package at.knowcenter.wag.egov.egiz.ldap.client;

import java.util.Hashtable;
import java.util.Iterator;

import org.apache.log4j.Logger;

import at.knowcenter.wag.egov.egiz.tools.Normalize;


/**
 * @author <a href="mailto:thomas.knall@iaik.tugraz.at">Thomas Knall</a>
 */
public abstract class LDAPClientFactory {
	
	private final Logger log = Logger.getLogger(getClass());
	
	private static Hashtable<String, LDAPClientFactory> ldapClientFactoryInstances = new Hashtable<String, LDAPClientFactory>();
	
	protected static final String DEFAULT_IDENTIFIER = "DEFAULT_IDENTIFIER";

	private Hashtable<String, LDAPMapping> registeredMappings;
	private boolean hasBeenConfigured;
	private Normalize normalizer;
	private boolean whiteSpaceRemoval;
	
	protected LDAPClientFactory() {
		this.registeredMappings = new Hashtable<String, LDAPMapping>();
		this.hasBeenConfigured = false;
		this.normalizer = null;
		this.whiteSpaceRemoval = false;
	}
	
	public void resetMappings() {
		this.registeredMappings = new Hashtable<String, LDAPMapping>();
		this.hasBeenConfigured = false;
	}
	
	public boolean hasBeenConfigured() {
		return this.hasBeenConfigured;
	}
	
	public LDAPMapping getMapping(String issuerName) {
		return this.registeredMappings.get(applyFilter(issuerName));
	}
	
	protected Normalize getNormalizer() {
		return this.normalizer;
	}

	public synchronized void registerMappings(Iterable<LDAPMapping> iterable) {
		Iterator<LDAPMapping> it = iterable.iterator();
		if (!it.hasNext()) {
			log.warn("There were no ldap mappings provided.");
		} else {
			this.hasBeenConfigured = true;
		}
		while (it.hasNext()) {
			this.registerMapping(it.next());
		}
	}
	
	public synchronized void registerMapping(LDAPMapping... ldapMappings) {
		if (ldapMappings.length == 0) {
			log.warn("There were no ldap mappings provided.");
		} else {
			this.hasBeenConfigured = true;
		}
		for (LDAPMapping ldapMapping : ldapMappings) {
			log.debug("Registering Mapping for " + LDAPClientFactory.class.getSimpleName() + ": " + ldapMapping + ".");
			String issuerName = applyFilter(ldapMapping.getIssuerName().getName());
			if (this.registeredMappings.containsKey(issuerName)) {
				log.warn("Skipping mapping for issuer name \"" + issuerName + "\" because it has already been registered.");
			} else {
				this.registeredMappings.put(issuerName, ldapMapping);
			}
		}
	}
	
	public void setNormalizer(Normalize normalizer) throws LDAPException {
		if (this.hasBeenConfigured) {
			throw new LDAPException("It is not allowed to set a normalizer after mappings have been defined.");
		}
		this.normalizer = normalizer;
	}
	
	public void setWhiteSpaceRemoval(boolean whiteSpaceRemoval) throws LDAPException {
		if (this.hasBeenConfigured) {
			throw new LDAPException("It is not allowed to set whitespace removal after mappings have been defined.");
		}
		this.whiteSpaceRemoval = whiteSpaceRemoval;
	}
	
	private String applyFilter(String text) {
		if (this.normalizer != null) {
			text = this.normalizer.normalize(text);
		}
		if (this.whiteSpaceRemoval) {
			text = text.replaceAll("\\s", "");
		}
		return text;
	}
	
	public static synchronized LDAPClientFactory getInstance(String idenfifier) {
		LDAPClientFactory ldapClientFactoryInstance = ldapClientFactoryInstances.get(idenfifier);
		if (ldapClientFactoryInstance == null) {
			ldapClientFactoryInstance = new LDAPClientFactoryImpl();
			ldapClientFactoryInstances.put(idenfifier, ldapClientFactoryInstance);
		}
		return ldapClientFactoryInstance;
	}
	
	public static synchronized LDAPClientFactory getInstance() {
		return getInstance(DEFAULT_IDENTIFIER);
	}
	
	public abstract LDAPClient createClient(String issuerName) throws LDAPException;
	
}