/*
 * eqparameterwidget.cpp - defination of EqParameterWidget class.
 *
 * Copyright (c) 2014 David French <dave/dot/french3/at/googlemail/dot/com>
 *
 * This file is part of LMMS - http://lmms.io
 *
 * 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.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */

#include "eqparameterwidget.h"
#include "QPainter"
#include "qwidget.h"
#include "lmms_math.h"

#include "MainWindow.h"
#include "QMouseEvent"

EqParameterWidget::EqParameterWidget( QWidget *parent ) :
    QWidget( parent ),
    m_bands ( 0 ),
    m_selectedBand ( 0 )
{
    m_bands = new EqBand[8];
    resize( 250, 116 );
    connect( Engine::mainWindow(), SIGNAL( periodicUpdate() ), this, SLOT( update() ) );
    float totalLength = log10( 21000 );
    m_pixelsPerUnitWidth = width( ) /  totalLength ;
    float totalHeight = 40;
    m_pixelsPerUnitHeight = (height() - 4) / ( totalHeight );
    m_scale = 1.5;
    m_pixelsPerOctave = freqToXPixel( 10000 ) - freqToXPixel( 5000 );
}




EqParameterWidget::~EqParameterWidget()
{

}




void EqParameterWidget::paintEvent( QPaintEvent *event )
{
    QPainter painter( this );
    for( int i = 0 ; i < bandCount() ; i++ )
    {
        m_bands[i].color.setAlpha(m_bands[i].active->value() ? activeAplha() : inactiveAlpha());
        painter.setPen( QPen( m_bands[i].color, 3, Qt::SolidLine, Qt::RoundCap, Qt::BevelJoin ) );
        float  x = freqToXPixel( m_bands[i].freq->value() );
        float y = height() * 0.5;
        float gain = 1;
        if( m_bands[i].gain )
        {
            gain = m_bands[i].gain->value();
        }
        y = gainToYPixel( gain ) + 3;
        float bw = m_bands[i].freq->value() / m_bands[i].res->value();
        m_bands[i].x = x; m_bands[i].y = y;
        painter.drawPoint( x, y );
        painter.setPen( QPen( m_bands[i].color, 1, Qt::SolidLine, Qt::RoundCap, Qt::BevelJoin ) );
        if(i == 0 || i == bandCount() - 1 ){
            painter.drawLine(x, y, x, y - (m_bands[i].res->value() * 4  ) );
        }
        else
        {
            painter.drawLine(freqToXPixel(m_bands[i].freq->value()-(bw * 0.5)),y,freqToXPixel(m_bands[i].freq->value()+(bw * 0.5)),y);
        }
    }
    //Draw color band
    int sectionLength = width() / bandCount();
    for( int i = 0; i < bandCount(); i++)
    {
        m_bands[i].color.setAlpha( 255 );
        painter.setPen( QPen( m_bands[i].color, 3, Qt::SolidLine, Qt::RoundCap, Qt::BevelJoin ) );
        painter.drawLine(sectionLength * i , 1, sectionLength * (i+1) , 1);
    }
}




void EqParameterWidget::mousePressEvent( QMouseEvent *event )
{
    m_oldX = event->x(); m_oldY = event->y();
    m_selectedBand = selectNearestHandle( event->x(), event->y() );
    m_mouseAction = none;
    if ( event->button() == Qt::LeftButton ) m_mouseAction = drag;
    if ( event->button() == Qt::RightButton ) m_mouseAction = res;
}




void EqParameterWidget::mouseReleaseEvent( QMouseEvent *event )
{
    m_selectedBand = 0;
    m_mouseAction = none;
}




void EqParameterWidget::mouseMoveEvent( QMouseEvent *event )
{
    int deltaX = event->x() - m_oldX;
    int deltaR = event->y() - m_oldY;
    m_oldX = event->x(); m_oldY = event->y();
    if(m_selectedBand && m_selectedBand->active->value() )
    {
        switch ( m_mouseAction ) {
        case none :
            break;
        case drag:
            if( m_selectedBand->freq ) m_selectedBand->freq->setValue( xPixelToFreq( m_oldX ) );
            if( m_selectedBand->gain )m_selectedBand->gain->setValue( yPixelToGain( m_oldY ) );
            break;
        case res:
            if( m_selectedBand->res )m_selectedBand->res->incValue( deltaX * resPixelMultiplyer() );
            if( m_selectedBand->res )m_selectedBand->res->incValue( (-deltaR) * resPixelMultiplyer() );
            break;
        default:
            break;
        }
    }
}




void EqParameterWidget::mouseDoubleClickEvent( QMouseEvent *event )
{
    EqBand* selected = selectNearestHandle( event->x() , event->y() );
    if( selected )
    {
        selected->active->setValue( selected->active->value() ? 0 : 1 );
    }
}




EqBand*  EqParameterWidget::selectNearestHandle( const int x, const  int y )
{
    EqBand* selectedModel = 0;
    float* distanceToHandles = new float[bandCount()];
    //calc distance to each handle
    for( int i = 0 ; i < bandCount() ; i++)
    {
        int xOffset = m_bands[i].x - x;
        int yOffset = m_bands[i].y - y;
        distanceToHandles[i] = fabs(sqrt((xOffset * xOffset ) + ( yOffset * yOffset ) ) );
    }
    //select band
    int shortestBand = 0;
    for (int i = 1 ; i < bandCount() ; i++ )
    {
        if ( distanceToHandles [i] < distanceToHandles[shortestBand] ){
            shortestBand = i;
        }
    }
    if(distanceToHandles[shortestBand] <  maxDistanceFromHandle() )
    {
        selectedModel = &m_bands[shortestBand];
    }
    delete distanceToHandles;
    return selectedModel;
}




EqBand::EqBand() :
    gain ( 0 ),
    res ( 0 ),
    freq ( 0 ),
    color ( QColor( 255, 255, 255 ) ),
    name ( QString( "" ) )
{
}