// Author:    Max Howell <max.howell@methylblue.com>, (C) 2003-5
//            Mark Kretschmann <markey@web.de>, (C) 2005
// Copyright: See COPYING file that comes with this distribution
//

#define DEBUG_PREFIX "BlockAnalyzer"

#include "blockanalyzer.h"

#include <cmath>

#include <QMouseEvent>
#include <QResizeEvent>
#include <cstdlib>
#include <QPainter>

const uint BlockAnalyzer::HEIGHT      = 2;
const uint BlockAnalyzer::WIDTH       = 4;
const uint BlockAnalyzer::MIN_ROWS    = 3;   //arbituary
const uint BlockAnalyzer::MIN_COLUMNS = 32;  //arbituary
const uint BlockAnalyzer::MAX_COLUMNS = 256; //must be 2**n
const uint BlockAnalyzer::FADE_SIZE   = 90;

const char* BlockAnalyzer::kName = QT_TRANSLATE_NOOP("AnalyzerContainer", "Block analyzer");

BlockAnalyzer::BlockAnalyzer( QWidget *parent )
        : Analyzer::Base( parent, 9 )
        , m_columns( 0 )         //uint
        , m_rows( 0 )            //uint
        , m_y( 0 )               //uint
        , m_barPixmap( 1, 1 )    //null qpixmaps cause crashes
        , m_topBarPixmap( WIDTH, HEIGHT )
        , m_scope( MIN_COLUMNS ) //Scope
        , m_store( 1 << 8, 0 )   //vector<uint>
        , m_fade_bars( FADE_SIZE ) //vector<QPixmap>
        , m_fade_pos( 1 << 8, 50 ) //vector<uint>
        , m_fade_intensity( 1 << 8, 32 ) //vector<uint>
{
    setMinimumSize( MIN_COLUMNS*(WIDTH+1) -1, MIN_ROWS*(HEIGHT+1) -1 ); //-1 is padding, no drawing takes place there
    setMaximumWidth( MAX_COLUMNS*(WIDTH+1) -1 );

    // mxcl says null pixmaps cause crashes, so let's play it safe
    for ( uint i = 0; i < FADE_SIZE; ++i )
        m_fade_bars[i] = QPixmap( 1, 1 );
}

BlockAnalyzer::~BlockAnalyzer()
{
}

void
BlockAnalyzer::resizeEvent( QResizeEvent *e )
{
   QWidget::resizeEvent( e );

   m_background = QPixmap(size());

   const uint oldRows = m_rows;

   //all is explained in analyze()..
   //+1 to counter -1 in maxSizes, trust me we need this!
   m_columns = qMax( uint(double(width()+1) / (WIDTH+1)), MAX_COLUMNS );
   m_rows    = uint(double(height()+1) / (HEIGHT+1));

   //this is the y-offset for drawing from the top of the widget
   m_y = (height() - (m_rows * (HEIGHT+1)) + 2) / 2;

   m_scope.resize( m_columns );

   if( m_rows != oldRows ) {
      m_barPixmap = QPixmap( WIDTH, m_rows*(HEIGHT+1) );

      for ( uint i = 0; i < FADE_SIZE; ++i )
         m_fade_bars[i] = QPixmap( WIDTH, m_rows*(HEIGHT+1) );

      m_yscale.resize( m_rows + 1 );

      const uint PRE = 1, PRO = 1; //PRE and PRO allow us to restrict the range somewhat

      for( uint z = 0; z < m_rows; ++z )
         m_yscale[z] = 1 - (log10( PRE+z ) / log10( PRE+m_rows+PRO ));

      m_yscale[m_rows] = 0;

      determineStep();
      paletteChange( palette() );
   }


   drawBackground();
}

void
BlockAnalyzer::determineStep()
{
    // falltime is dependent on rowcount due to our digital resolution (ie we have boxes/blocks of pixels)
    // I calculated the value 30 based on some trial and error

    const double fallTime = 30 * m_rows;
    m_step = double(m_rows * timeout()) / fallTime;
}

void
BlockAnalyzer::transform( Analyzer::Scope &s ) //pure virtual
{
    for( uint x = 0; x < s.size(); ++x )
        s[x] *= 2;

    float *front = static_cast<float*>( &s.front() );

    m_fht->spectrum( front );
    m_fht->scale( front, 1.0 / 20 );

    //the second half is pretty dull, so only show it if the user has a large analyzer
    //by setting to m_scope.size() if large we prevent interpolation of large analyzers, this is good!
    s.resize( m_scope.size() <= MAX_COLUMNS/2 ? MAX_COLUMNS/2 : m_scope.size() );
}

void
BlockAnalyzer::analyze( QPainter& p, const Analyzer::Scope &s, bool new_frame)
{
   // y = 2 3 2 1 0 2
   //     . . . . # .
   //     . . . # # .
   //     # . # # # #
   //     # # # # # #
   //
   // visual aid for how this analyzer works.
   // y represents the number of blanks
   // y starts from the top and increases in units of blocks

