/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp 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 General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.waarp.openr66.protocol.http.restv2.converters;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  import org.waarp.common.database.exception.WaarpDatabaseSqlException;
  import org.waarp.common.json.JsonHandler;
  import org.waarp.common.logging.SysErrLogger;
  import org.waarp.common.utility.ParametersChecker;
  import org.waarp.common.utility.WaarpStringUtils;
  import org.waarp.openr66.pojo.Host;
  import org.waarp.openr66.protocol.http.restv2.errors.RestError;
  import org.waarp.openr66.protocol.http.restv2.errors.RestErrorException;
  
  import javax.ws.rs.InternalServerErrorException;
  import java.util.ArrayList;
  import java.util.Comparator;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import static org.waarp.common.file.FileUtils.*;
  import static org.waarp.openr66.protocol.configuration.Configuration.*;
  import static org.waarp.openr66.protocol.http.restv2.RestConstants.HostFields.*;
  import static org.waarp.openr66.protocol.http.restv2.errors.RestErrors.*;
  
  /**
   * A collection of utility methods to convert {@link Host} objects to their
   * corresponding {@link ObjectNode}
   * and vice-versa.
   */
  public final class HostConverter {
  
    /**
     * Makes the default constructor of this utility class inaccessible.
     */
    private HostConverter() throws InstantiationException {
      throw new InstantiationException(
          getClass().getName() + " cannot be instantiated.");
    }
  
    // ########################### INNER CLASSES ################################
  
    /**
     * Represents all the possible ways to sort a list of host objects.
     */
    public enum Order {
      /**
       * By hostID, in ascending order.
       */
      ascId(new Comparator<Host>() {
        @Override
        public final int compare(final Host t1, final Host t2) {
          return t1.getHostid().compareTo(t2.getHostid());
        }
      }),
      /**
       * By hostID, in descending order.
       */
      descId(new Comparator<Host>() {
        @Override
        public final int compare(final Host t1, final Host t2) {
          return -t1.getHostid().compareTo(t2.getHostid());//NOSONAR
        }
      }),
      /**
       * By address, in ascending order.
       */
      ascAddress(new Comparator<Host>() {
        @Override
        public final int compare(final Host t1, final Host t2) {
          return t1.getAddress().compareTo(t2.getAddress());//NOSONAR
        }
      }),
      /**
       * By address, in descending order.
       */
      descAddress(new Comparator<Host>() {
        @Override
        public final int compare(final Host t1, final Host t2) {
         return -t1.getAddress().compareTo(t2.getAddress());//NOSONAR
       }
     });
 
     /**
      * The comparator used to sort the list of RestHost objects.
      */
     public final Comparator<Host> comparator;
 
     Order(final Comparator<Host> comparator) {
       this.comparator = comparator;
     }
   }
 
   // ########################### PUBLIC METHODS ###############################
 
   /**
    * Converts the given {@link Host} object into an {@link ObjectNode}.
    *
    * @param host the host to convert
    *
    * @return the converted ObjectNode
    */
   public static ObjectNode hostToNode(final Host host) {
     final ObjectNode node = JsonHandler.createObjectNode();
     node.put(HOST_NAME, host.getHostid());
     node.put(ADDRESS, host.getAddress());
     node.put(PORT, host.getPort());
     node.put(PASSWORD, host.getHostkey());
     node.put(IS_SSL, host.isSSL());
     node.put(IS_CLIENT, host.isClient());
     node.put(IS_ADMIN, host.isAdmin());
     node.put(IS_ACTIVE, host.isActive());
     node.put(IS_PROXY, host.isProxified());
 
     return node;
   }
 
   /**
    * Converts the given {@link ObjectNode} into a {@link Host} object.
    *
    * @param object the ObjectNode to convert
    *
    * @return the corresponding Host object
    *
    * @throws RestErrorException if the given ObjectNode does not
    *     represent a Host object
    * @throws InternalServerErrorException if an unexpected error
    *     occurred
    */
   public static Host nodeToNewHost(final ObjectNode object) {
     Host emptyHost = null;
     try {
       emptyHost =
           new Host(null, null, -1, null, false, false, false, false, true);
     } catch (final WaarpDatabaseSqlException e) {
       SysErrLogger.FAKE_LOGGER.syserr(e);
     }
 
