<?php
/*
************************************************************************
**
**  Copyright (c) 2009..2013 by
**    Core|Vision B.V.
**    Hambakenwetering 1
**    5231 DD  's-Hertogenbosch
**    The Netherlands
**
**  All Rights Reserved
**
************************************************************************
*/
/*
************************************************************************
**
**  Project name:   Dual Inventive: MTinfo Support Scripts
**  Filename:       plot-runavg.php
**  Author:         Jack Weeland
**  Date:           July 6, 2009
**  File version:   $Release$
**                  $Date: 2013/10/30 17:22:36 $
**
************************************************************************
*/
/*
************************************************************************
**
**  TEST SCRIPT FOR THE RUNNING AVERAGE COMPRESSION
**  ===============================================
**
**  Display a measurement in a graph.
**
**  Mandatory parameters, via "GET", all of which are retrieved from
**  the database
**    zkl           - database ID of the ZKL to query
**    logfile       - sdcard,rpgmcount,startup of the logfile to plot
**      and/or
**    tmin,tmax     - date/time of the time frame (the current time will
**                    be used if tmax is ommitted)
**  Optional output options:
**    w             - width of the output image
**    h             - height of the output image
**    show_rms      - also plot the RMS values
**    hide_title    - do not device id-code and date
**    hide_info     - do not show additional info
**
**  Notes:
**  - If both 'logfile' and a 'tmin'/'tmax' are specified, then the data
**    from the logfile will be scaled to the specified time frame.
**  - If _no_ 'logfile' is specified, all logfiles with data in the time
**    frame will be shown.
**  - Logfiles with an invalid date (i.e. 1970-1-1) are _never_ plotted.
**
************************************************************************
*/

//
//  Check inputs for SQL statement injection and such.
//  Items not tested below are not vulnerable for SQL statement injection, e.g.
//    a time is always converted using 'strtotime()' and other items are only
//    used in the PHP but never in the composition of an SQL statement
//  [security audit 2013-10-23]
//
if(
  (isset($_GET['zkl']) && !is_numeric($_GET['zkl'])) ||
  (isset($_GET['logfile']) && !preg_match('/^[0-9]+,[0-9]+,[0-9]+$/', $_GET['logfile']) && !in_array($_GET['logfile'], array('log_tcp','log_versienummer','log_realtime','log_secure_zkl'))) ||
  (isset($_GET['db']) && dirname($_GET['db']) != ".")
) {
  // don't do anything fancy or interruptive as fiddling with the GET parameters
  //  is intended by the author
  die("Parameter error");
}

require_once("../include/graphics.php");
require_once("../include/i18n.php");
require_once("../include/cp3000-tcpclient.php");
require_once("support.inc.php");

set_time_limit(0);

function clip($val, $min, $max)
{
  if( $val < $min )
    return $min;
  else if( $val > $max )
    return $max;
  else
    return $val;
}

function avg($array, $count, &$h_delta)
{
  if( $count == 0 ) {
    $h_delta = 0;
    return 0;
  }

  // sum and average
  $sum = 0;
  for( $i = 0; $i < $count; $i++ ) $sum += $array[$i];
  $avg = $sum / $count;
  
  // delta
  $h_delta = 0;
  for( $i = 0; $i < $count; $i++ ) {
    $delta = abs($array[$i] - $avg);
    if( $delta > $h_delta ) $h_delta = $delta;
  }
  
  return $avg;
}

// read the database information
if( isset($_GET['db']) ) $db_info = read_database(DBCONFIG_DIR, $_GET['db']);
else $db_info = array();
if( !isset($db_info['host'])   ) $db_info['host']   = "localhost";
if( !isset($db_info['user'])   ) $db_info['user']   = "root";
if( !isset($db_info['passwd']) ) $db_info['passwd'] = "";
if( !isset($db_info['db'])     ) $db_info['db']     = "di_zkl";

// open the database
$db_data_handle = mysql_connect($db_info['host'], $db_info['user'], $db_info['passwd']);
if( $db_data_handle === FALSE ) {
  echo mysql_error();
  exit(1);
}
mysql_select_db($db_info['database'], $db_data_handle);
if( $db_info['main'] ) {
  $db_main_info = read_database(DBCONFIG_DIR, $db_info['main']);
  $db_main_handle = mysql_connect($db_main_info['host'], $db_main_info['user'], $db_main_info['passwd'], true);
  if( $db_main_handle === FALSE ) {
    echo mysql_error();
    exit(1);
  }
  mysql_select_db($db_main_info['database'], $db_main_handle);
}
else {
  $db_main_handle = $db_data_handle;
  $db_main_info = $db_info;
}
}

// determine width and height
$width  = $_GET['w'];
$height = $_GET['h'];
if( !$width )  $width = 640;
if( !$height ) $height = 480;
  
