<?php
// $Id$

/**
 * Google Chart API
 * wrapper module
 **/
//@see README.txt

function _encode($value) {
  if ($value <= -1) {
    return '__';
  }
  else {
    $charTable = 
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-.';
    $secondChar = $value % 64;
    $firstChar = (int)(($value - $secondChar) / 64);
    return ($charTable[$firstChar] . $charTable[$secondChar]);
  }
}

function _is_valid_color_code($color) {
  if (
       ctype_xdigit( (string)$color ) &&
      (strlen( (string)$color ) == 6 || strlen( (string)$color ) == 8)
     ) { //valid colour code
    return true;
  }
  else {
    return false;
  }
}

function _shape_markers($datasetIndex, $valueIndex, $settings) {
  if (
      in_array($settings['shapemarker'][$datasetIndex][$valueIndex],
      array('a','c','d','o','s','v','V','h','x'))
     ) {
    $url_chm .= $settings['shapemarker'][$datasetIndex][$valueIndex];
    if (_is_valid_color_code
        ($settings['shapemarkercolor'][$datasetIndex][$valueIndex])
       ) {
      $url_chm .= ','.$settings['shapemarkercolor'][$datasetIndex][$valueIndex];
    }
    else { //if the colour code is invalid, default it to black
      $url_chm .= ',000000';
    }
    $url_chm .= ',' .$datasetIndex. ',' .$valueIndex;
    if (ctype_digit
        ((string)$settings['shapemarkersize'][$datasetIndex][$valueIndex])
       ) {
      $url_chm .= 
        ',' .$settings['shapemarkersize'][$datasetIndex][$valueIndex]. '|';
    }
    else { //if the size is not a valid number, default it to 10.
      $url_chm .= ',10|';
    }
  }
  return $url_chm;
}

function chart($data, $settings) {
  define('ERROR_INVALID_DATASET', 0x10);
  define('ERROR_INVALID_DATASET_TYPE', 0x11);
  define('ERROR_INVALID_WIDTH', 0x12);
  define('ERROR_INVALID_HEIGHT', 0x13);
  define('ERROR_INVALID_TYPE', 0x14);
  define('ERROR_CHART_TOO_LARGE', 0x15);

  // validate the datasets
  $float = false;
  while ((list(, $val1) = each($data)) && ($float == false)) {
    if (is_array($val1)) { // multiple data sets
      while ((list(, $val2) = each($val1)) && ($float == false)) {
        if (!is_array($val2)) {
          if (is_numeric($val2)) {
            if (is_float($val2)) {
              $float = true;
            }
          }
          else { // $val2 is not numeric
            return ERROR_INVALID_DATASET_TYPE;
          }
        }
        else { // $val2 is an array
          return ERROR_INVALID_DATASET;
        }
      }
    }
    else { // single data set
      if (is_numeric($val1)) {
        if (is_float($val1)) {
          $float = true;
        }
      }
      else { // $val1 is not numeric
        return ERROR_INVALID_DATASET_TYPE;
      }
    }
  }

  // validate the settings
  if (!ctype_digit( (string) $settings['width'] )) { //invalid width
  //use ctype_digit() instead of is_int() in case of form input
    return ERROR_INVALID_WIDTH;
  }
  if (!ctype_digit( (string) $settings['height'] )) { //invalid height
  //use ctype_digit() instead of is_int() in case of form input
    return ERROR_INVALID_HEIGHT;
  }
  if (!in_array($settings['type'],
        array('lc','lxy','bhs','bvs','bhg','bvg','p','p3','v','s'))
     ) {
    return ERROR_INVALID_TYPE;
  }
  if (($settings['width'] * $settings['height']) >= 300000) { //chart too large
    return ERROR_CHART_TOO_LARGE;
  }


