package ui.controller;

import java.awt.Point;
import java.util.ArrayDeque;
import java.util.ArrayList;

import classes.CpsEdge;
import classes.CpsNode;
import classes.CpsUpperNode;
import classes.AbstractCpsObject;
import classes.HolonObject;
import classes.HolonSwitch;
import classes.Position;
import interfaces.ObjectListener;
import ui.model.Model;

/**
 * Controller for the Canvas.
 * 
 * @author Gruppe14
 */
public class CanvasController {

	private Model model;
	private MultiPurposeController mpC;

	/**
	 * Constructor.
	 * 
	 * @param model
	 *            the Model
	 * @param mp
	 *            the MultipurposeController
	 */
	public CanvasController(Model model, MultiPurposeController mp) {
		this.model = model;
		this.mpC = mp;
	}

	/**
	 * Add an CpsObject to the model and notify the ObjectListener for update.
	 * 
	 * @param object
	 *            CpsObject to be added.
	 * @param replace when true objects could be replaced
	 */
	public void addObject(AbstractCpsObject object, boolean replace) {
		model.getCvsObjIdx().put(object.getId(), model.getObjectsOnCanvas().size());
		model.getObjectsOnCanvas().add(object);
		/**
		 * check if we should drag & drop replace
		 */
		if(!(object instanceof CpsNode) && replace){
			/** x of the dragged Object */
			int x = object.getPosition().x;
			
			/** y of the dragged Object */
			int y = object.getPosition().y;
			
			/** distance treshold for replacement */
			int treshhold = model.getScale()/2;
			
			/** number of Objects that might be replaced (should be 1) */
			int replaceCounter = 0;
			
			/** last object that could be replaced */
			AbstractCpsObject toBeReplaced = null;
			
			/** for each cps on Canvas */
			for (AbstractCpsObject cps : model.getObjectsOnCanvas()){
				
				/** same object -> ignore */
				if(cps == object)continue;
				
				/** x of object that might get replaced */
				int c_x = cps.getPosition().x;
				
				/** y of object that might get replaced */
				int c_y = cps.getPosition().y;
				
				/** if near enough */
				if(Math.abs(x-c_x)<treshhold && Math.abs(y-c_y)<treshhold){
					replaceCounter++;
					toBeReplaced = cps;
				}	
			}
			/** if replacement of exactly one object possible */
			if(replaceCounter == 1 && toBeReplaced != null){
				replaceObjectOnCanvas(toBeReplaced, object);
			}
		}
		
		
		notifyObjListeners();
	}

	/**
	 * Add a new Object.
	 * 
	 * @param object
	 *            the Object
	 */
	public void addNewObject(AbstractCpsObject object) {
		object.setSav("CVS");
		// object.setConnections(new ArrayList<CpsEdge>());
		addObject(object, true);
	}

	/**
	 * adds the ObjectListener.
	 * 
	 * @param objLis
	 *            ObjectListener
	 */
	public void addObjectListener(ObjectListener objLis) {
		model.getObjectListeners().add(objLis);
	}

	/**
	 * notifies all listeners about changes in the Canvas.
	 */
	public void notifyObjListeners() {
		for (ObjectListener l : model.getObjectListeners()) {
			l.onChange(model.getObjectsOnCanvas());
		}
	}

	/**
	 * Deletes an CpsObject on the Canvas and its connections.
	 * 
	 * @param obj
	 *            AbstractCpsObject
	 */
	public void deleteObjectOnCanvas(AbstractCpsObject obj) {
		CpsEdge e = null;
		for (AbstractCpsObject cps : model.getObjectsOnCanvas()) {
			for (CpsEdge p : cps.getConnections()) {
				if (p.getA() == obj || p.getB() == obj) {
					e = p;
				}
			}
			if (!model.getClipboradObjects().contains(cps)) {
				cps.getConnections().remove(e);
			}
			model.getEdgesOnCanvas().remove(e);
		}
		mpC.decIdx(obj.getId(), model.getCvsObjIdx());
		model.getCvsObjIdx().remove(obj.getId());
		model.getObjectsOnCanvas().remove(obj);
		notifyObjListeners();
	}