// get information about the device
if( isset($_GET['logfile']) ) {
  list($sdcard,$rpgmcount,$startup) = explode(',', $_GET['logfile']);
}
$query = "SELECT serienr,idcode,tcp_server,mcu_versie,wcpu_versie,IFNULL(gebruiker,eigenaar) AS gebruiker FROM zkl WHERE id=" . $_GET['zkl'];
$result = mysql_run($query, $db_main_handle);
$zkl_info = mysql_fetch_assoc($result);
if( $zkl_info['gebruiker'] ) {
  $query = "SELECT tz,i18n FROM klant WHERE id=" . $zkl_info['gebruiker'];
  $result = mysql_run($query, $db_main_handle);
  $tz_info = mysql_fetch_assoc($result);
}
else {
  $tz_info = array( 'tz' => date("e"), 'i18n' => "nl" );
}
if( $_GET['tz'] ) $tz_info['tz'] = $_GET['tz'];
if( $_GET['lc'] ) $tz_info['i18n'] = $_GET['lc'];
$zkl_info['tz']          = $tz_info['tz'];
$zkl_info['i18n']        = $tz_info['i18n'];
$zkl_info['mcu_versie']  = zkl_get_fw_version($zkl_info['mcu_versie']);
$zkl_info['wcpu_versie'] = zkl_get_fw_version($zkl_info['wcpu_versie']);
putenv("TZ=" . $zkl_info['tz']);
i18n_settext_language($zkl_info['i18n']);
setlocale(LC_ALL, $zkl_info['i18n']);

// get timeframe and log files
$logfiles = array();
if( isset($_GET['tmin']) ) {
  $tmin = strtotime($_GET['tmin']);
  if( isset($_GET['tmax']) && $_GET['tmax'] ) $tmax = strtotime($_GET['tmax']);
  else $tmax = time();
  if( isset($_GET['logfile']) ) {
    if( is_array($_GET['logfile']) ) foreach( $_GET['logfile'] as $logfile ) {
      list($sdcard,$rpgmcount,$startup) = explode(',', $logfile);
      $query  = "SELECT MIN(UNIX_TIMESTAMP(tijd)) AS tmin,MAX(UNIX_TIMESTAMP(tijd)) AS tmax ";
      $query .= "FROM log_zkl ";
      $query .= "WHERE ";
      $query .= "  zkl=" . $_GET['zkl'] . " AND ";
      $query .= "  sdcard=" . $sdcard . " AND ";
      $query .= "  rpgmcount=" . $rpgmcount . " AND ";
      $query .= "  startup=" . $startup;
      $result = mysql_run($query, $db_data_handle);
      $row = mysql_fetch_assoc($result);
      array_push($logfiles, array('sdcard' => $sdcard, 'rpgmcount' => $rpgmcount, 'startup' => $startup, 'tmin' => $row['tmin'], 'tmax' => $row['tmax']));
    }
    else {
      list($sdcard,$rpgmcount,$startup) = explode(',', $_GET['logfile']);
      $query  = "SELECT MIN(UNIX_TIMESTAMP(tijd)) AS tmin,MAX(UNIX_TIMESTAMP(tijd)) AS tmax ";
      $query .= "FROM log_zkl ";
      $query .= "WHERE ";
      $query .= "  zkl=" . $_GET['zkl'] . " AND ";
      $query .= "  sdcard=" . $sdcard . " AND ";
      $query .= "  rpgmcount=" . $rpgmcount . " AND ";
      $query .= "  startup=" . $startup;
      $result = mysql_run($query, $db_data_handle);
      $row = mysql_fetch_assoc($result);
      array_push($logfiles, array('sdcard' => $sdcard, 'rpgmcount' => $rpgmcount, 'startup' => $startup, 'tmin' => $row['tmin'], 'tmax' => $row['tmax']));
    }
  }
  else {
    // retrieve logfiles from the database
    $query  = "SELECT sdcard,rpgmcount,startup,MIN(UNIX_TIMESTAMP(tijd)) AS tmin,MAX(UNIX_TIMESTAMP(tijd)) AS tmax ";
    $query .= "FROM log_zkl ";
    $query .= "WHERE ";
    $query .= "  zkl=" . $_GET['zkl'] . " AND ";
    $query .= "  tijd BETWEEN FROM_UNIXTIME(" . $tmin . ") AND FROM_UNIXTIME(". $tmax . ") ";
    $query .= "GROUP BY sdcard,rpgmcount,startup";
    $result = mysql_run($query, $db_data_handle);
    while( $row = mysql_fetch_assoc($result) ) array_push($logfiles, $row);
  }
}
else {
  if( !isset($_GET['logfile']) ) {
    error_log($PHP_SELF . ": no log file or time range defined");
    exit(1);
  }
  list($sdcard,$rpgmcount,$startup) = explode(',', $_GET['logfile']);
  $query  = "SELECT MIN(UNIX_TIMESTAMP(tijd)) AS tmin,MAX(UNIX_TIMESTAMP(tijd)) AS tmax ";
  $query .= "FROM log_zkl ";
  $query .= "WHERE ";
  $query .= "  zkl=" . $_GET['zkl'] . " AND ";
  $query .= "  sdcard=" . $sdcard . " AND ";
  $query .= "  rpgmcount=" . $rpgmcount . " AND ";
  $query .= "  startup=" . $startup;
  $result = mysql_run($query, $db_data_handle);
  list($tmin,$tmax) = mysql_fetch_array($result);
  array_push($logfiles, array('sdcard' => $sdcard, 'rpgmcount' => $rpgmcount, 'startup' => $startup, 'tmin' => $tmin, 'tmax' => $tmax));
}
if( $tmin >= $tmax ) {
  error_log($PHP_SELF . ":  empty time range: " . strftime("%D %T", $tmin) . "-" . strftime("%D %T", $tmax));
  exit(1);
}
$tz_offset = date("Z");
$duration = $tmax - $tmin;