  $url = 'http://chart.apis.google.com/chart?'
    .'chs=' .$settings['width']. 'x' .$settings['height']
    .'&amp;cht=' .$settings['type']
    .'&amp;chd=e:';

  if ($settings['type'] == 'lc') { // for a normal line chart
    // quickly go through to find the maximum value to calculate the divider
    $i = 0;
    foreach ($data as $val1) {
      if (is_array($val1)) {
        $maxVal[$i] = max($val1);
        ++$i;
      }
      else {
        $maxVal[0] = $val1;
      }
    }
    if ($float) {
      $divider = 4095 / (max($maxVal) * 10);
    }
    else {
      $divider = 4095 / max($maxVal);
    }
  }

  foreach ($data as $val1Index => $val1) {
    if (is_array($val1)) { // multiple data sets
      $single_data_set = false; ///< used when filling area under the graph
      if ($settings['type'] != 'lc') { //for any other chart, calculate the
        $divider = 4095 / max($val1);  //divider here.
      }
      foreach ($val1 as $val2Index => $val2) { //no need to check if it's an 
        if ($float) {                          //array again
          $url .= _encode( (int)($val2 * 10 * $divider) );
        }
        else {
          $url .= _encode( (int)($val2 * $divider) );
        }
        // shape markers
        $url_chm .= _shape_markers($val1Index, $val2Index, $settings);
      }
      $url .= ',';
    }
    else { // single data set
      $single_data_set = true;
      $divider = 4095 / max($data);
      if ($float) {
        $url .= _encode( (int)($val1 * 10 * $divider) );
      }
      else {
        $url .= _encode( (int)($val1 * $divider) );
      }
      // shape markers
      $url_chm .= _shape_markers(0, $val1Index, $settings);
    }
  }
  $markers_defined = false;
  if ($url_chm != '') {
    $url .= '&amp;chm=' .rtrim($url_chm, '|');
    $markers_defined = true;
  }

  // range markers
  if ((is_array($settings['range']['direction'])) &&
      (is_array($settings['range']['start'])) &&
     (is_array($settings['range']['end']))) { //only if all these settings are 
    $url_chm = '';                            //defined
    foreach ($settings['range']['direction'] as $key => $dir) {
      switch ($dir) {
        case 'v': //vertical
          $url_chm_dir = 'R';
          break;
        case 'h': //horizontal
          $url_chm_dir = 'r';
          break;
      }
      if (_is_valid_color_code($settings['range']['color'][$key])) {
        $url_chm_color = $settings['range']['color'][$key];
      }
      else { //if this is not a valid colour, make it light blue
        $url_chm_color = 'eeeeff';
      }
      $url_chm .= $url_chm_dir. ','
                 .$url_chm_color. ',0,'
                 .$settings['range']['start'][$key]. ','
                 .$settings['range']['end'][$key]. '|';
    }
    if ($url_chm != '') {
      if (!$markers_defined) {
        $url .= '&amp;chm=';
      }
      else {
        $url .= '|';
      }
      $url .= rtrim($url_chm, '|');
      $markers_defined = true;
    }
  }

  // fill area
  $url_chm = '';
  if ($single_data_set) {
    if (_is_valid_color_code($settings['fill'])) {
      $url_chm = 'B,' .$settings['fill']. ',0,0,0|';
    }
  }
  else {
    if (is_array($settings['fill'])) {
      foreach($settings['fill'] as $top => $topVal) {
        foreach($topVal as $bottom => $color) {
          if (_is_valid_color_code($color)) {
            $url_chm .= 'b,' .$color. ',' .$top. ',' .$bottom. ',0|';
          }
        }
      }
    }
  }
  if ($url_chm != '') {
    if (!$markers_defined) {
      $url .= '&amp;chm=';
    }
    else {
      $url .= '|';
    }
    $url .= rtrim($url_chm, '|');
    $markers_defined = true;
  }

  if (isset($settings['barwidth'])) {
    $url .= '&amp;chbh=' .$settings['barwidth'];
    if (isset($settings['barspace'])) {
      $url .= ',' .$settings['barspace'];
    }
  }