   // m_yscale looks similar to: { 0.7, 0.5, 0.25, 0.15, 0.1, 0 }
   // if it contains 6 elements there are 5 rows in the analyzer

   Analyzer::interpolate( s, m_scope );

   // Paint the background
   p.drawPixmap(0, 0, m_background);

   for( uint y, x = 0; x < m_scope.size(); ++x )
   {
      // determine y
      for( y = 0; m_scope[x] < m_yscale[y]; ++y )
         ;

      // this is opposite to what you'd think, higher than y
      // means the bar is lower than y (physically)
      if( (float)y > m_store[x] )
         y = int(m_store[x] += m_step);
      else
         m_store[x] = y;

      // if y is lower than m_fade_pos, then the bar has exceeded the height of the fadeout
      // if the fadeout is quite faded now, then display the new one
      if( y <= m_fade_pos[x] /*|| m_fade_intensity[x] < FADE_SIZE / 3*/ ) {
         m_fade_pos[x] = y;
         m_fade_intensity[x] = FADE_SIZE;
      }

      if( m_fade_intensity[x] > 0 ) {
         const uint offset = --m_fade_intensity[x];
         const uint y = m_y + (m_fade_pos[x] * (HEIGHT+1));
         p.drawPixmap(x*(WIDTH+1), y, m_fade_bars[offset], 0, 0, WIDTH, height() - y);
      }

      if( m_fade_intensity[x] == 0 )
         m_fade_pos[x] = m_rows;

      //REMEMBER: y is a number from 0 to m_rows, 0 means all blocks are glowing, m_rows means none are
      p.drawPixmap( x*(WIDTH+1), y*(HEIGHT+1) + m_y, *bar(), 0, y*(HEIGHT+1), bar()->width(), bar()->height() );
   }

   for( uint x = 0; x < m_store.size(); ++x )
      p.drawPixmap(x*(WIDTH+1), int(m_store[x])*(HEIGHT+1) + m_y, m_topBarPixmap );
}





static inline void
adjustToLimits( int &b, int &f, uint &amount )
{
    // with a range of 0-255 and maximum adjustment of amount,
    // maximise the difference between f and b

    if( b < f ) {
        if( b > 255 - f ) {
            amount -= f;
            f = 0;
        } else {
            amount -= (255 - f);
            f = 255;
        }
    }
    else {
        if( f > 255 - b ) {
            amount -= f;
            f = 0;
        } else {
            amount -= (255 - f);
            f = 255;
        }
    }
}

/**
 * Clever contrast function
 *
 * It will try to adjust the foreground color such that it contrasts well with the background
 * It won't modify the hue of fg unless absolutely necessary
 * @return the adjusted form of fg
 */
QColor
ensureContrast( const QColor &bg, const QColor &fg, uint _amount = 150 )
{
    class OutputOnExit {
        public:
            OutputOnExit( const QColor &color ) : c( color ) {}
           ~OutputOnExit() { int h,s,v; c.getHsv( &h, &s, &v ); }
        private:
            const QColor &c;
    };

    // hack so I don't have to cast everywhere
    #define amount static_cast<int>(_amount)
//     #define STAMP debug() << (QValueList<int>() << fh << fs << fv) << endl;
//     #define STAMP1( string ) debug() << string << ": " << (QValueList<int>() << fh << fs << fv) << endl;
//     #define STAMP2( string, value ) debug() << string << "=" << value << ": " << (QValueList<int>() << fh << fs << fv) << endl;

    OutputOnExit allocateOnTheStack( fg );

    int bh, bs, bv;
    int fh, fs, fv;

    bg.getHsv( &bh, &bs, &bv );
    fg.getHsv( &fh, &fs, &fv );

    int dv = abs( bv - fv );

//     STAMP2( "DV", dv );

    // value is the best measure of contrast
    // if there is enough difference in value already, return fg unchanged
    if( dv > amount )
        return fg;

    int ds = abs( bs - fs );

//     STAMP2( "DS", ds );

    // saturation is good enough too. But not as good. TODO adapt this a little
    if( ds > amount )
        return fg;

    int dh = abs( bh - fh );

//     STAMP2( "DH", dh );

    if( dh > 120 ) {
        // a third of the colour wheel automatically guarentees contrast
        // but only if the values are high enough and saturations significant enough
        // to allow the colours to be visible and not be shades of grey or black

