package wikipedia.stirling;

import java.io.File;
import java.nio.file.InvalidPathException;
import java.nio.file.Paths;
import java.io.IOException;
import java.nio.file.Path;
import java.util.Locale;

import javax.swing.JFileChooser;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
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.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * 
 * The StirlingSvgManipulator takes a specially prepared template SVG file and from that it creates a
 * sequence of animated SVG files explaining a stirling engine. The template SVG was created with the
 * popular Inkscape illustration tool.
 * 
 * StirlingSvgManipulator opens the SVG file a XML based format by using a DOM parser. With DOM specially
 * tagged SVG graphic elements can be searched and manipulated. Mostly the "matrix" attribute from SVG
 * is used to translate and rotate elements. Further corners of a rectangular path are edited to expand
 * and shrink its volume. 
 *
 */

public class StirlingSvgManipulator {
	static final String filename = "stirling";
	static final String template = filename + "_template.svg";
	static final int duration =  4*10; // duration in seconds
	static final int framerate =  30; // frame rate per second
	static final double angularSpeed = 1./10.; // rotations per second

	static final double Length = 350.;
	static final double LengthPiston = 150.;
	static final double Excentricity = 100.;
	static final int OffsetX = 250;
	static final int OffsetY = 250;
	
	/**
	 * @param args
	 * 
	 * Opens a file chooser dialog which requires to select the directory where the template SVG is found
	 * and the resulting SVG files are placed.
	 * 
	 * @throws Exception 
	 */

	public static void main(String[] args) throws Exception {
		long startTime = System.currentTimeMillis();

		Path wspPath = null;
		Path templatePath = null;
		
	    JFileChooser filechooser = new JFileChooser();
	    filechooser.setCurrentDirectory(new java.io.File("."));
	    filechooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
	    filechooser.setAcceptAllFileFilterUsed(false);
	    filechooser.setDialogTitle("Select working directory");
	    int approve = filechooser.showOpenDialog(null);
	    if(approve == JFileChooser.APPROVE_OPTION) {
	    	System.out.println("You chose to open this file: " +
	    			filechooser.getSelectedFile().getAbsolutePath());
	    	Path path = filechooser.getSelectedFile().toPath();
	    	wspPath = Paths.get(path.toString(), "svg");
	    	templatePath = Paths.get(path.toString(), template);
	    	
	    } else {
	    	System.out.println("Execution canceled!");
	    	return;
	    }

		mkdirSvg(wspPath);

		StirlingSvgManipulator template = new StirlingSvgManipulator(templatePath);
		template.load();

		for (int count = 0 ; count <=  (duration * framerate); count++) { // time in seconds
			System.out.println("===============================");
			System.out.println("Iteration: " + String.valueOf(count));
			System.out.println("===============================");
			double time = (double) count / (double) framerate;
			template.setAngle(2. * Math.PI * angularSpeed * time);

			template.applySettings();

			Path destination = Paths.get(wspPath.toString(), filename + "-" + String.format("%04d", count) + ".svg");

			template.save(destination);
		}
		long endTime = System.currentTimeMillis();

		System.out.println("Execution time: " + String.valueOf((endTime-startTime)/1000) + "s");
		System.out.println("Finished");
	}

	public static void mkdirSvg(Path dir) throws IOException {
		boolean success = false;
		File directory = dir.toFile();

		if (directory.exists()) {
			System.out.println("Directory already exists!");
		} else {
			success = directory.mkdir();
			if (success == true) {
				System.out.println("Successful");
			} else {
				throw new IOException("can't make directory for " + dir.toString());
			}
		}

	}

	private Path templatePath = null;
	private Document document = null;
	private double angleRad = 0.;
	private double x;
	private double y;
	private double xStroke;
	private double yStroke;
	private double alpha1; // Angle between conrod and y axis
	private double alpha2; // Angle between conrod and x axis

