<?php

////////////////////////////////////////////////////
// Created By Alti 14/11/2000  altimir@hotmail.com//
////////////////////////////////////////////////////
// Significantly modified by Chris Gillings 2007-12
////////////////////////////////////////////////////

class graph {
var $image;
var $filename="graph.gif";
var $debug=0;
var $Bheight=600;
var $Bwidth=800;
var $datay=array();
var $nbhour=24;
var $nbday=31;
var $nbx=31;
var $nby=24;
var $labelX=array(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,"");
var $labelY=array(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24);
var $value;
var $colour=array(
'background_colour'=>0,
'black'=>0,
'white'=>0,
'ycolour'=>0,
'xcolour'=>0,
'text_colour'=>0,
);
var $hour_colour=array();
var $title="Temperature Range";
var $title_labelY="Hour";
var $title_labelX="Day";

// Initialise graph skeleton
function graph($Bwidth,$Bheight) {
$this->Bwidth=$Bwidth;
$this->Bheight=$Bheight;
$this->image=ImageCreateTrueColor($this->Bwidth,$this->Bheight);
$this->colour['background_colour']=ImageColorAllocate($this->image,255,255,255);
$this->colour['white']=ImageColorAllocate($this->image,255,255,255);
$this->colour['black']=ImageColorAllocate($this->image,0,0,0);
$this->colour['ycolour']=ImageColorAllocate($this->image,228,238,244);
$this->colour['xcolour']=ImageColorAllocate($this->image,234,245,252);
$this->colour['xycolour']=ImageColorAllocate($this->image,206,225,237);
$this->colour['text_colour']=ImageColorAllocate($this->image,0,0,0);

imagefilledrectangle( $this->image, 0, 0, $this->Bwidth - 2,$this->Bheight - 2, $this->colour['white'] );
imagerectangle( $this->image, 0, 0, $this->Bwidth,$this->Bheight, $this->colour['black'] );
}

# Set colour triplets
function colouris($num,$red,$green,$blue) {
$this->hour_colour[$num]=ImageColorAllocate($this->image,$red,$green,$blue);
}

function create_graph() {
  $autoscale=0;
  $lenY=0;
  for ($ii=0;$ii<=$this->nby;$ii++) {
        $var=$this->labelY[$ii];
        $lenY=($lenY>strlen($var))?$lenY:strlen($var);
  };
  $departx=$lenY*(5)+50;
  $departy=60;

  // width and height for the area of the graphics
  $height=$this->Bheight-2*$departy;
  $y=$height/($this->nby);
  $height=$y*$this->nby;
  $width=$this->Bwidth-2*$departx;
  $x=$width/($this->nbx);
  $width=$x*$this->nbx;
  $StartY=$this->Bheight-$departy;

    // title of graph
    ImageString($this->image,
                3,
                ($this->Bwidth/2)-strlen($this->title)*5/2,
                20,
                $this->title,
                $this->colour['text_colour']);
    // title label X
    ImageString($this->image,
                2,
                $width/2+$departx-strlen($this->title_labelX)*5/2,
                $this->Bheight-20,
                $this->title_labelX,
                $this->colour['text_colour']);
    // title label Y
    ImageStringUp($this->image,
                  2,
                  10,
                  $StartY-$height/2+strlen($this->title_labelY)*5/2,
                  $this->title_labelY,
                  $this->colour['text_colour']);

    // Draw the X axis labels

    $sub=0;
    $i=0;
    for($p=0;$p<=$this->nbx;$p++) {
     //if ($sub<=$p) {
     if ($sub<$p) {
          $NewX=$departx+$x*$sub+7;

          // Alternate positions of label - up/down
          $i=($i==0)?1:0;
          if ($i==1) { $YLineDelta = 5; $YStartDelta = 12; }
                else { $YLineDelta = 8; $YStartDelta = 22; }

          $espaceX=strlen($this->labelX[$sub])*sqrt(3);
          ImageLine($this->image,
                    $NewX,
                    $StartY,
                    $NewX,
                    $StartY+$YLineDelta,
                    $this->colour['black']);
          imageString($this->image,
                      1,
                      $NewX-$espaceX,
                      $StartY+$YStartDelta,
                      $this->labelX[$sub],
                      $this->colour['black']);
          $sub++;
     }
    }

    //  Draw the Y axis labels

    for($p=0;$p<=$this->nby;$p++) {
     imageString($this->image,
                 1,
                 $departx-strlen($this->labelY[$p])*5-5,
                 $StartY-$y*$p-5,
                 $this->labelY[$p],
                 $this->colour['black']);
    }

    $m=1;

$ncolours=count($this->hour_colour);
if ( $autoscale ) {
   // find max and min temperatures from data
   $maxval=-1000;
   $minval=1000;
   for ($i=0;$i<32;$i++) {
       for ($j=0;$j<25;$j++) {
           if ($this->datay[$j][$i]>-100) {
              $maxval=max($maxval,$this->datay[$j][$i]);
              $minval=min($minval,$this->datay[$j][$i]);
           }
       }
   }
} else {
   // fix max and min temperatures
   $maxval=41;
   $minval=0;
}

// Calculate increment through colour space for colour to temperature mapping
$nvalues=($maxval-$minval);
$norm=intval($ncolours/($maxval-$minval))-1;
//if ( $debug = 1 ) { echo "$nvalues, $ncolours, $maxval, $minval, $norm<br>";}