  // data set colours
  if (isset($settings['datasetcolor'])) { // are codes defined at all?
    if (is_array($settings['datasetcolor'])) { // codes for several sets
      $url .= '&amp;chco=';
      $i = 0;
      foreach($settings['datasetcolor'] as $key => $color) {
        if (_is_valid_color_code($color)) {
          if ($key != $i) {           //if a colour declaration was omitted, a
            for (; $i < $key; ++$i) { //nice orange will be defaulted for each
              $url .= 'ff9900,';      //of the omitted sets
            }
            $i = $key;
          }
          $url .= $color. ','; //append the current colour
          ++$i;
        }
      }
    }
  }
  $url = rtrim($url, ',');

  // data set line styles
  if (isset($settings['datasetstyle'])) {
    if (is_array($settings['datasetstyle'])) {
      $i = 0;
      foreach ($settings['datasetstyle'] as $key => $style) {
        if ($key != $i) { //if a declaration was omited, go for some defaults
          for (; $i < $key; ++$i) { //for each of the omitted sets
            $url_chls .= '1.5,1,0|';
          }
          $i = $key;
        }
        if (!isset($style['thick'])) {
          $url_chls .= '1.5';
        }
        else {
          $url_chls .= $style['thick'];
        }
        if (!isset($style['line'])) {
          $url_chls .= ',1';
        }
        else {
          $url_chls .= ','.$style['line'];
        }
        if (!isset($style['blank'])) {
          $url_chls .= ',0';
        }
        else {
          $url_chls .= ','.$style['blank'];
        }
        $url_chls .= '|';
        ++$i;
      }
      $url .= '&amp;chls=' .rtrim($url_chls, '|');
    }
  }

  // chart and background fill
  $declared = false;
  for ($counter = 0; $counter <= 1; ++$counter) {
    switch ($counter) {
      case 0:
        $bgOrCFull  = 'background';
        $bgOrCShort = 'bg';
        break;
      case 1:
        $bgOrCFull  = 'chart';
        $bgOrCShort = 'c';
        break;
    }
    $success = false; ///< stores whether at least one colour was added
    if ($settings[$bgOrCFull. 'filltype'] == 's') { // solid fill
      if (_is_valid_color_code($settings[$bgOrCFull. 'fillcolor'])) {
        $url_add .= 's,'.$settings[$bgOrCFull. 'fillcolor'];
        $success = true;
      }
    }
    elseif ($settings[$bgOrCFull. 'filltype'] == 'lg') { // linear gradient fill
      $url_add = 'lg,';
      if ( (0 <= (int)$settings[$bgOrCFull. 'fillangle']) &&
           ((int)$settings[$bgOrCFull. 'fillangle'] <= 90)) {//is angle 0 - 90?
        $url_add .= $settings[$bgOrCFull. 'fillangle'];
        if (is_array($settings[$bgOrCFull. 'fillcolor'])) { //array of colours
          $i = 0;
          foreach ($settings[$bgOrCFull. 'fillcolor'] as $color) {
            if (_is_valid_color_code($color)) {
              if ( (isset($settings[$bgOrCFull. 'filloffset'][$i])) &&
                  (0 <= (float)$settings[$bgOrCFull. 'filloffset'][$i]) &&
                  ((float)$settings[$bgOrCFull. 'filloffset'][$i] <= 1)) {
                $url_add .= ',' .$color. ',' .$settings[$bgOrCFull. 'filloffset'][$i];
                $success = true; // a colour was added
              }
            }
            ++$i;
          }
        }
      }
    }
    elseif ($settings[$bgOrCFull. 'filltype'] == 'ls') { // linear stripes fill
      $url_add = 'ls,';
      if ( (0 <= (int)$settings[$bgOrCFull. 'fillangle']) &&
           ((int)$settings[$bgOrCFull. 'fillangle'] <= 90)) {//is angle 0 - 90?
        $url_add .= $settings[$bgOrCFull. 'fillangle'];
        if (is_array($settings[$bgOrCFull. 'fillcolor'])) { //array of colours
          $i = 0;
          foreach ($settings[$bgOrCFull. 'fillcolor'] as $color) {
            if (_is_valid_color_code($color)) {
              if ( (isset($settings[$bgOrCFull. 'fillwidth'][$i])) &&
                  (0 <= (float)$settings[$bgOrCFull. 'fillwidth'][$i]) &&
                  ((float)$settings[$bgOrCFull. 'fillwidth'][$i] <= 1)) {
                $url_add .= ',' .$color. ','
                            .$settings[$bgOrCFull. 'fillwidth'][$i];
                $success = true; // a colour was added
              }
            }
            ++$i;
          }
        }
      }
    }
    if ($success) { //if at least one colour was added
      if ($declared) { //if a previous (eg. background) definition was there
        $url .= '|' .$bgOrCShort. ','.$url_add; //we can add it to the final url
      }
      else {
        $url .= '&amp;chf=' .$bgOrCShort. ',' .$url_add;
        $declared = true;
      }
    }
  }

