/*
    * Copyright (C) 2017-2019 Centre National d'Etudes Spatiales (CNES).
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 3.0 of the License, or (at your option) any later version.
    *
    * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   * MA 02110-1301  USA
   */
  package fr.cnes.doi.services;
  
  import fr.cnes.doi.client.ClientLandingPage;
  import fr.cnes.doi.client.ClientMDS;
  import fr.cnes.doi.db.AbstractProjectSuffixDBHelper;
  import fr.cnes.doi.db.model.DOIUser;
  import fr.cnes.doi.exception.DOIDbException;
  import fr.cnes.doi.plugin.PluginFactory;
  import fr.cnes.doi.settings.EmailSettings;
  import fr.cnes.doi.utils.spec.Requirement;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.restlet.data.Status;
  
  /**
   * Provides a check on the availability of each published landing page publisher
   *
   * @author Jean-Christophe Malapert (jean-christophe.malapert@cnes.fr)
   */
  @Requirement(reqId = Requirement.DOI_DISPO_020, reqName = Requirement.DOI_DISPO_020_NAME)
  public class LandingPageMonitoring implements Runnable {
  
      /**
       * Logger.
       */
      private static final Logger LOG = LogManager.getLogger(LandingPageMonitoring.class.getName());
      
      /**
       * Client MDS to get all DOIs.
       */
      private final ClientMDS client;
  
      public LandingPageMonitoring(final ClientMDS client) {
          this.client = client;
      }
      
      /**
       * run.
       */
      @Override
      public void run() {
          LOG.traceEntry();
          final EmailSettings email = EmailSettings.getInstance();
          final StringBuffer msg = new StringBuffer();
          try {
              final String subject;
              final Map<String, Map<String, Status>> doiErrors = new ConcurrentHashMap<>();           
              final List<String> response = client.getDois();
              final ClientLandingPage clientLandingPage = new ClientLandingPage(response);
  
              if (clientLandingPage.isSuccess()) {
                  subject = "Landing pages checked with success";
                  msg.append("All landing pages (").append(response.size()).append(") are on-line");
              } else {
                  subject = "Landing pages checked with errors";
  
                  final StringBuffer header = new StringBuffer();
                  header.append("List of off-line landing pages:\n");
                  header.append("-------------------------------\n");
  
                  final Map<String, Status> errors = clientLandingPage.getErrors();
                  msg.append(errors.size()).append(" are off-line !!!\n");
                  msg.append(header);
  
                  // build error index by projectID and a global message
                  for (final Entry<String, Status> entry : errors.entrySet()) {
                      msg.append(buildDetailMessage(entry));
  
                      final String projectID = this.extractProjIdFrom(entry.getKey());
                      if (doiErrors.containsKey(projectID)) {
                          doiErrors.get(projectID).put(entry.getKey(), entry.getValue());
                      } else {
                         doiErrors.put(projectID, new HashMap<>());
                         doiErrors.get(projectID).put(entry.getKey(), entry.getValue());
                     }
                 }
                 // build message by project
                 for (final Entry<String, Map<String, Status>> project : doiErrors.entrySet()) {
                     final StringBuffer body = new StringBuffer();
                     body.append(header);
                     final Map<String, Status> errorsDoi = project.getValue();
                     for (final Entry<String, Status> errorDoi : errorsDoi.entrySet()) {
                         body.append(buildDetailMessage(errorDoi));
                     }
                     sendMessageToMembers(project.getKey(), subject, body.toString(), email);
                 }
             }
             email.sendMessage(subject, msg.toString());
         } catch (Exception ex) {
             email.sendMessage("Unrecoverable errors when checking landing pages", ex.toString(),
                     null);
         }
     }
 
     /**
      * Build detail message for a record
      *
      * @param record record
      * @return the message
      */
     private StringBuffer buildDetailMessage(final Entry<String, Status> record) {
         final StringBuffer msg = new StringBuffer();
         msg.append("- ").append(record.getKey())
                 .append(" (").append(record.getValue().getCode())
                 .append(" - ").append(record.getValue().getDescription()).append(" )")
                 .append("\n");
         return msg;
     }
 
     /**
      * Extract projectID from the DOI
      *
      * @param doi doi
      * @return project ID
      */
     private String extractProjIdFrom(final String doi) {
         // parse project suffix from doi
         final String doiRegex = "^(.+)\\/(.+)\\/(.+)$";
         final Pattern doiPattern = Pattern.compile(doiRegex);
         final Matcher doiMatcher = doiPattern.matcher(doi);
         doiMatcher.matches();
         return doiMatcher.group(2);
     }
 
     /**
      * Send message by email to project members.
      *
      * @param doiSuffix project ID
      * @param subject email subject
      * @param body email body
      * @param email email settings
      */
     private void sendMessageToMembers(final String doiSuffix, final String subject,
             final String body, final EmailSettings email) {
         final AbstractProjectSuffixDBHelper manageProjects = PluginFactory.getProjectSuffix();
         List<DOIUser> members;
         try {
             members = manageProjects.getAllDOIUsersForProject(Integer.parseInt(doiSuffix));
         } catch (DOIDbException ex) {
             members = new ArrayList<>();
         }
         for (final DOIUser member : members) {
             email.sendMessage(subject, body, member.getEmail());
         }
     }
 }