
    //color.setRgb(GUIPalette::getColour(GUIPalette::LoopHighlight));

    if (composition.getLoopMode() == Composition::LoopAll)
        color.setRgb(220-64, 220-64, 220);
    else if (Preferences::getAdvancedLooping()  &&
             composition.getLoopMode() == Composition::LoopOff)
        color.setRgb(0,0,0);
    else
        color.setRgb(220,220,200);

    paint->setBrush(color);
    paint->setPen(color);
    paint->drawRect(x1, 0, x2 - x1, m_height);

    paint->restore();
}

double
LoopRuler::mouseEventToSceneX(QMouseEvent *mouseEvent)
{
    double x = mouseEvent->pos().x() - m_currentXOffset;
    return x;
}

void
LoopRuler::mousePressEvent(QMouseEvent *mouseEvent)
{
    //RG_DEBUG << "LoopRuler::mousePressEvent: x = " << mouseEvent->x();

    const double x = mouseEventToSceneX(mouseEvent);

    const bool leftButton = (mouseEvent->button() == Qt::LeftButton);
    const bool rightButton = (mouseEvent->button() == Qt::RightButton);
    const bool shift = ((mouseEvent->modifiers() & Qt::ShiftModifier) != 0);

    // If loop mode has been requested
    if ((shift  &&  leftButton)  ||  rightButton) {
        // Loop mode
        m_loopDrag = true;
        m_startDrag = m_loopGrid->snapX(x);
        m_endDrag = m_startDrag;

        emit startMouseMove(FOLLOW_HORIZONTAL);

        return;
    }

    // Left button pointer drag
    if (leftButton) {

        // If we are still using the default grid, that means we are being
        // used by the TrackEditor (instead of the MatrixEditor).
        if (m_grid == &m_defaultGrid) {
            // If the ctrl key is pressed, enable snap to beat
            if ((mouseEvent->modifiers() & Qt::ControlModifier) != 0)
                m_defaultGrid.setSnapTime(SnapGrid::SnapToBeat);
            else
                m_defaultGrid.setSnapTime(SnapGrid::NoSnap);
        }

        // No -- now that we're emitting when the button is
        // released, we _don't_ want to emit here as well --
        // otherwise we get an irritating stutter when simply
        // clicking on the ruler during playback
        //emit setPointerPosition(m_rulerScale->getTimeForX(x));

        // But we want to see the pointer under the mouse as soon as the
        // button is pressed, before we begin to drag it.
        emit dragPointerToPosition(m_grid->snapX(x));

        m_lastMouseXPos = x;

        // ??? This signal is never emitted with any other argument.
        //     Remove the parameter.  This gets a little tricky because
        //     some clients need this and share slots with other signal
        //     sources.  It would probably be best to connect this signal
        //     to a slot in the client that is specific to LoopRuler.
        emit startMouseMove(FOLLOW_HORIZONTAL);

    }

}

void
LoopRuler::mouseReleaseEvent(QMouseEvent *mouseEvent)
{
    //RG_DEBUG << "mouseReleaseEvent()";

    Composition &composition = m_doc->getComposition();

    // If we were in looping mode
    if (m_loopDrag) {

        // Drag is complete.
        m_loopDrag = false;

        if (Preferences::getAdvancedLooping()) {
            // ??? Advanced behavior.
            // No drag
            if (m_endDrag == m_startDrag) {
                // Toggle the loop mode.
                if (composition.getLoopMode() == Composition::LoopOff  ||
                    composition.getLoopMode() == Composition::LoopAll)
                    composition.setLoopMode(Composition::LoopOn);
                else if (composition.getLoopMode() == Composition::LoopOn)
                    composition.setLoopMode(Composition::LoopAll);
            } else {  // Drag
                // Start must be before end.
                if (m_startDrag > m_endDrag)
                    std::swap(m_startDrag, m_endDrag);

                composition.setLoopStart(m_startDrag);
                composition.setLoopEnd(m_endDrag);
            }

            // Refresh everything.
            emit m_doc->loopChanged();

        } else {  // Classic Looping
            // No drag
            if (m_endDrag == m_startDrag) {
                // Toggle the loop mode.
                if (composition.getLoopMode() == Composition::LoopOff)
                    composition.setLoopMode(Composition::LoopOn);
                else
                    composition.setLoopMode(Composition::LoopOff);
            } else {  // Drag
                // Start must be before end.
                if (m_startDrag > m_endDrag)
                    std::swap(m_startDrag, m_endDrag);

                composition.setLoopMode(Composition::LoopOn);
                composition.setLoopStart(m_startDrag);
                composition.setLoopEnd(m_endDrag);
            }

            // Refresh everything.
            emit m_doc->loopChanged();
        }

        emit stopMouseMove();
    }

    if (mouseEvent->button() == Qt::LeftButton) {
        // we need to re-emit this signal so that when the user releases
        // the button after dragging the pointer, the pointer's position
        // is updated again in the other views (typically, in the seg.
        // canvas while the user has dragged the pointer in an edit view)
        emit setPointerPosition(m_grid->snapX(m_lastMouseXPos));

        emit stopMouseMove();
    }
}

void
LoopRuler::mouseDoubleClickEvent(QMouseEvent *mE)
{
    double x = mouseEventToSceneX(mE);
    if (x < 0)
        x = 0;

    RG_DEBUG << "LoopRuler::mouseDoubleClickEvent: x = " << x << ", looping = " << m_loopDrag;

	if (mE->button() == Qt::LeftButton  &&  !m_loopDrag)
        emit setPlayPosition(m_grid->snapX(x));
}

void
LoopRuler::mouseMoveEvent(QMouseEvent *mE)
{
    // If we are still using the default grid, that means we are being
    // used by the TrackEditor (instead of the MatrixEditor).
    if (m_grid == &m_defaultGrid) {
        // If the ctrl key is pressed, enable snap to beat
        if ((mE->modifiers() & Qt::ControlModifier) != 0)
            m_defaultGrid.setSnapTime(SnapGrid::SnapToBeat);
        else
            m_defaultGrid.setSnapTime(SnapGrid::NoSnap);
    }

    double x = mouseEventToSceneX(mE);
    if (x < 0)
        x = 0;

    if (m_loopDrag) {
        if (m_loopGrid->snapX(x) != m_endDrag) {
            m_endDrag = m_loopGrid->snapX(x);
            update();
        }
    } else {
        emit dragPointerToPosition(m_grid->snapX(x));

        m_lastMouseXPos = x;

    }
}

void LoopRuler::slotLoopChanged()
{
    update();
}


}