     return nodeToUpdatedHost(object, emptyHost);
   }
 
   /**
    * Returns the given {@link Host} object updated with the values defined in
    * the {@link ObjectNode} parameter.
    * All fields missing in the JSON object will stay unchanged in the updated
    * host entry.
    *
    * @param object the ObjectNode to convert.
    * @param oldHost the host entry to update.
    *
    * @return the updated host entry
    *
    * @throws RestErrorException if the given ObjectNode does not
    *     represent a Host object
    * @throws InternalServerErrorException if an unexpected error
    *     occurred
    */
   public static Host nodeToUpdatedHost(final ObjectNode object,
                                        final Host oldHost) {
 
     final List<RestError> errors = new ArrayList<RestError>();
 
     final Iterator<Map.Entry<String, JsonNode>> fields = object.fields();
     while (fields.hasNext()) {
       final Map.Entry<String, JsonNode> field = fields.next();
       final String name = field.getKey();
       final JsonNode value = field.getValue();
 
       if (name.equalsIgnoreCase(HOST_NAME)) {
         if (value.isTextual()) {
           if (oldHost.getHostid() == null) {
             oldHost.setHostid(value.asText());
           } else if (!oldHost.getHostid().equals(value.asText())) {
             errors.add(FIELD_NOT_ALLOWED(HOST_NAME));
           }
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(ADDRESS)) {
         if (value.isTextual()) {
           oldHost.setAddress(value.asText());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(PORT)) {
         if (value.canConvertToInt() && value.asInt() >= 0 &&
             value.asInt() < ZERO_COPY_CHUNK_SIZE) {
           oldHost.setPort(value.asInt());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(PASSWORD)) {
         if (value.isTextual()) {
           oldHost.setHostkey(encryptPassword(value.asText()));
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(IS_SSL)) {
         if (value.isBoolean()) {
           oldHost.setSSL(value.asBoolean());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(IS_CLIENT)) {
         if (value.isBoolean()) {
           oldHost.setClient(value.asBoolean());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(IS_ADMIN)) {
         if (value.isBoolean()) {
           oldHost.setAdmin(value.asBoolean());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(IS_ACTIVE)) {
         if (value.isBoolean()) {
           oldHost.setActive(value.asBoolean());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else if (name.equalsIgnoreCase(IS_PROXY)) {
         if (value.isBoolean()) {
           oldHost.setProxified(value.asBoolean());
         } else {
           errors.add(ILLEGAL_FIELD_VALUE(name, value.toString()));
         }
       } else {
         errors.add(UNKNOWN_FIELD(name));
       }
     }
 
     errors.addAll(checkRequiredFields(oldHost));
 
     if (errors.isEmpty()) {
       return oldHost;
     } else {
       throw new RestErrorException(errors);
     }
   }
 
   // ########################## PRIVATE METHODS ###############################
 
   /**
    * Encrypts the given password String using the server's cryptographic key.
    *
    * @param password the password to encrypt
    *
    * @return the encrypted password
    *
    * @throws InternalServerErrorException If an error occurred when
    *     encrypting the password.
    */
   private static byte[] encryptPassword(final String password) {
     try {
       return configuration.getCryptoKey().cryptToHex(password)
                           .getBytes(WaarpStringUtils.UTF8);
     } catch (final Exception e) {
       throw new InternalServerErrorException(
           "Failed to encrypt the host password", e);
     }
   }
 
   /**
    * List all missing required fields. This method returns a list of {@link
    * RestError} representing all the
    * errors encountered when checking the given host's required fields. If all
    * required fields have indeed been
    * initialized, an empty list is returned.
    *
    * @param host the host entry to check
    *
    * @return the list of encountered errors
    */
   private static List<RestError> checkRequiredFields(final Host host) {
     final List<RestError> errors = new ArrayList<RestError>();
     if (ParametersChecker.isEmpty(host.getHostid())) {
       errors.add(MISSING_FIELD(HOST_NAME));
     }
     if (ParametersChecker.isEmpty(host.getAddress())) {
       errors.add(MISSING_FIELD(ADDRESS));
     }
     if (host.getPort() == -1) {
       errors.add(MISSING_FIELD(PORT));
     }
     if (host.getHostkey() == null || host.getHostkey().length == 0) {
       errors.add(MISSING_FIELD(PASSWORD));
     }
 
     return errors;
   }
 }