/**
    * This file Copyright (c) 2017 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.rest.delivery.jcr;
  
  import static java.util.stream.Collectors.joining;
  
  import java.time.LocalDate;
  import java.time.ZoneId;
  import java.time.ZonedDateTime;
  import java.time.format.DateTimeFormatter;
  import java.util.Arrays;
  
  /**
   * This class is used to get filtering condition SQL.
   */
  public class FilteringCondition {
      private static final String ISO_DATE_TIME_REGEX = "^(?:[1-9]\\d{3}-(?:(?:0[1-9]|1[0-2])-(?:0[1-9]|1\\d|2[0-8])|(?:0[13-9]|1[0-2])-(?:29|30)|(?:0[13578]|1[02])-31)|(?:[1-9]\\d(?:0[48]|[2468][048]|[13579][26])|(?:[2468][048]|[13579][26])00)-02-29)T(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d.[0-9]{3}(?:Z|[+-][01]\\d:[0-5]\\d)$";
      private static final String ISO_DATE_REGEX = "^(?:[1-9]\\d{3}-(?:(?:0[1-9]|1[0-2])-(?:0[1-9]|1\\d|2[0-8])|(?:0[13-9]|1[0-2])-(?:29|30)|(?:0[13578]|1[02])-31)|(?:[1-9]\\d(?:0[48]|[2468][048]|[13579][26])|(?:[2468][048]|[13579][26])00)-02-29)$";
      private static final String NUMBER_REGEX = "[+-]?(([1-9][0-9]*)|(0))([.,][0-9]+)?";
      private static final String NAME_PROPERTY = "@name";
      private static final String PARENT_PROPERTY = "@ancestor";
  
      static final DateTimeFormatter JCR_OFFSET_DATE_TIME = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
  
      private static final String VALUES_SPLITTER = "\\|";
  
      private static final String OPERATOR_OPEN = "[";
      private static final String OPERATOR_CLOSE = "]";
  
      private final String property;
      private final Operator operator;
      private final String[] values;
  
      public FilteringCondition(String property, String value) {
          // TODO: Draft support for query parameter operators. This is prone to change! (see MGNLREST-120)
          int openPosition = property.lastIndexOf(OPERATOR_OPEN);
          int closePosition = property.lastIndexOf(OPERATOR_CLOSE);
          this.property = openPosition == -1 ? property : property.substring(0, openPosition);
          this.operator = openPosition == -1 ? Operator.EQ : Operator.from(property.substring(openPosition + 1, closePosition));
  
          // TODO: Draft support for multi-value query parameters. This is prone to change! (see MGNLREST-122)
          this.values = value.split(VALUES_SPLITTER);
      }
  
      public String asSqlString() {
          return Arrays.stream(values)
                  .map(this::getConditionPattern)
                  .collect(joining(" OR "));
      }
  
      private String getConditionPattern(String value) {
          if (PARENT_PROPERTY.equalsIgnoreCase(property)) {
              return String.format("ISDESCENDANTNODE('%s')", value);
          }
  
          if (NAME_PROPERTY.equalsIgnoreCase(property)) {
              return String.format("LOWER(NAME(t)) %s '%s'", operator.asSqlString(), value);
          }
  
          return String.format("[%s] %s %s", property, operator.asSqlString(), resolveValue(value));
      }
  
      private String resolveValue(String value) {
          if (value.matches(NUMBER_REGEX)) {
              return value;
          } else if (value.matches(ISO_DATE_TIME_REGEX)) {
              return String.format("CAST('%s' AS DATE)", value);
          } else if (value.matches(ISO_DATE_REGEX)) {
             DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
             LocalDate localDate = LocalDate.parse(value, dateTimeFormatter);
             ZonedDateTime zonedDateTime = localDate.atStartOfDay(ZoneId.systemDefault());
             String formattedDateTime = zonedDateTime.format(JCR_OFFSET_DATE_TIME);
             return String.format("CAST('%s' AS DATE)", formattedDateTime);
         }
 
         return String.format("'%s'", value);
     }
 
     @Override
     public String toString() {
         return asSqlString();
     }
 }