package org.bouncycastle.tsp.cms;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;

import org.bouncycastle.asn1.BERTags;
import org.bouncycastle.asn1.DERIA5String;
import org.bouncycastle.asn1.cms.AttributeTable;
import org.bouncycastle.asn1.cms.CMSObjectIdentifiers;
import org.bouncycastle.asn1.cms.ContentInfoParser;
import org.bouncycastle.asn1.cms.TimeStampedDataParser;
import org.bouncycastle.cms.CMSContentInfoParser;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.operator.DigestCalculator;
import org.bouncycastle.operator.DigestCalculatorProvider;
import org.bouncycastle.operator.OperatorCreationException;
import org.bouncycastle.tsp.TimeStampToken;
import org.bouncycastle.util.io.Streams;

public class CMSTimeStampedDataParser
    extends CMSContentInfoParser
{
    private TimeStampedDataParser timeStampedData;
    private TimeStampDataUtil util;

    public CMSTimeStampedDataParser(InputStream in)
        throws CMSException
    {
        super(in);

        initialize(_contentInfo);
    }

    public CMSTimeStampedDataParser(byte[] baseData)
        throws CMSException
    {
        this(new ByteArrayInputStream(baseData));
    }

    private void initialize(ContentInfoParser contentInfo)
        throws CMSException
    {
        try
        {
            if (CMSObjectIdentifiers.timestampedData.equals(contentInfo.getContentType()))
            {
                this.timeStampedData = TimeStampedDataParser.getInstance(contentInfo.getContent(BERTags.SEQUENCE));
            }
            else
            {
                throw new IllegalArgumentException("Malformed content - type must be " + CMSObjectIdentifiers.timestampedData.getId());
            }
        }
        catch (IOException e)
        {
            throw new CMSException("parsing exception: " + e.getMessage(), e);
        }
    }

    public byte[] calculateNextHash(DigestCalculator calculator)
        throws CMSException
    {
        return util.calculateNextHash(calculator);
    }

    public InputStream getContent()
    {
        if (timeStampedData.getContent() != null)
        {
            return timeStampedData.getContent().getOctetStream();
        }

        return null;
    }

    public URI getDataUri()
        throws URISyntaxException
    {
        DERIA5String dataURI = this.timeStampedData.getDataUri();

        if (dataURI != null)
        {
           return new URI(dataURI.getString());
        }

        return null;
    }

    public String getFileName()
    {
        return util.getFileName();
    }

    public String getMediaType()
    {
        return util.getMediaType();
    }

    public AttributeTable getOtherMetaData()
    {
        return util.getOtherMetaData();
    }

    
Initialise the passed in calculator with the MetaData for this message, if it is
required as part of the initial message imprint calculation.
Params:
calculator – the digest calculator to be initialised.
Throws:
CMSException – if the MetaData is required and cannot be processed/**
     * Initialise the passed in calculator with the MetaData for this message, if it is
     * required as part of the initial message imprint calculation.
     *
     * @param calculator the digest calculator to be initialised.
     * @throws CMSException if the MetaData is required and cannot be processed
     */
    public void initialiseMessageImprintDigestCalculator(DigestCalculator calculator)
        throws CMSException
    {
        util.initialiseMessageImprintDigestCalculator(calculator);
    }

    
Returns an appropriately initialised digest calculator based on the message imprint algorithm
described in the first time stamp in the TemporalData for this message. If the metadata is required
to be included in the digest calculation, the returned calculator will be pre-initialised.
Params:
calculatorProvider –  a provider of DigestCalculator objects.
Throws:
OperatorCreationException – if the provider is unable to create the calculator.
Returns:
an initialised digest calculator./**
     * Returns an appropriately initialised digest calculator based on the message imprint algorithm
     * described in the first time stamp in the TemporalData for this message. If the metadata is required
     * to be included in the digest calculation, the returned calculator will be pre-initialised.
     *
     * @param calculatorProvider  a provider of DigestCalculator objects.
     * @return an initialised digest calculator.
     * @throws OperatorCreationException if the provider is unable to create the calculator.
     */
    public DigestCalculator getMessageImprintDigestCalculator(DigestCalculatorProvider calculatorProvider)
        throws OperatorCreationException
    {
        try
        {
            parseTimeStamps();
        }
        catch (CMSException e)
        {
            throw new OperatorCreationException("unable to extract algorithm ID: " + e.getMessage(), e);
        }

        return util.getMessageImprintDigestCalculator(calculatorProvider);
    }

    public TimeStampToken[] getTimeStampTokens()
        throws CMSException
    {
        parseTimeStamps();

        return util.getTimeStampTokens();
    }

    
Validate the digests present in the TimeStampTokens contained in the CMSTimeStampedData.
Params:
calculatorProvider – provider for digest calculators
dataDigest – the calculated data digest for the message
Throws:
ImprintDigestInvalidException – if an imprint digest fails to compare
CMSException –  if an exception occurs processing the message./**
     * Validate the digests present in the TimeStampTokens contained in the CMSTimeStampedData.
     *
     * @param calculatorProvider provider for digest calculators
     * @param dataDigest the calculated data digest for the message
     * @throws ImprintDigestInvalidException if an imprint digest fails to compare
     * @throws CMSException  if an exception occurs processing the message.
     */
    public void validate(DigestCalculatorProvider calculatorProvider, byte[] dataDigest)
        throws ImprintDigestInvalidException, CMSException
    {
        parseTimeStamps();

        util.validate(calculatorProvider, dataDigest);
    }

    
Validate the passed in timestamp token against the tokens and data present in the message.
Params:
calculatorProvider – provider for digest calculators
dataDigest – the calculated data digest for the message.
timeStampToken –  the timestamp token of interest.
Throws:
ImprintDigestInvalidException – if the token is not present in the message, or an imprint digest fails to compare.
CMSException – if an exception occurs processing the message./**
     * Validate the passed in timestamp token against the tokens and data present in the message.
     *
     * @param calculatorProvider provider for digest calculators
     * @param dataDigest the calculated data digest for the message.
     * @param timeStampToken  the timestamp token of interest.
     * @throws ImprintDigestInvalidException if the token is not present in the message, or an imprint digest fails to compare.
     * @throws CMSException if an exception occurs processing the message.
     */
    public void validate(DigestCalculatorProvider calculatorProvider, byte[] dataDigest, TimeStampToken timeStampToken)
        throws ImprintDigestInvalidException, CMSException
    {
        parseTimeStamps();

        util.validate(calculatorProvider, dataDigest, timeStampToken);
    }

    private void parseTimeStamps()
        throws CMSException
    {
        try
        {
            if (util == null)
            {
                InputStream cont = this.getContent();

                if (cont != null)
                {
                    Streams.drain(cont);
                }

                util = new TimeStampDataUtil(timeStampedData);
            }
        }
        catch (IOException e)
        {
            throw new CMSException("unable to parse evidence block: " + e.getMessage(), e);
        }
    }
}