//
//  Draw the graph
//

header("Content-type: image/png");
header('Pragma: no-cache');

// create the image
$im = imagecreatetruecolor($width,$height);
if( function_exists("imageantialias") )
  imageantialias($im, true);
$black   = imagecolorstring($im, "black");
$white   = imagecolorstring($im, "white");
$grey    = imagecolorallocate($im, 192, 192, 192);
$lgrey   = imagecolorallocate($im, 240, 240, 240);
$dgrey   = imagecolorallocate($im, 128, 128, 128);
$green   = imagecolorallocate($im,   0, 192,   0);
$lgreen  = imagecolorallocate($im, 192, 255, 192);
$llgreen = imagecolorallocate($im, 248, 255, 248);
$dgreen  = imagecolorallocate($im,   0, 160,   0);
$tdgreen = imagecolorallocatealpha($im,   0, 160,   0, 96);
$red     = imagecolorstring($im, "red");
$lred    = imagecolorstring($im, "#FFC0C0");
$dred    = imagecolorallocate($im, 160,   0,   0);
$blue    = imagecolorallocate($im,   0,   0, 224);
$tblue   = imagecolorallocatealpha($im,   0,   0, 224, 96);
$dblue   = imagecolorallocate($im,   0,   0, 160);
$purple  = imagecolorallocate($im, 224,   0, 224);
$dpurple = imagecolorallocate($im, 160,   0, 160);
$font    = 2;  // 6x13
$bfont   = 3;  // 7x13 medium bold
$tfont   = 1;  // 5x8

//
//  Colors and font to use
//
$bgcolor        = imagecolorallocatealpha($im, 255, 255, 255, $_GET['transparent'] ? 127 : 0);
$bgcolor_transp = imagecolorallocatealpha($im, 255, 255, 255, 96);
$gridcolor      = $black;    // main grid and markers
$sgridcolor     = $lgrey;    // guides in the gred
$nextdaycolor   = $grey;    // next day line
$cal_b_a_color  = $lred;    // b/a limit line
$cal_info_color = $red;      //  info with the above
$cal_rms_color  = $llgreen;    // very light green
$cal_rms_bcolor = $lgreen;    // border for legend, a bit darker light green
$b_a_color      = $blue;    // line of the b/a graph
$b_a_tcolor     = $tblue;    // line of the b/a graph
$rms_color      = $dgreen;    // line of the rms graph
$rms_tcolor     = $tdgreen;    // line of the rms graph

//
//  Font selection (dependent on image size)
//
// labels and legenda
if( $width <= 320 || $height <= 240 ) {
  $labelfont = 1;
  $infofont  = 1;
}
else if( $width >= 2048 && $height >= 1536 ) {
  $labelfont = 5;
  $infofont  = 3;
}
else if( $width >= 1280 && $height >= 1024 ) {
  $labelfont = 3;
  $infofont  = 2;
}
else {
  $labelfont = 2;
  $infofont  = 1;
}

//
//  Draw the grid
//

// draw background
imagefill($im, 0, 0, $bgcolor);

// offsets with the drawing grid
// largest value label: 1.000
//  x: left to right
//  y: bottom to top
global $x_off, $x_ext, $y_off, $y_ext;
$x_off = 5 * imagefontwidth($labelfont)                  // value labels + 
       + imagefontheight($labelfont)                  // legend + 
     + (imagefontheight($labelfont) >> 1);              // extra spacing
$x_ext = $width - $x_off - (imagefontheight($labelfont) >> 1);      // + extent of the last date label
$y_off = $height - 10 * imagefontwidth($labelfont);            // date/time
$y_ext = $y_off;
if( !isset($_GET['hide_title']) )
  $y_ext -= imagefontheight($labelfont);                // title
else
  $y_ext -= imagefontheight($labelfont) >> 1;              // extent of the top value label
if( !isset($_GET['hide_info']) )
  $y_ext -= imagefontheight($infofont) << 1;              // info + arrow

// draw valid/okay RMS indicator below anything else
if( isset($_GET['show_rms']) ) {
  imagefilledrectangle($im,
    $x_off,          $y_off - ($y_ext * (sqrt(5735) / 100.0)),
    $x_off + $x_ext, $y_off - ($y_ext * (sqrt( 800) / 100.0)),
    $cal_rms_color
  );
}

