<?php

    //read file in ?file= parameter

    if(isset($_GET["im"])){
        header("Content-type: image/png");
    }

    $val = $_GET["val"]-1; //Byte 1 - 19
    $annotation = $_GET["alt"]; //comment
    $fh = fopen($_GET["file"],"r");
    $data = fread($fh,filesize($_GET["file"]));
    $lines = explode("\n",$data);
    $numlines = count($lines); // wie viel zeilen die data.log hat.

    //graph
    $imheight = 300;

    //$im = imagecreatefrompng("empty.png"); // wird nur für transparent gebraucht, unnötig

    $im = imagecreate(($numlines*3)+32,$imheight);

    //colors

    $black = imagecolorallocate($im,0,0,0);
    $red = imagecolorallocate($im,255,0,0);
    $gray = imagecolorallocate($im,65,55,55);
    $white = imagecolorallocate($im,255,255,255);
    $blue = imagecolorallocate($im,0,0,255);

    imagefill($im,0,0,0);

    for($i = 0;$i < $numlines;$i++){
        $rawdata[$i] = explode(",", $lines[$i]); //rawdata[byte] beinhaltet ein array für den jeweiligen byte.  beispiel: $wert = rawdata[$byte][$zeile]
    }

    $tval;

    //für min & max wert bestimmung.
    $minval = 99999;
    $maxval = -99999;
    $minposx = 0;
    $minposy = 0;
    $maxposx = 0;
    $maxposy = 0;
    $maxval2 = -99999;
    $minval2 = 99999;



    for($i=0;$i<$numlines;$i++){
        $val2 = $rawdata[$i][$val];
        if($val2 >= $maxval){$maxval = $val2;}
        if($val2 <= $minval){$minval = $val2;}
        if(!$minval){$minval =0;}
    }

    $nullval = 0;
    if($val == 19){
        imagettftext ($im,20,0,32,128,$gray, "arial.ttf", "Byte 20 isnt a Byte. its the recording time in seconds. range 0 to ".$numlines);
    }elseif($val >19 || $val < 0){
        imagettftext ($im,30,0,32,128,$gray, "arial.ttf", "Your value ". $val+1 ." isnt valid, it goes from 1 to 20!");
    }else{
        imagettftext ($im,20,0,32,128,$gray, "arial.ttf", "Value ranging from ".$minval." to ".$maxval." on byte ".($val+1));
        imagettftext ($im,20,0,32,256,$gray, "arial.ttf", "".$annotation);
        for($i = 0;$i < $numlines;$i++){
            $value = $rawdata[$i][$val];
            $value2 = $rawdata[$i-1][$val];

            //falls länger eine 0 kommt zum sepperieren mehrere aneinandergefügter daten.
            if($rawdata[$i][1] == 0){
                $nullval++;
                $txt = true;
            }else{
                $nullval=0;
            }

            if($nullval < 2){
                if($txt == true && $nullval < 1){
                    imagestring($im,5,($i*3)-150,250,"NEUER DATENSATZ",$white);
                    $txt = false;
                }
                imageline($im,($i*3)+10,280-$value2,($i*3)+11,280-$value,$white);
            }

            $tval++;

            if($value > $maxval2)
            {
                $maxval2 = $value;
                $maxposx=$i*3;
                $maxposy=260-$value;
            }

            if($value < $minval2)
            {
                $minval2 = $value;
                $minposx=($i*3)+5;
                $minposy=280-$value;
            }


            if($tval >= 100){ // jede 100 datensätze eine linie und text.

                imagestring($im,5,$maxposx,$maxposy,"". $maxval2,$red);
                imagestring($im,5,$minposx,$minposy,"". $minval2,$blue);

                $maxval2 = -99999;
                $minval2 = 99999;
                $minposx = 0;
                $minposy = 0;
                $maxposx = 0;
                $maxposy = 0;

                //imagestring($im,5,($i*3),280-$value,"". $value,$white);
                imageline($im,($i*3),0,($i*3),$imheight-10,$gray);
                imagestring($im,3,($i*3)-10,285,$i+1,$white);
                $tval = 0;
            }


        }

    }



    imageline($im,0,1,3600,1,$white);
    imageline($im,0,$imheight,3600,$imheight,$white);

    imagestring($im,5,1,270,"0",$white);
    imagestring($im,5,1,20,"255",$white);

    imagepng($im);
    imagedestroy($im);

    fclose($fh);

?>