package eu.stork.peps.auth.commons;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;

import org.apache.log4j.Logger;

/**
 * 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: 1.50 $, $Date: 2013-11-28 $
 */
public final class Linker implements Serializable {
	/**
	 * Unique identifier.
	 */
	private static final long serialVersionUID = -3268006381745987237L;

	/**
	 * Logger object.
	 */
	private static final Logger LOG = Logger.getLogger(Linker.class.getName());

	/**
	 * Attributes Providers map.
	 */
	private IAttributeProvidersMap attributeProvidersMap;

	/**
	 * Assertion map.
	 */
	private LinkedHashMap<AttributeSource, STORKAttrQueryResponse> assertions;

	/**
	 * 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;
		
		assertions = new LinkedHashMap<AttributeSource, STORKAttrQueryResponse>();
	}

	/**
	 * 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++;

		//Assertion storage
		this.assertions.put(source, attrResponse);
        // previously: getTotalPersonalAttributeList() in both cases
		if ( source.getSourceType()==AttributeSource.SOURCE_REMOTE_COUNTRY )
			this.attributeProvidersMap.put(source, attrResponse.getTotalPersonalAttributeList());
		else
		this.attributeProvidersMap.put(source, attrResponse.getPersonalAttributeList());
		//this.attributeProvidersMap.put(source, attrResponse.getTotalPersonalAttributeList());
	}

	/**
	 * 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.
	 *
	 * @param source The attributeSource in reference
	 * 
	 * @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;
	}

	/**
	 * Returns the merged Personal Attribute list from all the Attribute Sources.
	 *
	 * @return The IPersonalAttributeList merged Personal Attribute list or null if empty
	 *
	 * @see IPersonalAttributeList
	 */
	public IPersonalAttributeList getAllAttributes() {
		Iterator<AttributeSource> iterator;
		AttributeSource source;
		IPersonalAttributeList list, merged;

		merged = null;

		if ( attributeProvidersMap !=null && !attributeProvidersMap.isEmpty() ) {
			iterator = attributeProvidersMap.keyIterator();

			merged = new PersonalAttributeList();
			while (iterator.hasNext()) {
				source = iterator.next();
				list = this.getProviderAttributes(source);

				for (final PersonalAttribute pa : list) {
					merged.add(pa);
				}
			}
		}

		return merged;
	}

	/**
	 * Returns a List with all the assertions gathered by the AAS-PEPS module
	 * returned both by local APs or remote A-PEPS.
	 * 
	 * @return The assertions returned from the APs and A-PEPS
	 */
	public List<STORKAttrQueryResponse> getAttrQueryResponseList() {
		List<STORKAttrQueryResponse> originalAssertions;
		
		originalAssertions = new ArrayList<STORKAttrQueryResponse>();

		//Gather all assertions
	    for (STORKAttrQueryResponse element : this.assertions.values()) {
			originalAssertions.add(element);
	    }

		return originalAssertions;
	}

	/**
	 * Checks the internal state of the Linker and if all Attribute Sources where visited
	 * returns true, otherwise it returns false. So if you go directly from AtPLinkerAction
	 * to MoreAttributesAction the call will have, since the method setProviderReponse
	 * was not executed from every Attribute Source.
	 * 
	 * @return true if everything is OK, false otherwise
	 */
	public boolean isComplete() {
		boolean outcome = false;

		LOG.debug("Check if linkder is complete: R[" + remoteIndex + "], L[" + localIndex + "], S[" + attributeProvidersMap.size() + "]");
		if ( attributeProvidersMap !=null && !attributeProvidersMap.isEmpty() ) {
			if ( (remoteIndex + localIndex)==attributeProvidersMap.size() )
				outcome = true;
		}
		else {
			outcome = true;
		}

		return outcome;
	}

	/**
	 * Merge the two Linker objects. 
	 * 
	 * @param previous The other Linker object to merge with this one.
	 */
	public void mergeWith(Linker previous) {
		//BEFORE
		if ( LOG.isDebugEnabled() ) {
			LOG.debug("The attributeProvidersMap from the current object.");
			((AttributeProvidersMap)this.attributeProvidersMap).trace();
			LOG.debug("The attributeProvidersMap from the provided object.");
			((AttributeProvidersMap)previous.getAttributeProvidersMap()).trace();
		}

		IAttributeProvidersMap map = previous.getAttributeProvidersMap();
		Iterator<AttributeSource> items = map.keyIterator();
		while( items.hasNext() ) {
			AttributeSource item = items.next();
			IPersonalAttributeList pal = map.get(item);

			if ( this.attributeProvidersMap.containsKey(item) ) {
				IPersonalAttributeList new_pal = this.attributeProvidersMap.get(item);

				for(PersonalAttribute pa : pal)
					new_pal.add(pa);
			}
			else {
				if ( item.getSourceType()==AttributeSource.SOURCE_REMOTE_COUNTRY )
					remoteIndex++;
				else
					localIndex++;

				this.attributeProvidersMap.put(item, pal);
			}
		}

		//AFTER
		if ( LOG.isDebugEnabled() ) {
			LOG.debug("The attributeProvidersMap after the merge.");
			((AttributeProvidersMap)this.attributeProvidersMap).trace();
		}
	}
}