package org.simantics.interop.mapping.data;


import org.simantics.utils.datastructures.hints.HintContext;

public class Link <T> extends HintContext {
	private GraphNode<T> from;
	private GraphNode<T> to;
	private String name;
	
	private Link<T> inverseLink;
	private Link<T> mainLink;

	Link(GraphNode<T> from, String name, GraphNode<T> to) {
		this.from = from;
		this.to = to;
		this.name = name;
	}
	
	public GraphNode<T> from() {
		return from;
	}
	
	public GraphNode<T> to() {
		return to;
	}
	
	public String getName() {
		return name;
	}
	
	void setInverseLink(Link<T> inverseLink) {
		this.inverseLink = inverseLink;
	}
	
	void setMainLink(Link<T> mainLink) {
		this.mainLink = mainLink;
	}
	
	public String getInverseName() {
		if (inverseLink != null)
			return inverseLink.getName();
		if (mainLink != null)
			return mainLink.getName();
		return null;
	}
	
	public boolean hasInverse() {
		return inverseLink != null || mainLink != null;
	}
	
	public Link<T> getInverse() {
		if (inverseLink != null)
			return inverseLink;
		if (mainLink != null)
			return mainLink;
		return null;
	}
	
	public boolean isInverse() {
		return mainLink != null;
	}
	
	public boolean isMain() {
		return inverseLink != null;
	}
	
	@Override
	public boolean equals(Object obj) {
		if (!obj.getClass().equals(getClass()))
			return false;
		Link<?> other = (Link<?>)obj;
		if (!from.equals(other.from))
			return false;
		if (!to.equals(other.to))
			return false;
		if (!GraphNode.equals(name,other.name))
			return false;
		return true;
		
	}
	
	@Override
	public int hashCode() {
		return from.hashCode() * to.hashCode() + name.hashCode();
	}
	
	@Override
    public void setHint(Key key, Object value) {
		if (value == null)
			return;
		super.setHint(key, value);
	}

	
	public String toString() {
		return name + "/" + getInverseName() + " -> " + to.toString();
	}
}