package classes;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.UUID;

import classes.holonControlUnit.HolonControlUnit;
import ui.controller.Control;
import ui.model.DecoratedNetwork;
import ui.model.IntermediateCableWithState;
import ui.model.MinimumModel;
import ui.model.Model;

public class Holon {
	public String name = new String();
	private Holon parent = null;
	public ArrayList<Holon> childHolons = new ArrayList<Holon>();
	private List<HolonElement> elements = new ArrayList<HolonElement>();
	//HolonObject is the lowest representation of a holon.
	private final HolonObject holonObject;
	public final boolean isPhysical; 
	public HolonControlUnit holonControlUnit;
	private String uniqueID;
	public Model model;
	private MinimumModel minModel;
	/** stores whether the part between this holon and the child is occupied by the superholon */
	private boolean canRunIndependentFromParent;
	
	public Holon(String name, Model model) {
		this.name = name;
		this.parent = parent;
		this.holonObject = null;
		isPhysical = false;
		this.uniqueID = UUID.randomUUID().toString();
		this.model = model;
		this.holonControlUnit = new HolonControlUnit(this);
		this.minModel = new MinimumModel(new ArrayList<AbstractCanvasObject>(), new ArrayList<Edge>());
		this.canRunIndependentFromParent = true;
	}
	
	public Holon(HolonObject object, Model model) {
		holonObject = object;
		object.holon = this;
		this.parent = parent;
		name = object.getName();
		elements.addAll(object.getElements());
		for(HolonElement ele : elements) {
			ele.holon = this;
		}
		isPhysical = true;
		this.uniqueID = UUID.randomUUID().toString();
		this.model = model;
		this.holonControlUnit = new HolonControlUnit(this);
		ArrayList<AbstractCanvasObject> list = new ArrayList<AbstractCanvasObject>();
		list.add(object);
		this.minModel = new MinimumModel(list, new ArrayList<Edge>());
		this.canRunIndependentFromParent = true;
	}
	
	
	public void addElement(HolonElement element) {
		element.holon = this;
		elements.add(element);
	}
	public void removeElement(HolonElement element) {
		element.holon = null;
		elements.remove(element);
	}
	public int elementsCount() {
		return elements.size();
	}
	
	public void addChild(Holon child) {
		if(!this.childHolons.contains(child)) {
			child.parent = this;
			this.childHolons.add(child);
		}
		this.holonControlUnit.addSubHolon(child);
	}
	
	public void addChildHolon(Holon child, int index) {
		if(!this.childHolons.contains(child)) {
			child.parent = this;
			childHolons.add(index, child);
		}
		this.holonControlUnit.addSubHolon(child);
	}
	
	public void removeChildHolon(Holon child) {
		child.parent = null;
		childHolons.remove(child);
		this.holonControlUnit.getHierarchyController().removeSubHolon(child.getUniqueID());
		revalidateMinModel();
	}
	
	public void removeFromParent() {
		if(parent != null) {
			parent.removeChildHolon(this);
		}
		parent = model.getStateHolon();
	}
	
	
	public int getChildCount() {
		return childHolons.size();
	}
	
	public Holon getParent() {
		return parent;
	}
	
	public void setParent(Holon parent) {
		this.parent = parent;
		this.holonControlUnit.getHierarchyController().setSuperHolon(parent.getUniqueID());
	}
	
	public HolonObject getHolonObject() {
		return holonObject;
	}
	
	
	
	public List<Holon> getChildView(){
		return Collections.unmodifiableList(childHolons);
	}
	
	public List<HolonElement> getElementView(){
		return Collections.unmodifiableList(elements);
	}
	
	@Override
	public String toString() {
		return name;
	}

	public void reassignAllChildren(Holon other) {
		for(Holon child: this.childHolons) {
			other.merge(child);
		}
		childHolons.clear();
	}
	
	
	public void removeAllRefrences() {
		parent = null;
		this.childHolons.clear();
		this.elements.clear();
	}
	
	
	
	public int getLayer() {
		return parent != null ? parent.getLayer() +  1 : 0;
	}
	
	
	
	public Holon cloneWithoutParent() {
		Holon cloned = new Holon(this.name, this.model);
		model.getHolonsByID().put(cloned.getUniqueID(), cloned);
		cloned.childHolons = this.childHolons;
		cloned.elements = this.elements;
		return cloned;
	}
	
	public boolean checkHolonArePhysicalConnected(Holon other, Control control) {
		HashMap<HolonObject, DecoratedNetwork> table = control.getSimManager().getActualDecorState().getHolonObjectNetworkTable();
		HolonObject a = tryGetAPhysicalHolon();
		HolonObject b = other.tryGetAPhysicalHolon();
		boolean aHolonIsPureAbstract = a == null || b == null;
		return  aHolonIsPureAbstract || table.get(a) == table.get(b);
	}
	
