#!/usr/bin/perl
#Copyright (c) 2008 Emin Gabrielyan, Switzernet

$k=1.6;

$width=400;
$height=200;
$xscaleh=140;
$yscalew=50;
$fsz=10;
$ptsz=2;
$sample_len=20;
$legendw=75;

$grid_color="0.85 0.85 1";
$xscalen=18;
$yscalen=10;
$yscaledecpt=2;


$width*=$k;
$height*=$k;
$xscaleh*=$k;
$yscalew*=$k;
$fsz*=$k;
$ptsz*=$k;
$sample_len*=$k;
$legendw*=$k;


if(@ARGV != 2)
{
  print "two arguments are required: <csv file name> <ps file name>\n";
  exit 1;
}

$psfname=$ARGV[1];

$fname=$ARGV[0];

if(! open fh, $fname)
{
  print "error opening file $fname\n";
  exit 1;
}

@lines=<fh>;
close fh;

foreach $_ (@lines)
{
  s/[\r\n]//g;
  @r=split/,/;

  if(/^([\d]+)(,([\d.]*))+$/)
  {
    if(!defined($xmax) || $r[0]>=$xmax)
    {
      $xmax=$r[0];
    }
    else
    {
      print "time is not increasing\n";
      exit 2;
    }
    if(!defined($xmin) || $r[0]<$xmin)
    {
      $xmin=$r[0];
    }    
    for($i=1;$i<@r;$i++)
    {
      if(defined($r[$i]) && $r[$i] ne "")
      {
        if(!defined($ymax) || $r[$i]>$ymax)
        {
          $ymax=$r[$i];
        }
        if(!defined($ymin) || $r[$i]<$ymin)
        {
          $ymin=$r[$i];
        }
      }
    }
  }
  elsif(/^time(,([\w]+))+$/)
  {
    if(!defined(@h))
    {
      @h=@r;
    }
    else
    {
      print "multiple header lines\n";
      exit 2;
    }
  }
  else
  {
    print "file format error\n";
    exit 2;
  }
}

if(!defined(@h))
{
  print "no header line\n";
  exit 2;
}

if(!defined($xmin) || !defined($xmax))
{
  print "no value on the X scale\n";
  exit 2;
}

if(!defined($ymin) || !defined($ymax))
{
  print "no value on the Y scale\n";
  exit 2;
}

if($xmin==$xmax)
{
  print "only one value on the X scale\n";
  exit 3;
}

if($ymin==$ymax)
{
  print "only one value on the Y scale\n";
  exit 3;
}

if(! open ps,">".$psfname)
{
  print "error opening file $psfname\n";
  exit 4;
}
print ps "%!PS-Adobe-3.0 EPSF-3.0\r\n";
printf ps "%%%%BoundingBox: 0 0 %f %f\r\n",$yscalew+$width+$legendw,$xscaleh+$height+$fsz;
print ps "/Courier findfont $fsz scalefont setfont\r\n";
print ps "1 setlinecap\r\n";

for($i=0;$i<$xscalen;$i++)
{
  $t=$xmin+$i/($xscalen-1)*($xmax-$xmin);
  $x=$yscalew+$i/($xscalen-1)*$width;
  print ps "gsave $grid_color setrgbcolor\r\n";
  print ps "$x $xscaleh $fsz 3 div sub moveto $x $xscaleh $height add lineto stroke\r\n";
  print ps "grestore\r\n";
  print ps "gsave\r\n";
  print ps "$x $xscaleh translate\r\n";
  print ps "90 rotate\r\n";
  ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($t);
  printf ps "(%s-%02d-%02d %02d:%02d:%02d) dup\r\n",$year+1900,$mon+1,$mday,$hour,$min,$sec;
  print ps "stringwidth pop $fsz 2 div add neg $fsz 1 3 div mul neg moveto\r\n";
  print ps "show\r\n";
  print ps "grestore\r\n";
}

