package net.sourceforge.fenixedu.domain.accessControl;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import net.sourceforge.fenixedu.domain.Person;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.Argument;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.GroupBuilder;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.StaticArgument;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.exceptions.WrongNumberOfArgumentsException;

/**
 * Predicate group that accepts or rejects every person based on the boolean
 * flag given in it's construction.
 * 
 * @author pcma
 */
public class IfTrueGroup extends LeafGroup {

    /**
     * Default serialization id.
     */
    private static final long serialVersionUID = 1L;

    private final boolean flag;

    public IfTrueGroup(boolean flag) {
	super();

	this.flag = flag;
    }

    protected boolean isFlag() {
	return flag;
    }

    @Override
    public boolean isMember(Person person) {
	return this.flag;
    }

    @Override
    public Set<Person> getElements() {
	if (this.flag) {
	    return new HashSet<Person>(Person.readAllPersons());
	} else {
	    return Collections.emptySet();
	}
    }

    @Override
    protected Argument[] getExpressionArguments() {
	return new Argument[] { new StaticArgument(flag) };
    }

    public static class Builder implements GroupBuilder {

	public Group build(Object[] arguments) {
	    if (arguments.length != 1) {
		throw new WrongNumberOfArgumentsException(arguments.length, getMinArguments(), getMaxArguments());
	    }

	    return new IfTrueGroup(Boolean.valueOf(String.valueOf(arguments[0])));
	}

	public int getMaxArguments() {
	    return 1;
	}

	public int getMinArguments() {
	    return 1;
	}

    }
}