<?php
  /**
   * read meter data from SMA device
   * and post it to volkszaehler
   * $Header: /home/wf/smaspot/RCS/sma2vz.php,v 1.6 2014/06/01 10:40:27 wf Exp wf $
   */

// common code for reading and posting
require __DIR__.'/vzapihelper.php';

  /**
   * check the daytime values
   */
  function daytime($latitude,$longitude) {
    $result=array();
    // 08:53 CEST
    // $time_format = 'H:i T';
    // 08:53
    $time_format = 'H:i';

    // find time offset in hours
    $tzoffset = date("Z")/60 / 60;

    $zenith = 90+(50/60); // True sunrise/sunset

    // determine sunrise time
    $sunrise = date_sunrise(time(), SUNFUNCS_RET_STRING, $latitude, $longitude, $zenith, $tzoffset);
    $sunrise_time = date($time_format, strtotime(date("Y-m-d") . ' '. $sunrise));
    // determine sunset time
    $sunset = date_sunset(time(), SUNFUNCS_RET_STRING, $latitude, $longitude, $zenith, $tzoffset);
    $sunset_time = date($time_format, strtotime(date("Y-m-d") . ' '. $sunset));

    // check whether it's daytime
    $sunrise_epoch = date_sunrise(time(), SUNFUNCS_RET_TIMESTAMP, $latitude, $longitude, $zenith, $tzoffset);
    $sunset_epoch  = date_sunset(time(), SUNFUNCS_RET_TIMESTAMP, $latitude, $longitude, $zenith, $tzoffset);
    $time_epoch = time(); // time now

    $result["daytime"]=($time_epoch < $sunset_epoch and $time_epoch > $sunrise_epoch);

    $result["rise"] = $sunrise_time;
    $result["set"] = $sunset_time;
    $result["time"] = date("Y-m-d H:i:s",time());
    return $result;
  } 

  $loop=0;
  // possible command line options
  // --vzurl= --cuuid_pwr= --cuuid_kwh= --daytimeonly
  $longopts=array("vzurl:","cuuid_pwr:","cuuid_kwh:","lat:","lon:","daytimeonly:");
  $shortopts="";
  $options=getopt($shortopts,$longopts);
  // the volkszaehler middleware url
  $vzurl=checkoption("vzurl",$options);
  // channel uuids
  // power (watts)
  $cuuid_pwr=checkoption("cuuid_pwr",$options);
  // energy (kWh)
  $cuuid_kwh=checkoption("cuuid_kwh",$options);
  // daytimeonly? 
  $daytimeonly=checkoption("daytimeonly",$options);
  if ($daytimeonly) {
    $latitude=checkoption("lat",$options);
    $longitude=checkoption("lon",$options);
  }
  
  $jsonlines=file("php://stdin");
  $tmeter=array();
  foreach ($jsonlines as $line_nume => $json) {
    // get the meter reading
    $meter=json_decode($json, true);
    #var_dump($meter);
    foreach ($meter as $name => $value) {
      if (!array_key_exists($name,$tmeter)) 
        $tmeter[$name]=0;
      $tmeter[$name]+=$value;
    }
  }
  #var_dump($tmeter);
  //array(3) { ["etoday"]=> float(2.52)
  // ["etotal"]=> float(6632.462)
  //["totalpac"]=> float(2.478) }
  $etotal=$tmeter["etotal"];
  $totalpac=$tmeter["totalpac"]*1000;
  if ($daytimeonly) {
    $daytime=daytime($latitude,$longitude);
    if (!$daytime["daytime"]) {
      printf("%s after sunset: %s wait for sunrise: %s\n",$daytime["time"],$daytime["set"],$daytime["rise"]);
      exit(2); 
    }
  }
  # total wattage of all inverters
  post2vz($vzurl,$cuuid_pwr,$totalpac);
  # total kwh of all inverters 
  post2vz($vzurl,$cuuid_kwh,$etotal);
  if ($daytimeonly) {
    printf("%s PV: % 5d Watt % 10.3f kwH sun rise:%s set:%s\n",$daytime["time"],$totalpac,$etotal,$daytime["rise"],$daytime["set"]); 
  } else {
    printf("PV Current/Total: %4.0f Watt %.3f kwH\n",$totalpac,$etotal); 
  }
  exit(0);
?>