// The grid is drawn _under_ the lines and ornaments like the title etc
// Y tick marks every 0.100
for( $y_tick = 0; $y_tick <= 1.0; $y_tick += 0.1 ) {
  $y = $y_tick * $y_ext;
  imageline($im, $x_off, $y_off - $y, $x_off + $x_ext, $y_off - $y, $lgrey);
  imageline($im, $x_off - 2, $y_off - $y, $x_off, $y_off - $y, $black);
  imagestringalign($im, $labelfont, $x_off - 2, $y_off - $y, sprintf("%.2f", $y / $y_ext), $gridcolor, ALV_MIDDLE | ALH_RIGHT);
}
// X tick marks
// find a correct stepping for the date labels first
$x_tick_sec = array(5,15,1*60,5*60,15*60,30*60,60*60,2*60*60,4*60*60,6*60*60,8*60*60,12*60*60,24*60*60,7*24*60*60);
for(
  $step = 0, $x_tick_step = 0;
  $x_tick_step < (imagefontheight($labelfont) << 1) && $step < count($x_tick_sec);
  $step++
) {
  $x_tick_off   = $x_tick_sec[$step];
  $x_tick_step  = ($x_ext * $x_tick_off) / $duration;
  $x_tick_val   = $x_tick_off - (($tmin + $tz_offset) % $x_tick_off);
  if( $x_tick_val == $x_tick_off ) $x_tick_val = 0;
}
for( $x = ($x_ext * $x_tick_val) / $duration; $x <= $x_ext; $x += $x_tick_step ) {
  $x_time = $tmin + $x_tick_val;
  if( $x_tick_off >= (24*60*60)  ) {
    if( strftime("%d", $x_time) == "01" ) {
      imageline($im, $x_off + $x, $y_off    , $x_off + $x, $y_off - $y_ext - 1, $nextdaycolor);
      imageline($im, $x_off + $x, $y_off + 2, $x_off + $x, $y_off, $gridcolor);
      imagestringupalign($im, $labelfont, $x_off + $x, $y_off - 2, strftime("%B", $x_time), $nextdaycolor, ALV_BOTTOM | ALH_LEFT);
    }
    else {
      imageline($im, $x_off + $x, $y_off    , $x_off + $x, $y_off - $y_ext - 1, $sgridcolor);
      imageline($im, $x_off + $x, $y_off + 2, $x_off + $x, $y_off, $gridcolor);
    }
    imagestringupalign($im, $labelfont, $x_off + $x, $y_off + 2, strftime("%x", $x_time), $gridcolor, ALV_TOP | ALH_CENTER);
  }
  else {
    if( strftime("%H%M%S", $x_time) == "000000" ) {
      imageline($im, $x_off + $x, $y_off    , $x_off + $x, $y_off - $y_ext - 1, $nextdaycolor);
      imageline($im, $x_off + $x, $y_off + 2, $x_off + $x, $y_off, $gridcolor);
      imagestringupalign($im, $labelfont, $x_off + $x, $y_off - 2, strftime("%x", $x_time), $nextdaycolor, ALV_BOTTOM | ALH_LEFT);
    }
    else {
      imageline($im, $x_off + $x, $y_off    , $x_off + $x, $y_off - $y_ext - 1, $sgridcolor);
      imageline($im, $x_off + $x, $y_off + 2, $x_off + $x, $y_off, $gridcolor);
    }
    imagestringupalign($im, $labelfont, $x_off + $x, $y_off + 2, strftime("%X", $x_time), $gridcolor, ALV_TOP | ALH_CENTER);
  }
  $x_tick_val += $x_tick_off;
}
if( $x_tick_off != (24*60*60)  )
  imagestringupalign($im, $labelfont, $x_off, $y_off - 2, strftime("%x", $tmin), $grey, ALV_BOTTOM | ALH_LEFT);

//
//  Draw the legend
//
$y_legend_off = $y_off;
if( isset($_GET['show_rms']) ) {
  $y_legend_off -= ($y_ext - (8+4+11+4+8+4+14) * imagefontwidth($labelfont)) >> 1;
  imagestringupalign($im, $labelfont, 0, $y_legend_off - 4 * imagefontwidth($labelfont), "rms", $gridcolor, ALV_TOP | ALH_LEFT);
  imageline($im,
    imagefontheight($labelfont) >> 1, $y_legend_off - 5.5 * imagefontwidth($labelfont),  /* space */
    imagefontheight($labelfont) >> 1, $y_legend_off - 8 * imagefontwidth($labelfont),  /* line length */
    $rms_color
  );
  $y_legend_off -= (8+4) * imagefontwidth($labelfont);

  imagestringupalign($im, $labelfont, 0, $y_legend_off - 7 * imagefontwidth($labelfont), "rms ok", $gridcolor, ALV_TOP | ALH_LEFT);
  imagefilledrectangle($im,
    0, $y_legend_off - 11 * imagefontwidth($labelfont),
    imagefontheight($labelfont), $y_legend_off - 8 * imagefontwidth($labelfont),
    $cal_rms_color
  );
  imagerectangle($im,
    0, $y_legend_off - 11 * imagefontwidth($labelfont),
    imagefontheight($labelfont), $y_legend_off - 8 * imagefontwidth($labelfont),
    $cal_rms_bcolor
  );
  $y_legend_off -= (11+4) * imagefontwidth($labelfont);
}
else {
  $y_legend_off -= ($y_ext - (8+4+14) * imagefontwidth($labelfont)) >> 1;
};
imagestringupalign($im, $labelfont, 0, $y_legend_off - 4 * imagefontwidth($labelfont), "b/a", $gridcolor, ALV_TOP | ALH_LEFT);
imageline($im,
  imagefontheight($labelfont) >> 1, $y_legend_off - 5 * imagefontwidth($labelfont),  /* space */
  imagefontheight($labelfont) >> 1, $y_legend_off - 8 * imagefontwidth($labelfont),  /* line length */
  $b_a_color
);
$y_legend_off -= (8+4) * imagefontwidth($labelfont);

