package visualizationElements;

import java.awt.Color;
import java.awt.Graphics;


/**
 * Represents an edge of a graph.
 * @author MSchaefer
 *
 */
public class Edge  {
	
	private Vertex source;
	private Vertex destination;
	private Color color; 
	private String marking;
	int[] xPoints;
    int[] yPoints;
    float baseX; 
    float baseY ;

	/**
	 * Creates a new Edge.
	 * @param source The vertex the edge starts at.
	 * @param destination The vertex the edge ends at.
	 * @param marking Marking of the edge.
	 * @param color Coloring the edge is drawn.
	 */
	public Edge(Vertex source, Vertex destination, String marking, Color color) {
		
		this.setSource(source);
		this.setDestination(destination);
		this.setColor(color);
		this.setMarking(marking);
	}
	
	
	/**
	 * Creates a new Edge.
	 * @param source The vertex the edge starts at.
	 * @param destination The vertex the edge ends at.
	 * @param color Coloring the edge is drawn.
	 */
	public Edge(Vertex source, Vertex destination, Color color) {
		
		this.setSource(source);
		this.setDestination(destination);
		this.setColor(color);
		this.setMarking("");
	}
	
	
	/**
	 * Creates a new Edge.
	 * @param source The vertex the edge starts at.
	 * @param destination The vertex the edge ends at.
	 * @param marking Marking of the edge.
	 */
	public Edge(Vertex source, Vertex destination, String marking) {
		
		this.setSource(source);
		this.setDestination(destination);
		this.setColor(Color.BLACK);
		this.setMarking(marking);
	}
	
	
	/**
	 * Creates a new Edge.
	 * @param source The vertex the edge starts at.
	 * @param destination The vertex the edge ends at.
	 */
	public Edge(Vertex source, Vertex destination) {
		
		this.setSource(source);
		this.setDestination(destination);
		this.setColor(Color.BLACK);
		this.setMarking("");
	}
	

	/**
	 * @param source the source to set
	 */
	public void setSource(Vertex source) {
		this.source = source;
	}

	
	/**
	 * @return the source
	 */
	public Vertex getSource() {
		return source;
	}

	
	/**
	 * @param destination the destination to set
	 */
	public void setDestination(Vertex destination) {
		this.destination = destination;
	}

	
	/**
	 * @return the destination
	 */
	public Vertex getDestination() {
		return destination;
	}

	
	/**
	 * @param color the color to set
	 */
	public void setColor(Color color) {
		this.color = color;
	}

	
	/**
	 * @return the color
	 */
	public Color getColor() {
		return color;
	}

	
	/**
	 * @param marking the marking to set
	 */
	public void setMarking(String marking) {
		this.marking = marking;
	}

	
	/**
	 * @return the marking
	 */
	public String getMarking() {
		return marking;
	}

	
	/**
	 * Draws an undirected double edge directly from one vertex to another.
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawUndirectedDirectDoubleEdge(Graphics g) {
		g.drawLine( getSource().getXpos() + (getSource().getVertexDiameter()/3),
				getSource().getYpos() + (getSource().getVertexDiameter()/3), 
				getDestination().getXpos() + (getSource().getVertexDiameter()/3), 
				getDestination().getYpos() + (getSource().getVertexDiameter()/3));
		g.drawString(getMarking(), (getSource().getXpos() + getDestination().getXpos())/2, (getSource().getYpos() + getDestination().getYpos())/2);
	
		g.drawLine(getSource().getXpos() + ((2*getSource().getVertexDiameter())/3),
			  getSource().getYpos() + ((2*getSource().getVertexDiameter())/3), 
			  getDestination().getXpos() + ((2*getSource().getVertexDiameter())/3), 
			  getDestination().getYpos() + ((2*getSource().getVertexDiameter())/3));
		g.drawString(getMarking(), (getSource().getXpos() + getDestination().getXpos())/2 , (getSource().getYpos() + getDestination().getYpos())/2 + 35);		
	}

	
	/**
	 * Draws an undirected loop.
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawUndirectedLoop(Graphics g) {
		g.drawOval(getSource().getXpos()+ getSource().getVertexDiameter()/2, getSource().getYpos()+getSource().getVertexDiameter()/2, getSource().getVertexDiameter(), getSource().getVertexDiameter());		
	}

	
	/**
	 * Draws an undirected edge directly from one vertex to another.
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawUndirectedDirectEdge(Graphics g) {
		g.drawLine(getSource().getXpos() + getSource().getVertexDiameter()/2,
				getSource().getYpos() + getSource().getVertexDiameter()/2, 
				getDestination().getXpos() + getDestination().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2);					
	
		g.drawString(getMarking(), (getSource().getXpos() + getDestination().getXpos())/2, (getSource().getYpos() + getDestination().getYpos())/2);	
	}

	
	/**
	 * Draws an undirected angled loop. 
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawUndirectedAngeledLoop(Graphics g) {
		g.drawRect(getSource().getXpos()+ getSource().getVertexDiameter()/2, getSource().getYpos() + getSource().getVertexDiameter()/2, getSource().getVertexDiameter(), getSource().getVertexDiameter());
	}

	
	/**
	 * Draws an undirected angled edge from source vertex to destination vertex. 
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawUndirectedAngledEdge(Graphics g) {		
		g.drawLine(getSource().getXpos() + getSource().getVertexDiameter()/2, 
				getSource().getYpos() + getSource().getVertexDiameter()/2, 
				getSource().getXpos() + getSource().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2);
		
		g.drawLine(getSource().getXpos() + getSource().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2, 
				getDestination().getXpos() + getDestination().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2);	
	}
	
