/*
    * 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.dbhandlers;
  
  import com.fasterxml.jackson.databind.node.ArrayNode;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  import io.cdap.http.HttpResponder;
  import io.netty.handler.codec.http.DefaultHttpHeaders;
  import io.netty.handler.codec.http.HttpHeaders;
  import io.netty.handler.codec.http.HttpMethod;
  import io.netty.handler.codec.http.HttpRequest;
  import org.waarp.common.json.JsonHandler;
  import org.waarp.common.role.RoleDefault.ROLE;
  import org.waarp.common.utility.ParametersChecker;
  import org.waarp.openr66.dao.DAOFactory;
  import org.waarp.openr66.dao.Filter;
  import org.waarp.openr66.dao.RuleDAO;
  import org.waarp.openr66.dao.exception.DAOConnectionException;
  import org.waarp.openr66.pojo.Rule;
  import org.waarp.openr66.protocol.http.restv2.errors.RestError;
  import org.waarp.openr66.protocol.http.restv2.errors.RestErrorException;
  import org.waarp.openr66.protocol.http.restv2.utils.RestUtils;
  
  import javax.ws.rs.Consumes;
  import javax.ws.rs.DefaultValue;
  import javax.ws.rs.GET;
  import javax.ws.rs.InternalServerErrorException;
  import javax.ws.rs.OPTIONS;
  import javax.ws.rs.POST;
  import javax.ws.rs.Path;
  import javax.ws.rs.QueryParam;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import static io.netty.handler.codec.http.HttpResponseStatus.*;
  import static javax.ws.rs.core.HttpHeaders.*;
  import static javax.ws.rs.core.MediaType.*;
  import static org.waarp.openr66.dao.database.DBRuleDAO.*;
  import static org.waarp.openr66.protocol.http.restv2.RestConstants.*;
  import static org.waarp.openr66.protocol.http.restv2.RestConstants.GetRulesParams.*;
  import static org.waarp.openr66.protocol.http.restv2.converters.RuleConverter.*;
  import static org.waarp.openr66.protocol.http.restv2.converters.RuleConverter.Order.*;
  import static org.waarp.openr66.protocol.http.restv2.errors.RestErrors.*;
  import static org.waarp.openr66.protocol.http.restv2.utils.JsonUtils.*;
  
  /**
   * This is the {@link AbstractRestDbHandler} handling all operations on the
   * host's transfer rule database.
   */
  @Path(RULES_HANDLER_URI)
  public class RulesHandler extends AbstractRestDbHandler {
  
    /**
     * The content of the 'Allow' header sent when an 'OPTIONS' request is made
     * on the handler.
     */
    private static final HttpHeaders OPTIONS_HEADERS;
  
    static {
      OPTIONS_HEADERS = new DefaultHttpHeaders();
      final List<HttpMethod> allow = new ArrayList<HttpMethod>();
      allow.add(HttpMethod.GET);
      allow.add(HttpMethod.POST);
      allow.add(HttpMethod.OPTIONS);
      OPTIONS_HEADERS.add(ALLOW, allow);
    }
  
    public RulesHandler(final byte crud) {
      super(crud);
    }
  
    /**
     * Method called to obtain a list of transfer rules based on the filters in
     * the query parameters.
     *
     * @param request the HttpRequest made on the resource
     * @param responder the HttpResponder which sends the reply to the
     *     request
     * @param limitStr the maximum number of entries allowed in the
     *     response
    * @param offsetStr the index of the first accepted entry in the
    *     list of all valid answers
    * @param orderStr the criteria used to sort the entries and the
    *     way of ordering them
    * @param modeTransStr only keep rules that use this transfer mode
    */
   @GET
   @Consumes(APPLICATION_FORM_URLENCODED)
   @RequiredRole(ROLE.READONLY)
   public final void filterRules(final HttpRequest request,
                                 final HttpResponder responder,
                                 @QueryParam(LIMIT) @DefaultValue("20")
                                 final String limitStr,
                                 @QueryParam(OFFSET) @DefaultValue("0")
                                 final String offsetStr,
                                 @QueryParam(ORDER) @DefaultValue("ascName")
                                 final String orderStr,
                                 @QueryParam(MODE_TRANS) @DefaultValue("")
                                 final String modeTransStr,
                                 @QueryParam(COUNT_ORDER) @DefaultValue("")
                                 final String countOrder) {
     checkSanity(limitStr, offsetStr, orderStr, modeTransStr, countOrder);
     final List<RestError> errors = new ArrayList<RestError>();
 
