package org.apache.tuscany.sca.impl.layout;

import java.util.ArrayList;

import org.apache.tuscany.sca.impl.artifacts.Component;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class EntityBuilder {
	
	private Document dom;
	private final int initPoint = 100;
	private final int spaceX = Component.DEFAULT_WIDTH*2;
	private final int spaceY = Component.DEFAULT_HEIGHT*2;
	private ArrayList<Integer> levelCount = new ArrayList<Integer>();
	
	public EntityBuilder(Document aDom){
		dom = aDom;
	}
	
	public Entity[] buildEntities(){
		Entity[] elts = null;
		//get the root element
		Element docEle = dom.getDocumentElement();

		//get a nodelist of elements
		NodeList nl = docEle.getElementsByTagName("sca:component");
		if(nl != null && nl.getLength() > 0 ) {
			elts = new Entity[nl.getLength()];
			for(int i = 0 ; i < nl.getLength();i++) {
				Element nVal = (Element)nl.item(i);
				elts[i].setComponentName(nVal.getAttribute("name"));
				setReferences(nVal, elts[i]);
				setServices(nVal, elts[i]);
				setProperties(nVal, elts[i]);
				elts[i].referenceHeight();
				elts[i].serviceHeight();
				elts[i].propertyLength();
			}
		}
		
		//get a nodelist of elements
		NodeList nl2 = docEle.getElementsByTagName("sca:wire");
		if(nl2 != null && nl2.getLength() > 0 ) {
			
			for(int i = 0 ; i < nl2.getLength();i++) {
				Element nVal = (Element)nl2.item(i);
				String[] source = splitValues(nVal.getAttribute("source"));
				String[] target = splitValues(nVal.getAttribute("target"));
				
				for(Entity ent: elts){
					if(ent.getComponentName().equalsIgnoreCase(source[0])){
						ent.addAnAdjacentEntity(target[0]);
						ent.addToRefToSerMap(source[1], target[1]);
						break;
					}
				}
			}
		}
		
		positionEntities(elts);
		
		return elts;
			
	}
	
	private void positionEntities(Entity[] ents){
		Entity startEnt = null;
		for(Entity ent: ents){
			if(ent.getAdjacentEntities().size() != 0){
				setPosition(ent, initPoint, initPoint, 0, 0);
				levelCount.add(0, 1);
				startEnt = ent;
				break;
			}
		}
		
		if(startEnt != null)
			assignPositions(ents, startEnt);
		
	}
	
	private void assignPositions(Entity[] ents, Entity ent){
		int i=0;
		for(String name: ent.getAdjacentEntities()){
			for(Entity aEnt: ents){
				if(name.equalsIgnoreCase(aEnt.getComponentName())){
					int lane = ent.getLane()+1;
					if(levelCount.get(lane) != null){
						levelCount.add(lane, 1);
						setPosition(aEnt, ent.getX()+spaceX, ent.getY(), 0, lane);
					}
					else{
						int level = levelCount.get(lane);
						levelCount.add(lane, level+1);
						setPosition(aEnt, ent.getX()+spaceX, ent.getY()+spaceY*level, level, lane);
					}
					assignPositions(ents, aEnt);
					break;
				}
			}
			i++;
		}
	}
	
	private void setPosition(Entity ent, int x, int y, int level, int lane){
		ent.setX(x);
		ent.setY(y);
		ent.setLevel(level);
		ent.setLane(lane);
	}
	
	
	private String[] splitValues(String str){
		return str.split("/");
	}

	private void setReferences(Element nVal, Entity ent) {

		NodeList nl = nVal.getElementsByTagName("sca:reference");
		if(nl != null && nl.getLength() > 0 ) {
			for(int i = 0 ; i < nl.getLength();i++) {
				Element elt = (Element)nl.item(i);
				ent.addAReference(elt.getAttribute("name"));
			}
		}
	}
	
	private void setServices(Element nVal, Entity ent) {

		NodeList nl = nVal.getElementsByTagName("sca:service");
		if(nl != null && nl.getLength() > 0 ) {
			for(int i = 0 ; i < nl.getLength();i++) {
				Element elt = (Element)nl.item(i);
				ent.addAService(elt.getAttribute("name"));
			}
		}
	}
	
	private void setProperties(Element nVal, Entity ent) {

		NodeList nl = nVal.getElementsByTagName("sca:property");
		if(nl != null && nl.getLength() > 0 ) {
			for(int i = 0 ; i < nl.getLength();i++) {
				Element elt = (Element)nl.item(i);
				ent.addAProperty(elt.getAttribute("name"));
			}
		}
	}
	
	

}