	/**
	 *
	 * Konstruktor
	 * 
	 * @param templatePath
	 */
	public StirlingSvgManipulator(Path templatePath) {
		// TODO Auto-generated constructor stub
		this.templatePath = templatePath;
	}

	/**
	 * 
	 * Load template with StaXParser
	 * @throws Exception 
	 * 
	 */
	public void load() throws Exception {
		// TODO Auto-generated method stub
		try {
			DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
			DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
			document = docBuilder.parse(templatePath.toFile());

		} catch (IOException | ParserConfigurationException e) {
			System.out.print("Error loading " + templatePath.toString() + "\n");

			e.printStackTrace();
			throw e;
		}

	}

	/**
	 * 
	 * Write XML file with StaXParser
	 * 
	 * @param destination
	 * @throws TransformerException 
	 */
	public void save(Path destination) throws TransformerException {
		try {

			TransformerFactory transFactory = TransformerFactory.newInstance();
			Transformer trans = transFactory.newTransformer();
			trans.setOutputProperty(OutputKeys.INDENT, "yes");
			trans.setOutputProperty(OutputKeys.METHOD, "xml");
			trans.transform(new DOMSource(document), new StreamResult(destination.toFile()));
		} catch (TransformerConfigurationException e) {
			e.printStackTrace();
			throw e;
		} catch (TransformerException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			throw e;
		}
	}

	/**
	 * 
	 * @param rad Angular position for the engine
	 */
	public void setAngle(double rad) {
		angleRad = rad;
	}

	public void applySettings() {

		System.out.println( "calcParameters();");
		calcParameters();
		System.out.println( "applyKolben();");
		applyPiston();
		System.out.println( "applyHeatexchanger();");
		applyHeatexchanger();
		System.out.println( "applyVolumen();");
		applyVolume();

	}

	private void calcParameters() {
		x = Math.cos(angleRad);
		y = Math.sin(angleRad);
		alpha1 = Math.acos(x * Excentricity / Length);
		alpha2 = Math.acos(y * Excentricity / Length);

		xStroke = x * Excentricity + Math.sqrt(Length * Length - (y*Excentricity)*(y*Excentricity)) - Length;
		yStroke = y * Excentricity + Math.sqrt(Length * Length - (x*Excentricity)*(x*Excentricity)) - Length; // Pythagoras
	}

	private void applyVolume() {
		NodeList nodes = document.getElementsByTagName("g");
		System.out.println( "Gefunden: " + Integer.toString(nodes.getLength()) + " groups");
		nodes.item(0);	

		for (int i = 0; i < nodes.getLength(); ++i) {
			Node node = nodes.item(i);
			NamedNodeMap attributes = node.getAttributes();
			Node id = attributes.getNamedItem("id");
			if(id.getNodeValue().equals("gVolume1") == true) {
				NodeList childNodes = node.getChildNodes();
				Node volumen = childNodes.item(1);
				NamedNodeMap childAttributes = volumen.getAttributes();
				Node childId = childAttributes.getNamedItem("id");
				if(childId.getNodeValue().equals("pVolume1") == true) {
					Node d = childAttributes.getNamedItem("d");
					System.out.print("Volume path d: " + d.getNodeValue() + "\n");
					String[] parameters =  d.getNodeValue().split(" ");
					if(parameters.length != 6) {
						throw new NullPointerException(); 
					}
					String[] links = parameters[3].split(",");
					String[] rechts = parameters[4].split(",");

					links[1] = String.format(Locale.US, "%.3f", yStroke);
					rechts[1] = String.format( Locale.US, "%.3f", yStroke);

