//Author:    Max Howell <max.howell@methylblue.com>, (C) 2003-4
//Copyright: See COPYING file that comes with this distribution

#include <kstringhandler.h>
#include <qfont.h>
#include <qfontmetrics.h>
#include <qpainter.h>
#include <qptrlist.h>

#include "Config.h"
#include "fileTree.h"
#include "radialMap.h"
#include "sincos.h"
#include "widget.h"



namespace RadialMap
{
    struct Label
    {
        Label( const RadialMap::Segment *s, int l ) : segment( s ), lvl( l ), a( segment->start() + (segment->length() / 2) ) { }

        bool tooClose( const int &aa ) const { return ( a > aa - LABEL_ANGLE_MARGIN && a < aa + LABEL_ANGLE_MARGIN ); }

        const RadialMap::Segment *segment;
        const unsigned int lvl;
        const int a;

        int x1, y1, x2, y2, x3;
        int tx, ty;

        QString qs;
    };

    class LabelList : public QPtrList<Label>
    {
    protected:
        int compareItems( QPtrCollection::Item item1, QPtrCollection::Item item2 )
        {
            //you add 1440 to work round the fact that later you want the circle split vertically
            //and as it is you start at 3 o' clock. It's to do with rightPrevY, stops annoying bug

            int a1 = ((Label*)item1)->a + 1440;
            int a2 = ((Label*)item2)->a + 1440;

            if( a1 == a2 )
            return 0;

            if( a1 > 5760 ) a1 -= 5760;
            if( a2 > 5760 ) a2 -= 5760;

            if( a1 > a2 )
            return 1;

            return -1;
        }
    };
}


void
RadialMap::Widget::paintExplodedLabels( QPainter &paint ) const
{
  //we are a friend of RadialMap::Map

  LabelList list; list.setAutoDelete( true );
  QPtrListIterator<Label> it( list );
  unsigned int startLevel = 0;


  //1. Create list of labels  sorted in the order they will be rendered

  if( m_focus != NULL && m_focus->file() != m_tree ) //separate behavior for selected vs unselected segments
  {
    //don't bother with files
    if( m_focus->file() == 0 || !m_focus->file()->isDir() ) return;

    //find the range of levels we will be potentially drawing labels for
    for( const Directory *p = (const Directory *)m_focus->file();
         p != m_tree;
         ++startLevel ) //startLevel is the level above whatever m_focus is in
    {
      p = p->parent();
    }

    //range=2 means 2 levels to draw labels for

    unsigned int a1, a2, minAngle;

    a1 = m_focus->start();
    a2 = m_focus->end();  //boundry angles
    minAngle = int(m_focus->length() * LABEL_MIN_ANGLE_FACTOR);


    #define segment (*it)
    #define ring (m_map.m_signature + i)

    //**** Levels should be on a scale starting with 0
    //**** range is a useless parameter
    //**** keep a topblock var which is the lowestLevel OR startLevel for identation purposes
    for( unsigned int i = startLevel; i <= m_map.m_visibleDepth; ++i )
    {
      for( Iterator<Segment> it = ring->iterator(); it != ring->end(); ++it )
        if( segment->start() >= a1 && segment->end() <= a2 )
          if( segment->length() > minAngle )
            list.inSort( new Label( segment, i ) );
    }

    #undef ring
    #undef segment

  } else {

    #define ring m_map.m_signature

    for( Iterator<Segment> it = ring->iterator(); it != ring->end(); ++it )
      if( (*it)->length() > 288 )
        list.inSort( new Label( (*it), 0 ) );

    #undef ring

  }

  //2. Check to see if any adjacent labels are too close together
  //   if so, remove the least significant labels

  it.toFirst();
  QPtrListIterator<Label> jt( it );
  ++jt;

  while( jt ) //**** no need to check _it_ as jt will be NULL if _it_ was too
  {
    //this method is fairly efficient

    if( (*it)->tooClose( (*jt)->a ) )
    {
      if( (*it)->lvl > (*jt)->lvl )
      {
          list.remove( *it );
          it = jt;
      }
      else
          list.remove( *jt );
    }
    else
      ++it;

    jt = it;
    ++jt;
  }

  //used in next two steps
  bool varySizes;
  //**** should perhaps use doubles
  int  *sizes = new int [ m_map.m_visibleDepth + 1 ]; //**** make sizes an array of floats I think instead (or doubles)

  do
  {
    //3. Calculate font sizes

    {
      //determine current range of levels to draw for
      unsigned int range = 0;

      for( it.toFirst(); it != 0; ++it )
      {
        unsigned int lvl = (*it)->lvl;
        if( lvl > range )
          range = lvl;

        //**** better way would just be to assign if nothing is range
      }

      range -= startLevel; //range 0 means 1 level of labels

      varySizes = Config::varyLabelFontSizes && (range != 0);

      if( varySizes )
      {
        //create an array of font sizes for various levels
        //will exceed normal font pitch automatically if necessary, but not minPitch
        //**** this needs to be checked lots

        //**** what if this is negative (min size gtr than default size)
        unsigned int step = (paint.font().pointSize() - Config::minFontPitch) / range;
        if( step == 0 ) step = 1;

        for( unsigned int x = range + startLevel, y = Config::minFontPitch;
             x >= startLevel;
             y += step, --x )
        {
          sizes[x] = y;
        }
      }
    }

