/*
 * oxAuth is available under the MIT License (2008). See http://opensource.org/licenses/MIT for full text.
 *
 * Copyright (c) 2014, Gluu
 */

package org.xdi.oxauth.service.fido.u2f;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashSet;
import java.util.Set;

import javax.ejb.Stateless;
import javax.inject.Inject;
import javax.inject.Named;

import org.apache.commons.lang.ArrayUtils;
import org.slf4j.Logger;
import org.xdi.oxauth.model.fido.u2f.exception.BadInputException;
import org.xdi.oxauth.model.fido.u2f.protocol.ClientData;

/**
 * Client data validation service
 *
 * @author Yuriy Movchan Date: 05/20/2015
 */
@Stateless
@Named
public class ClientDataValidationService {

	@Inject
	private Logger log;

	public void checkContent(ClientData clientData, String[] types, String challenge, Set<String> facets) throws BadInputException {
		if (!ArrayUtils.contains(types, clientData.getTyp())) {
			throw new BadInputException("Bad clientData: wrong typ " + clientData.getTyp());
		}

		if (!challenge.equals(clientData.getChallenge())) {
			throw new BadInputException("Bad clientData: wrong challenge");
		}

		if (facets != null && !facets.isEmpty()) {
			Set<String> allowedFacets = canonicalizeOrigins(facets);
			String canonicalOrigin;
			try {
				canonicalOrigin = canonicalizeOrigin(clientData.getOrigin());
			} catch (RuntimeException e) {
				throw new BadInputException("Bad clientData: Malformed origin", e);
			}
			verifyOrigin(canonicalOrigin, allowedFacets);
		}
	}

	private static void verifyOrigin(String origin, Set<String> allowedOrigins) throws BadInputException {
		if (!allowedOrigins.contains(origin)) {
			throw new BadInputException(origin + " is not a recognized facet for this application");
		}
	}

	public static Set<String> canonicalizeOrigins(Set<String> origins) {
		Set<String> result = new HashSet<String>();
		for (String origin : origins) {
			result.add(canonicalizeOrigin(origin));
		}
		return result;
	}

	public static String canonicalizeOrigin(String url) {
		try {
			URI uri = new URI(url);
			if (uri.getAuthority() == null) {
				return url;
			}
			return uri.getScheme() + "://" + uri.getAuthority();
		} catch (URISyntaxException e) {
			throw new IllegalArgumentException("Specified bad origin", e);
		}
	}

}