imagestringupalign($im, $labelfont, 0, $y_legend_off - 10 * imagefontwidth($labelfont), "b/a limit", $gridcolor, ALV_TOP | ALH_LEFT);
imageline($im,
  imagefontheight($labelfont) >> 1, $y_legend_off - 11 * imagefontwidth($labelfont),  /* space */
  imagefontheight($labelfont) >> 1, $y_legend_off - 14 * imagefontwidth($labelfont),  /* line length */
  $cal_b_a_color
);

//
//  Draw the border to the left and bottom of the canvas
//
imageline($im, $x_off, $y_off, $x_off, $y_off - $y_ext + 1, $gridcolor);
imageline($im, $x_off, $y_off, $x_off + $x_ext, $y_off, $gridcolor);

//
//  Plot the data
//
$h_size = 64;

$h_b_a = array();
$h_rms = array();

for( $i = 0; $i < $h_size; $i++ ) {
  $h_b_a[$i] = 1.0;
  $h_rms[$i] = 0;
}

foreach( $logfiles as $logfile ) {
  // get tmin,tmax for this logfile
  $log_tmin = $logfile['tmin'];
  $log_tmax = $logfile['tmax'];
  if( $log_tmin < $tmin ) $log_tmin = $tmin;
  if( $log_tmax > $tmax ) $log_tmax = $tmax;

  //
  $sdcard    = $logfile['sdcard'];
  $rpgmcount = $logfile['rpgmcount'];
  $startup   = $logfile['startup'];

  // measurement start/end
  $m_begin = array();
  $m_end   = array();
  $query  = "SELECT UNIX_TIMESTAMP(tijd) AS tijd,major ";
  $query .= "FROM log_zkl ";
  $query .= "WHERE ";
  $query .= "  zkl=" . $_GET['zkl'] . " AND ";
  $query .= "  sdcard=" . $sdcard . " AND ";
  $query .= "  rpgmcount=" . $rpgmcount . " AND ";
  $query .= "  startup=" . $startup . " AND ";
  $query .= "  (major=1 OR major=2) ";
  $query .= "ORDER BY id";
  $result = mysql_run($query, $db_data_handle);
  while( $row = mysql_fetch_assoc($result) ) {
    if( $row['major'] == 1 )
      array_push($m_begin, $row['tijd']);
    else
      array_push($m_end, $row['tijd']);
  }
  $n_begin = count($m_begin);
  $n_end   = count($m_end);
  // valid measurements? if not, bail out here
  if( $n_begin == 0 ) continue;

  //
  //  Draw b/a limit line
  //
  $query  = "SELECT UNIX_TIMESTAMP(log_zkl.tijd) AS tijd,log_zkl.minor,log_calibratie.b_a,log_calibratie.freq ";
  $query .= "FROM log_zkl,log_calibratie ";
  $query .= "WHERE ";
  $query .= "  log_zkl.id=log_calibratie.id AND ";
  $query .= "  log_zkl.zkl=" . $_GET['zkl'] . " AND ";
  $query .= "  log_zkl.sdcard=" . $sdcard . " AND ";
  $query .= "  log_zkl.rpgmcount=" . $rpgmcount . " AND ";
  $query .= "  log_zkl.startup=" . $startup . " AND ";
  $query .= "  log_calibratie.b_a <> 0 ";          // failed auto-calibration
  $query .= "ORDER BY log_zkl.id";
  $result = mysql_run($query, $db_data_handle);
  $p_begin = 0;
  $p_end   = 0;
  $t_cal_start = array();
  while( $row = mysql_fetch_assoc($result) ) array_push($t_cal_start, $row);
  $cal = 0;
  while( $cal < count($t_cal_start) ) {
    $b_a     = $t_cal_start[$cal]['b_a'];
    $t_begin = $t_cal_start[$cal]['tijd'];
    $t_end   = ($cal + 1 < count($t_cal_start)) ? $t_cal_start[$cal + 1]['tijd'] : $log_tmax;
    if( $t_end <= $m_begin[$p_begin] ) {
      $cal++;
      continue;
    }
    if( $p_begin < $n_begin ) {
      if( $t_begin <= $m_begin[$p_begin] ) {
        $t_begin = $m_begin[$p_begin];
      }
    }
    while( 1 ) {
      if( $p_end < $n_end && $t_end >= $m_end[$p_end] ) {
        $t_end = $m_end[$p_end];
        $p_begin++;
        $p_end++;
      }
      else {
        // last piece of the line will be drawn
        $cal++;
        break;
      }
    }
    
    if( $t_begin < $log_tmin ) $t_begin = $log_tmin;
    if( $t_end < $log_tmin ) continue;
    else if( $t_end > $log_tmax ) $t_end = $log_tmax;
    
    imageline($im,
      $x_off + ((($t_begin - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
      $x_off + ((($t_end - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
      $lred
    );
  }