     boolean count = false;
     try {
       if (ParametersChecker.isNotEmpty(countOrder) &&
           RestUtils.stringToBoolean(countOrder)) {
         count = true;
       }
     } catch (final Exception ignore) {
       // Ignore
     }
     int limit = 20;
     int offset = 0;
     Order order = ascName;
     ModeTrans modeTrans = null;
     try {
       limit = Integer.parseInt(limitStr);
       order = Order.valueOf(orderStr);
     } catch (final NumberFormatException e) {
       errors.add(ILLEGAL_PARAMETER_VALUE(LIMIT, limitStr));
     } catch (final IllegalArgumentException e) {
       errors.add(ILLEGAL_PARAMETER_VALUE(ORDER, orderStr));
     }
     try {
       offset = Integer.parseInt(offsetStr);
       if (!modeTransStr.isEmpty()) {
         modeTrans = ModeTrans.valueOf(modeTransStr);
       }
     } catch (final NumberFormatException e) {
       errors.add(ILLEGAL_PARAMETER_VALUE(OFFSET, offsetStr));
     } catch (final IllegalArgumentException e) {
       errors.add(ILLEGAL_PARAMETER_VALUE(MODE_TRANS, e.getMessage()));
     }
 
     if (limit <= 0) {
       errors.add(ILLEGAL_PARAMETER_VALUE(LIMIT, limitStr));
     } else if (offset < 0) {
       errors.add(ILLEGAL_PARAMETER_VALUE(OFFSET, offsetStr));
     }
 
     if (!errors.isEmpty()) {
       throw new RestErrorException(errors);
     }
     final List<Filter> filters = new ArrayList<Filter>();
     if (modeTrans != null) {
       filters.add(new Filter(MODE_TRANS_FIELD, "=",
                              Integer.toString(modeTrans.ordinal())));
     }
 
     final ObjectNode responseObject = JsonHandler.createObjectNode();
     RuleDAO ruleDAO = null;
     if (count) {
       long nbCount = -1;
       try {
         ruleDAO = DAO_FACTORY.getRuleDAO(false);
         nbCount = ruleDAO.count(filters);
       } catch (final DAOConnectionException e) {
         throw new InternalServerErrorException(e);
       } finally {
         DAOFactory.closeDAO(ruleDAO);
       }
       responseObject.put("totalResults", nbCount);
     } else {
       List<Rule> rules;
       try {
         ruleDAO = DAO_FACTORY.getRuleDAO(false);
         rules = ruleDAO.find(filters);
       } catch (final DAOConnectionException e) {
         throw new InternalServerErrorException(e);
       } finally {
         DAOFactory.closeDAO(ruleDAO);
       }
       final int totalResults = rules.size();
       Collections.sort(rules, order.comparator);
 
       final ArrayNode results = JsonHandler.createArrayNode();
       for (int i = offset; i < offset + limit && i < rules.size(); i++) {
         results.add(ruleToNode(rules.get(i)));
       }
       responseObject.put("totalResults", totalResults);
       responseObject.set("results", results);
     }
     final String responseText = nodeToString(responseObject);
     responder.sendJson(OK, responseText);
   }
 
   /**
    * Method called to add a new transfer rule in the server database. The
    * reply will contain the created entry
    * in JSON format, unless an unexpected error prevents it or if the request
    * is invalid.
    *
    * @param request the HttpRequest made on the resource
    * @param responder the HttpResponder which sends the reply to the
    *     request.
    */
   @POST
   @Consumes(APPLICATION_JSON)
   @RequiredRole(ROLE.RULE)
   public final void addRule(final HttpRequest request,
                             final HttpResponder responder) {
     final ObjectNode requestObject = deserializeRequest(request);
     checkSanity(requestObject);
     final Rule rule = nodeToNewRule(requestObject);
 
     RuleDAO ruleDAO = null;
     try {
       ruleDAO = DAO_FACTORY.getRuleDAO(false);
 
       if (ruleDAO.exist(rule.getName())) {
         throw new RestErrorException(ALREADY_EXISTING(rule.getName()));
       }
 
       ruleDAO.insert(rule);
     } catch (final DAOConnectionException e) {
       throw new InternalServerErrorException(e);
     } finally {
       DAOFactory.closeDAO(ruleDAO);
     }
 
     final ObjectNode responseObject = ruleToNode(rule);
     final String responseText = nodeToString(responseObject);
 
     final DefaultHttpHeaders headers = new DefaultHttpHeaders();
     headers.add(CONTENT_TYPE, APPLICATION_JSON);
     headers.add("ruleURI", RULES_HANDLER_URI + rule.getName());
 
     responder.sendString(CREATED, responseText, headers);
   }
 
   /**
    * Method called to get a list of all allowed HTTP methods on this entry
    * point. The HTTP methods are sent as
    * an array in the reply's headers.
    *
    * @param request the HttpRequest made on the resource
    * @param responder The {@link HttpResponder} which sends the reply
    *     to the request.
    */
   @OPTIONS
   @Consumes(WILDCARD)
   @RequiredRole(ROLE.NOACCESS)
   public final void options(final HttpRequest request,
                             final HttpResponder responder) {
     responder.sendStatus(OK, OPTIONS_HEADERS);
   }
 }