<?php
/* 
 * November 2010
 *
 * Process the planet dump into Gamin tiles that are as large as possible
 * This is essentially a two stage process;
 * 1. Initial split to generate large tiles, some of which might be processed successfully. The ones that don't pass go into the second step.
 * 
 * 2. A recursive process in which:
 * 2a. Split the tile with a diminishing --max-nodes setting until Splitter returns at least two subtiles.
 * 2b. The resulting subtiles can be processed by Mkgmap. If a subtile can't be processed then go back to 2.
 *
 * Initial splitting and other housekeeping stuff is done in function DoIt() while processing is done by the function render() and subsplitting is performed by subsplit().
 * 
  * Please note: This file is a cleaned-up version of my working script. It might not work perfectly right out of the box but it should demonstrate the concept of recursive splitting of an OSM planet file just fine.
*/

doIt();

function doIt() {
	$name = "world";
	$mapid = 63240001;
	$max_nodes = 1200000;
	$planet = "~/planet.openstreetmap.org/planet-latest.osm.bz2";
	$build_dir = "~/garmin/$name/build";
	$cities = "~/garmin/cities15000.zip";

	// Housekeeping
	mkdir($build_dir);
	chdir($build_dir);

	echo "Removing older render attempts\n";
	delTree($build_dir."/render/");

	// Initial split 
	echo "Start initial split\n";
	$split = "java -Xmx6000m -ea -jar ~/garmin/utils/splitter/splitter.jar --no-trim --max-areas=255 --cache=cache --mapid=$mapid --max-nodes=$max_nodes --write-kml=$name.kml --geonames-file=$cities";
	$command = "bunzip2 -c -k $planet | $split";
	echo $command."\n";
	passthru($command);
	
	echo "Removing intermediate files produced by Splitter\n";
	delTree($build_dir."/cache/");

	// The real tile processing work starts here. This is a recursive process
	echo "Find files to process\n";
	$maxid = getMaxSourceId();
	$files = getSourceIds();
	echo "Start rendering.\n";
	foreach($files as $file) {
		echo "Render top level file $file\n";
		$maxid = render($file, $maxid, 0);
	}
	
	// Update the initial KML split result file that lists all the tiles with the actual tiles produced by the recursive splitting process
	// The list of tiles can be useful for further reference but is not necessary for the splitting process.
	updateKml($name);

	echo "Done!\n";
}

/*
 *Recursive functions that renders and subsplits a tile until success (or no solution)
 */
 
// Please note: the Mkgmap configuration parameters have been removed from the commandline for clarity. The full command is listed at the end of this file.
function render($sourceid, $maxid, $level) {
	$mapid = $maxid+1;

	$file = $sourceid.".osm.gz";
	$name = $sourceid.".img";

	$output = passthru("java -Xmx1792M -ea -jar ~/garmin/utils/mkgmap/mkgmap.jar --input-file=$file", $retval);
	if ($retval == 1 || !file_exists($name)) {
		echo "Processing file $file failed ($retval), removing $name\n";
		if (file_exists($name)) {
			unlink($name);
		}
		$level++;
		$maxid = subsplit($sourceid, $maxid, $level);
	}
	return $maxid;
}

// Split a tile into at least two subtiles by gradually reducing the node count 
function subsplit($tileid, $maxid, $level) {
	$mapid = $maxid+1;
	$newtileid = $tileid;

	$cities = "~/garmin/cities15000.zip";
	$nodes = 1200000 - ($level * 100000);

	if ($nodes >= 100000) {
		echo "Splitting $tileid with nodes=$nodes, starting at $mapid. Max id was $maxid, level = $level\n";

		$command = "java -Xmx1792M -jar ~/garmin/utils/splitter/splitter.jar --no-trim --mapid=".$mapid." --max-nodes=".$nodes." --write-kml=".$tileid.".kml --geonames-file=$cities $tileid.osm.gz";
		passthru($command);
		$newtileid = $maxid;

		// Determine the maximum id produced by the split
		$newmaxid = getMaxSourceId();
		
		// require at least two sub files
		if (($newmaxid - $maxid) < 2) {
			echo "The split did not result in at least two subtiles, try again with less nodes per tile\n";
			$level++;
			$newmaxid = subsplit($tileid, $maxid, $level);
		} else {
			// Render the new source files
			$maxid++;
			$tiles = $newmaxid - $maxid;
			for ($i = 0; $i <= $tiles; $i++) {
				echo "Start a new recursive render with $maxid, $newmaxid, $level, $nodes\n";
				$newmaxid = render($maxid, $newmaxid, $level);
				$maxid++;
			}
			echo "Done with subsplit at level $level\n";
		}
	} else {
		echo "Subsplitting passed the minimum node count. Giving up....\n";
		$newmaxid = $maxid;
	}	
	return $newmaxid;
}