	/**
     * Replaces {@code toBeReplaced} by {@code by} on the canvas
     * @param toBeReplaced the object that will be replaced
     * @param by the object that will replace it
     */
	public void replaceObjectOnCanvas(AbstractCpsObject toBeReplaced, AbstractCpsObject by) {
		/** let all edges of 'toBeReplaced' connect to 'by' */
		for(CpsEdge e: toBeReplaced.getConnections()){
			if(e.getA() == toBeReplaced){
				e.setA(by);
			}else if(e.getB() == toBeReplaced){
				e.setB(by);
			}
			
			/** if edge from an object to itself -> remove it */
			if(e.getA() == e.getB())
				removeEdgesOnCanvas(e);
			else/** else add edge to 'by' */
				by.addConnection(e);
		}
		/** delete 'toBeReplaced' new empty connections, to prevent Nullpointer*/
		toBeReplaced.setConnections(new ArrayList<CpsEdge>(1));
		/**
		 * set Position of by to exactly toBeReplaced
		 */
		by.setPosition(toBeReplaced.getPosition());
		deleteObjectOnCanvas(toBeReplaced);
	}
	
	/**
	 * Add an edge to the Canvas.
	 * 
	 * @param edge
	 *            the edge
	 */
	public void addEdgeOnCanvas(CpsEdge edge) {
		model.getEdgesOnCanvas().add(edge);
	}

	/**
	 * Removes an Edge from the Canvas.
	 * 
	 * @param edge
	 *            the edge to remove
	 */
	public void removeEdgesOnCanvas(CpsEdge edge) {
		edge.getA().getConnections().remove(edge);
		edge.getB().getConnections().remove(edge);
		model.getEdgesOnCanvas().remove(edge);
		if (edge.getA() instanceof CpsUpperNode || edge.getB() instanceof CpsUpperNode)
			handleUpperNodes(edge);
	}

	/**
	 * Paste all Selected Objects.
	 * 
	 * @param p
	 *            the mouse Position
	 */
	public void pasteObjects(Point p) {
		model.getSelectedCpsObjects().clear();
		AbstractCpsObject tCps = null;
		int x = Integer.MAX_VALUE, y = Integer.MAX_VALUE;

		// Location whre to copy the Elements
		for (AbstractCpsObject cps : model.getClipboradObjects()) {
			if (cps.getPosition().x < x) {
				x = cps.getPosition().x;
			}
			if (cps.getPosition().y < y) {
				y = cps.getPosition().y;
			}
		}

		ArrayList<AbstractCpsObject> tempList = new ArrayList<>();

		// Objects
		for (AbstractCpsObject cps : model.getClipboradObjects()) {
			if (cps instanceof HolonObject) {
				tCps = new HolonObject((HolonObject) cps);
			} else if (cps instanceof HolonSwitch) {
				tCps = new HolonSwitch((HolonSwitch) cps);
			} else {
				tCps = new CpsNode("Node");
			}
			tCps.setPosition(new Position(p.x + (cps.getPosition().x - x), p.y + (cps.getPosition().y - y)));
			tCps.setSav(cps.getSav());
			tempList.add(tCps);
			addObject(tCps, false);
			// MODEL.getSelectedCpsObjects().add(tCps);
		}

		// Edges
		boolean newEdge = true;
		for (AbstractCpsObject cps : model.getClipboradObjects()) {
			for (CpsEdge e : cps.getConnections()) {
				// A and B of e in the copied Elements?
				if (model.getClipboradObjects().indexOf(e.getA()) != -1
						&& model.getClipboradObjects().indexOf(e.getB()) != -1) {
					AbstractCpsObject a = tempList.get(model.getClipboradObjects().indexOf(e.getA()));
					AbstractCpsObject b = tempList.get(model.getClipboradObjects().indexOf(e.getB()));
					// was this Edge created or not?
					for (CpsEdge et : tempList.get(model.getClipboradObjects().indexOf(cps)).getConnections()) {
						for (CpsEdge etA : et.getA().getConnections()) {
							if (et.getA() == a && et.getB() == b) {
								newEdge = false;
							}
						}
						for (CpsEdge etB : et.getB().getConnections()) {
							if (et.getA() == a && et.getB() == b) {
								newEdge = false;
							}
						}
					}
					if (newEdge) {
						CpsEdge tempE = new CpsEdge(tempList.get(model.getClipboradObjects().indexOf(e.getA())), // A
								tempList.get(model.getClipboradObjects().indexOf(e.getB())), /* B */
								e.getCapacity());
						addEdgeOnCanvas(tempE);
					}
					newEdge = true;
				}
			}
		}