  //
  //  Plot the data
  //
  $h_ptr  =  0;
  $h_count = 0;
  $h_delta = 0;
  $prev_time = 0;
  $ref_avg   = 0;
  $ref_b_a   = 0;
  $ref_delta = 1;

  // get the data
  $query  = "SELECT UNIX_TIMESTAMP(log_zkl.tijd) AS tijd,log_meting.b_a,log_meting.rms";
  $query .= " ";
  $query .= "FROM log_zkl,log_meting ";
  $query .= "WHERE ";
  $query .= "  log_zkl.id=log_meting.id AND ";
  $query .= "  log_zkl.zkl=" . $_GET['zkl'] . " AND ";
  $query .= "  log_zkl.sdcard=" . $sdcard . " AND ";
  $query .= "  log_zkl.rpgmcount=" . $rpgmcount . " AND ";
  $query .= "  log_zkl.startup=" . $startup . " ";
  $query .= "ORDER BY log_zkl.id";
  $result = mysql_run($query, $db_data_handle);
  unset($t_start);
  $p_begin = 0;
  $p_end   = 0;
  while( $row = mysql_fetch_assoc($result) ) {
    if( !isset($t_start) ) {
      $t_start = $row['tijd'];
      $b_a     = $row['b_a'];
      $rms     = $row['rms'];
      $d_b_a   = 0;
      //$d_rms   = $row['d_rms'];
    }
    else {
      $time = strtotime($row['tijd']);
      if( $prev_time > 0 ) {
        while( ++$prev_time < $time ) {
          // should be done twice, but it's only to give an idea
          //  of how good the algorithm works
          $h_b_a[$h_ptr] = $prev_b_a;
          $h_rms[$h_ptr] = $prev_rms;
          $h_ptr = ($h_ptr + 1) & ($h_size - 1);
          if( $h_count < $h_size ) $h_count++;
        }
        // probably this:
        $ref_b_a = $prev_b_a;
        //$ref_avg = avg($h_b_a, $h_count, $h_delta);
      }
      $prev_time = $time;

      $t_this = $t_end = $row['tijd'];
      if(
        $p_begin < $n_begin && 
        $t_end >= $m_begin[$p_begin] &&
        $t_end >= $log_tmin &&
        ($p_end == $n_end || $t_start < $m_end[$p_end]) &&
        $t_start <= $log_tmax
      ) {
        // adjust start and end of the line
        if( $t_start < $m_begin[$p_begin] ) {
          $t_start = $m_begin[$p_begin];
          // new measurement
          $b_a = $row['b_a'];
          $rms = $row['rms'];
        }
        if( $p_end < $n_end && $t_end >= $m_end[$p_end] ) {
          $t_end = $m_end[$p_end];
          $p_begin++;
          $p_end++;
        }
        
        if( $t_start < $log_tmin ) $t_start = $log_tmin;
        if( $t_end < $log_tmin ) break;
        else if( $t_end > $log_tmax ) $t_end = $log_tmax;

        $avg = avg($h_b_a, $h_count, $h_delta);
        $delta = abs($row['b_a'] - $avg);
  
        $log = false;
        if( $delta > .25 ) {
          $log = true;
          $h_ptr = 0;
          $h_count = 0;
          $ref_avg   = $avg = $row['b_a'];
          $ref_delta = 0;
        }
        else if( $delta > ($h_delta + (16/1024)) ) {
          // delta of this measurement is higher than the historical data
          //  (plus a little margin)
          $log = true;
          $ref_avg   = $avg;
          $ref_delta = $delta;
        }
        else if( abs($h_delta - $ref_delta) > (8/1024) ) {
          // change in historical delta
          $log = true;
          $ref_avg   = $avg;
          $ref_delta = $h_delta;
        }
        else if( abs($avg - $ref_avg) > (8/1024) ) {
          // change in running average
          $log = true;
          $ref_avg = $avg;
          $ref_delta = $h_delta;
        }

        if( $log ) {
          // b/a is more important than the rms-value
          if( isset($_GET['show_rms']) ) {
            $prev_rms = sqrt($rms) / 100.0;
            $new_rms  = sqrt($row['rms']) / 100.0;

            if(
              $zkl_info['firmware']['wcpu']['datecode'] >= 0x20091006 &&
              $d_rms &&
              ($d_rms * $y_ext) > 1
            ) {
              // draw a (lighter) rectangle to show the delta
              $min_rms = sqrt($rms + $d_rms) / 100.0;
              $max_rms = sqrt($rms - $d_rms) / 100.0;

              imagefilledrectangle($im,
                $x_off + ((($t_start - $tmin) / $duration) * $x_ext)    , $y_off - ($y_ext * clip($min_rms, 0.0, 1.0)),
                $x_off + ((($t_end   - $tmin) / $duration) * $x_ext) - 1, $y_off - ($y_ext * clip($max_rms, 0.0, 1.0)),
                $rms_tcolor
              );
            }
            imageline($im,
              $x_off + ((($t_start - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $prev_rms),
              $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $prev_rms),
              $rms_color
            );
            imageline($im,
              $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $prev_rms),
              $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $new_rms),
              $rms_color
            );
          }
      