// Draw legend showing colours for temperature values

$LegX=560;
$LegY=440;
$height=intval(350/$norm);
$height=intval(360/$nvalues);
for ($i=$nvalues;$i>0;$i--) {
   $Xs1=$LegX;
   $Ys1=$LegY-$i*$height;
   $Xs2=$LegX;
   $Ys2=$LegY-($i+1)*$height;
   $Xi2=$LegX+$x;
   $Yi2=$LegY-($i+1)*$height;
   $Xi1=$LegX+$x;
   $Yi1=$LegY-$i*$height;
   ImageFilledPolygon($this->image,array($Xi1,$Yi1,$Xi2,$Yi2,$Xs2,$Ys2,$Xs1,$Ys1),4,$this->hour_colour[$i*$norm]);
   imageString($this->image,1,$Xi2+$x/2,$Yi2,$minval+$i-1,$this->colour['black']);
}

// Draw the colour squares

for ($l=0;$l<($this->nbday);$l++) {

   $h=(($l+1)<=$this->nbday)?($l+1):($l);

   for ($j=0;$j<$this->nbhour;$j++) {

      $kk=(($j+1)<=$this->nbhour)?($j+1):($j);
      //if ( $debug  = 1) { echo "$j, $h<br>"; }

      /* $value is the index of the colour array */
      $value=($this->datay[$j][$l]-$minval+1)*$norm;

      // Calculate the coordinates of the coloured square
      $Xs1=$departx+$h*$x;
      $Ys1=$StartY-($j*$y);
      $Xs2=$departx+$h*$x;
      $Ys2=$StartY-($kk*$y);
      $Xi1=$departx+$l*$x;
      $Yi1=$StartY-($j*$y);
      $Xi2=$departx+$l*$x;
      $Yi2=$StartY-($kk*$y);

      // Draw the square in a valid colour
      if ($value > 0 && $value < $ncolours ) {
         $colour=$this->hour_colour[$value];
         ImageFilledPolygon($this->image,array($Xi1,$Yi1,$Xi2,$Yi2,$Xs2,$Ys2,$Xs1,$Ys1),4,$colour);
      };

   }; // end for $j=0;$j<$this->nbday;$j++
} // end for $h=($this->nbhour-1);$h>0;$h--

}

function create() {
    Imagegif($this->image, $this->filename);
}

function destroy() {
    ImageDestroy($this->image);
}

}

$graph=new graph(600,500); //width and height of the graph
srand(time());

if ($argv)
    for ($i=1;$i<count($argv);$i++)
    {
        $it = split("=",$argv[$i]);
        $_GET[$it[0]] = $it[1];
    }

$DEBUG=0;
$MONTH=$_GET['month'];
$im=$MONTH;
$graph->filename=$im.".gif";
$graph->datay=array();
$graph->nbcurve=24; //number of lines
$graph->nbday=31;
$graph->nbx=31; // nnmber of x on axe
$graph->nby=24; // number of y on axe
$graph->labelX=array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32);
$graph->labelY=array("00","01","02","03","04","05","06","07","08","09","10","11","12","13","14","15","16","17","18","19","20","21","22","23","24");

$graph->title="Daily Temperature - ".$MONTH;
$graph->title_labelY="Hour";
$graph->title_labelX="Day";

   // Generate a hue colour sequence from light blue through red to yellow
   $index=0;
   $red=0; $green=255; $blue=255;
   for ($green=255;$green>=0;$green--) { $graph->colourtemp[$index][0]=$red; $graph->colourtemp[$index][1]=$green; $graph->colourtemp[$index][2]=$blue; $index++; }
   $green=0;
   for ($red=0;$red<256;$red++) { $graph->colourtemp[$index][0]=$red; $graph->colourtemp[$index][1]=$green; $graph->colourtemp[$index][2]=$blue; $index++; }
   $red=255;
   for ($blue=255;$blue>=0;$blue--) { $graph->colourtemp[$index][0]=$red; $graph->colourtemp[$index][1]=$green; $graph->colourtemp[$index][2]=$blue; $index++; }
   $blue=0;
   for ($green=0;$green<256;$green++) { $graph->colourtemp[$index][0]=$red; $graph->colourtemp[$index][1]=$green; $graph->colourtemp[$index][2]=$blue; $index++; }

   // load a subset into the colour palette for the graph
   $offset=0;
   $offscale=1;
   for ($ne=0;$ne<$index;$ne++) {
      $ne2=($ne*$offscale)+$offset;
      if ($ne2<$index) {
      $graph->colouris($ne,$graph->colourtemp[$ne2][0],$graph->colourtemp[$ne2][1],$graph->colourtemp[$ne2][2]);
      }
   }

for ($ne=0;$ne<32;$ne++) { for ($nh=0;$nh<25;$nh++) { $graph->datay[$nh][$ne]=-100; } }
for ($element=0;$element<800;$element++) { $xmldata[$element] = -100; }

# read in the RRD XML file 
$MONTH=$_GET['month'];
$XMLFILE="$MONTH.vals";
if (! $fh=fopen($XMLFILE,"r") ) {
   echo "No such XML file $XMLFILE\n";
} else {
$element=0;
while (!feof($fh))
{
    $string = chop(fgets($fh,32));
    if ( $DEBUG ) echo "$string  ";
    if ( strcmp($string,"NaN") ) {
       $xmldata[$element] = (float) $string;
       if ( $xmldata[$element] == 0 ) $xmldata[$element] = -1000;
    }
    if ( $DEBUG ) echo "$xmldata[$element]<br>";
    $element++;
}
$element=0;
for ($ne=0;$ne<31;$ne++) {
   for ($nh=0;$nh<24;$nh++) {
//echo "$nh, $ne<br>";
      $graph->datay[$nh][$ne] = round($xmldata[$element]);
      $element++;
   }
}
fclose ($fh);

$graph->create_graph();
$graph->create(); // create image
$graph->destroy(); // destroy image
}

?>