					parameters[3] = links[0] + "," + links[1];
					parameters[4] = rechts[0] + "," + rechts[1];
					StringBuilder parametersBuild = new StringBuilder();
					for(String parameter : parameters) {
						parametersBuild.append(parameter + " ");
					}
					d.setNodeValue(parametersBuild.toString().trim());
				}
				Node transform = attributes.getNamedItem("transform");
				System.out.print("transform: " + transform.getNodeValue() + "\n");
				String offset = String.format(Locale.US, "%.3f",  (double) OffsetY + Length + LengthPiston);
				String matrix = "translate(" + String.valueOf(OffsetX) + "," + offset + ")";
				System.out.println(matrix);
				transform.setNodeValue(matrix);
			}
			if(id.getNodeValue().equals("gVolume2") == true) {
				NodeList childNodes = node.getChildNodes();
				Node volumen = childNodes.item(1);
				NamedNodeMap childAttributes = volumen.getAttributes();
				Node childId = childAttributes.getNamedItem("id");
				if(childId.getNodeValue().equals("pVolume2") == true) {
					Node d = childAttributes.getNamedItem("d");
					System.out.print("Volume path d: " + d.getNodeValue() + "\n");
					String[] parameters =  d.getNodeValue().split(" ");
					if(parameters.length != 6) {
						throw new NullPointerException(); 
					}
					String[] links = parameters[3].split(",");
					String[] rechts = parameters[4].split(",");

					links[0] = String.format(Locale.US, "%.3f", xStroke);
					rechts[0] = String.format( Locale.US, "%.3f", xStroke);

					parameters[3] = links[0] + "," + links[1];
					parameters[4] = rechts[0] + "," + rechts[1];
					StringBuilder parametersBuild = new StringBuilder();
					for(String parameter : parameters) {
						parametersBuild.append(parameter + " ");
					}
					d.setNodeValue(parametersBuild.toString().trim());
				}
				Node transform = attributes.getNamedItem("transform");
				System.out.print("transform: " + transform.getNodeValue() + "\n");
				String offset = String.format(Locale.US, "%.3f",  (double) OffsetX + Length + LengthPiston);
				String matrix = "translate(" + offset + "," + String.valueOf(OffsetY) + ")";
				System.out.println(matrix);
				transform.setNodeValue(matrix);
			}
		}
	}

	/**
	 * 
	 * applyHeatexchanter()
	 * 
	 * This Drawing is not very precise and just for illustration to get an idea about the state of the heat exchanger.
	 * 
	 */
	private void applyHeatexchanger() {
		NodeList nodes = document.getElementsByTagName("linearGradient");
		System.out.println( "Gefunden: " + Integer.toString(nodes.getLength()) + " linear Gradient(s)");
		nodes.item(0);

		double sum = ( x + -1. * y)/Math.sqrt(2.);
		double pos = 0.5 + 0.4 * sum; // TODO magic numbers
		double delta = 0.1;
		System.out.println("");
		//double sum = 
		// V_1 / V_2
		// V_1 = x_hub
		// V_2 = y_hub

		for (int i = 0; i < nodes.getLength(); i++) {
			Node node = nodes.item(i);
			NamedNodeMap attributes = node.getAttributes();
			Node id = attributes.getNamedItem("id");
			System.out.println("Gradient -ID: " + id.getNodeValue());
			if(id.getNodeValue().equals("linearGradientHeat") == true) {
				NodeList stopNodes = node.getChildNodes();
				System.out.println( "Gefunden: " + Integer.toString(stopNodes.getLength()) + " stop(s)");
				// stopNodes.item(0);
				for (int j = 0; j < stopNodes.getLength(); j++) {
					Node stopNode = stopNodes.item(j);
					if(stopNode.getNodeName().equals("stop") == true) {
						NamedNodeMap stopAttributes = stopNode.getAttributes();
						System.out.println( "Gefunden: " + Integer.toString(stopAttributes.getLength()) + " stop attribut(e)");
						Node stopId = stopAttributes.getNamedItem("id");
						if(stopId.getNodeValue().equals("stopRed") == true) {
							System.out.println("Stop ID: " + stopId.getNodeValue());
							Node offset = stopAttributes.getNamedItem("offset");
							offset.setNodeValue(String.valueOf(pos - delta));
						}
						if(stopId.getNodeValue().equals("stopBlue1") == true) {
							System.out.println("Stop ID: " + stopId.getNodeValue());
							Node offset = stopAttributes.getNamedItem("offset");
							offset.setNodeValue(String.valueOf(pos + delta));    	    			
						}
					}

