package eu.simstadt.nf;

import java.io.StringWriter;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.geotools.geometry.GeneralDirectPosition;
import org.geotools.referencing.CRS;
import org.opengis.geometry.DirectPosition;
import org.opengis.geometry.MismatchedDimensionException;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.NoSuchAuthorityCodeException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.operation.TransformException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * Builds nF import and export jobs using nF's XML job format.
 * 
 * @author Marcel Bruse
 */
public class NFJobBuilder {
	
	/**
	 * This is an intermediate prototype.
	 * 
	 * @param regionPolygon A polygon of geo coordinates which encloses the buildings to be downloaded.
	 * @return Returns a string representation of the nF export job.
	 */
	public static String buildExportJob(List<Coord> regionPolygon) {
		String result = null;
		
		try {
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = factory.newDocumentBuilder();
			
			Document doc = builder.newDocument();
			Element root = doc.createElement("EXPORT_JOB");
			root.setAttribute("version", "1.0.0");
			doc.appendChild(root);
			
			Element job = doc.createElement("job");
			root.appendChild(job);
			
				Element initiator = doc.createElement("initiator");
				initiator.appendChild(doc.createTextNode("2758"));
				job.appendChild(initiator);
				
				Element jobnumber = doc.createElement("jobnumber");
				jobnumber.appendChild(doc.createTextNode("GR_EXPORT_CITYGML_LOD1"));
				job.appendChild(jobnumber);
				
				Element account = doc.createElement("account");
				account.appendChild(doc.createTextNode("Habib"));
				job.appendChild(account);
				
			Element product = doc.createElement("product");
			product.appendChild(doc.createTextNode("LBTEST"));
			root.appendChild(product);
			
			Element layers = doc.createElement("layers");
			layers.setAttribute("color", "0");
			layers.setAttribute("mono", "0");
			layers.setAttribute("plotLabelSrs", "-1");
			layers.setAttribute("plotframe", "0");
			layers.setAttribute("single", "1");
			root.appendChild(layers);
			
				Element layer = doc.createElement("layer");
				layer.setAttribute("name", "GML");
				layer.setAttribute("product", "LBTEST");
				layer.setAttribute("style", "#000000");
				layers.appendChild(layer);
			
			Element srs = doc.createElement("srs");
			srs.appendChild(doc.createTextNode("31467"));
			root.appendChild(srs);
			
			Element extent = doc.createElement("extent");
			extent.setAttribute("merge_mapsheets", "off");
			extent.setAttribute("tile1asgn", "false");
			root.appendChild(extent);
			
				Element polygon = appendRegionPolygon(doc, regionPolygon);
				extent.appendChild(polygon);
				
			Element resolution = doc.createElement("resolution");
			resolution.appendChild(doc.createTextNode("100.0"));
			root.appendChild(resolution);
			
			Element scale = doc.createElement("scale");
			scale.appendChild(doc.createTextNode("10000.0"));
			root.appendChild(scale);
			
			Element format = doc.createElement("format");
			format.setAttribute("alphalinscale", "0.0");
			format.setAttribute("alphascale", "1.0");
			format.setAttribute("citygml_actfunc", "tolod1");
			format.setAttribute("citygml_apptheme", "");
			format.setAttribute("citygml_elemclasses", "true");
			format.setAttribute("citygml_lodmode", "all");
			format.setAttribute("citygml_lods", "1");
			format.setAttribute("citygml_metadata", "true");
			format.setAttribute("citygml_outmode", "normal");
			format.setAttribute("dtm", "false");
			format.setAttribute("foredit", "false");
			format.setAttribute("materialcopymode", "none");
			format.setAttribute("polyopts_reverse", "false");
			format.setAttribute("relcoords", "false");
			format.setAttribute("rooftxr", "false");
			format.setAttribute("roundcoords", "3");
			format.setAttribute("schemetxr", "false");
			format.setAttribute("solar", "false");
			format.setAttribute("solargeoplex", "false");
			format.setAttribute("tex", "false");
			format.setAttribute("tolod1", "true");
			format.setAttribute("tolod1_add", "false");
			format.setAttribute("tolod1_delrest", "false");
			format.setAttribute("tolod1_dstattrabsgrnd", "");
			format.setAttribute("tolod1_dstattrabsheight", "");
			format.setAttribute("tolod1_dstattrrelheight", "");
			format.setAttribute("tolod1_dstattrzmode", "");
			format.setAttribute("tolod1_geommode", "lod1solid");
			format.setAttribute("tolod1_lodsrcmode", "all");
			format.setAttribute("tolod1_triangulate", "false");
			format.setAttribute("tolod1_zroofmode", "mid");
			format.setAttribute("tolod1_zusegenattrs", "");
			format.setAttribute("tolod1_zusemeasuredheight", "false");
			format.setAttribute("xyz", "false");
			format.appendChild(doc.createTextNode("CityGML"));
			root.appendChild(format);
			