  // labels
  // chart title
  if (isset($settings['title'])) {
    $url .= '&amp;chtt='
            .preg_replace("/\\%0D\\%0A|\\%0A|\\%0D/", '|',
            urlencode($settings['title']));
    $colorDefined = false; //useful if only size is set
    if (_is_valid_color_code($settings['titlecolor'])) {
      $colorDefined = true;
      $url .= '&amp;chts=' .$settings['titlecolor'];
    }
    if (ctype_digit($settings['titlesize'])) {
      if ($colorDefined) {
        $url .= ',' .$settings['titlesize'];
      }
      else {
        $url .= '&amp;chts=000000,' .$settings['titlesize'];
      }
    }
  }
  // legend/pie chart labels
  if (is_array($settings['label'])) {
    $url .= '&amp;';
    if (($settings['type'] == 'p') || ($settings['type'] == 'p3')) {
      $url .= 'chl=';
    }
    else {
      $url .= 'chdl=';
    }
    foreach ($settings['label'] as $key => $label) {
      $url .= $label;
      if (count($settings['label']) > ($key + 1)) {
        $url .= '|';
      }
    }
  }
  // axis labels
  if (is_array($settings['axis'])) {
    $url_chxt = '';
    $url_chxl = '';
    $url_chxp = '';
    $url_chxr = '';
    $url_chxs = '';
    $i = 0;
    foreach ($settings['axis'] as $axis => $values) {
      if ( ($axis == 'x') ||
           ($axis == 't') ||
           ($axis == 'y') ||
          ($axis == 'r') ) {
        if (is_array($values)) {
          foreach ($values as $key => $value) {
            $url_chxt .= $axis;
            $url_chxt .= ',';
            if (isset($value)) {
              $url_chxl .= $i. ':|';
              if (is_array($value)) {
                $url_chxl .= implode('|', $value). '|';
                if (isset($settings['axisposition'][$axis][$key])) {
                  $url_chxp .= $i. ',';
                  if (is_array($settings['axisposition'][$axis][$key])) {
                    $url_chxp .=
                            implode(',', $settings['axisposition'][$axis][$key])
                            . '|';
                  }
                  else {
                    $url_chxp .= $settings['axisposition'][$axis][$key]. '|';
                  }
                }
              }
              else {
                $url_chxl .= $value. '|';
                if (isset($settings['axisposition'][$axis][$key])) {
                  $url_chxp .= $i. ',';
                  $url_chxp .= $settings['axisposition'][$axis][$key]. '|';
                }
              }
              if ((isset($settings['axisrange'][$axis][$key]['start'])) &&
                  (isset($settings['axisrange'][$axis][$key]['end']))) {
                $url_chxr .= $i. ','
                             .$settings['axisrange'][$axis][$key]['start']. ','
                             .$settings['axisrange'][$axis][$key]['end']. '|';
              }
              $url_chxs_color = $settings['axiscolor'][$axis][$key];
              $url_chxs_size  = $settings['axissize'][$axis][$key];
              switch ($settings['axisalign'][$axis][$key]) {
                case 'l':
                  $url_chxs_align = '-1';
                  break;
                case 'c':
                  $url_chxs_align = '0';
                  break;
                case 'r':
                  $url_chxs_align = '1';
                  break;
              }

