package net.sourceforge.fenixedu.domain.accessControl;

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

import net.sourceforge.fenixedu.applicationTier.IUserView;
import net.sourceforge.fenixedu.domain.Person;
import net.sourceforge.fenixedu.domain.Role;
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.GroupDynamicExpressionException;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.exceptions.WrongNumberOfArgumentsException;
import net.sourceforge.fenixedu.domain.accessControl.groups.language.exceptions.WrongTypeOfArgumentException;
import net.sourceforge.fenixedu.domain.exceptions.DomainException;
import net.sourceforge.fenixedu.domain.person.RoleType;

/**
 * 
 * @author cfgi
 */
public class RoleGroup extends LeafGroup {

    private static final long serialVersionUID = 1L;

    private final RoleType roleType;

    public RoleGroup(RoleType roleType) {
	super();

	if (roleType == null) {
	    throw new DomainException("accessControl.group.domainBacked.null");
	}

	this.roleType = roleType;
    }

    public RoleGroup(Role role) {
	this(role == null ? null : role.getRoleType());
    }

    public Role getRole() {
	return Role.getRoleByRoleType(roleType);
    }

    @Override
    public int getElementsCount() {
	return getRole().getAssociatedPersonsCount();
    }

    @Override
    public Set<Person> getElements() {
	Set<Person> elements = new HashSet<Person>();
	elements.addAll(getRole().getAssociatedPersons());
	return elements;
    }

    /**
     * The host may have restriction on the roles available so checking if a
     * <tt>UserView</tt> is allowed or checking directly is a person is member
     * of this groups has different behaviours. The <tt>UserView</tt> as all the
     * person roles that are allowed in the current host while the person has
     * all the roles assigned to it.
     * 
     * <p>
     * This method checks if the <tt>UserView</tt> contains the same role as
     * this group.
     */
    @Override
    public boolean allows(IUserView userView) {
	return userView != null && userView.hasRoleType(roleType);
    }

    @Override
    public boolean isMember(Person person) {
	return person != null && person.hasRole(roleType);
    }

    @Override
    protected Argument[] getExpressionArguments() {
	return new Argument[] { new StaticArgument(roleType.getName()) };
    }

    @Override
    public boolean equals(Object obj) {
	if (!(obj instanceof RoleGroup)) {
	    return false;
	}

	return this.roleType.equals(((RoleGroup) obj).roleType);
    }

    @Override
    public int hashCode() {
	return this.roleType.hashCode();
    }

    @Override
    public String getName() {
	return new RoleTypeGroup(roleType).getName();
    }

    /**
     * Builder used to create a RoleGroup from a group expression.
     * 
     * @author cfgi
     */
    public static class Builder implements GroupBuilder {

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

	    try {
		String roleName = (String) arguments[0];
		RoleType roleType = RoleType.valueOf(roleName);

		if (roleType == null) {
		    throw new GroupDynamicExpressionException("accessControl.group.builder.role.type.notAvailable", roleName);
		}

		return new RoleGroup(roleType);
	    } catch (ClassCastException e) {
		throw new WrongTypeOfArgumentException(1, String.class, arguments[0].getClass());
	    } catch (IllegalArgumentException e) {
		throw new GroupDynamicExpressionException("accessControl.group.builder.role.type.doesNotExist", String
			.valueOf(arguments[0]));
	    }
	}

	public int getMinArguments() {
	    return 1;
	}

	public int getMaxArguments() {
	    return 1;
	}

    }

}