package holeg.ui.controller;

import java.awt.*;
import java.util.List;
import java.util.Collection;
import java.util.LinkedList;

import holeg.model.AbstractCanvasObject;
import holeg.model.Edge;
import holeg.model.GroupNode;
import holeg.model.Node;
import holeg.ui.model.GuiSettings;
import holeg.ui.model.Model;
import holeg.utility.math.vector.Vec2i;


class NodeController {

	private Model model;
	private CanvasController cvs;
	private Point point;

    NodeController(Model model, CanvasController cvs) {
        this.model = model;
		this.cvs = cvs;
	}

	/**
	 * Add a CpsUpperNode into Canvas
	 */
    void addGroupNode(String nodeName, GroupNode groupNode, List<AbstractCanvasObject> toGroup) {
		GroupNode node = new GroupNode(nodeName);
		node.setPosition(calculatePos(toGroup));
		makeGroupNode(node, groupNode, toGroup);
		if (groupNode == null) {
			cvs.addNewObject(node);
		}
		else {
			addObjectInGroupNode(node, groupNode, false);			
		}

	}

	/**
	 * Delete a CpsUpperNode from the Canvas
	 */
    void undoGroupNode(GroupNode node, GroupNode groupNode) {
    	if(node.getObjectsInThisLayer().findAny().isPresent()) {
    		cvs.deleteObjectOnCanvas(node);
    		return;
    	}
		Vec2i old = calculatePos(node.getObjectsInThisLayer().toList());
		Vec2i p = node.getPosition();
		point = new Point(old.getX() - p.getX(), old.getY() - p.getY());

		unmakeNodesOfNodes(node, groupNode);
		if (groupNode == null)
			cvs.deleteObjectOnCanvas(node);
		else
			deleteObjectInGroupNode(node, groupNode);
	}

	/**
	 * Put selected Nodes inside the Upper Node
	 */
	private void makeGroupNode(GroupNode node, GroupNode groupNode, List<AbstractCanvasObject> toGroup) {
	

		// Put all selected Nodes into the Upper Node
        for (AbstractCanvasObject obj : toGroup) {
			addObjectInGroupNode(obj, node, false);
		}

		for (AbstractCanvasObject abs : toGroup) {
			if (groupNode == null)
				removeForNodeOfNode(abs);
			else
				removeForNodeOfNode(abs, groupNode);
		}

	}

	/**
	 * Transfer all relevant data from Node into the next higher layer of Node
	 * (upperNode)
	 */
	private void unmakeNodesOfNodes(GroupNode node, GroupNode upperNode) {
		// add all nodes into upperNode

		node.getObjectsInThisLayer().forEach(obj -> {
			updatePosition(obj, upperNode);
		});
		if (upperNode == null) {
			model.getCanvas().addAll(node.getObjectsInThisLayer());
		} else {
			node.getObjectsInThisLayer().forEach(obj -> upperNode.add(obj));
		}
		
	}



	/**
	 * Calculate new Position of the Upper Node
	 */
    Vec2i calculatePos(Collection<AbstractCanvasObject> toGroup) {
		Vec2i pos = new Vec2i(0, 0);
		for (AbstractCanvasObject abs : toGroup) {
			pos = pos.add(abs.getPosition());
		}
		return pos.divide(toGroup.size());
	}

	/**
	 * Removes the Given Obj from current Layer and adjusts the idx
	 */
	private void removeForNodeOfNode(AbstractCanvasObject obj, GroupNode upperNode) {
		upperNode.remove(obj);
	}

	/**
	 * Removes the Given Obj from current Layer and adjusts the idx
	 */
	private void removeForNodeOfNode(AbstractCanvasObject obj) {
		model.getCanvas().remove(obj);
	}


	/**
	 * Adds object to the upperNode, might replace objects if replace==true
	 * @param object
	 * @param upperNode
	 * @param replace
	 */
    void addObjectInGroupNode(AbstractCanvasObject object, GroupNode upperNode, boolean replace) {
        if(object == null){
        		new Error("object == null while adding to "+upperNode.toString()).printStackTrace();
        		return;
        	}
        if(upperNode == null){
    		new Error("upperNode == null while adding "+object.toString()).printStackTrace();
    		return;
    	}
		upperNode.add(object);
		
		/**
		 * check if we should drag & drop replace
		 */
		if(replace && !(object instanceof Node) ){
			/** x of the dragged Object */
			int x = object.getPosition().getX();
		
			/** y of the dragged Object */
			int y = object.getPosition().getY();
			
			/** distance threshold for replacement */
			int treshhold = GuiSettings.getPictureScaleDiv2();
		
			/** number of Objects that might be replaced (should be 1) */
			int replaceCounter = 0;
		
			/** last object that could be replaced */
			AbstractCanvasObject toBeReplaced = null;
			
			/** for each cps on Canvas */
			for (AbstractCanvasObject cps : upperNode.getObjectsInThisLayer().toList()){
				
				/** same object -> ignore */
				if(cps == object)continue;
			
				/** x of object that might get replaced */
				int c_x = cps.getPosition().getX();
				
				/** y of object that might get replaced */
				int c_y = cps.getPosition().getY();
				
				/** 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){
				replaceObjectInUpperNode(toBeReplaced, object, upperNode);
			}
		}
	}

	/**
	 * Delete a AbstactCpsObject from CPSUpperNode
	 */
    void deleteObjectInGroupNode(AbstractCanvasObject object, GroupNode groupNode) {
		LinkedList<Edge> edgesToDelete = new LinkedList<Edge>();
		for (Edge p : model.getEdgesOnCanvas()) {
			if(p.isConnectedTo(object)) {
				edgesToDelete.add(p);
			}
		}
		model.getEdgesOnCanvas().removeAll(edgesToDelete);				
		groupNode.remove(object);
	}

    /**
     * Replaces {@code toBePlaced} by {@code by} in {@code upperNode}
     * @param toBeReplaced
     * @param by
     * @param upperNode
     */
	public void replaceObjectInUpperNode(AbstractCanvasObject toBeReplaced,
			AbstractCanvasObject by, GroupNode upperNode) {
		/** let all edges of 'toBeReplaced' connect to 'by' */
		/**
		 * set Position of by to exactly toBeReplaced
		 */
		by.setPosition(toBeReplaced.getPosition());
		deleteObjectInGroupNode(toBeReplaced, upperNode);
	}

    private void updatePosition(AbstractCanvasObject temp, GroupNode upperNode) {
        int x = temp.getPosition().getX() - point.x;
        int y = temp.getPosition().getY() - point.y;

        if (y < 0)
            y = 0 + GuiSettings.getPictureScaleDiv2() + 1;
        if (upperNode != null) {
            if (x < GuiSettings.getPictureScaleDiv2() + 1)
                x = GuiSettings.getPictureScaleDiv2() + 1;
        } else if (x < 0)
            x = 0 + GuiSettings.getPictureScaleDiv2() + 1;
        if (x > GuiSettings.canvasSize.getX())
            x = GuiSettings.canvasSize.getX() - GuiSettings.getPictureScaleDiv2() - 1;
        if (y > GuiSettings.canvasSize.getY())
            y = GuiSettings.canvasSize.getY() - GuiSettings.getPictureScaleDiv2() - 1;

        temp.setPosition(new Vec2i(x, y));
    }
}