			Element exportmetadata = doc.createElement("exportmetadata");
			exportmetadata.setAttribute("calibration", "0");
			exportmetadata.setAttribute("xmetadata", "0");
			exportmetadata.appendChild(doc.createTextNode("1"));
			root.appendChild(exportmetadata);
			
			Element addfile = doc.createElement("addfile");
			addfile.setAttribute("col", "0");
			addfile.setAttribute("eck", "");
			root.appendChild(addfile);
			
			Element usenodatamask = doc.createElement("usenodatamask");
			usenodatamask.appendChild(doc.createTextNode("0"));
			root.appendChild(usenodatamask);
			
			Element usepdctborderpoly = doc.createElement("usepdctborderpoly");
			usepdctborderpoly.appendChild(doc.createTextNode("0"));
			root.appendChild(usepdctborderpoly);
			
			Element dhkresolvereferences = doc.createElement("dhkresolvereferences");
			dhkresolvereferences.appendChild(doc.createTextNode("1"));
			root.appendChild(dhkresolvereferences);
			
			Element zipresult = doc.createElement("zipresult");
			zipresult.appendChild(doc.createTextNode("0"));
			root.appendChild(zipresult);
			
			Element userdescription = doc.createElement("userdescription");
			root.appendChild(userdescription);
			
			Element namingpattern = doc.createElement("namingpattern");
			root.appendChild(namingpattern);
			
			TransformerFactory transformerFactory = TransformerFactory.newInstance();
			Transformer transformer = transformerFactory.newTransformer();
			StringWriter writer = new StringWriter();
			StreamResult streamResult = new StreamResult(writer);
			transformer.transform(new DOMSource(doc), streamResult);
			
			result = writer.toString();
		} catch (ParserConfigurationException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		} catch (TransformerConfigurationException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		} catch (TransformerException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		}
		return result;
	}
	
	/**
	 * Transforms a global WGS 84 position into a coordinate of the given target SRS.
	 *  
	 * @param wgs84Position The WGS 84 position to be transformed to a position within the target SRS.
	 * @param targetCRS The target SRS for the transformation.
	 * @return The transformed target position within the target SRS.
	 */
	public static DirectPosition transformCoordinate(DirectPosition wgs84Position, 
			CoordinateReferenceSystem targetCRS) {
		DirectPosition result = null;
		try {
			CoordinateReferenceSystem sourceCRS = CRS.decode("EPSG:4326"); // WGS 84 (used by Google Maps)
			MathTransform transform = CRS.findMathTransform(sourceCRS, targetCRS, true);
			result = transform.transform(wgs84Position, null);
		} catch (NoSuchAuthorityCodeException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		} catch (FactoryException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		} catch (MismatchedDimensionException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		} catch (TransformException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		}
		return result;
	}
	
	/**
	 * Appends the region polygon to the XML export job document. In order to do this, the given WGS 84 region
	 * polygon will be transformed into a DHDN Gauss-Kruger zone 3 polygon. 
	 * 
	 * @param doc The XML export job document.
	 * @param regionPolygon The polygon of the region which has been selected to be exported.
	 * @return The w3c.dom.Element of the XML export job which describes the region polygon.
	 */
	private static Element appendRegionPolygon(Document doc, List<Coord> regionPolygon) {
		Element polygon = doc.createElement("polygon");
		polygon.setAttribute("srs", "31467");
		try {
			CoordinateReferenceSystem targetCRS	= CRS.decode("EPSG:31467"); // DHDN Gauss-Kruger zone 3
			for (Coord coord : regionPolygon) {
				DirectPosition sourcePosition = new GeneralDirectPosition(coord.latitude, coord.longitude);
				DirectPosition targetPosition = transformCoordinate(sourcePosition, targetCRS);
				
				Element vertex = doc.createElement("vertex");
				vertex.setAttribute("x", String.valueOf(targetPosition.getCoordinate()[1]));
				vertex.setAttribute("y", String.valueOf(targetPosition.getCoordinate()[0]));
				polygon.appendChild(vertex);
			}
		} catch (FactoryException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		}
		return polygon;
	}

}