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package graph.algorithm;

import graph.core.AbstractGraphAlgorithm;
import graph.core.Edge;
import graph.core.Graph;
import graph.core.Vertex;
import graph.gui.GraphOverlay;
import graph.util.LinkedList;
import graph.util.Heap;
import graph.util.List;
import graph.util.Position;
import graph.util.PriorityQueue;

import java.awt.Color;
import java.util.HashMap;
import java.util.Map;


public class PrimJarnikMSTAlgorithm extends AbstractGraphAlgorithm {
	@SuppressWarnings("rawtypes")
	private class PrimJarnikMSTOverlay implements GraphOverlay {
		@Override
		public Color edgeColor(Edge edge) {
			for (Edge e : parentMap.values()) {
				if (edge.equals(e)) return Color.RED;
			}
			return Color.BLACK;
		}

		@Override
		public Color vertexColor(Vertex vertex) {
			return Color.RED;
		}
	}
	
	private Graph G;
	private Map, Integer> distanceMap;
	private Map, Position>> positionMap;
	private Map, Edge> parentMap;
	
	public PrimJarnikMSTAlgorithm() {
		super();
		distanceMap = new HashMap, Integer>();
		positionMap = new HashMap, Position>>();
		parentMap = new HashMap, Edge>();
	}
	
	public PrimJarnikMSTAlgorithm(Graph graph) {
		this();
		G = graph;
	}
	
	public void setGraph(Graph graph) {
		G = graph;
	}
	
	public void search(Map> parameters) {
		Vertex s = G.vertices().first().element();
		List> cloud = new LinkedList>();
		
		PriorityQueue> Q = new Heap>();
		
		distanceMap.clear();
		parentMap.clear();
		for (Vertex vertex: G.vertices()) {
			int value = Integer.MAX_VALUE;
			if (vertex.equals(s)) value = 0;
			distanceMap.put(vertex, value);
			Position> p = Q.insert(value, vertex);
			positionMap.put(vertex, p);
		}
		
		while (!Q.isEmpty()) {
			Vertex u = Q.remove();
			cloud.insertLast(u);
			for (Edge e : G.incidentEdges(u)) {
				Vertex z = G.opposite(u, e);
				if (!inCloud(cloud, z)) {
					int r = Integer.parseInt(e.element().toString());
					if (r < distanceMap.get(z)) {
						distanceMap.put(z, r);
						parentMap.put(z, e);
						Q.replaceKey(positionMap.get(z), r);
					}
				}
			}
		}
	}
	
	private boolean inCloud(List> cloud, Vertex z) {
		for (Vertex vertex : cloud) {
			if (vertex.equals(z)) return true;
		}
		return false;
	}
	
	@Override
	public GraphOverlay getOverlay() {
		return new PrimJarnikMSTOverlay();
	}
}