package org.bouncycastle.jce.provider;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.bouncycastle.jce.X509LDAPCertStoreParameters;
import org.bouncycastle.util.Selector;
import org.bouncycastle.util.StoreException;
import org.bouncycastle.x509.X509CertPairStoreSelector;
import org.bouncycastle.x509.X509CertStoreSelector;
import org.bouncycastle.x509.X509CertificatePair;
import org.bouncycastle.x509.X509StoreParameters;
import org.bouncycastle.x509.X509StoreSpi;
import org.bouncycastle.x509.util.LDAPStoreHelper;

A SPI implementation of Bouncy Castle X509Store for getting
certificates form a LDAP directory.
See Also:
X509Store/**
 * A SPI implementation of Bouncy Castle <code>X509Store</code> for getting
 * certificates form a LDAP directory.
 *
 * @see org.bouncycastle.x509.X509Store
 */
public class X509StoreLDAPCerts
    extends X509StoreSpi
{

    private LDAPStoreHelper helper;

    public X509StoreLDAPCerts()
    {
    }

    
Initializes this LDAP cert store implementation.
Params:
params – X509LDAPCertStoreParameters.
Throws:
IllegalArgumentException – if params is not an instance of
                                 X509LDAPCertStoreParameters./**
     * Initializes this LDAP cert store implementation.
     *
     * @param params <code>X509LDAPCertStoreParameters</code>.
     * @throws IllegalArgumentException if <code>params</code> is not an instance of
     *                                  <code>X509LDAPCertStoreParameters</code>.
     */
    public void engineInit(X509StoreParameters params)
    {
        if (!(params instanceof X509LDAPCertStoreParameters))
        {
            throw new IllegalArgumentException(
                "Initialization parameters must be an instance of "
                    + X509LDAPCertStoreParameters.class.getName() + ".");
        }
        helper = new LDAPStoreHelper((X509LDAPCertStoreParameters)params);
    }

    
Returns a collection of matching certificates from the LDAP location.

The selector must be a of type X509CertStoreSelector. If
it is not an empty collection is returned.
 The implementation searches only for CA certificates, if the method X509CertSelector.getBasicConstraints() is greater or equal to 0. If it is -2 only end certificates are searched. 

The subject and the serial number for end certificates should be
reasonable criterias for a selector.

Params:
selector – The selector to use for finding.
Throws:
StoreException – if an exception occurs while searching.
Returns:
A collection with the matches./**
     * Returns a collection of matching certificates from the LDAP location.
     * <p>
     * The selector must be a of type <code>X509CertStoreSelector</code>. If
     * it is not an empty collection is returned.
     * </p><p>
     * The implementation searches only for CA certificates, if the method
     * {@link java.security.cert.X509CertSelector#getBasicConstraints()} is
     * greater or equal to 0. If it is -2 only end certificates are searched.
     * </p><p>
     * The subject and the serial number for end certificates should be
     * reasonable criterias for a selector.
     * </p>
     * @param selector The selector to use for finding.
     * @return A collection with the matches.
     * @throws StoreException if an exception occurs while searching.
     */
    public Collection engineGetMatches(Selector selector) throws StoreException
    {
        if (!(selector instanceof X509CertStoreSelector))
        {
            return Collections.EMPTY_SET;
        }
        X509CertStoreSelector xselector = (X509CertStoreSelector)selector;
        Set set = new HashSet();
        // test if only CA certificates should be selected
        if (xselector.getBasicConstraints() > 0)
        {
            set.addAll(helper.getCACertificates(xselector));
            set.addAll(getCertificatesFromCrossCertificatePairs(xselector));
        }
        // only end certificates should be selected
        else if (xselector.getBasicConstraints() == -2)
        {
            set.addAll(helper.getUserCertificates(xselector));
        }
        // nothing specified
        else
        {
            set.addAll(helper.getUserCertificates(xselector));
            set.addAll(helper.getCACertificates(xselector));
            set.addAll(getCertificatesFromCrossCertificatePairs(xselector));
        }
        return set;
    }

    private Collection getCertificatesFromCrossCertificatePairs(
        X509CertStoreSelector xselector) throws StoreException
    {
        Set set = new HashSet();
        X509CertPairStoreSelector ps = new X509CertPairStoreSelector();

        ps.setForwardSelector(xselector);
        ps.setReverseSelector(new X509CertStoreSelector());
        
        Set crossCerts = new HashSet(helper.getCrossCertificatePairs(ps));
        Set forward = new HashSet();
        Set reverse = new HashSet();
        Iterator it = crossCerts.iterator();
        while (it.hasNext())
        {
            X509CertificatePair pair = (X509CertificatePair)it.next();
            if (pair.getForward() != null)
            {
                forward.add(pair.getForward());
            }
            if (pair.getReverse() != null)
            {
                reverse.add(pair.getReverse());
            }
        }
        set.addAll(forward);
        set.addAll(reverse);
        return set;
    }
}