package org.bouncycastle.asn1.cms;

import java.util.Enumeration;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1Set;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.BERSequence;
import org.bouncycastle.asn1.DEREncodable;
import org.bouncycastle.asn1.DERInteger;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERTaggedObject;

public class EnvelopedData
    implements DEREncodable
{
	private DERInteger              version;
	private OriginatorInfo          originatorInfo;
	private ASN1Set                 recipientInfos;
	private EncryptedContentInfo    encryptedContentInfo;
	private ASN1Set                 unprotectedAttrs;

	public EnvelopedData(
        OriginatorInfo          originatorInfo,
        ASN1Set                 recipientInfos,
        EncryptedContentInfo    encryptedContentInfo,
        ASN1Set                 unprotectedAttrs)
    {
        if (originatorInfo != null || unprotectedAttrs != null)
        {
			version = new DERInteger(2);
		}
		else
        {
			version = new DERInteger(0);

            Enumeration e = recipientInfos.getObjects();

            while (e.hasMoreElements())
            {
                RecipientInfo   ri = RecipientInfo.getInstance(e.nextElement());

                if (!ri.getVersion().equals(version))
                {
                    version = new DERInteger(2);
                    break;
                }
            }
		}

		this.originatorInfo = originatorInfo;
		this.recipientInfos = recipientInfos;
		this.encryptedContentInfo = encryptedContentInfo;
		this.unprotectedAttrs = unprotectedAttrs;
	}
	                     
	public EnvelopedData(
        ASN1Sequence seq)
    {
		int     index = 0;
		
		version = (DERInteger)seq.getObjectAt(index++);
		
		Object  tmp = seq.getObjectAt(index++);

		if (tmp instanceof ASN1TaggedObject)
        {
			originatorInfo = OriginatorInfo.getInstance((ASN1TaggedObject)tmp, false);
			tmp = seq.getObjectAt(index++);
		}

		recipientInfos = ASN1Set.getInstance(tmp);
		
		encryptedContentInfo = EncryptedContentInfo.getInstance(seq.getObjectAt(index++));
		
		if(seq.size() > index)
        {
			unprotectedAttrs = ASN1Set.getInstance((ASN1TaggedObject)seq.getObjectAt(index), false);
		}
	}
	
    /**
     * return an EnvelopedData object from a tagged object.
     *
     * @param obj the tagged object holding the object we want.
     * @param explicit true if the object is meant to be explicitly
     *              tagged false otherwise.
     * @exception IllegalArgumentException if the object held by the
     *          tagged object cannot be converted.
     */
	public static EnvelopedData getInstance(
        ASN1TaggedObject obj,
        boolean explicit)
    {
		return getInstance(ASN1Sequence.getInstance(obj, explicit));
	}
	
    /**
     * return an EnvelopedData object from the given object.
     *
     * @param obj the object we want converted.
     * @exception IllegalArgumentException if the object cannot be converted.
     */
	public static EnvelopedData getInstance(
        Object obj)
    {
		if (obj == null || obj instanceof EnvelopedData)
        {
			return (EnvelopedData)obj;
		}
		
		if (obj instanceof ASN1Sequence)
        {
			return new EnvelopedData((ASN1Sequence)obj);
		}
		
		throw new IllegalArgumentException("Invalid EnvelopedData: " + obj.getClass().getName());
	}

	public DERInteger getVersion()
    {
		return version;
	}
	
	public OriginatorInfo getOriginatorInfo()
    {
		return originatorInfo;
	}

	public ASN1Set getRecipientInfos()
    {
		return recipientInfos;
	}

	public EncryptedContentInfo getEncryptedContentInfo()
    {
		return encryptedContentInfo;
	}

	public ASN1Set getUnprotectedAttrs()
    {
		return unprotectedAttrs;
	}

    /** 
     * <pre>
     * EnvelopedData ::= SEQUENCE {
     * 	version CMSVersion,
     * 	originatorInfo [0] IMPLICIT OriginatorInfo OPTIONAL,
     * 	recipientInfos RecipientInfos,
     * 	encryptedContentInfo EncryptedContentInfo,
     * 	unprotectedAttrs [1] IMPLICIT UnprotectedAttributes OPTIONAL 
     * }
     * </pre>
     */
	public DERObject getDERObject()
    {
        ASN1EncodableVector  v = new ASN1EncodableVector();
		
		v.add(version);

		if (originatorInfo != null)
        {
			v.add(new DERTaggedObject(false, 0, originatorInfo));
		}

		v.add(recipientInfos);
		v.add(encryptedContentInfo);

		if (unprotectedAttrs != null)
        {
			v.add(new DERTaggedObject(false, 1, unprotectedAttrs));
		}
		
		return new BERSequence(v);
	}
}
