package eu.stork.peps.auth.commons;

import java.util.Iterator;

/**
 * This class is a bean used to store the information of Attribute Providers, the Attribute
 * List to be requested, the Assertions returned by the Attribute Providers and the values
 * that each Attribute has. This information along with the current status of the Linker (the
 * attribute providers that were queried and the remaining providers) is used by the PEPS
 * actions in order to complete the Attribute gathering.
 * 
 * @author Stelios Lelis (stelios.lelis@aegean.gr), Elias Pastos (ilias@aegean.gr)
 *
 * @version $Revision: 1.20 $, $Date: 2013-10-28 $
 */
public final class Linker {
	/**
	 * Attributes Providers map.
	 */
	private IAttributeProvidersMap attributeProvidersMap;

	/**
	 * The current index of local (domestic) Attribute Providers.
	 */
	private int localIndex;

	/**
	 * The current index of remote (foreign) Attribute Providers - countries.
	 */
	private int remoteIndex;

	/**
	 * Constructs an empty Linker object.
	 */
	public Linker() {
		localIndex = 0;
		remoteIndex = 0;
	}

	/**
	 * Based on the internal state of the Linker it returns the next local Attribute Source
	 *
	 * @return The next Attribute Source or null if not found
	 *
	 * @see AttributeSource
	 */
	public AttributeSource getNextLocalProvider() {
		Iterator<AttributeSource> iterator;
		AttributeSource source, found;
		int curIndex = 0;

		found = null;

		if ( attributeProvidersMap!=null && !attributeProvidersMap.isEmpty() ) {
			iterator = attributeProvidersMap.keyIterator();
			while (iterator.hasNext()) {
				source = iterator.next();

				if ( source.getSourceType()==AttributeSource.SOURCE_LOCAL_APROVIDER ) {
					if ( curIndex>=localIndex ) {
						found = source;

						break;
					}

					curIndex++;
				}
			}
		}

		return found;
	}

	/**
	 * Based on the internal state of the Linker it returns the next remote Attribute Source
	 *
	 * @return The next Attribute Source or null if not found
	 *
	 * @see AttributeSource
	 */
	public AttributeSource getNextRemoteProvider() {
		Iterator<AttributeSource> iterator;
		AttributeSource source, found;
		int curIndex = 0;

		found = null;

		if ( attributeProvidersMap !=null && !attributeProvidersMap.isEmpty() ) {
			iterator = attributeProvidersMap.keyIterator();
			while (iterator.hasNext()) {
				source = iterator.next();

				if ( source.getSourceType()==AttributeSource.SOURCE_REMOTE_COUNTRY ) {
					if ( curIndex>=remoteIndex ) {
						found = source;

						break;
					}

					curIndex++;
				}
			}
		}

		return found;
	}

	/**
	 * It updates the Linker with the values returned by the Attribute Source. It also advances
	 * to the next index in order to mark this attribute source as completed.
	 * 
	 * @param source The Attribute Source that was queried for attribute values.
	 * @param attrResponse The attrResponse returned by the Attribute Source that contains the attribute values.
	 *
	 * @see AttributeSource, STORKAttrQueryResponse
	 */
	public void setProviderReponse(AttributeSource source, STORKAttrQueryResponse attrResponse) {
		if ( source.getSourceType()==AttributeSource.SOURCE_REMOTE_COUNTRY )
			remoteIndex++;
		else
			localIndex++;

		//TODO How to store Assertions (format: byte, base64 string, entire object?)

		this.attributeProvidersMap.put(source, attrResponse.getPersonalAttributeList());
	}

	/**
	 * Reset the internal state of the local Attribute Source in order to start over.
	 */
	public void resetLocalIndex() {
		localIndex = 0;
	}

	/**
	 * Reset the internal state of the remote Attribute Source in order to start over.
	 */
	public void resetRemoteIndex() {
		remoteIndex = 0;
	}

	/**
	 * Setter for attributeProvidersMap.
	 * 
	 * @param attributeProvidersMap The attributeProvidersMap to set.
	 */
	public void setAttributeProvidersMap(IAttributeProvidersMap attributeProvidersMap) {
		this.attributeProvidersMap = attributeProvidersMap;
	}

	/**
	 * Getter for attributeProvidersMap.
	 * 
	 * @return attributeProvidersMap
	 */
	public IAttributeProvidersMap getAttributeProvidersMap() {
		return attributeProvidersMap;
	}

	/**
	 * Returns the Personal Attribute list of the provided Attribute Source.
	 *
	 * @return The IPersonalAttributeList assosiated with this source or null if empty
	 *
	 * @see IPersonalAttributeList
	 */
	public IPersonalAttributeList getProviderAttributes(AttributeSource source) {
		if ( attributeProvidersMap.containsKey(source) )
			return attributeProvidersMap.get(source);
		else
			return null;
	}
}