              if (!isset($url_chxs_color)) { //if the colour is not set
                $url_chxs_color = '666666'; //default it to grey
              }
              if (!isset($url_chxs_size)) { //if the size is not set
                $url_chxs_size = '11.5';   //default it to 11.5
              }
              $url_chxs_ = $i. ',' .$url_chxs_color. ',' .$url_chxs_size;
              if (!isset($url_chxs_align)) { //if the alignment is not present
                $url_chxs_ .= '|';          //just omit the unneeded declaration
              }
              else {
                $url_chxs_ .= ',' .$url_chxs_align .'|';
              }
              if ($url_chxs_ != ($i .',666666,11.5|')) { //if it's not just all 
                $url_chxs .= $url_chxs_;    //defaults then append it to the url
              }
              ++$i;
            }
          }
        }
      }
    }
    if ($url_chxt != '') {
      $url .= '&amp;chxt=' .rtrim($url_chxt, ',');
    }
    if ($url_chxl != '') {
      $url .= '&amp;chxl=' .rtrim($url_chxl, '|');
    }
    if ($url_chxp != '') {
      $url .= '&amp;chxp=' .rtrim($url_chxp, '|');
    }
    if ($url_chxr != '') {
      $url .= '&amp;chxr=' .rtrim($url_chxr, '|');
    }
    if ($url_chxs != '') {
      $url .= '&amp;chxs=' .rtrim($url_chxs, '|');
    }
  }

  // grid lines
  if (is_array($settings['grid'])) {
    if (isset($settings['grid']['xstep'])) {
      $url .= '&amp;chg=' .$settings['grid']['xstep'];
    }
    else { //if xstep is not defined, make every 1st level label of x axis where
      if (isset($settings['axis']['x'][0])) { //the gridlines appear
        $count = count($settings['axis']['x'][0]) - 1;
        if ($count == 0) { //if there is only one label on x axis
          $count = 10000; //make 100/count very small so it is rounded up to 0.
        }  
        $url .= '&amp;chg=' .number_format(100 / $count, 1, '.', '');
      }
      else { //if that also fails, make no x-axis gridlines whatsoever
        $url .= '&amp;chg=100';
      }
    }
    if (isset($settings['grid']['ystep'])) {
      $url .= ',' .$settings['grid']['ystep'];
    }
    else { //if ystep is not defined, make every 1st level label of y axis where
      if (isset($settings['axis']['y'][0])) { //the gridlines appear
        $count = count($settings['axis']['y'][0]) - 1;
        if ($count == 0) { //if there is only one label on x axis
          $count = 10000; //make 100/count very small so it is rounded up to 0.
        }
        $url .= ',' .number_format(100 / $count, 1, '.', '');
      }
      else { //if that also fails, make no y-axis gridlines whatsoever
        $url .= ',100';
      }
    }
    $grid_defined = true;
  }
  // grid line style
  if (is_array($settings['gridstyle'])) {
    if ($grid_defined) { //don't bother if there are no grids defined
      if ( (isset($settings['gridstyle']['line'])) &&  //only add if all of the
           (isset($settings['gridstyle']['blank'])) ) { // settings are present
        $url .= ',' .$settings['gridstyle']['line']. ',' .$settings['gridstyle']['blank'];
      }
    }
  }

  //return the whole resultant url.
  return $url;
}
?>