for($i=0;$i<$yscalen;$i++)
{
  $v=$ymin+$i/($yscalen-1)*($ymax-$ymin);
  $y=$xscaleh+$i/($yscalen-1)*$height;
  print ps "gsave $grid_color setrgbcolor\r\n";
  print ps "$yscalew $fsz 3 div sub $y moveto $yscalew $width add $y lineto stroke\r\n";
  print ps "grestore\r\n";
  print ps "gsave\r\n";
  print ps "$yscalew $y translate\r\n";
  printf ps "(%.${yscaledecpt}f) dup\r\n",$v;
  print ps "stringwidth pop $fsz 2 div add neg $fsz 1 3 div mul neg moveto\r\n";
  print ps "show\r\n";
  print ps "grestore\r\n";
}

print ps "$yscalew $xscaleh moveto\r\n";
print ps "$width 0 rlineto stroke\r\n";
print ps "$yscalew $xscaleh moveto\r\n";
print ps "0 $height rlineto stroke\r\n";

sub green
{
  local($a)=($_[0]);
  if($a>=0 && $a<=0.5)
  {
    $a*2;
  }
  elsif($a>=0.5 && $a<=1.5)
  {
    1;
  }
  elsif($a>=1.5 && $a<=2)
  {
    1-($a-1.5)*2;
  }
  elsif($a>=2 && $a<=3)
  {
    0;
  }
  else
  {
    -1;
  }
}

sub red
{
  local($a)=($_[0]);
  $a+=1;
  $a=$a>=3?$a-3:$a;
  &green($a);
}

sub blue
{
  local($a)=($_[0]);
  $a+=2;
  $a=$a>=3?$a-3:$a;
  &green($a);
}

sub rgb
{
  #according to: http://4z.com/People/emin-gabrielyan/public/050401-linkviews/
  local($a,$k)=($_[0],0.75);
  $a*=3;
  (&red($a)*$k,&green($a)*$k,&blue($a)*$k);
}

for($i=1;$i<=@h-1;$i++)
{
  ($rgb_r,$rgb_g,$rgb_b)=&rgb(($i-1)/(@h-1));
  $rgb_color[$i]="$rgb_r $rgb_g $rgb_b";
}

$y=$xscaleh+$height;
for($i=1;$i<=@h-1;$i++)
{
  print ps "gsave $rgb_color[$i] setrgbcolor\r\n"; 
  print ps "$yscalew $width add 1.0 $sample_len mul add $y moveto $sample_len 0 rlineto stroke\r\n";
  print ps "$yscalew $width add 1.5 $sample_len mul add $y $ptsz 2 div 0 360 arc fill\r\n";
  print ps "$yscalew $width add 2.0 $sample_len mul add $y moveto\r\n";
  print ps "$fsz 2 div $fsz 1 4 div mul neg rmoveto ($h[$i]) show\r\n";
  print ps "grestore\r\n"; 
  $y-=$fsz;
}

for($i=1;$i<=@h-1;$i++)
{
  print ps "gsave $rgb_color[$i] setrgbcolor\r\n"; 
  $mvln="moveto";
  foreach $_ (@lines)
  {
    s/[\r\n]//g;
    @r=split/,/;
    if(/^([\d]+)(,([\d.]*))+$/)
    {
      if(defined($r[$i]) && $r[$i]!~/^\s*$/)
      {     
        $x=$yscalew+($r[0]-$xmin)/($xmax-$xmin)*$width;
        $y=$xscaleh+($r[$i]-$ymin)/($ymax-$ymin)*$height;
        print ps "$x $y $mvln\r\n";
        $mvln="lineto";
      }
      else
      {
        $mvln="moveto";
      }
    }
  }
  print ps "stroke\r\n";
  foreach $_ (@lines)
  {
    s/[\r\n]//g;
    @r=split/,/;
    if(/^([\d]+)(,([\d.]*))+$/)
    {
      if(defined($r[$i]) && $r[$i]!~/^\s*$/)
      {     
        $x=$yscalew+($r[0]-$xmin)/($xmax-$xmin)*$width;
        $y=$xscaleh+($r[$i]-$ymin)/($ymax-$ymin)*$height;
        print ps "$x $y $ptsz 2 div 0 360 arc fill\r\n";
      }
    }
  }
  print ps "grestore\r\n"; 
}

print ps "showpage\r\n";
close ps