        // check the saturation for the two colours is sufficient that hue alone can
        // provide sufficient contrast
        if( ds > amount / 2 && (bs > 125 && fs > 125) )
//             STAMP1( "Sufficient saturation difference, and hues are compliemtary" );
            return fg;
        else if( dv > amount / 2 && (bv > 125 && fv > 125) )
//             STAMP1( "Sufficient value difference, and hues are compliemtary" );
            return fg;

//         STAMP1( "Hues are complimentary but we must modify the value or saturation of the contrasting colour" );

        //but either the colours are two desaturated, or too dark
        //so we need to adjust the system, although not as much
        ///_amount /= 2;
    }

    if( fs < 50 && ds < 40 ) {
       // low saturation on a low saturation is sad
       const int tmp = 50 - fs;
       fs = 50;
       if( amount > tmp )
          _amount -= tmp;
       else
          _amount = 0;
    }

    // test that there is available value to honor our contrast requirement
    if( 255 - dv < amount )
    {
        // we have to modify the value and saturation of fg
        //adjustToLimits( bv, fv, amount );

//         STAMP

        // see if we need to adjust the saturation
        if( amount > 0 )
            adjustToLimits( bs, fs, _amount );

//         STAMP

        // see if we need to adjust the hue
        if( amount > 0 )
            fh += amount; // cycles around;

//         STAMP

        return QColor::fromHsv(fh, fs, fv);
    }

//     STAMP

    if( fv > bv && bv > amount )
        return QColor::fromHsv( fh, fs, bv - amount);

//     STAMP

    if( fv < bv && fv > amount )
        return QColor::fromHsv( fh, fs, fv - amount);

//     STAMP

    if( fv > bv && (255 - fv > amount) )
        return QColor::fromHsv( fh, fs, fv + amount);

//     STAMP

    if( fv < bv && (255 - bv > amount ) )
        return QColor::fromHsv( fh, fs, bv + amount);

//     STAMP
//     debug() << "Something went wrong!\n";

    return Qt::blue;

    #undef amount
//     #undef STAMP
}

void
BlockAnalyzer::paletteChange( const QPalette& ) //virtual
{
   const QColor bg = palette().color(QPalette::Background);
   const QColor fg = ensureContrast( bg, palette().color(QPalette::Highlight) );

   m_topBarPixmap.fill( fg );

   const double dr = 15*double(bg.red()   - fg.red())   / (m_rows*16);
   const double dg = 15*double(bg.green() - fg.green()) / (m_rows*16);
   const double db = 15*double(bg.blue()  - fg.blue())  / (m_rows*16);
   const int r = fg.red(), g = fg.green(), b = fg.blue();

   bar()->fill( bg );

   QPainter p( bar() );
   for( int y = 0; (uint)y < m_rows; ++y )
      //graduate the fg color
      p.fillRect( 0, y*(HEIGHT+1), WIDTH, HEIGHT, QColor( r+int(dr*y), g+int(dg*y), b+int(db*y) ) );

   {
      const QColor bg = palette().color(QPalette::Background).dark( 112 );

      //make a complimentary fadebar colour
      //TODO dark is not always correct, dumbo!
      int h,s,v; palette().color(QPalette::Background).dark( 150 ).getHsv( &h, &s, &v );
      const QColor fg( QColor::fromHsv(h + 120, s, v));

      const double dr = fg.red() - bg.red();
      const double dg = fg.green() - bg.green();
      const double db = fg.blue() - bg.blue();
      const int r = bg.red(), g = bg.green(), b = bg.blue();

      // Precalculate all fade-bar pixmaps
      for( uint y = 0; y < FADE_SIZE; ++y ) {
         m_fade_bars[y].fill( palette().color(QPalette::Background) );
         QPainter f( &m_fade_bars[y] );
         for( int z = 0; (uint)z < m_rows; ++z ) {
            const double Y = 1.0 - (log10( FADE_SIZE - y ) / log10( FADE_SIZE ));
            f.fillRect( 0, z*(HEIGHT+1), WIDTH, HEIGHT, QColor( r+int(dr*Y), g+int(dg*Y), b+int(db*Y) ) );
         }
      }
   }

   drawBackground();
}

void
BlockAnalyzer::drawBackground()
{
    const QColor bg = palette().color(QPalette::Background);
    const QColor bgdark = bg.dark( 112 );

    m_background.fill( bg );

    QPainter p( &m_background );
    for( int x = 0; (uint)x < m_columns; ++x )
        for( int y = 0; (uint)y < m_rows; ++y )
            p.fillRect( x*(WIDTH+1), y*(HEIGHT+1) + m_y, WIDTH, HEIGHT, bgdark );
}