	private HolonObject tryGetAPhysicalHolon() {
		if(holonObject != null) {
			return holonObject;
		}
		for(Holon holon : childHolons) {
			HolonObject object = holon.tryGetAPhysicalHolon();
			if(object != null) {
				return object;
			}
		}
		return null;
	}
	
	
	public void checkRepairHolarchy(HashMap<HolonObject, DecoratedNetwork> table, Holon stateHolon) {
		if(childHolons.isEmpty()) {
			return;
		}
		//To establish the invariant that all child holons are repaired
		for(Holon other : childHolons) {
			other.checkRepairHolarchy(table, stateHolon);
		}
		//Repair this Holon
		HolonObject first = tryGetAPhysicalHolon();
		if(first == null) {
			return;
		}
		List<Holon> removeList = new ArrayList<Holon>();
		for(Holon other : childHolons) {
			HolonObject otherHolonObject = other.tryGetAPhysicalHolon();
			boolean isPureAbstract = otherHolonObject == null;
			if(isPureAbstract) {
				continue;
			}
			boolean isPhysicalConnected = model.checkHolonObjectsAreConnected(this, other);
			if(!isPhysicalConnected) {
				removeList.add(other);
			}
		}
		//Remove holons
		for(Holon holon : removeList) {
			holon.split(stateHolon);
		}
		
	}
	
	public void addNewVirtualNeighbor(String virtualNeighbor) {
		if(!this.uniqueID.equals(virtualNeighbor)) {
			this.holonControlUnit.addNewVirtualNeighbor(virtualNeighbor);
		}
	}
	
	public String getUniqueID() {
		return uniqueID;
	}
	
	public ArrayList<HolonObject> getAllHolonObjects() {
		ArrayList<HolonObject> list = new ArrayList<HolonObject>();
		for(Holon h : this.childHolons) {
			list.addAll(h.getAllHolonObjects());
		}
		if(this.holonObject != null) {
			list.add(this.holonObject);
		}
		return list;
	}
	
	public MinimumModel getMinimumModel() {
		return this.minModel;
	}
	
	public void merge(Holon child) {
		if(!this.model.getHolonsByID().containsKey(child.getUniqueID())) {
			System.err.println("could not find: "+child.getHolonObject());
			return;
		}
		
		if(this.childHolons.contains(child)) {
			return;
		}
		
		if(this.getLayer() == 0) {
			this.addChild(child);
			return;
		}
		
		//check if path between this holon and child holon is already occupied
		ArrayList<HolonObject> holarchy = getAllHolonObjects();
		holarchy.addAll(child.getAllHolonObjects());
		HashMap<Float, ArrayList<Edge>> paths = this.model.getShortestPathToHolarchy(this.minModel, child.getMinimumModel(), holarchy);
		HashMap<Float, ArrayList<Edge>> free_paths = new HashMap<Float, ArrayList<Edge>>();
		HashMap<Float, ArrayList<Edge>> occ_paths = new HashMap<Float, ArrayList<Edge>>();
		HashMap<ArrayList<Edge>, Holon> occ_by = new HashMap<ArrayList<Edge>, Holon>();
		
		for(Float f : paths.keySet()) {
			ArrayList<Edge> path = paths.get(f);
			Holon holder = isPathOccupied(path);
			if(holder == null || holder.getLayer() == 0 || holder.equals(this.parent)) {
				free_paths.put(f, path);
			} else {
				occ_paths.put(f, path);
				occ_by.put(path, holder);
			}
		}
		
		if(free_paths.size() > 0) {
			//there is a free path, take it and add child directly
			this.addChild(child);
			this.addChildToMinModel(child, free_paths.get(getShortestPath(free_paths)));
			if(this.getLayer() > 1) {
				this.parent.recalculateMinModel();
			}
			return;
		}
		if(occ_paths.size() < 1) {
			System.err.println("something went wrong when looking for shortest path while merging "+this.uniqueID+" and "+child.getUniqueID());
		}
		ArrayList<ArrayList<Edge>> shortestPaths = sortPaths(occ_paths);
		for(int i=0; i< shortestPaths.size(); i++) {
			//check if holon should merge with holder of this path
			ArrayList<Edge> path = shortestPaths.get(i);
			Holon holder = occ_by.get(path);
			//if true try to merge with holon which is using the path
			if(holder != null && holder.getLayer() > 0) {
				this.split(holder);
				this.addChild(child);
				this.addChildToMinModel(child, path);
				if(this.parent != null && this.getLayer() > 1) {
					this.parent.recalculateMinModel();
				}
				this.canRunIndependentFromParent = false;
			}
			break;
		}
	}
	