// Return the number of the file with the highest filenumber
function getMaxSourceId() {
	$maxid = 0;
	$ids = getSourceIds();
	foreach ($ids as $id) {
		if ($id > $maxid)
			$maxid = $id;
	}
	return $maxid;
}

// Return the available filenumbers
function getSourceIds() {
	$ids = array();
	foreach (glob("*.osm.gz") as $filename) {
		$parts = explode(".", $filename);
		$ids[] = $parts[0];
	}
	return $ids;
}

// Delete a directory tree. Please ensure $dir ends with a slash
function delTree($dir) {
    $files = glob( $dir . '*', GLOB_MARK );
    foreach( $files as $file ){
        if( substr( $file, -1 ) == '/' )
            delTree( $file );
        else
            unlink( $file );
    }
    rmdir( $dir );
} 

/* 
 * Below are some functions to update the list of available tiles from the initial split with the subsplit results
 */
function simplexml_append(SimpleXMLElement $parent, SimpleXMLElement $new_child){
    $node1 = dom_import_simplexml($parent);
    $dom_sxe = dom_import_simplexml($new_child);
    $node2 = $node1->ownerDocument->importNode($dom_sxe, true);
    $node1->appendChild($node2);
} 

function simplexml_replace(SimpleXMLElement $parent, SimpleXMLElement $new_child){
   $node1 = dom_import_simplexml($parent);
   $dom_sxe = dom_import_simplexml($new_child);
   $node2 = $node1->ownerDocument->importNode($dom_sxe, true);
   $node1->parentNode->replaceChild($node2,$node1);
}

function updateKml($name) {
	$kmlRed = "
  <Style id='Red'>
    <LineStyle>
      <color>ffff0000</color>
      <width>1.5</width>
    </LineStyle>
    <PolyStyle>
      <color>7d0000ff</color>
    </PolyStyle>
  </Style>";
	$kmlBlue = "
  <Style id='Blue'>
    <LineStyle>
      <color>ffff0000</color>
      <width>1.5</width>
    </LineStyle>
    <PolyStyle>
      <color>00007dff</color>
    </PolyStyle>
  </Style>";

	// Load the original KML file
	if (file_exists("$name.kml")) {
		$xml = simplexml_load_file("$name.kml");
	} else {
		exit("Failed to open $name.kml.");
	}
	
	// loop through all KML files to update the original KML file
	foreach (glob("*.kml") as $replacement) {
		if (strpos($replacement, $name) === false) {
			$id = explode(".", $replacement);
		
			// Load each new KML file
			$newxml = simplexml_load_file($replacement);
			foreach ($xml->Document->Placemark as $oldPlacemark) {
				if (strpos($oldPlacemark->name, $id[0]) !== false) {
					// This KML file contains subtiles -> delete the tile they replace
				
					$oNode = dom_import_simplexml($oldPlacemark);
					$oNode->parentNode->removeChild($oNode);
					break;
				}
			}
		
			// Add the subtiles
			foreach ($newxml->Document->Placemark as $newPlacemark) {
				simplexml_append($xml->Document, $newPlacemark);
			}
		}
	}

	// Determine which tiles actually exist (update KML rendering)
	$red = simplexml_load_string($kmlRed);
	$blue = simplexml_load_string($kmlBlue);
	simplexml_replace($xml->Document->Style, $red);
	simplexml_append($xml->Document, $blue);
	
	foreach ($xml->Document->Placemark as $tile) {
		$id = $tile->name;
		if (file_exists($id.".img") == true) {
			$tile->styleUrl = "#Blue";
		} else {
			$tile->styleUrl = "#Red";
		}
	}

	// Write out the new version of the KML file
	$fh = fopen("$name.kml.1", "w+");
	if ($fh) {
		fwrite($fh, $xml->asXML());
		fclose($fh);
	}
	// rename original KML file to old
	rename("$name.kml", "$name.kml.old");
	
	// rename new KML file to original
	rename("$name.kml.1", "$name.kml");
}

/* The original Mkgmap commandline from the render() function:
 * $output = passthru("ulimit -t 600 && java -Xmx1792M -ea -jar ~/garmin/utils/mkgmap/mkgmap.jar --adjust-turn-headings --latin1 --name-tag-list=name:en,int_name,name:zh_py,name:engels,name --remove-short-arcs --add-pois-to-areas --make-opposite-cycleways --link-pois-to-ways --route --description='OSM World Routable' --series-name='OSM World Routable' --input-file=$file", $retval);
 */
?>