				}

			}
		}		
	}

	private void applyPiston() {
		NodeList nodes = document.getElementsByTagName("g");
		System.out.println( "Found: " + Integer.toString(nodes.getLength()) + " groups");
		nodes.item(0);

		double alpha_x1 = Math.cos(alpha1);
		double alpha_y1 = Math.sin(alpha1);
		double alpha_x2 = Math.cos(alpha2);
		double alpha_y2 = Math.sin(alpha2);

		System.out.println("alpha: " + String.format(Locale.US, "%.3f, alpha_x: ", alpha1) +
				String.format(Locale.US, "%.3f, alpha_y: ", alpha_x1) + String.format( Locale.US, "%.3f, ", alpha_y1));

		for (int i = 0; i < nodes.getLength(); ++i) {
			Node node = nodes.item(i);
			NamedNodeMap attributes = node.getAttributes();
			Node id = attributes.getNamedItem("id");
			System.out.println("Group-ID: " + id.getNodeValue());
			if(id.getNodeValue().equals("gCrankShaft") == true) {
				Node transform = attributes.getNamedItem("transform");
				System.out.print("transform: " + transform.getNodeValue() + "\n");
				String matrix = "matrix(" + String.valueOf(-1. * y) + "," + String.valueOf(x) +
						"," + String.valueOf(-1. * x) + "," + String.valueOf(-1. * y) + ",0,0)";
				System.out.println(matrix);
				transform.setNodeValue(matrix);
			}
			if(id.getNodeValue().equals("gConrod1") == true) { // Pleuel
				Node transform = attributes.getNamedItem("transform");
				System.out.print("transform: " + transform.getNodeValue() + "\n");
				String matrix = "matrix(" + String.valueOf(alpha_y1) + "," + String.valueOf(alpha_x1) +
						"," + String.valueOf(-1. * alpha_x1) + "," + String.valueOf(alpha_y1) + "," +
						String.valueOf(Excentricity * x) + "," + String.valueOf(Excentricity * y) + ")";
				System.out.println(matrix);
				transform.setNodeValue(matrix);			        
			}
			if(id.getNodeValue().equals("gPiston1") == true) {
				Node transform = attributes.getNamedItem("transform");
				String yMove = String.format(Locale.US, "%.3f", yStroke + Length);
				String translate = "translate(0," + yMove + ")";

				transform.setNodeValue(translate);
			}
			if(id.getNodeValue().equals("gConrod2") == true) { // Pleuel
				Node transform = attributes.getNamedItem("transform");
				System.out.print("transform: " + transform.getNodeValue() + "\n");
				String matrix = "matrix("
						+ String.valueOf(alpha_x2) + "," +  String.valueOf(alpha_y2) +
						"," + String.valueOf(alpha_y2) + "," + String.valueOf(-1. *alpha_x2) + "," +
						String.valueOf(Excentricity * x) + "," + String.valueOf(Excentricity * y) + ")";
				System.out.println(matrix);
				transform.setNodeValue(matrix);			        
			}
			if(id.getNodeValue().equals("gPiston2") == true) {
				Node transform = attributes.getNamedItem("transform");
				String xMove = String.format(Locale.US, "%.3f", xStroke + Length);
				String translate = "translate(" + xMove + ",0)";

				transform.setNodeValue(translate);
			}
			if(id.getNodeValue().equals("gCrankDrive") == true) {
				Node transform = attributes.getNamedItem("transform");
				System.out.print("transform: " + transform.getNodeValue() + "\n");
				String matrix = "translate(" + String.valueOf(OffsetX) + "," + String.valueOf(OffsetY) + ")";
				System.out.println(matrix);
				transform.setNodeValue(matrix);
			}

		}		    
	}

}