package eu.simstadt.nf4j;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

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.osgeo.proj4j.BasicCoordinateTransform;
import org.osgeo.proj4j.CRSFactory;
import org.osgeo.proj4j.CoordinateReferenceSystem;
import org.osgeo.proj4j.ProjCoordinate;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * Builds nF import and export jobs using nF's XML job format. Please read the nF manual if you want more
 * details about the numerous job attributes listed below. 
 *  
 * @author Marcel Bruse
 */
public class JobBuilderImpl implements JobBuilder<ImportJobDescriptor, ExportJobDescriptor> {
	
	/** Supported version of the novaFACTORY. */
	public static final String NOVA_FACTORY_VERSION = "6.3.1.1";
	
	/** The version of the XML export job format. */
	public static final String EXPORT_JOB_VERSION = "1.0.0";
	
	@Override
	public String supportsNFVersion() {
		return NOVA_FACTORY_VERSION;
	}

	@Override
	public String supportsExportJobVersion() {
		return EXPORT_JOB_VERSION;
	}

	@Override
	public String supportsImportJobVersion() {
		return null;
	}
	
	/**
	 * This is an intermediate prototype.
	 * 
	 * @param jobDescriptor A job descriptor which describes the export job with all its attributes according to
	 * a valid nF export job DTD.
	 * @return Returns a string representation of the nF export job.
	 */
	@Override
	public File buildExportJobFile(ExportJobDescriptor jobDescriptor) {
		File result = null;
		if (Objects.nonNull(jobDescriptor) && jobDescriptor.isValid()) {
			try {
				DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
				DocumentBuilder builder = factory.newDocumentBuilder();
				
				Document doc = builder.newDocument();
				Element root = doc.createElement("EXPORT_JOB");
				root.setAttribute("version", supportsExportJobVersion());
				doc.appendChild(root);
				
				Element job = doc.createElement("job");
				root.appendChild(job);
				
				Element initiator = doc.createElement("initiator");
				initiator.appendChild(doc.createTextNode(jobDescriptor.getInitiator()));
				job.appendChild(initiator);
				
				Element jobnumber = doc.createElement("jobnumber");
				jobnumber.appendChild(doc.createTextNode(jobDescriptor.getJobnumber()));
				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(jobDescriptor.getProduct()));
				root.appendChild(product);
				
				Element layers = doc.createElement("layers");
				layers.setAttribute("color", jobDescriptor.getColor());
				layers.setAttribute("mono", jobDescriptor.getMono());
				layers.setAttribute("plotLabelSrs", jobDescriptor.getPlotLabelSrs());
				layers.setAttribute("plotframe", jobDescriptor.getPlotframe());
				layers.setAttribute("single", jobDescriptor.getSingle());
				root.appendChild(layers);
				
				appendLayers(doc, layers, jobDescriptor.getLayerList());
				
				Element srs = doc.createElement("srs");
				srs.appendChild(doc.createTextNode(jobDescriptor.getSrs()));
				root.appendChild(srs);
				
				Element extent = doc.createElement("extent");
				extent.setAttribute("merge_mapsheets", jobDescriptor.getMergeMapsheets());
				root.appendChild(extent);
				
				Element polygon = appendRegionPolygon(doc, jobDescriptor.regionPolygon);
				extent.appendChild(polygon);
				
				Element resolution = doc.createElement("resolution");
				resolution.appendChild(doc.createTextNode(jobDescriptor.getResolution()));
				root.appendChild(resolution);
				
				Element scale = doc.createElement("scale");
				scale.appendChild(doc.createTextNode(jobDescriptor.getScale()));
				root.appendChild(scale);
				
				Element format = doc.createElement("format");
				
				// TODO
				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", jobDescriptor.getCalibration());
				exportmetadata.setAttribute("xmetadata", jobDescriptor.getXmetadata());
				exportmetadata.appendChild(doc.createTextNode(jobDescriptor.getExportmetadata()));
				root.appendChild(exportmetadata);
				
				Element addfile = doc.createElement("addfile");
				addfile.setAttribute("col", jobDescriptor.getCol());
				addfile.setAttribute("eck", jobDescriptor.getEck());
				root.appendChild(addfile);
				
				Element usenodatamask = doc.createElement("usenodatamask");
				usenodatamask.appendChild(doc.createTextNode(jobDescriptor.getUsenodatamask()));
				root.appendChild(usenodatamask);
				
				Element usepdctborderpoly = doc.createElement("usepdctborderpoly");
				usepdctborderpoly.appendChild(doc.createTextNode(jobDescriptor.getUsepdctborderpoly()));
				root.appendChild(usepdctborderpoly);
				
				Element dhkresolvereferences = doc.createElement("dhkresolvereferences");
				dhkresolvereferences.appendChild(doc.createTextNode(jobDescriptor.getDhkresolvereferences()));
				root.appendChild(dhkresolvereferences);
				