	/**
	 * checks whether a path is occupied
	 * if true returns the holon in which the path is located
	 * @param path
	 * @return
	 */
	private Holon isPathOccupied(ArrayList<Edge> path) {
		Holon h = this.parent;
		Holon r = this;
		Holon holder = null;
		while(h != null) {
			holder = h.containsPath(path, r);
			if(holder != null) {
				//found a holon which contains the path
				return holder;
			}
			r = h;
			h = h.parent;
		}
		return null;
	}
	
	private ArrayList<ArrayList<Edge>> sortPaths(HashMap<Float, ArrayList<Edge>> paths) {
		ArrayList<ArrayList<Edge>> shortestPaths = new ArrayList<ArrayList<Edge>>();
		
		while(paths.size() > 0) {
			shortestPaths.add(paths.remove(getShortestPath(paths)));
		}
		
		return shortestPaths;
	}
	
	private Float getShortestPath(HashMap<Float, ArrayList<Edge>> paths){
		float min = Float.MAX_VALUE;
		for(Float f : paths.keySet()) {
			if(f < min) {
				min = f;
			}
		}
		return min;
	}
	
	/**
	 * removes this holon from current superholon and merge with new superholon
	 */
	public void split(Holon newParent) {
		if(newParent == null) {
			System.err.println("can not split without new super holon");
			return;
		}
		
		//ensure that this holarchy can run independent(path is not occupied by superholon) from the superholon
		if(!this.canRunIndependentFromParent) {
			return;
		}
		
		if(this.parent != null) {
			this.parent.removeChildHolon(this);
		}
		
		newParent.merge(this);
	}
	
	/**
	 * recalculates the min model after a holon was added to a subholon
	 * does NOT recalculate the shortest paths between its subholons
	 */
	public void recalculateMinModel() {
		ArrayList<AbstractCanvasObject> objects = new ArrayList<AbstractCanvasObject>();
		ArrayList<Edge> edges = new ArrayList<Edge>();
		for(Holon child : this.childHolons) {
			MinimumModel cmm = child.getMinimumModel();
			objects.addAll(cmm.getHolonObjectList());
			objects.addAll(cmm.getNodeList());
			objects.addAll(cmm.getSwitchList());
			for(IntermediateCableWithState icws : cmm.getEdgeList()) {
				edges.add(icws.getModel());
			}
		}
		//go through the edge list and add all edges connecting the subholons
		for(IntermediateCableWithState icws : this.minModel.getEdgeList()) {
			if(!edges.contains(icws.getModel())) {
				edges.add(icws.getModel());
			}
		}
		
		this.minModel = new MinimumModel(objects, edges);
		
		//notify superholon to recalculate its minModel
		if(this.parent != null && this.getLayer() > 0) {
			this.parent.recalculateMinModel();
		}
	}
	
	/**
	 * adds a child and its min model (incl. all its subholons) to this min model
	 * @param child
	 */
	private void addChildToMinModel(Holon child, ArrayList<Edge> path) {
		if(this.minModel.getHolonObjectList().contains(child.getHolonObject()) || getLayer() == 0)
			return;
		
		ArrayList<Edge> edgeList = new ArrayList<Edge>();
		//add all holon objects that are part of this holarchy
		ArrayList<HolonObject> holarchy = getAllHolonObjects();
		holarchy.addAll(child.getAllHolonObjects());
		edgeList.addAll(path);
		for(IntermediateCableWithState icws : this.minModel.getEdgeList()) {
			edgeList.add(icws.getModel());
		}
		for(IntermediateCableWithState icws : child.minModel.getEdgeList()) {
			edgeList.add(icws.getModel());
		}
		//aggregate all objects
		ArrayList<AbstractCanvasObject> objects = new ArrayList<AbstractCanvasObject>();
		for(Edge e : edgeList) {
			AbstractCanvasObject a = e.getA();
			AbstractCanvasObject b = e.getB();
			if(!objects.contains(a)) {
				objects.add(a);
			}
			if(!objects.contains(b)) {
				objects.add(b);
			}
		}
		
		this.minModel = new MinimumModel(objects, edgeList);
	}
	
	/**
	 * revalidate this min model after a subholon was removed
	 */
	public void revalidateMinModel() {
		if(getLayer() == 0)
			return;

		this.canRunIndependentFromParent = true;
		ArrayList<AbstractCanvasObject> list = new ArrayList<AbstractCanvasObject>();
		list.add(this.holonObject);
		this.minModel = new MinimumModel(list, new ArrayList<Edge>());
		for(int i=0; i< this.childHolons.size(); i++) {
			Holon child = this.childHolons.remove(0);
			this.merge(child);
		}
		
		if(this.parent != null) {
			this.parent.revalidateMinModel();
		}
	}
	
	/**
	 * returns the holon which uses the specified path if it is included in min model, otherwise null
	 */
	public Holon containsPath(ArrayList<Edge> path, Holon requester) {
		if(this.minModel.containsPath(path) || this.getLayer() == 0) {
			for(Holon child : this.childHolons) {
				if(child.equals(requester))
					continue;
				Holon h = child.containsPath(path, this);
				if(h != null) {
					return h;
				}
			}
			
			return this;
		}
		
		return null;
	}
}