package org.bouncycastle.asn1.x509;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERSequence;

import java.util.Enumeration;

Target information extension for attributes certificates according to RFC
3281.
          SEQUENCE OF Targets

/**
 * Target information extension for attributes certificates according to RFC
 * 3281.
 * 
 * <pre>
 *           SEQUENCE OF Targets
 * </pre>
 * 
 */
public class TargetInformation
    extends ASN1Encodable
{
    private ASN1Sequence targets;

    
Creates an instance of a TargetInformation from the given object.

obj can be a TargetInformation or a ASN1Sequence 
Params:
obj – The object.
Throws:
IllegalArgumentException – if the given object cannot be
            interpreted as TargetInformation.
Returns:
A TargetInformation instance./**
     * Creates an instance of a TargetInformation from the given object.
     * <p>
     * <code>obj</code> can be a TargetInformation or a {@link ASN1Sequence}
     * 
     * @param obj The object.
     * @return A TargetInformation instance.
     * @throws IllegalArgumentException if the given object cannot be
     *             interpreted as TargetInformation.
     */
    public static TargetInformation getInstance(Object obj)
    {
        if (obj instanceof TargetInformation)
        {
            return (TargetInformation) obj;
        }
        else if (obj instanceof ASN1Sequence)
        {
            return new TargetInformation((ASN1Sequence) obj);
        }

        throw new IllegalArgumentException("unknown object in factory: "
            + obj.getClass());
    }

    
Constructor from a ASN1Sequence.
Params:
seq – The ASN1Sequence.
Throws:
IllegalArgumentException – if the sequence does not contain
            correctly encoded Targets elements./**
     * Constructor from a ASN1Sequence.
     * 
     * @param seq The ASN1Sequence.
     * @throws IllegalArgumentException if the sequence does not contain
     *             correctly encoded Targets elements.
     */
    private TargetInformation(ASN1Sequence seq)
    {
        targets = seq;
    }

    
Returns the targets in this target information extension.
Returns:
Returns the targets./**
     * Returns the targets in this target information extension.
     * 
     * @return Returns the targets.
     */
    public Targets[] getTargetsObjects()
    {
        Targets[] copy = new Targets[targets.size()];
        int count = 0;
        for (Enumeration e = targets.getObjects(); e.hasMoreElements();)
        {
            copy[count++] = Targets.getInstance(e.nextElement());
        }
        return copy;
    }

    
Constructs a target information from a single targets element. 
According to RFC 3281 only one targets element must be produced.
Params:
targets – A Targets instance./**
     * Constructs a target information from a single targets element. 
     * According to RFC 3281 only one targets element must be produced.
     * 
     * @param targets A Targets instance.
     */
    public TargetInformation(Targets targets)
    {
        this.targets = new DERSequence(targets);
    }

    
According to RFC 3281 only one targets element must be produced. If
multiple targets are given they must be merged in
into one targets element.
Params:
targets – An array with Targets./**
     * According to RFC 3281 only one targets element must be produced. If
     * multiple targets are given they must be merged in
     * into one targets element.
     *
     * @param targets An array with {@link Targets}.
     */
    public TargetInformation(Target[] targets)
    {
        this(new Targets(targets));
    }

    
Produce an object suitable for an ASN1OutputStream.
Returns:
         SEQUENCE OF Targets

 According to RFC 3281 only one targets element must be produced. If multiple targets are given in the constructor they are merged into one targets element. If this was produced from a ASN1Sequence the encoding is kept. 
Returns:
a DERObject/**
     * Produce an object suitable for an ASN1OutputStream.
     * 
     * Returns:
     * 
     * <pre>
     *          SEQUENCE OF Targets
     * </pre>
     * 
     * <p>
     * According to RFC 3281 only one targets element must be produced. If
     * multiple targets are given in the constructor they are merged into one
     * targets element. If this was produced from a
     * {@link org.bouncycastle.asn1.ASN1Sequence} the encoding is kept.
     * 
     * @return a DERObject
     */
    public DERObject toASN1Object()
    {
        return targets;
    }
}