				Element zipresult = doc.createElement("zipresult");
				zipresult.appendChild(doc.createTextNode(jobDescriptor.getZipresult()));
				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);
				
				File tempfile = File.createTempFile(jobDescriptor.getProduct() + "_", ".xml");
				PrintWriter printWriter = new PrintWriter(tempfile);
				printWriter.print(writer.toString());
				printWriter.close();
				
				return tempfile;
			} 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();
			} catch (FileNotFoundException ex) {
				// TODO Auto-generated catch block
				ex.printStackTrace();
			} catch (IOException ex) {
				// TODO Auto-generated catch block
				ex.printStackTrace();
			}
		}
		return result;
	}
	
	private void appendLayers(Document doc, Element layers,
			ArrayList<Layer> layerList) {
		for (Layer layer : layerList) {
			Element layerElement = doc.createElement("layer");
			layerElement.setAttribute("name", layer.getName());
			String product = layer.getProduct();
			if (Objects.nonNull(product) && !product.isEmpty()) {
				layerElement.setAttribute("product", product);				
			}
			String style = layer.getStyle();
			if (Objects.nonNull(style) && !style.isEmpty()) {
				layerElement.setAttribute("style", style);				
			}
			layers.appendChild(layerElement);		
		}
	}

	/**
	 * 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 ProjCoordinate transformCoordinate(ProjCoordinate wgs84Position, 
			CoordinateReferenceSystem targetCRS) {
		ProjCoordinate result = new ProjCoordinate();
		CRSFactory f = new CRSFactory();
		CoordinateReferenceSystem sourceCRS = f.createFromName(CRSWKT.EPSG_4326.wkt); // WGS 84 (used by Google Maps / OpenStreetMap)
		BasicCoordinateTransform transform = new BasicCoordinateTransform(sourceCRS, targetCRS);
		transform.transform(wgs84Position, result);
		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");
		CRSFactory f = new CRSFactory();
		CoordinateReferenceSystem targetCRS = f.createFromName(CRSWKT.EPSG_31467.wkt); // DHDN Gauss-Kruger zone 3
		for (Coord coord : regionPolygon) {
			ProjCoordinate sourcePosition = new ProjCoordinate(coord.longitude, coord.latitude);
			ProjCoordinate targetPosition = transformCoordinate(sourcePosition, targetCRS);
			Element vertex = doc.createElement("vertex");
			vertex.setAttribute("x", String.valueOf(targetPosition.x));
			vertex.setAttribute("y", String.valueOf(targetPosition.y));
			polygon.appendChild(vertex);
		}
		return polygon;
	}

	/**
	 * Builds a zipped import job file. This file can be sent to a nF server instance by the caller afterwards.
	 * 
	 * @param jobDescriptor A job descriptor which describes the import job with all its attributes according to
	 * a valid nF import job DTD.
	 * @return Returns a XML import job document.
	 */
	@Override
	public File buildImportJobFile(ImportJobDescriptor jobDescriptor) {
		try {
			// Write the nF start file which triggers and controls the processing of the CityGML file.
			String startFilename = jobDescriptor.getProduct() + "_"	+ jobDescriptor.getLeaf() + ".start";
			File startfile = new File(System.getProperty("java.io.tmpdir"), startFilename);
			PrintWriter writer = new PrintWriter(startfile);
			writer.print(jobDescriptor.getLevel());
			writer.close();
			
			// Zip start file and CityGML file
			File zippedCityGMLFile = File.createTempFile("nF_Import_", ".zip");
			ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zippedCityGMLFile));
			File cityGMLFile = jobDescriptor.getCityGMLFile();
			writeBytesToZipFile(new FileInputStream(cityGMLFile), zos, jobDescriptor.getProduct() + "_" 
					+ jobDescriptor.getLeaf() + "_"
					+ jobDescriptor.getLevel() + "_"
					+ jobDescriptor.getOperation() + ".gml");
			writeBytesToZipFile(new FileInputStream(startfile), zos, startFilename);
			zos.close();
			
			return zippedCityGMLFile;
		} catch (FileNotFoundException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		} catch (IOException ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		}
		return null;
	}
	
	/**
	 * Writes a file to the given ZipOutputStream which compresses the file.
	 *  
	 * @param fis The file input stream to be compressed.
	 * @param zos The zip output stream. 
	 * @param zipEntry The new zip entry for the file to be compressed.
	 * @throws IOException You will get some of this, if your streams point to nirvana.
	 */
	private void writeBytesToZipFile(FileInputStream fis, ZipOutputStream zos, String zipEntry) 
			throws IOException {
		zos.putNextEntry(new ZipEntry(zipEntry));
		byte[] b = new byte[1024];
		int chunkSize;
		while ((chunkSize = fis.read(b)) > 0) {
			zos.write(b, 0, chunkSize);
		}
		fis.close();
	}

}