	}

	/**
	 * Cut all Selected Objects.
	 */
	@SuppressWarnings("unchecked")
	public void cutObjects() {
		model.setClipboradObjects((ArrayList<AbstractCpsObject>) model.getSelectedCpsObjects().clone());

		for (AbstractCpsObject cps : model.getClipboradObjects()) {
			deleteObjectOnCanvas(cps);
		}

		model.getSelectedCpsObjects().clear();
	}

	/**
	 * In Case if a One or Both Side of the to Removing Edge is a CpsUpperNode
	 * 
	 * @param edge
	 * @param upperNode
	 */
	public void handleUpperNodes(CpsEdge edge) {
		CpsUpperNode upper = null;
		ArrayList<CpsEdge> toDelete = new ArrayList<>();

		// wenn A ist upperNOde
		if (edge.getA() instanceof CpsUpperNode) {

			upper = (CpsUpperNode) edge.getA();

			// wenn in OldEdges eine B enhält
			for (CpsEdge cpsEdge : upper.getOldEdges()) {
				if (cpsEdge.getA().equals(edge.getB()) || cpsEdge.getB().equals(edge.getB()))
					toDelete.add(cpsEdge);
			}
			// lösche alle Edges mit B
			upper.getOldEdges().removeAll(toDelete);
			// lösche hier alle Connections
			for (CpsEdge cpsEdge : toDelete) {
				cpsEdge.getA().getConnections().remove(cpsEdge);
				cpsEdge.getB().getConnections().remove(cpsEdge);
			}
			toDelete.clear();
		}
		// Hier analog
		if (edge.getB() instanceof CpsUpperNode) {

			upper = (CpsUpperNode) edge.getB();

			for (CpsEdge cpsEdge : upper.getOldEdges()) {
				if (cpsEdge.getA().equals(edge.getA()) || cpsEdge.getB().equals(edge.getA()))
					toDelete.add(cpsEdge);
			}
			upper.getOldEdges().removeAll(toDelete);
			for (CpsEdge cpsEdge : toDelete) {
				cpsEdge.getA().getConnections().remove(cpsEdge);
				cpsEdge.getB().getConnections().remove(cpsEdge);
			}
			toDelete.clear();
		}

	}

	/**
	 * Some cleaning Algorithm which traverses the UpperNode through BFS Can be
	 * extended with other cleaning stuff No need for coloring since there tree
	 * is only directed in one direction
	 * 
	 * @param node
	 */
	public void bfsNodeCleaner(CpsUpperNode node) {

		ArrayDeque<AbstractCpsObject> queue = new ArrayDeque<>();
		AbstractCpsObject u = node;

		queue.add(u);
		while (!queue.isEmpty()) {
			u = queue.pop();

			deleteConnections(u);
			if (u instanceof CpsUpperNode)
				for (AbstractCpsObject adjacent : ((CpsUpperNode) u).getNodes()) {
					queue.add(adjacent);
				}
		}

	}

	/**
	 * Deletes all Connections to Objects inside the to deleting UpperNode
	 * 
	 * @param obj
	 */
	private void deleteConnections(AbstractCpsObject obj) {

		ArrayDeque<CpsEdge> queue = new ArrayDeque<>();
		CpsEdge e = null;

		for (CpsEdge edge : obj.getConnections()) {
			queue.add(edge);
		}
		while (!queue.isEmpty()) {
			e = queue.pop();
			e.getA().getConnections().remove(e);
			e.getB().getConnections().remove(e);
		}

	}
	
	/**
	 * Set the Background Image;
	 * 
	 * @param imagePath
	 *            Image Path
	 * @param mode
	 *            Image Mode
	 * @param width
	 *            Image custom width
	 * @param height
	 *            Image custom height
	 */
	public void setBackgroundImage(String imagePath, int mode, int width, int height) {
		model.setCanvasImagePath(imagePath);
		model.setCanvasImageMode(mode);
		model.setCanvasImageWidth(width);
		model.setCanvasImageHeight(height);
	}
}