/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package eu.dnetlib.oauth.handlers;

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpMethod;
import org.surfnet.oaaas.auth.AbstractAuthenticator;
import org.surfnet.oaaas.auth.AbstractUserConsentHandler;
import org.surfnet.oaaas.auth.principal.AuthenticatedPrincipal;
import org.surfnet.oaaas.model.AccessToken;
import org.surfnet.oaaas.model.AuthorizationRequest;
import org.surfnet.oaaas.model.Client;
import org.surfnet.oaaas.repository.AccessTokenRepository;
import org.surfnet.oaaas.repository.AuthorizationRequestRepository;

import javax.inject.Inject;
import javax.inject.Named;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

/**
 * Example {@link AbstractUserConsentHandler} that forwards to a form.
 */
//TODO named-> this is what spring understands
@Named("formConsentHandler")
public class FormUserConsentHandler extends AbstractUserConsentHandler {

    private static final String USER_OAUTH_APPROVAL = "user_oauth_approval";
    private final Logger log = LoggerFactory.getLogger(this.getClass());
    @Inject
    private AccessTokenRepository accessTokenRepository;

    @Inject
    private AuthorizationRequestRepository authorizationRequestRepository;

    @Override
    public void handleUserConsent(HttpServletRequest request, HttpServletResponse response, FilterChain chain,
                                  String authStateValue, String returnUri, Client client) throws IOException, ServletException {
        if (isUserConsentPost(request)) {
            log.info("CONSENT IS POST : Process form");
            if (processForm(request, response)) {
                chain.doFilter(request, response);
            }
        } else {

            log.info("CONSENT IS NOT POST: process Initial");
            processInitial(request, response, chain, returnUri, authStateValue, client);
        }
    }

    private boolean isUserConsentPost(HttpServletRequest request) {
        String oauthApproval = request.getParameter(USER_OAUTH_APPROVAL);
        return request.getMethod().equals(HttpMethod.POST.toString()) && StringUtils.isNotBlank(oauthApproval);
    }

    private void processInitial(HttpServletRequest request, ServletResponse response, FilterChain chain,
                                String returnUri, String authStateValue, Client client) throws ServletException, IOException {


        AuthenticatedPrincipal principal = (AuthenticatedPrincipal) request.getAttribute(AbstractAuthenticator.PRINCIPAL);


        // log.info("processInitial principal" + principal.toString());
        List<AccessToken> tokens = accessTokenRepository.findByResourceOwnerIdAndClient(principal.getName(), client);


        if (!CollectionUtils.isEmpty(tokens)) {
            // If another token is already present for this resource owner and client, no new consent should be requested
            List<String> grantedScopes = tokens.get(0).getScopes(); // take the scopes of the first access token found.
            setGrantedScopes(request, grantedScopes.toArray(new String[grantedScopes.size()]));
            chain.doFilter(request, response);
        } else {


            AuthorizationRequest authorizationRequest = authorizationRequestRepository.findByAuthState(authStateValue);
            request.setAttribute("requestedScopes", authorizationRequest.getRequestedScopes());
            request.setAttribute("client", client);
            request.setAttribute(AUTH_STATE, authStateValue);
            request.setAttribute("actionUri", returnUri);
            ((HttpServletResponse) response).setHeader("X-Frame-Options", "SAMEORIGIN");


            log.info("User consent URL is " + getUserConsentUrl());
            request.getRequestDispatcher(getUserConsentUrl()).forward(request, response);
        }

    }

    /**
     * Return the path to the User Consent page. Subclasses can use this hook by
     * providing a custom html/jsp.
     *
     * @return the path to the User Consent page
     */
    protected String getUserConsentUrl() {
        return "/WEB-INF/jsp/userconsent.jsp";
    }

    private boolean processForm(final HttpServletRequest request, final HttpServletResponse response)
            throws ServletException, IOException {
        if (Boolean.valueOf(request.getParameter(USER_OAUTH_APPROVAL))) {

            log.info("User_oauth_approval is true");

            setAuthStateValue(request, request.getParameter(AUTH_STATE));
            String[] scopes = request.getParameterValues(GRANTED_SCOPES);
            setGrantedScopes(request, scopes);
            return true;
        } else {
            log.info("User_oauth_approval is denied");

            request.getRequestDispatcher(getUserConsentDeniedUrl()).forward(request, response);

            return false;
        }
    }

    /**
     * @return
     */
    protected String getUserConsentDeniedUrl() {
        return "/WEB-INF/jsp/userconsent_denied.jsp";
    }

}