<?php

// gets coordinates and returns an array of lon/lat coordinate pairs, e.g.
// 47.12 N 11.87 E
// 47.13 N 11.70 E
// ->
// array(array(11.87, 47.12), array(11.70, 47.13))
function geo_to_coordinates($input) {
	$matches = array();
	$num_matches = preg_match_all('/\s*(\d+\.?\d*)\s*N?\s+(\d+\.?\d*)\s*E?\s*/', $input, $matches);
	$result = array();
	for ($i=0; $i!=$num_matches; ++$i) {
		$result[] = array(floatval($matches[2][$i]), floatval($matches[1][$i]));
	}
	if (implode($matches[0]) != $input) throw new Exception('Falsches Koordinatenformat: ' . $input);
	return $result;
}


// convert sledruns to geojson (http://www.geojson.org/geojson-spec.html)
// Returns an array of features
function sledruns_to_json_features() {
	$json_features = array(); // result
	$dbr = wfGetDB(DB_SLAVE);
	$res = $dbr->select(array('wrsledruncache', 'wrreportcache'), array('wrsledruncache.page_title', 'position_latitude', 'position_longitude', 'date_report', '`condition`'), array('show_in_overview', 'not under_construction'), __METHOD__, array(), array('wrreportcache' => array('left outer join', 'wrsledruncache.page_id=wrreportcache.page_id')));
	while ($sledrun = $dbr->fetchRow($res)) {
		$lat = $sledrun['position_latitude'];
		$lon = $sledrun['position_longitude'];
		if (is_null($lat) || is_null($lon)) continue;
		$lat = floatval($lat);
		$lon = floatval($lon);
		$title = Title::newFromText($sledrun['page_title']);
		$properties = array('type' => 'sledrun', 'name' => $title->getText(), 'wiki' => $title->getLocalUrl());
		if (!is_null($sledrun['date_report'])) $properties[] = $sledrun['date_report'];
		if (!is_null($sledrun['condition'])) $properties[] = intval($sledrun['condition']);
		$json_feature = array(
			'type' => 'feature',
			'geometry' => array(
				'type' => 'Point',
				'coordinates' => array($lon, $lat)
			),
			'properties' => $properties
		);
		$json_features[] = $json_feature;
	}
	$dbr->freeResult($res);
	return $json_features;
}


// convert XML to geojson (http://www.geojson.org/geojson-spec.html)
// Returns an array of features
function xml_to_json_features($input) {
	libxml_use_internal_errors(true); // without that, we get PHP Warnings if the $input is not well-formed
	$xml = new SimpleXMLElement($input); // input
	$json_features = array(); // output
	$point_type = array('gasthaus' => 'inn', 'haltestelle' => 'busstop', 'parkplatz' => 'carpark', 'achtung' => 'attention', 'punkt' => 'point');
	$line_type = array('rodelbahn' => 'sledrun', 'gehweg' => 'walk', 'alternative' => 'alternative', 'lift' => 'lift', 'linie' => 'line'); # TODO: anfahrt
	foreach ($xml as $feature) {
		$given_properties = array();
		foreach ($feature->attributes() as $key => $value) $given_properties[] = $key;

		// determine feature type
		$is_point = in_array($feature->getName(), array_keys($point_type));
		$is_line = in_array($feature->getName(), array_keys($line_type));
		if (!$is_point && !$is_line) {
			throw new Exception('Unbekanntes Element <' . $feature->getName() . '>. Erlaubt sind: <' . implode('>, <', array_keys(array_merge($point_type, $line_type))) . '>.');
		}

