/* -*- c++ -*- */
/* + + +   This Software is released under the "Simplified BSD License"  + + +
 * Copyright 2010 Moe Wheatley. All rights reserved.
 * Copyright 2011-2013 Alexandru Csete OZ9AEC.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY Moe Wheatley ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Moe Wheatley OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of Moe Wheatley.
 */
#include <stdlib.h>
#include <QDebug>
#include "meter.h"


//ratio to total control width or height
#define CTRL_MARGIN 0.07		//left/right margin
#define CTRL_MAJOR_START 0.3	//top of major tic line
#define CTRL_MINOR_START 0.3	//top of minor tic line
#define CTRL_XAXIS_HEGHT 0.4	//vert position of horizontal axis
#define CTRL_NEEDLE_TOP 0.4		//vert position of top of needle triangle

#define MIN_DB -100.0
#define MAX_DB +0.0


CMeter::CMeter(QWidget *parent) : QFrame(parent)
{
    setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    setFocusPolicy(Qt::StrongFocus);
    setAttribute(Qt::WA_PaintOnScreen,false);
    setAutoFillBackground(false);
    setAttribute(Qt::WA_OpaquePaintEvent, false);
    setAttribute(Qt::WA_NoSystemBackground, true);
    setMouseTracking(true);

    m_2DPixmap = QPixmap(0,0);
    m_OverlayPixmap = QPixmap(0,0);
    m_Size = QSize(0,0);
    m_Slevel = 0;
    m_dBm = -120;
    d_alpha_decay = 0.25; // FIXME: Should set delta-t and Fs instead
    d_alpha_rise = 0.7;   // FIXME: Should set delta-t and Fs instead
}

CMeter::~CMeter()
{

}

//////////////////////////////////////////////////////////////////////
// Sizing interface
//////////////////////////////////////////////////////////////////////
QSize CMeter::minimumSizeHint() const
{
    return QSize(20, 10);
}

QSize CMeter::sizeHint() const
{
    return QSize(100, 30);
}


//////////////////////////////////////////////////////////////////////
// Called when screen size changes so must recalculate bitmaps
//////////////////////////////////////////////////////////////////////
void CMeter::resizeEvent(QResizeEvent* )
{
    if (!size().isValid())
        return;

    if (m_Size != size()) {	//if size changed, resize pixmaps to new screensize
        m_Size = size();
        m_OverlayPixmap = QPixmap(m_Size.width(), m_Size.height());
        m_OverlayPixmap.fill(Qt::black);
        m_2DPixmap = QPixmap(m_Size.width(), m_Size.height());
        m_2DPixmap.fill(Qt::black);
    }

    DrawOverlay();
    draw();
}


//////////////////////////////////////////////////////////////////////
// Slot called to update meter level position
//////////////////////////////////////////////////////////////////////
void CMeter::setLevel(float dbfs)
{
    if(dbfs < MIN_DB)
        dbfs = MIN_DB;

    if(dbfs > MAX_DB)
        dbfs = MAX_DB;

    // decay delay
    float level = (float)m_dBm;
    if (dbfs < level) {
        level = level*(1-d_alpha_decay) + dbfs*d_alpha_decay;
    }
    else {
        level = level*(1-d_alpha_rise) + dbfs*d_alpha_rise;
    }

    m_dBm = (int)level;

    qreal w = (qreal)m_2DPixmap.width();
    w = w - 2.0*CTRL_MARGIN*w;	// width of meter scale in pixels

    // pixels / dB
    qreal pixperdb = w / fabs(MAX_DB - MIN_DB);
    m_Slevel = (int)(-(MIN_DB-level)*pixperdb);

    draw();
}

//////////////////////////////////////////////////////////////////////
// Called by QT when screen needs to be redrawn
//////////////////////////////////////////////////////////////////////
void CMeter::paintEvent(QPaintEvent *)
{
    QPainter painter(this);

    painter.drawPixmap(0,0,m_2DPixmap);
    return;
}


//////////////////////////////////////////////////////////////////////
// Called to update s-meter data for displaying on the screen
//////////////////////////////////////////////////////////////////////
void CMeter::draw()
{
    int w;
    int h;

    if(m_2DPixmap.isNull())
        return;

    // get/draw the 2D spectrum
    w = m_2DPixmap.width();
    h = m_2DPixmap.height();

    // first copy into 2Dbitmap the overlay bitmap.
    m_2DPixmap = m_OverlayPixmap.copy(0,0,w,h);
    QPainter painter(&m_2DPixmap);

