<?



define('bg_color',    0xffffff);
define('dot_color',   0xff0000);
define('prec_color',  0xc0c0c0);
define('max_color',   0x0000ff);
define('grid_color',  0xcccccc);
define('label_color', 0xcccccc);

require_once('const.inc.php');
require_once('lib.inc.php');
require_once('timelib.inc.php');
require_once('mysql_requester_class.inc.php');
$sql = new mysql_requester();

$width  = isset($_GET['w']) && is_numeric($_GET['w']) ? $_GET['w'] : 800;
$height = isset($_GET['h']) && is_numeric($_GET['h']) ? $_GET['h'] : 600;

$oid = isset($_GET['oid']) && is_numeric($_GET['oid']) ? (int)$_GET['oid'] : 0;

$data = $sql->get("SELECT * FROM mutual_phenomena_data WHERE obs_id=$oid ORDER BY dt, ms");
$obs  = $sql->get_record(0, "SELECT * FROM mutual_phenomena_obs WHERE id=$oid LIMIT 1");

$img = imagecreatetruecolor($width, $height);
imagefill($img, 0, 0, bg_color);

if (!$data || !$obs)
{
  imagestring($img, 5, 10, 10, "No valid data for observation ID $oid", 0xFF0000);
  
  header('Content-type: image/png');
  imagepng($img);

  die;
};


$cnt = count($data);

$jd_min = $data[0]['jd'];
$jd_max = $data[$cnt-1]['jd'];
$jd_len = $jd_max - $jd_min;

$rm_min = $rm_max = $data[0]['rel_mag'];

foreach($data as $p)
{
  if ($rm_max < $p['rel_mag']) $rm_max = $p['rel_mag'];
  if ($rm_min > $p['rel_mag']) $rm_min = $p['rel_mag'];
};
$rm_len = $rm_max - $rm_min;



$img = imagecreatetruecolor($width, $height);
imagefill($img, 0, 0, bg_color);

function jd2x($jd)
{
  global $width, $jd_min, $jd_len;
  return round(50 + ($width-60) * ($jd - $jd_min)/$jd_len);
};

function mag2y($mag)
{
  global $rm_min, $rm_len, $height;
  return round(30 + ($height-60) * ($mag - $rm_min)/$rm_len);
};


// обсчет координатной сетки
$ut = strtotime(substr($data[0]['dt'], 0, 16).' GMT');
$mins = $jd_len*24*60;
if     ($mins > 60) $step = 15;
elseif ($mins > 30) $step = 10;
elseif ($mins > 10) $step = 5;
elseif ($mins >  5) $step = 2;
else                $step = 1;
$step *= 60;
while(true)
{
  $jd = datetime_to_jd('UT'.$ut);
  if ($jd >= $jd_max) break;
  $dt = gmdate('H:i', $ut);
  $x = jd2x($jd);
  imageline($img, $x, 0, $x, $height, grid_color);
  imagestring($img, 4, $x-18, $height-16, $dt, label_color);
  $ut += $step;
};

$step = 1;
$i = 0;
while(($rm_len*100 / $step) > 10)
{
  $step *= ($i%2) ? 5 : 2;
  $i++;
};
$step = $step / 100;

$rm = floor($rm_min/$step)*$step;
while($rm <= $rm_max)
{
  $rm = round($rm, 4);
  $y = mag2y($rm);
  imageline($img, 0, $y, $width, $y, grid_color);
  imagestring($img, 4, 0, $y, $rm, label_color);
  $rm += $step;
};



$dy = mag2y($obs['sigma_mag']) - mag2y(0);

foreach($data as $p)
{
  $x  = jd2x($p['jd']);
  $y  = mag2y($p['rel_mag']);
  //imageline($img, $x, $y-$dy/2, $x, $y+$dy/2, prec_color);
  imagefilledellipse($img, $x, $y, 3, 3, dot_color);
};
$x  = jd2x($obs['jd']);
imageline($img, $x, 0, $x, $height, max_color);
imagestring($img, 4, $x+10, 0, 'JD: '.$obs['jd'], max_color);

/*
$y = mag2y($rm_min);
imageline($img, 0, $y, $width, $y, prec_color);
imagestring($img, 4, 0, $y-15, "$rm_min mag", prec_color);

$y = mag2y($rm_max);
imageline($img, 0, $y, $width, $y, prec_color);
imagestring($img, 4, 0, $y, "$rm_max mag", prec_color);
*/


header('Content-type: image/png');
imagepng($img);