package edu.stanford.rt.datatype;

import java.util.*;

import edu.stanford.rt.credential.*;

/**
 * @author Ninghui Li, Sandra Qiu<br>
 * 
    A SetValueSet object contains a set of DataValue objects, which are 
    instances of  IntegerValue, DecimalValue, StringValue, EnumValue, 
    or PrincipalValue. All members have the same type.
 */
public class SetValueSet extends ValueSet
{
	private HashSet values;

	/**
	 * Constructor for an empty SetValueSet object.
	 */
	public SetValueSet(SimpleType type)
	{
		super(type);
		this.values = new HashSet();

	}

	/**
	 * Constructor for SetValueSet.
	 */
	public SetValueSet(SimpleType type, HashSet values)
		throws DomainSpecException
	{
		super(type);
		this.values = new HashSet();

		Iterator it = values.iterator();
		while (it.hasNext())
		{
			Object o = it.next();
			if (o == null)
				continue;

			if (!(o instanceof IntegerValue)
				&& !(o instanceof DecimalValue)
				&& !(o instanceof StringValue)
				&& !(o instanceof EnumValue)
				&& !(o instanceof PrincipalValue))
			{
				throw new DomainSpecException("Illegal argument type");
			}

			this.values.add((DataValue) o);
		}

	}

	/**
	    Add a data value to this set.
	    Exception is thrown if the given value is not an instance of 
	    IntegerValue, DecimalValue, StringValue, EnumValue, or PrincipalValue.
	*/
	public synchronized void addValue(DataValue value)
		throws DomainSpecException
	{
		if (value != null)
		{
			if (!(value instanceof IntegerValue)
				|| !(value instanceof DecimalValue)
				|| !(value instanceof StringValue)
				|| !(value instanceof EnumValue)
				|| !(value instanceof PrincipalValue))
			{
				throw new DomainSpecException("Illegal argument type");
			}

			this.values.add(value);
		}
	}

	/** Returns an unmodifiable view of the values.*/
	public Set getValues()
	{
		return Collections.unmodifiableSet(values);
	}

	/* (non-Javadoc)
	 * @see edu.stanford.rt.datatype.ValueSet#toString(String)
	 */
	public String toString(String indent)
	{
		String thisIndent = indent + "  ";
		StringBuffer sb = new StringBuffer();
		sb.append(thisIndent).append("SetValueSet: \n");
		sb.append(thisIndent + "  ").append(
			getType().toString()).append(
			"\n");
		Iterator it = values.iterator();
		while (it.hasNext())
		{
			DataValue value = (DataValue) it.next();
			sb.append(thisIndent + "  ").append(
				value.toString()).append(
				"\n");
		}

		return sb.toString();
	}

}