package org.simantics.interop.update.model;

import org.simantics.db.Resource;
import org.simantics.db.Statement;
import org.simantics.db.WriteGraph;
import org.simantics.db.exception.DatabaseException;
import org.simantics.interop.test.GraphChanges;
import org.simantics.utils.datastructures.Pair;

public class PropertyChange {
	protected GraphChanges changes;
	protected Pair<Statement, Statement> pair;
	protected boolean applied = false;
	protected boolean selected = false;
	protected boolean visible = true;
	
	
	public PropertyChange(GraphChanges changes, Statement first, Statement second) {
		if (first == null && second == null)
			throw new IllegalArgumentException("At least one of the stamenents must be non null.");
		this.pair = new Pair<Statement, Statement>(first, second);
		this.changes = changes;
	}
	
	public PropertyChange(GraphChanges changes, Pair<Statement, Statement> change) {
		if (change == null || (change.first == null && change.second == null))
			throw new IllegalArgumentException("At least one of the stamenents must be non null.");
		this.pair = change;
		this.changes = changes;
	}
	
	public Statement getFirst() {
		return pair.first;
	}
	
	public Statement getSecond() {
		return pair.second;
	}
	
	public GraphChanges getChanges() {
		return changes;
	}
	
	@Override
	public int hashCode() {
		return pair.hashCode();
	}
	
	@Override
	public boolean equals(Object obj) {
		if (obj == null)
			return false;
		if (obj.getClass() != this.getClass())
			return false;
		PropertyChange c = (PropertyChange)obj;
		return pair.equals(c.pair);
	}
	
	public void apply(WriteGraph graph) throws DatabaseException {
		if (applied)
			return;
		if (pair.second == null) {
			graph.deny(pair.first);
			return;
		} 
		Resource s = changes.getComparable().getLeft(pair.second.getSubject());
		//Resource s = pair.first.getSubject();
		Resource pred = pair.second.getPredicate();
		if (graph.hasValue(pair.second.getObject())) {
			Object value = graph.getValue(pair.second.getObject());
			graph.claimLiteral(s, pred, value);
		} else {
			graph.deny(s,pred);
		}
		applied = true;
		
	}
	
	public boolean select(boolean select) {
		if (applied)
			return false;
		this.selected = select;
		return true;
	}
	
	
	public boolean selected() {
		return selected;
	}
	
	public boolean applied() {
		return applied;
	}
	
	public boolean isVisible() {
		return visible;
	}
	
	public void setVisible(boolean visible) {
		this.visible = visible;
	}
	
	@Override
	public String toString() {
		String s = "PropertyChange";
		if (pair.first != null)
			s += " (" + (pair.first.getSubject()) + " , " + pair.first.getPredicate() + " , " + pair.first.getObject() + ")";
		if (pair.second != null)
			s += " (" + (pair.second.getSubject()) + " , " + pair.second.getPredicate() + " , " + pair.second.getObject() + ")";
		return s;
	}
	
}