package edu.stanford.rt.credential;

import java.util.*;

import edu.stanford.rt.util.*;
import edu.stanford.rt.datatype.*;

/**
 * @author Ninghui Li, Sandra Qiu<br>
 * 
 * Implementation of <code>RoleTerm</code> element.  Each RoleTerm object 
 * has  a reference to its corresponding RoleDeclaration object and stores 
 * its parameter values, if any.
 * 
 */
public class RoleTerm
{
	// The corresponding role declaration.
	private RoleDeclaration roleDeclaration;

	// Stores parameter values according to the prefix positions in role declaration.
	private ValueSet[] paramValues;

    /**
     * Constructor for RoleTerm.
     * 
     * @param roleDeclaration
     *      corresponding role declaration.
     */
	public RoleTerm(RoleDeclaration roleDeclaration)
	{
		this.roleDeclaration = roleDeclaration;
		this.paramValues =
			new ValueSet[roleDeclaration.getTotalPrefixes() + 1];
		this.paramValues[0] = null;
	}

	/**
	 * Returns the roleDeclaration.
	 * @return RoleDeclaration  
	 * 		The corresonding role decalration for this role term.
	 */
	public RoleDeclaration getRoleDeclaration()
	{
		return roleDeclaration;
	}

	/**
	 * Method putParameterValue.
     *      puts parameter value according to the position of the 
     *      its prefix.
	 * @param prefix
     *      the parameter prefix
	 * @param parameterValue
     *      the parameter value
	 */
	public void putParameterValue(
		String prefix,
		ValueSet parameterValue)
	{
		//RTUtil.debugInfo("RoleTerm.putParameterValue().roleDeclaration = " 
		//          +roleDeclaration.getName());
		RTUtil.debugInfo(
			"RoleTerm.putParameterValue().prefix = " + prefix);

		int index = roleDeclaration.getPosition(prefix);
		RTUtil.debugInfo(
			"RoleTerm.putParameterValue().index = " + index);
		// empty element for index 0
		paramValues[index] = parameterValue;
	}

	/**
	 * Method getParameterValue.
	 * @param prefix
	 * @return ValueSet
	 */
	public ValueSet getParameterValue(String prefix)
	{
		int index = roleDeclaration.getPosition(prefix);
		return paramValues[index];
	}

	/**
	 * Method getParameterValueAt.
	 * @param index
	 * @return ValueSet
	 */
	public ValueSet getParameterValueAt(int index)
	{
		return paramValues[index];
	}

	/**
	 * Method getParameterType.
	 * @param parameterName
	 * @return DataType
	 * @throws DomainSpecException
	 */
	public DataType getParameterType(String parameterName)
		throws DomainSpecException
	{
		return roleDeclaration.getParameterType(parameterName);
	}

	public String toString(String indent)
	{
		String thisIndent = indent + "  ";
		StringBuffer sb = new StringBuffer();
		sb.append(thisIndent).append("RoleTerm: \n");
		sb.append(thisIndent + "  ").append(
			"Corresponding role declaration: ");
		sb.append(roleDeclaration.getName()).append("\n");
		sb.append(thisIndent + "  ").append("Parameters: \n");
		for (int i = 1; i < paramValues.length; i++)
		{
			if (paramValues[i] != null
				&& !isParameterValueNull(paramValues[i]))
				sb
					.append(thisIndent + "    ")
					.append(paramValues[i].toString(thisIndent))
					.append("\n");
		}

		return sb.toString();
	}
    
    /**
     * Method isParameterValueNull.
     *      checks if the parameter value is null. It can be null when 
     *      the parameter has <code>Equals</code> or <code>Special Principal</code>
     *      child element.
     * @param paramValue
     * @return boolean
     */
    public boolean isParameterValueNull(ValueSet paramValue)
    {
        if (paramValue == null)
            return true;

        if (!(paramValue instanceof TreeValueSet)
            && !(paramValue instanceof IntervalValueSet)
            && !(paramValue instanceof SetValueSet)
            && !(paramValue instanceof SingletonValueSet))
            return true;
        else
            return false;
    }



}