/*******************************************************************************
 * ============LICENSE_START==================================================
 * * org.onap.dmaap
 * * ===========================================================================
 * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
 * * ===========================================================================
 * * Licensed 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.
 * * ============LICENSE_END====================================================
 * *
 * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 * *
 ******************************************************************************/


package org.onap.dmaap.datarouter.provisioning;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.util.Collection;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONObject;
import org.onap.dmaap.datarouter.authz.AuthorizationResponse;
import org.onap.dmaap.datarouter.provisioning.beans.EventLogRecord;
import org.onap.dmaap.datarouter.provisioning.beans.Feed;
import org.onap.dmaap.datarouter.provisioning.beans.Subscription;
import org.onap.dmaap.datarouter.provisioning.eelf.EelfMsgs;
import org.onap.dmaap.datarouter.provisioning.utils.JSONUtilities;

import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;

import static org.onap.dmaap.datarouter.provisioning.utils.HttpServletUtils.sendResponseError;

/**
 * This servlet handles provisioning for the <subscribeURL> which is generated by the provisioning server to
 * handle the creation and inspection of subscriptions to a specific feed.
 *
 * @author Robert Eby
 * @version $Id$
 */
@SuppressWarnings("serial")
public class SubscribeServlet extends ProxyServlet {

    //Adding EELF Logger Rally:US664892
    private static EELFLogger eelflogger = EELFManager.getInstance()
        .getLogger("org.onap.dmaap.datarouter.provisioning.SubscribeServlet");

    /**
     * DELETE on the <subscribeUrl> -- not supported.
     */
    @Override
    public void doDelete(HttpServletRequest req, HttpServletResponse resp) {
        setIpAndFqdnForEelf("doDelete");
        eelflogger.info(EelfMsgs.MESSAGE_WITH_BEHALF_AND_SUBID, req.getHeader(BEHALF_HEADER), getIdFromPath(req) + "");
        String message = "DELETE not allowed for the subscribeURL.";
        EventLogRecord elr = new EventLogRecord(req);
        elr.setMessage(message);
        elr.setResult(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
        eventlogger.info(elr);
        sendResponseError(resp, HttpServletResponse.SC_METHOD_NOT_ALLOWED, message, eventlogger);
    }

    /**
     * GET on the &lt;subscribeUrl&gt; -- get the list of subscriptions to a feed. See the <i>Subscription Collection
     * Query</i> section in the <b>Provisioning API</b> document for details on how this method should be invoked.
     */
    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) {
        setIpAndFqdnForEelf("doGet");
        eelflogger.info(EelfMsgs.MESSAGE_WITH_BEHALF_AND_SUBID, req.getHeader(BEHALF_HEADER), getIdFromPath(req) + "");
        EventLogRecord elr = new EventLogRecord(req);
        String message = isAuthorizedForProvisioning(req);
        if (message != null) {
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_FORBIDDEN);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_FORBIDDEN, message, eventlogger);
            return;
        }
        if (isProxyServer()) {
            try {
                super.doGet(req, resp);
            } catch (IOException ioe) {
                eventlogger.error("IOException: " + ioe.getMessage());
            }
            return;
        }
        String bhdr = req.getHeader(BEHALF_HEADER);
        if (bhdr == null) {
            message = "Missing " + BEHALF_HEADER + " header.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_BAD_REQUEST);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_BAD_REQUEST, message, eventlogger);
            return;
        }
        int feedid = getIdFromPath(req);
        if (feedid < 0) {
            message = "Missing or bad feed number.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_BAD_REQUEST);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_BAD_REQUEST, message, eventlogger);
            return;
        }
        Feed feed = Feed.getFeedById(feedid);
        if (feed == null || feed.isDeleted()) {
            message = "Missing or bad feed number.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_NOT_FOUND);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_NOT_FOUND, message, eventlogger);
            return;
        }
        // Check with the Authorizer
        AuthorizationResponse aresp = authz.decide(req);
        if (!aresp.isAuthorized()) {
            message = "Policy Engine disallows access.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_FORBIDDEN);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_FORBIDDEN, message, eventlogger);
            return;
        }

        // Display a list of URLs
        Collection<String> list = Subscription.getSubscriptionUrlList(feedid);
        String t = JSONUtilities.createJSONArray(list);

        // send response
        elr.setResult(HttpServletResponse.SC_OK);
        eventlogger.info(elr);
        resp.setStatus(HttpServletResponse.SC_OK);
        resp.setContentType(SUBLIST_CONTENT_TYPE);
        try {
            resp.getOutputStream().print(t);
        } catch (IOException ioe) {
            eventlogger.error("IOException: " + ioe.getMessage());
        }
    }

    /**
     * PUT on the &lt;subscribeUrl&gt; -- not supported.
     */
    @Override
    public void doPut(HttpServletRequest req, HttpServletResponse resp) {
        setIpAndFqdnForEelf("doPut");
        eelflogger.info(EelfMsgs.MESSAGE_WITH_BEHALF_AND_SUBID, req.getHeader(BEHALF_HEADER), getIdFromPath(req) + "");
        String message = "PUT not allowed for the subscribeURL.";
        EventLogRecord elr = new EventLogRecord(req);
        elr.setMessage(message);
        elr.setResult(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
        eventlogger.info(elr);
        sendResponseError(resp, HttpServletResponse.SC_METHOD_NOT_ALLOWED, message, eventlogger);
    }

