/*******************************************************************************
 * Copyright 2014 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 *******************************************************************************/
package at.gv.egovernment.moa.id.protocols.oauth20.protocol;

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

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;

import at.gv.egiz.eaaf.core.api.idp.IConfiguration;
import at.gv.egiz.eaaf.core.api.idp.ISPConfiguration;
import at.gv.egiz.eaaf.core.exceptions.EAAFConfigurationException;
import at.gv.egiz.eaaf.core.impl.idp.controller.protocols.RequestImpl;
import at.gv.egovernment.moa.id.commons.config.MOAIDConfigurationConstants;
import at.gv.egovernment.moa.id.protocols.oauth20.OAuth20Constants;
import at.gv.egovernment.moa.id.protocols.oauth20.exceptions.OAuth20Exception;
import at.gv.egovernment.moa.id.protocols.oauth20.exceptions.OAuth20OANotSupportedException;
import at.gv.egovernment.moa.id.protocols.oauth20.exceptions.OAuth20WrongParameterException;
import at.gv.egovernment.moa.id.util.ParamValidatorUtils;
import at.gv.egovernment.moa.logging.Logger;

abstract class OAuth20BaseRequest extends RequestImpl {
	
	private static final long serialVersionUID = 1L;
	
	protected Set<String> allowedParameters = new HashSet<String>();
			
	protected String getParam(final HttpServletRequest request, final String name, final boolean isNeeded) throws OAuth20Exception {
		String param = request.getParameter(name);
		Logger.debug("Reading param " + name + " from HttpServletRequest with value " + param);
		
		if (isNeeded && StringUtils.isEmpty(param)) {
			throw new OAuth20WrongParameterException(name);
		}
		
		this.allowedParameters.add(name);
		
		return param;
	}
	
	protected void populateParameters(final HttpServletRequest request, IConfiguration authConfig) throws OAuth20Exception {
		
		// moa id - load oa with client id!
		try {
			String oaURL = StringEscapeUtils.escapeHtml(this.getParam(request, OAuth20Constants.PARAM_CLIENT_ID, true));
			if (!ParamValidatorUtils.isValidOA(oaURL)) {
				throw new OAuth20WrongParameterException(OAuth20Constants.PARAM_CLIENT_ID);
			}
			this.setSPEntityId(oaURL);
			ISPConfiguration oaParam = authConfig.getServiceProviderConfiguration(oaURL);
			
			if (oaParam == null) {
				throw new OAuth20WrongParameterException(OAuth20Constants.PARAM_CLIENT_ID);
			}
			
			if (StringUtils.isEmpty(oaParam.getConfigurationValue(MOAIDConfigurationConstants.SERVICE_PROTOCOLS_OPENID_CLIENTSECRET)) 
					|| StringUtils.isEmpty(oaParam.getConfigurationValue(MOAIDConfigurationConstants.SERVICE_PROTOCOLS_OPENID_CLIENTID))
					|| StringUtils.isEmpty(oaParam.getConfigurationValue(MOAIDConfigurationConstants.SERVICE_PROTOCOLS_OPENID_REDIRECTURL))) {
				throw new OAuth20OANotSupportedException();
			}
		}
		catch (EAAFConfigurationException e) {
			throw new OAuth20WrongParameterException(OAuth20Constants.PARAM_CLIENT_ID);
		}
		
		// oAuth
		this.populateSpecialParameters(request, authConfig);
		
		// cleanup parameters
		this.checkAllowedParameters(request);
	}
	
	private void checkAllowedParameters(final HttpServletRequest request) throws OAuth20WrongParameterException {
		Logger.debug("Going to check for allowed parameters");
		this.allowedParameters.add(OAuth20Constants.PARAM_MOA_ACTION);
		this.allowedParameters.add(OAuth20Constants.PARAM_MOA_MOD);
		
		@SuppressWarnings("rawtypes")
		Iterator iter = request.getParameterMap().keySet().iterator();
		while (iter.hasNext()) {
			String name = (String) iter.next();
			if (!this.allowedParameters.contains(name)) {
				
				Logger.debug("Found wrong parameter: " + name);
				throw new OAuth20WrongParameterException(name);
			}
		}
		
	}
	
	protected abstract void populateSpecialParameters(final HttpServletRequest request, IConfiguration authConfig) throws OAuth20Exception;
	
}