		// point
		if ($is_point) {
			$properties = array('type' => $point_type[$feature->getName()]);
			$allowed_properties = array('name', 'wiki');
			$wrong_properties = array_diff($given_properties, $allowed_properties);
			if (count($wrong_properties) > 0) throw new Exception("Das Attribut '" . reset($wrong_properties) . "' ist nicht erlaubt bei <" . $feature->getName() . ">. Erlaubt sind: '" . implode("', '", $allowed_properties) . "'.");
			foreach ($given_properties as $property) {
				$properties[$property] = (string) $feature[$property];
			}
			$coordinates = geo_to_coordinates($feature);
			if (count($coordinates) != 1) throw new Exception('Das Element <' . $feature->getName() . '> muss genau ein Koordinatenpaar haben.');
			$json_feature = array(
				'type' => 'feature',
				'geometry' => array(
					'type' => 'Point',
					'coordinates' => reset($coordinates)
				),
				'properties' => $properties
			);
			$json_features[] = $json_feature;
		}
		// line
		if ($is_line) {
			$properties = array('type' => $line_type[$feature->getName()]);
			$allowed_properties = array('farbe', 'dicke');
			$wrong_properties = array_diff($given_properties, $allowed_properties);
			if (count($wrong_properties) > 0) throw new Exception("Das Attribut '" . reset($wrong_properties) . "' ist nicht erlaubt bei <" . $feature->getName() . ">. Erlaubt sind: '" . implode("', '", $allowed_properties) . "'.");
			if (isset($feature['farbe'])) $properties['strokeColor'] = (string) $feature['farbe']; // e.g. #a200b7 // TODO: Check
			if (isset($feature['dicke'])) $properties['strokeWidth'] = (int) $feature['dicke']; // e.g. 6 // TODO: Check
			$json_feature = array(
				'type' => 'feature',
				'geometry' => array(
					'type' => 'LineString',
					'coordinates' => geo_to_coordinates($feature)
				),
				'properties' => $properties
			);
			$json_features[] = $json_feature;
		}
	}
	return $json_features;
}


class WrBaseMap {
	/// Renders the <wrgmap> tag and the <wrmap> tag.
	/// This class would be the only class needed but as the function render() toes not provide an argument
	/// telling which tag name called the function, a trick with two inherited classes has to be used.
	/// @param $content string - the content of the <wrgmap> tag
	/// @param $args array - the array of attribute name/value pairs for the tag
	/// @param $parser Parser - the MW Parser object for the current page
	///
	/// @return string - the html for rendering the map
	public static function render($content, $args, $parser, $frame) {
		// Unfortunately, $tagname is no argument of this function, therefore we have to use a trick with derived classes.
		$tagname = strtolower(get_called_class()); // either wrmap or wrgmap
		assert(in_array($tagname, array('wrmap', 'wrgmap')));

		// Get center and zoom level from $args // TODO: What happens if the values are no correct e.g. float?
		if (isset($args['lat'])) $latitude = floatval($args['lat']); else $latitude = 47.267648;   // latitude as float value
		if (isset($args['lon'])) $longitude = floatval($args['lon']); else $longitude = 11.404655; // longitude as float value
		if (isset($args['zoom'])) $zoom = intval($args['zoom']); else $zoom = 10; // Google Zoom Level
		if (isset($args['width'])) $width = intval($args['width']); else $width = null; // null corresponds to 100%
		if (isset($args['height'])) $height = intval($args['height']); else $height = 450;
		$latitude_s = sprintf('%.6F', $latitude);
		$longitude_s = sprintf('%.6F', $longitude);
		$width_s = is_null($width) ? '100%' : $width . 'px';
		$height_s = $height . 'px';
		$show_sledruns = ($tagname == 'wrgmap');

		$parserOutput = $parser->getOutput();
		$parserOutput->addHeadItem('<script type="text/javascript" src="http://maps.google.com/maps/api/js?v=3.8&amp;sensor=false"></script>', 'googlemaps');
		$parserOutput->addModules('ext.wrmap');
		
		$json_features = array();

		// append all sledruns as icon
		if ($show_sledruns) {
			$json_features = array_merge($json_features, sledruns_to_json_features());
		}

		// append all elements in the XML
		try {
			$json_features = array_merge($json_features, xml_to_json_features('<wrmap>' . $content . '</wrmap>'));
		} catch (Exception $e) {
			return '<div class="error">' . htmlspecialchars("Fehler beim Parsen der Landkarte: " . $e->getMessage()) . '</div>';
		}

		// create final geojson
		$json = array(
			'type' => 'FeatureCollection',
			'features' => $json_features
		);
		$json_string = json_encode($json);

		// Create <div/> element where the map is placed in
		global $wgExtensionAssetsPath;
		$output = "<div class=\"wrmap\" style=\"width: $width_s; height: $height_s; border-style:none;\" data-center-lon=\"$longitude_s\" data-center-lat=\"$latitude_s\" data-zoom=\"$zoom\" data-img-path=\"$wgExtensionAssetsPath/wrmap/openlayers/img/\">";
		$output .= "<script type=\"application/json\">";
		$output .= htmlspecialchars($json_string, ENT_NOQUOTES);
		$output .= "</script>";
		$output .= "</div>\n";
		
		return $output;
	}
}


// <wrmap> tag
class WrMap extends WrBaseMap {
}


// <wrgmap> tag
class WrGMap extends WrBaseMap {
}

?>