    /**
     * POST on the &lt;subscribeUrl&gt; -- create a new subscription to a feed. See the <i>Creating a Subscription</i>
     * section in the <b>Provisioning API</b> document for details on how this method should be invoked.
     */
    @Override
    public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        setIpAndFqdnForEelf("doPost");
        eelflogger.info(EelfMsgs.MESSAGE_WITH_BEHALF, req.getHeader(BEHALF_HEADER));
        EventLogRecord elr = new EventLogRecord(req);
        String message = isAuthorizedForProvisioning(req);
        if (message != null) {
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_FORBIDDEN);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_FORBIDDEN, message, eventlogger);
            return;
        }
        if (isProxyServer()) {
            try {
                super.doPost(req, resp);
            } catch (IOException ioe) {
                eventlogger.error("IOException: " + ioe.getMessage());
            }
            return;
        }
        String bhdr = req.getHeader(BEHALF_HEADER);
        if (bhdr == null) {
            message = "Missing " + BEHALF_HEADER + " header.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_BAD_REQUEST);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_BAD_REQUEST, message, eventlogger);
            return;
        }
        int feedid = getIdFromPath(req);
        if (feedid < 0) {
            message = "Missing or bad feed number.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_BAD_REQUEST);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_BAD_REQUEST, message, eventlogger);
            return;
        }
        Feed feed = Feed.getFeedById(feedid);
        if (feed == null || feed.isDeleted()) {
            message = "Missing or bad feed number.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_NOT_FOUND);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_NOT_FOUND, message, eventlogger);
            return;
        }
        // Check with the Authorizer
        AuthorizationResponse aresp = authz.decide(req);
        if (!aresp.isAuthorized()) {
            message = "Policy Engine disallows access.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_FORBIDDEN);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_FORBIDDEN, message, eventlogger);
            return;
        }

        // check content type is SUB_CONTENT_TYPE, version 1.0
        ContentHeader ch = getContentHeader(req);
        String ver = ch.getAttribute("version");
        if (!ch.getType().equals(SUB_BASECONTENT_TYPE) || !(ver.equals("1.0") || ver.equals("2.0"))) {
            intlogger.debug("Content-type is: " + req.getHeader("Content-Type"));
            message = "Incorrect content-type";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_UNSUPPORTED_MEDIA_TYPE);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_UNSUPPORTED_MEDIA_TYPE, message, eventlogger);
            return;
        }
        JSONObject jo = getJSONfromInput(req);
        if (jo == null) {
            message = "Badly formed JSON";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_BAD_REQUEST);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_BAD_REQUEST, message, eventlogger);
            return;
        }
        if (intlogger.isDebugEnabled()) {
            intlogger.debug(jo.toString());
        }
        if (++activeSubs > maxSubs) {
            activeSubs--;
            message = "Cannot create subscription; the maximum number of subscriptions has been configured.";
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_CONFLICT);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_CONFLICT, message, eventlogger);
            return;
        }
        Subscription sub = null;
        try {
            sub = new Subscription(jo);
        } catch (InvalidObjectException e) {
            activeSubs--;
            message = e.getMessage();
            elr.setMessage(message);
            elr.setResult(HttpServletResponse.SC_BAD_REQUEST);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_BAD_REQUEST, message, eventlogger);
            return;
        }
        sub.setFeedid(feedid);
        sub.setSubscriber(bhdr);    // set from X-ATT-DR-ON-BEHALF-OF header

        // Check if this subscription already exists; not an error (yet), just warn
        Subscription sub2 = Subscription.getSubscriptionMatching(sub);
        if (sub2 != null) {
            intlogger.warn(
                "PROV0011 Creating a duplicate subscription: new subid=" + sub.getSubid() + ", old subid=" + sub2
                    .getSubid());
        }

        // Create SUBSCRIPTIONS table entries
        if (doInsert(sub)) {
            // send response
            elr.setResult(HttpServletResponse.SC_CREATED);
            eventlogger.info(elr);
            resp.setStatus(HttpServletResponse.SC_CREATED);
            resp.setContentType(SUBFULL_CONTENT_TYPE);
            resp.setHeader("Location", sub.getLinks().getSelf());
            try {
                resp.getOutputStream().print(sub.asLimitedJSONObject().toString());
            } catch (IOException ioe) {
                eventlogger.error("IOException: " + ioe.getMessage());
            }

            provisioningDataChanged();
        } else {
            // Something went wrong with the INSERT
            activeSubs--;
            elr.setResult(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            eventlogger.info(elr);
            sendResponseError(resp, HttpServletResponse.SC_INTERNAL_SERVER_ERROR, DB_PROBLEM_MSG, eventlogger);
        }
    }
}