          if(
            $d_b_a &&
            ($d_b_a * $y_ext) > 1
          ) {
            // draw a (lighter) rectangle to show the delta
            imagefilledrectangle($im,
              $x_off + ((($t_start - $tmin) / $duration) * $x_ext)    , $y_off - ($y_ext * clip($b_a + $d_b_a, 0.0, 1.0)),
              $x_off + ((($t_end   - $tmin) / $duration) * $x_ext) - 1, $y_off - ($y_ext * clip($b_a - $d_b_a, 0.0, 1.0)),
              $b_a_tcolor
            );
          }
          imageline($im,
            $x_off + ((($t_start - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
            $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
            $b_a_color
          );
          imageline($im,
            $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
            $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $avg),
            $b_a_color
          );
        }
      }
      else if( $p_end < $n_end && $t_end >= $m_end[$p_end] ) {
        $p_begin++;
        $p_end++;
      }
      if( $log ) {
        $t_start = $t_this;
        $b_a     = $avg;//$row['b_a'];
        $rms     = $row['rms'];
        $d_b_a   = $h_delta;
        //$d_rms   = $row['d_rms'];
      }
    }
  
    $h_b_a[$h_ptr] = $row['b_a'];
    $h_rms[$h_ptr] = $row['rms'];
    $h_ptr = ($h_ptr + 1) & ($h_size - 1);
    if( $h_count < $h_size ) $h_count++;
  
    // save
    $prev_b_a = $row['b_a'];
    $prev_rms = $row['rms'];
  }
  // draw last segment
  $t_end = $log_tmax;
  if(
    $p_begin < $n_begin &&
    $t_end >= $m_begin[$p_begin] &&
    $t_end >= $log_tmin &&
    ($p_end == $n_end || $t_start < $m_end[$p_end]) &&
    $t_start <= $log_tmax
  ) {
    // adjust start and end of the line
    if( $t_start < $m_begin[$p_begin] ) $t_start = $m_begin[$p_begin];
    if( $p_end < $n_end && $t_end >= $m_end[$p_end] ) {
      $t_end = $m_end[$p_end];
    }
    
    if( $t_start < $log_tmin ) $t_start = $log_tmin;
    if( $t_end > $log_tmin ) {
      if( $t_end > $log_tmax ) $t_end = $log_tmax;
    
      if( isset($_GET['show_rms']) ) {
        $prev_rms = sqrt($rms) / 100.0;

        if(
          $d_rms &&
          ($d_rms * $y_ext) > 1
        ) {
          // draw a (lighter) rectangle to show the delta
          $min_rms = sqrt($rms + $d_rms) / 100.0;
          $max_rms = sqrt($rms - $d_rms) / 100.0;

          imagefilledrectangle($im,
            $x_off + ((($t_start - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * clip($min_rms, 0.0, 1.0)),
            $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * clip($max_rms, 0.0, 1.0)),
            $rms_tcolor
          );
        }
        imageline($im,
          $x_off + ((($t_start - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $prev_rms),
          $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $prev_rms),
          $rms_color
        );
      }

      if(
        $d_b_a &&
        ($d_b_a * $y_ext) > 1
      ) {
        // draw a (lighter) rectangle to show the delta
        imagefilledrectangle($im,
          $x_off + ((($t_start - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * clip($b_a + $d_b_a, 0.0, 1.0)),
          $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * clip($b_a - $d_b_a, 0.0, 1.0)),
          $b_a_tcolor
        );
      }
      imageline($im,
        $x_off + ((($t_start - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
        $x_off + ((($t_end   - $tmin) / $duration) * $x_ext), $y_off - ($y_ext * $b_a),
        $b_a_color
      );
    }
  }

  //
  //  Print additional info
  //
  if( !isset($_GET['hide_info']) ) {
    // discard "doubles" in the $t_cal_start array
    $dt   = (9 * imagefontwidth($infofont) * $duration) / $x_ext;
    $db_a = (4 * imagefontheight($infofont)) / $y_ext;
    for( $i = 1; $i < count($t_cal_start); $i++ ) {
      $j = $i;
      while( --$j >= 0 ) {
        if(
          abs($t_cal_start[$j]['tijd'] - $t_cal_start[$i]['tijd']) < $dt &&
          abs($t_cal_start[$j]['b_a']  - $t_cal_start[$i]['b_a'])  < $db_a
        ) $t_cal_start[$j]['hide'] = TRUE;
      }
    } 
    // get "events"
    $query  = "SELECT id,UNIX_TIMESTAMP(tijd) AS tijd,minor ";
    $query .= "FROM log_zkl ";
    $query .= "WHERE ";
    $query .= "  zkl=" . $_GET['zkl'] . " AND ";
    $query .= "  sdcard=" . $sdcard . " AND ";
    $query .= "  rpgmcount=" . $rpgmcount . " AND ";
    $query .= "  startup=" . $startup . " AND ";
    $query .= "  major=5 AND ";
    $query .= "  (minor=0x11 OR minor=0x23) ";
    $query .= "ORDER BY id";
    $result = mysql_run($query, $db_data_handle);
    // try to match the events with an entry in the array of calibration data
    while( $row = mysql_fetch_assoc($result) ) {
      for( $i = 0; $i < count($t_cal_start); $i++ ) {
        if( $t_cal_start[$i]['tijd'] >= $row['tijd'] && !$t_cal_start[$i]['hide'] ) {
          switch( $row['minor'] ) {
            case 0x23:
              $autocal_query = "SELECT aan_uit,status FROM log_calibratiestart WHERE id=" . $row['id'];
              $autocal_result = mysql_run($autocal_query, $db_data_handle);
              $autocal_row = mysql_fetch_assoc($autocal_result);
              if( $autocal_row['aan_uit'] == 'uit' && $autocal_row['status'] == 'ok' )
                $t_cal_start[$i]['event'] = 'auto-cal';
              break;
            case 0x11:
              $t_cal_start[$i]['event'] = 'sweep';
              break;
          }
          break;
        }
      }
    }
    // plot them in the graph
    foreach( $t_cal_start as $cal_info ) if( !$cal_info['hide'] ) {
      $t_cal = $cal_info['tijd'];
      if( $t_cal < $log_tmin ) $t_cal = $log_tmin;
      if( $t_cal > $log_tmax ) $t_cal = $log_tmax;