    // DrawCurrent position indicator
    qreal hline = (qreal)h*CTRL_XAXIS_HEGHT;
    qreal marg = (qreal)w*CTRL_MARGIN;
    qreal ht = (qreal)h*CTRL_NEEDLE_TOP;
    qreal x = marg + m_Slevel;
    QPoint pts[3];
    pts[0].setX(x); pts[0].setY(ht+2);
    pts[1].setX(x-6); pts[1].setY(hline+8);
    pts[2].setX(x+6); pts[2].setY(hline+8);


    //painter.setBrush(QBrush(Qt::green));
    painter.setBrush(QBrush(QColor(0, 190, 0, 255)));
    painter.setOpacity(1.0);

// Qt 4.8+ has a 1-pixel error (or they fixed line drawing)
// see http://stackoverflow.com/questions/16990326
#if QT_VERSION >= 0x040800
    painter.drawRect(marg-1, ht+1, x-marg, 6);
#else
    painter.drawRect(marg, ht+2, x-marg, 6);
#endif

    // create Font to use for scales
    QFont Font("Arial");
    QFontMetrics metrics(Font);
    int y = (h)/4;
    Font.setPixelSize(y);
    Font.setWeight(QFont::Normal);
    painter.setFont(Font);

    painter.setPen(QColor(0xEF,0xEF,0xEF,0xFF));
    painter.setOpacity(1.0);
    m_Str.setNum(m_dBm);
    painter.drawText(marg, h-2, m_Str+" dBFS" );

    update();
}

//////////////////////////////////////////////////////////////////////
// Called to draw an overlay bitmap containing items that
// does not need to be recreated every fft data update.
//////////////////////////////////////////////////////////////////////
void CMeter::DrawOverlay()
{
    if(m_OverlayPixmap.isNull())
        return;

    int w = m_OverlayPixmap.width();
    int h = m_OverlayPixmap.height();
    int x,y;
    QRect rect;
    QPainter painter(&m_OverlayPixmap);

    m_OverlayPixmap.fill(QColor(0x20,0x20,0x20,0xFF));
#if 0
    //fill background with gradient
    QLinearGradient gradient(0, 0, 0 ,h);
    gradient.setColorAt(1, Qt::black);
    gradient.setColorAt(0, Qt::black);
    painter.setBrush(gradient);
    painter.drawRect(0, 0, w, h);
#endif

    //Draw scale lines
    qreal marg = (qreal)w*CTRL_MARGIN;
    qreal hline = (qreal)h*CTRL_XAXIS_HEGHT;
    qreal magstart = (qreal)h*CTRL_MAJOR_START;
    qreal minstart = (qreal)h*CTRL_MINOR_START;
    qreal hstop = (qreal)w-marg;
    painter.setPen(QPen(Qt::white, 1, Qt::SolidLine));
    painter.drawLine(QLineF(marg, hline, hstop, hline));       // top line with ticks
    painter.drawLine(QLineF(marg, hline+8, hstop, hline+8)); // bottom line
    qreal xpos = marg;
    for(x=0; x<11; x++) {
        if(x&1)	//minor tics
            painter.drawLine( QLineF(xpos, minstart, xpos, hline) );
        else
            painter.drawLine( QLineF(xpos, magstart, xpos, hline) );
        xpos += (hstop-marg)/10.0;
    }

    //draw scale text
    //create Font to use for scales
    QFont Font("Arial");
    QFontMetrics metrics(Font);
    y = h/4;
    Font.setPixelSize(y);
    Font.setWeight(QFont::Normal);
    painter.setFont(Font);
    int rwidth = (int)((hstop-marg)/5.0);
    m_Str = "-100";
    rect.setRect(marg/2-5, 0, rwidth, magstart);

    for (x = MIN_DB; x <= MAX_DB; x += 20)
    {
        m_Str.setNum(x);
        painter.drawText(rect, Qt::AlignHCenter|Qt::AlignVCenter, m_Str);
        rect.translate(rwidth, 0);
    }

    /*
    for(x=1; x<=9; x+=2) {
        m_Str.setNum(x);
        painter.drawText(rect, Qt::AlignHCenter|Qt::AlignVCenter, m_Str);
        rect.translate( rwidth,0);
    }
    painter.setPen(QPen(Qt::red, 1,Qt::SolidLine));
    for(x=20; x<=60; x+=20) {
        m_Str = "+" + m_Str.setNum(x);
        painter.drawText(rect, Qt::AlignHCenter|Qt::AlignVCenter, m_Str);
        rect.translate( rwidth,0);
    }
    */
}