package org.bouncycastle.asn1.cms;

import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DEREncodable;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERTaggedObject;

public class SignerIdentifier
    implements DEREncodable
{
	private DEREncodable id;
	
	public SignerIdentifier(
        IssuerAndSerialNumber id)
    {
        this.id = id;
	}
	
	public SignerIdentifier(
        ASN1OctetString id)
    {
        this.id = new DERTaggedObject(false, 0, id);
	}
	
	public SignerIdentifier(
        DERObject id)
    {
        this.id = id;
	}
	
    /**
     * return a SignerIdentifier object from the given object.
     *
     * @param o the object we want converted.
     * @exception IllegalArgumentException if the object cannot be converted.
     */
	public static SignerIdentifier getInstance(
        Object o)
    {
		if (o == null || o instanceof SignerIdentifier)
        {
			return (SignerIdentifier)o;
		}
		
		if (o instanceof IssuerAndSerialNumber)
        {
			return new SignerIdentifier((IssuerAndSerialNumber)o);
		}
		
		if (o instanceof ASN1OctetString)
        {
			return new SignerIdentifier((ASN1OctetString)o);
		}
		
		if (o instanceof DERObject)
        {
			return new SignerIdentifier((DERObject)o);
		}
		
		throw new IllegalArgumentException(
             "Illegal object in SignerIdentifier: " + o.getClass().getName());
	} 

    public boolean isTagged()
    {
        return (id instanceof ASN1TaggedObject);
    }

	public DEREncodable getId()
    {
        if (id instanceof ASN1TaggedObject)
        {
            return ASN1OctetString.getInstance((ASN1TaggedObject)id, false);
        }

		return id;
	}

    /** 
     * Produce an object suitable for an ASN1OutputStream.
     * <pre>
     * SignerIdentifier ::= CHOICE {
     * 	issuerAndSerialNumber IssuerAndSerialNumber,
     * 	subjectKeyIdentifier [0] SubjectKeyIdentifier 
     * }
     *
     * SubjectKeyIdentifier ::= OCTET STRING
     * </pre>
     */
	public DERObject getDERObject()
    {
        return id.getDERObject();
	}
}
