package net.sourceforge.fenixedu.domain.accessControl;

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

import net.sourceforge.fenixedu.commons.CollectionUtils;
import net.sourceforge.fenixedu.domain.Attends;
import net.sourceforge.fenixedu.domain.ExecutionCourse;
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.exceptions.GroupDynamicExpressionException;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.operators.IdOperator;

import org.apache.commons.collections.Transformer;

public class ExecutionCourseStudentsGroup extends ExecutionCourseGroup {

    private static final long serialVersionUID = 1L;

    private class AttendPersonTransformer implements Transformer {
	public Object transform(Object object) {
	    Attends attend = (Attends) object;
	    return attend.getRegistration().getPerson();
	}
    }

    public ExecutionCourseStudentsGroup(ExecutionCourse executionCourse) {
	super(executionCourse);
    }

    @Override
    public int getElementsCount() {
	return this.getExecutionCourse().getAttendsCount();
    }

    @Override
    public Set<Person> getElements() {
	return super.freezeSet(new HashSet<Person>(CollectionUtils.collect(getExecutionCourse().getAttends(),
		new AttendPersonTransformer())));
    }

    @Override
    public boolean isMember(Person person) {
	if (person != null && person.hasStudent() && hasExecutionCourse()) {
	    for (final Attends attends : getExecutionCourse().getAttendsSet()) {
		if (attends.getRegistration().getStudent() == person.getStudent()) {
		    return true;
		}
	    }
	}
	return false;
    }

    @Override
    protected Argument[] getExpressionArguments() {
	return new Argument[] { new IdOperator(getObject()) };
    }

    public static class Builder implements GroupBuilder {

	public Group build(Object[] arguments) {
	    try {
		return new ExecutionCourseStudentsGroup((ExecutionCourse) arguments[0]);
	    } catch (ClassCastException e) {
		throw new GroupDynamicExpressionException("accessControl.group.builder.executionCourse.notExecutionCourse",
			arguments[0].toString());
	    }
	}

	public int getMinArguments() {
	    return 0;
	}

	public int getMaxArguments() {
	    return 1;
	}

    }
}