package luan.impl;

import luan.Luan;
import luan.LuanFunction;
import luan.LuanState;
import luan.LuanException;
import luan.LuanCloner;
import luan.LuanCloneable;
import luan.LuanJavaOk;


public abstract class Closure extends LuanFunction implements LuanCloneable, Cloneable {
	protected Pointer[] upValues;
	protected LuanJavaOk javaOk;
	private LuanCloner cloner;

	public Closure(int nUpValues,LuanJavaOk javaOk) throws LuanException {
		this.upValues = new Pointer[nUpValues];
		this.javaOk = javaOk;
	}

	@Override public Closure shallowClone() {
		check();
		try {
			return (Closure)clone();
		} catch(CloneNotSupportedException e) {
			throw new RuntimeException(e);
		}
	}

	@Override public void deepenClone(LuanCloneable dc,LuanCloner cloner) {
		Closure clone = (Closure)dc;
		switch( cloner.type ) {
		case COMPLETE:
			clone.upValues = (Pointer[])cloner.clone(upValues);
			clone.javaOk = (LuanJavaOk)cloner.clone(javaOk);
			return;
		case INCREMENTAL:
			clone.cloner = cloner;
			clone.upValues = upValues;
			clone.javaOk = javaOk;
			return;
		}
	}

	private void check() {
		if( cloner != null ) {
			upValues = (Pointer[])cloner.clone(upValues);
			javaOk = (LuanJavaOk)cloner.clone(javaOk);
			cloner = null;
		}
	}

	@Override public final Object call(LuanState luan,Object[] args) throws LuanException {
		if( luan.isLocked )
			throw new RuntimeException("luan is locked");
		check();
		LuanJavaOk old = luan.javaOk;
		luan.javaOk = javaOk;
		try {
			return doCall(luan,args);
		} catch(StackOverflowError e) {
			throw new LuanException( "stack overflow" );
		} finally {
			luan.javaOk = old;
		}	
	}

	public abstract Object doCall(LuanState luan,Object[] args) throws LuanException;
}