      $x = $x_off + ((($t_cal - $tmin) * $x_ext) / $duration);
      $y = $y_off - ($y_ext * $cal_info['b_a']);
      if( $x < $x_off + 9 * imagefontwidth($infofont) ) {
        imageline($im, $x, $y, $x , $y - imagefontwidth($infofont), $cal_info_color);
        imageline($im, $x, $y, $x + imagefontwidth($infofont), $y, $cal_info_color);
        imageline($im, $x, $y, $x + imagefontheight($infofont) * .7, $y - imagefontheight($infofont) * .7, $cal_info_color);
        $x += imagefontheight($infofont);
        $align = ALH_LEFT | ALV_BOTTOM;
      }
      else {
        imageline($im, $x, $y - 1, $x - (imagefontwidth($infofont) >> 1), $y - 1 -(imagefontwidth($infofont) >> 1), $cal_info_color);
        imageline($im, $x, $y - 1, $x + (imagefontwidth($infofont) >> 1), $y - 1 - (imagefontwidth($infofont) >> 1), $cal_info_color);
        imageline($im, $x, $y, $x, $y - imagefontheight($infofont), $cal_info_color);
        $align = ALH_CENTER | ALV_BOTTOM;
      }
      imagestringborderalign($im, $infofont, $x, $y - imagefontheight($infofont), $cal_info['event'] . "\n" . sprintf("b/a=%.3f", $cal_info['b_a']) . "\n" . sprintf("f  =%5.0f", $cal_info['freq']), $cal_info_color, $bgcolor_transp, $align);
    }

    // get relais events
    $query  = "SELECT UNIX_TIMESTAMP(tijd) AS tijd,minor ";
    $query .= "FROM log_zkl ";
    $query .= "WHERE ";
    $query .= "  zkl=" . $_GET['zkl'] . " AND ";
    $query .= "  sdcard=" . $sdcard . " AND ";
    $query .= "  rpgmcount=" . $rpgmcount . " AND ";
    $query .= "  startup=" . $startup . " AND ";
    $query .= "  major=0xD AND ";
    $query .= "  (minor=0x18 OR minor=0x19) ";
    $query .= "ORDER BY id";
    $result = mysql_run($query, $db_data_handle);
    while( $row = mysql_fetch_assoc($result) ) {
      $t_cal = $row['tijd'];
      if( $t_cal < $log_tmin ) $t_cal = $log_tmin;
      if( $t_cal > $log_tmax ) $t_cal = $log_tmax;

      $x = $x_off + ((($t_cal - $tmin) * $x_ext) / $duration);
      $y = $y_off - $y_ext;      // always at the b/a=1.000 line
      imageline($im, $x, $y - 1, $x - (imagefontwidth($infofont) >> 1), $y - 1 -(imagefontwidth($infofont) >> 1), $cal_info_color);
      imageline($im, $x, $y - 1, $x + (imagefontwidth($infofont) >> 1), $y - 1 - (imagefontwidth($infofont) >> 1), $cal_info_color);
      imageline($im, $x, $y, $x, $y - imagefontheight($infofont), $cal_info_color);
      $align = ALH_CENTER | ALV_BOTTOM;
      imagestringborderalign($im, $infofont, $x, $y - imagefontheight($infofont), _("relais") . "\n" . ($row['minor'] == 0x18 ? _("uit") : _("aan")), $cal_info_color, $bgcolor_transp, $align);
    }
  }
}

//
//  Draw the title, on top of everything else
//
if( !isset($_GET['hide_title']) ) {
  imagestringborderalign($im, $labelfont, $width >> 1, 0, sprintf(_("%s - Meting - %s tot %s"), $zkl_info['idcode'], strftime("%c", $tmin), strftime("%c", $tmax)), $gridcolor, $bgcolor_transp, ALV_TOP | ALH_CENTER);
}

//
//  Output the final image
//
imagepng($im);
imagedestroy($im);

?>