    //4. determine label co-ordinates

    int x1, y1, x2, y2, x3, tx, ty; //coords
    double sinra, cosra, ra;  //angles

    int cx = m_map.width()  / 2 + m_offset.x();  //centre relative to canvas
    int cy = m_map.height() / 2 + m_offset.y();

    int spacer, preSpacer = int(m_map.m_ringBreadth * 0.5) + m_map.m_innerRadius;
    int fullStrutLength = ( m_map.width() - m_map.MAP_2MARGIN ) / 2 + LABEL_MAP_SPACER; //full length of a strut from map center

    int prevLeftY  = 0;
    int prevRightY = height();

    bool rightSide;

    QFont font;

    for( it.toFirst(); it != 0; ++it )
    {
      //** bear in mind that text is drawn with QPoint param as BOTTOM left corner of text box
      if( varySizes ) font.setPointSize( sizes[(*it)->lvl] );
      QFontMetrics fm( font );
      int fmh  = fm.height(); //used to ensure label texts don't overlap
      int fmhD4 = fmh / 4;

      fmh += LABEL_TEXT_VMARGIN;

      rightSide = ( (*it)->a < 1440 || (*it)->a > 4320 );

      ra = M_PI/2880 * (*it)->a; //convert to radians
#if 0
      sincos( ra, &sinra, &cosra );
#endif
	sinra = sin(ra); cosra = cos(ra);

      spacer = preSpacer + m_map.m_ringBreadth * (*it)->lvl;

      x1 = cx + (int)(cosra * spacer);
      y1 = cy - (int)(sinra * spacer);
      y2 = y1 - (int)(sinra * (fullStrutLength - spacer));

      if( rightSide ) { //righthand side, going upwards

        if( y2 > prevRightY /*- fmh*/ ) //then it is too low, needs to be drawn higher
          y2 = prevRightY /*- fmh*/;

      } else { //lefthand side, going downwards

        if( y2 < prevLeftY/* + fmh*/ ) //then we're too high, need to be drawn lower
          y2 = prevLeftY /*+ fmh*/;
      }

      x2 = x1 - int(double(y2 - y1) / tan( ra ));
      ty = y2 + fmhD4;

      QString qs;
      if( rightSide ) {

        if( x2 > width() || ty < fmh || x2 < x1 )
        {
          //skip this strut
          //**** don't duplicate this code
          list.remove( *it ); //will delete the label and set it to list.current() which _should_ be the next ptr
          break;
        }

        prevRightY = ty - fmh - fmhD4; //must be after above's "continue"

        qs = KStringHandler::cPixelSqueeze( (*it)->segment->file()->name(), fm, width() - x2 );

        x3 = width() - fm.width( qs )
             - LABEL_HMARGIN //outer margin
             - LABEL_TEXT_HMARGIN //margin between strut and text
             //- ((*it)->lvl - startLevel) * LABEL_HMARGIN //indentation
             ;
        if( x3 < x2 ) x3 = x2;
        tx = x3 + LABEL_TEXT_HMARGIN;

      } else {

        if( x2 < 0 || ty > height() || x2 > x1 )
        {
          //skip this strut
          list.remove( *it ); //will delete the label and set it to list.current() which _should_ be the next ptr
          break;
        }

        prevLeftY = ty + fmh - fmhD4;

        qs = KStringHandler::cPixelSqueeze( (*it)->segment->file()->name(), fm, x2 );

        //**** needs a little tweaking:

        tx = fm.width( qs ) + LABEL_HMARGIN/* + ((*it)->lvl - startLevel) * LABEL_HMARGIN*/;
        if( tx > x2 ) { //text is too long
          tx = LABEL_HMARGIN + x2 - tx; //some text will be lost from sight
          x3 = x2; //no text margin (right side of text here)
        } else {
          x3 = tx + LABEL_TEXT_HMARGIN;
          tx = LABEL_HMARGIN /* + ((*it)->lvl - startLevel) * LABEL_HMARGIN*/;
        }
      }

      (*it)->x1 = x1;
      (*it)->y1 = y1;
      (*it)->x2 = x2;
      (*it)->y2 = y2;
      (*it)->x3 = x3;
      (*it)->tx = tx;
      (*it)->ty = ty;
      (*it)->qs = qs;
    }

    //if an element is deleted at this stage, we need to do this whole
    //iteration again, thus the following loop
    //**** in rare case that deleted label was last label in top level
    //     and last in labelList too, this will not work as expected (not critical)

  } while( it != 0 );


  //5. Render labels

  paint.setPen( QPen( Qt::black, 1 ) );

    for( it.toFirst(); it != 0; ++it )
    {
      if( varySizes )
      {
        //**** how much overhead in making new QFont each time?
        //     (implicate sharing remember)
        QFont font = paint.font();
        font.setPointSize( sizes[(*it)->lvl] );
        paint.setFont( font );
      }

      paint.drawEllipse( (*it)->x1 - 3, (*it)->y1 - 3, 7, 7 ); //**** CPU intensive! better to use a pixmap
      paint.drawLine(  (*it)->x1,  (*it)->y1, (*it)->x2, (*it)->y2 );
      paint.drawLine( (*it)->x2, (*it)->y2, (*it)->x3, (*it)->y2);
      paint.drawText( (*it)->tx, (*it)->ty, (*it)->qs );
    }

   delete [] sizes;
}