	
	/**
	 * Draws a directed edge directly from source vertex to destination vertex.
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawDirectedAngeledEdge(Graphics g) {
		createArrowDataForDirectEdges(EdgeStyle.Angled);
		
		g.drawLine(getSource().getXpos() + getSource().getVertexDiameter()/2, 
				getSource().getYpos() + getSource().getVertexDiameter()/2, 
				getSource().getXpos() + getSource().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2);
		
		g.drawLine(getSource().getXpos() + getSource().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2, 
				getDestination().getXpos() + getDestination().getVertexDiameter()/2, 
				getDestination().getYpos() + getDestination().getVertexDiameter()/2);
		g.fillPolygon(xPoints, yPoints, 3);
	}
	
	
	/**
	 * Draws a directed loop.
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawDirectedLoop(Graphics g) {
		createArrowDataForLoops();
		g.drawRect(getSource().getXpos() + getSource().getVertexDiameter()/2, getSource().getYpos() + getSource().getVertexDiameter()/2, 2*getSource().getVertexDiameter(), getSource().getVertexDiameter());
		g.fillPolygon(xPoints, yPoints, 3);
	}
	
	
	/**
	 * Draws a directed edge directly from source vertex to destination vertex.
	 * @param g Graphics object to draw to DrawArea.
	 */
	public void drawDirectedDirectEdge(Graphics g) {
		createArrowDataForDirectEdges(EdgeStyle.Direct);
		
		g.drawLine( getSource().getXpos() + getSource().getVertexDiameter()/2, getSource().getYpos() + getSource().getVertexDiameter()/2, (int)baseX, (int)baseY );	  
    	g.fillPolygon(xPoints, yPoints, 3);		
	}
	
	
	/**
	 * Creates an arrow for directed edges.
	 */
	private void createArrowDataForDirectEdges(EdgeStyle edgeStyle) {
		int sourceX = getSource().getXpos() + getSource().getVertexDiameter()/2;
		
		int sourceY;
		if(edgeStyle == EdgeStyle.Direct){
			sourceY = getSource().getYpos() + getSource().getVertexDiameter()/2;
		}
		else{
			sourceY = getDestination().getYpos() + getDestination().getVertexDiameter()/2;
		}
		int destinationX = getDestination().getXpos() + getDestination().getVertexDiameter()/2;
		int destinationY = getDestination().getYpos() + getDestination().getVertexDiameter()/2;
		
		createArrow(sourceX, sourceY, destinationX, destinationY);		
	}
	
	
	/**
	 * Creates an arrow for directed loops.
	 */
	private void createArrowDataForLoops() {
		int sourceX = getSource().getXpos() + getSource().getVertexDiameter()/2 + getSource().getVertexDiameter();		
		int sourceY = getSource().getYpos() + getSource().getVertexDiameter()/2;
		
		int destinationX = getDestination().getXpos() + getDestination().getVertexDiameter()/2;
		int destinationY = getDestination().getYpos() + getDestination().getVertexDiameter()/2;
		
		createArrow(sourceX, sourceY, destinationX, destinationY);			
	}
	
	
	/**
	 * Creates data to draw an arrow for directed edges.
	 * @param sourceX x position of the source vertex.
	 * @param sourceY y position of the source vertex.
	 * @param destinationX x position of the destination vertex.
	 * @param destinationY y position of the destination vertex.
	 */
	private void createArrow(int sourceX, int sourceY, int destinationX,int destinationY) {
		xPoints = new int[ 3 ] ;
		yPoints = new int[ 3 ] ;
		
	    float arrowWidth = 10.0f ;
	    float theta = 0.423f ;
	    float[] vecLine = new float[ 2 ] ;
	    float[] vecLeft = new float[ 2 ] ;
	    float fLength;
	    float th;
	    float ta;

	    xPoints[ 0 ] = destinationX ;
	    yPoints[ 0 ] = destinationY ;

	    // build the line vector
	    vecLine[ 0 ] = (float)xPoints[ 0 ] - sourceX ;
	    vecLine[ 1 ] = (float)yPoints[ 0 ] - sourceY ;

	    // build the arrow base vector - normal to the line
	    vecLeft[ 0 ] = -vecLine[ 1 ] ;
	    vecLeft[ 1 ] = vecLine[ 0 ] ;

	    // setup length parameters
	    fLength = (float)Math.sqrt( vecLine[0] * vecLine[0] + vecLine[1] * vecLine[1] ) ;
	    th = arrowWidth / ( 2.0f * fLength ) ;
	    ta = arrowWidth / ( 2.0f * ( (float)Math.tan( theta ) / 2.0f ) * fLength ) ;

	    // find the base of the arrow
	    baseX = ( (float)xPoints[ 0 ] - ta * vecLine[0]);
	    baseY = ( (float)yPoints[ 0 ] - ta * vecLine[1]);

	    // build the points on the sides of the arrow
	    xPoints[ 1 ] = (int)( baseX + th * vecLeft[0] );
	    yPoints[ 1 ] = (int)( baseY + th * vecLeft[1] );
	    xPoints[ 2 ] = (int)( baseX - th * vecLeft[0] );
	    yPoints[ 2 ] = (int)( baseY - th * vecLeft[1] );
	}
}