/*
    * Copyright 2019-2022 the original author or authors.
    *
    * 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.
   */
  
  package org.bremersee.comparator.model;
  
  import static java.util.Objects.isNull;
  
  import com.fasterxml.jackson.annotation.JsonCreator;
  import com.fasterxml.jackson.annotation.JsonIgnore;
  import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
  import com.fasterxml.jackson.annotation.JsonProperty;
  import io.swagger.v3.oas.annotations.media.Schema;
  import jakarta.xml.bind.annotation.XmlAccessType;
  import jakarta.xml.bind.annotation.XmlAccessorType;
  import jakarta.xml.bind.annotation.XmlElementRef;
  import jakarta.xml.bind.annotation.XmlRootElement;
  import jakarta.xml.bind.annotation.XmlTransient;
  import jakarta.xml.bind.annotation.XmlType;
  import java.io.Serial;
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  import java.util.StringTokenizer;
  import java.util.stream.Collectors;
  import lombok.EqualsAndHashCode;
  
  /**
   * The sort order is a list of sort order items.
   *
   * @author Christian Bremer
   */
  @XmlAccessorType(XmlAccessType.FIELD)
  @XmlRootElement(name = "sortOrder")
  @XmlType(name = "sortOrderType")
  @JsonIgnoreProperties(ignoreUnknown = true)
  @Schema(description = "The sort order.")
  @EqualsAndHashCode
  public class SortOrder implements Serializable {
  
    @Serial
    private static final long serialVersionUID = 1;
  
    /**
     * The constant DEFAULT_SEPARATOR.
     */
    public static final String DEFAULT_SEPARATOR = ";";
  
    @Schema(description = "The sort order items.")
    @XmlElementRef
    private final List<SortOrderItem> items = new ArrayList<>();
  
    /**
     * Instantiates an empty sort order.
     */
    protected SortOrder() {
      super();
    }
  
    /**
     * Instantiates a new unmodifiable sort order.
     *
     * @param sortOrderItems the sort order items
     */
    @JsonCreator
    public SortOrder(@JsonProperty("items") Collection<? extends SortOrderItem> sortOrderItems) {
      if (!isNull(sortOrderItems)) {
        this.items.addAll(sortOrderItems);
      }
    }
  
    /**
     * Gets the unmodifiable list of sort order items.
     *
     * @return the list of sort order items
     */
    public List<SortOrderItem> getItems() {
      return Collections.unmodifiableList(items);
    }
  
    /**
     * Checks whether the list of items is empty or not.
     *
    * @return {@code true} if the list of items is empty, otherwise {@code false}
    */
   @XmlTransient
   @JsonIgnore
   public boolean isEmpty() {
     return items.isEmpty();
   }
 
   /**
    * Checks whether this sort order contains any entries. If there are entries, this is sorted,
    * otherwise it is unsorted.
    *
    * @return {@code true} if the list of sort orders is not empty (aka sorted), otherwise
    *     {@code false}
    */
   @XmlTransient
   @JsonIgnore
   public boolean isSorted() {
     return !isEmpty();
   }
 
   /**
    * Checks whether this sort order contains any entries. If there are no entries, this is unsorted,
    * otherwise it is sorted.
    *
    * @return {@code true} if the list of sort orders is empty (aka unsorted), otherwise
    *     {@code false}
    */
   @XmlTransient
   @JsonIgnore
   public boolean isUnsorted() {
     return !isSorted();
   }
 
   /**
    * Creates the sort order text of this ordering descriptions.
    *
    * <p>The syntax of the ordering description is
    * <pre>
    * fieldNameOrPath0,direction,case-handling,null-handling;fieldNameOrPath1,direction,case-handling,null-handling
    * </pre>
    *
    * <p>For example
    * <pre>
    * created,desc;person.lastName,asc;person.firstName,asc
    * </pre>
    *
    * @return the sort order text
    */
   @JsonIgnore
   @XmlTransient
   public String getSortOrderText() {
     return getSortOrderText(SortOrderTextSeparators.defaults());
   }
 
   /**
    * Creates the sort order text of this ordering descriptions.
    *
    * <p>The syntax of the ordering description is
    * <pre>
    * fieldNameOrPath0,direction,case-handling,null-handling;fieldNameOrPath1,direction,case-handling,null-handling
    * </pre>
    *
    * <p>For example
    * <pre>
    * created,desc;person.lastName,asc;person.firstName,asc
    * </pre>
    *
    * @param separators the separators
    * @return the sort order text
    */
   public String getSortOrderText(SortOrderTextSeparators separators) {
     String separator = Optional.ofNullable(separators)
         .orElseGet(SortOrderTextSeparators::defaults)
         .getChainSeparator();
     return items.stream()
         .map(item -> item.getSortOrderText(separators))
         .collect(Collectors.joining(separator));
   }
 
   @Override
   public String toString() {
     return getSortOrderText();
   }
 
   /**
    * From sort order text.
    *
    * @param source the sort order text
    * @return the sort order
    */
   public static SortOrder fromSortOrderText(String source) {
     return fromSortOrderText(source, SortOrderTextSeparators.defaults());
   }
 
   /**
    * From sort order text.
    *
    * @param source the sort order text
    * @param separators the separators
    * @return the sort order
    */
   public static SortOrder fromSortOrderText(String source, SortOrderTextSeparators separators) {
     if (isNull(source)) {
       return unsorted();
     }
     String separator = Optional.ofNullable(separators)
         .orElseGet(SortOrderTextSeparators::defaults)
         .getChainSeparator();
     return Optional.of(source.trim())
         .map(text -> {
           List<SortOrderItem> sortOrderItems = new ArrayList<>();
           StringTokenizer tokenizer = new StringTokenizer(text, separator);
           while (tokenizer.hasMoreTokens()) {
             sortOrderItems.add(SortOrderItem
                 .fromSortOrderText(tokenizer.nextToken(), separators));
           }
           if (sortOrderItems.isEmpty()) {
             sortOrderItems.add(new SortOrderItem());
           }
           return new SortOrder(sortOrderItems);
         })
         .orElseGet(SortOrder::new);
   }
 
   /**
    * Creates new sort order with the given items.
    *
    * @param sortOrderItems the sort orders
    * @return the sort order
    */
   public static SortOrder by(SortOrderItem... sortOrderItems) {
     return Optional.ofNullable(sortOrderItems)
         .map(so -> new SortOrder(Arrays.asList(so)))
         .orElseGet(SortOrder::new);
   }
 
   public static SortOrder unsorted() {
     return new SortOrder();
   }
 
 }