/*
    * Copyright 2004-2022 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
    *
    *    https://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 com.ibatis.common.util;
  
  import java.util.*;
  
  /**
   * Implementation of PaginatedList backed by an ArrayList.
   *
   * @deprecated All paginated list features have been deprecated
   */
  public class PaginatedArrayList implements PaginatedList {
  
    /** The Constant EMPTY_LIST. */
    private static final ArrayList EMPTY_LIST = new ArrayList(0);
  
    /** The list. */
    private List list;
  
    /** The page. */
    private List page;
  
    /** The page size. */
    private int pageSize;
  
    /** The index. */
    private int index;
  
    /**
     * Instantiates a new paginated array list.
     *
     * @param pageSize
     *          the page size
     */
    public PaginatedArrayList(int pageSize) {
      this.pageSize = pageSize;
      this.index = 0;
      this.list = new ArrayList();
      repaginate();
    }
  
    /**
     * Constructor to set the initial size and the page size.
     *
     * @param initialCapacity
     *          - the initial size
     * @param pageSize
     *          - the page size
     */
    public PaginatedArrayList(int initialCapacity, int pageSize) {
      this.pageSize = pageSize;
      this.index = 0;
      this.list = new ArrayList(initialCapacity);
      repaginate();
    }
  
    /**
     * Constructor to create an instance using an existing collection.
     *
     * @param c
     *          - the collection to build the instance with
     * @param pageSize
     *          - the page size
     */
    public PaginatedArrayList(Collection c, int pageSize) {
      this.pageSize = pageSize;
      this.index = 0;
      this.list = new ArrayList(c);
      repaginate();
    }
  
    /**
     * Repaginate.
     */
    private void repaginate() {
      if (list.isEmpty()) {
        page = EMPTY_LIST;
      } else {
        int start = index * pageSize;
        int end = start + pageSize - 1;
        if (end >= list.size()) {
          end = list.size() - 1;
        }
        if (start >= list.size()) {
          index = 0;
          repaginate();
       } else if (start < 0) {
         index = list.size() / pageSize;
         if (list.size() % pageSize == 0) {
           index--;
         }
         repaginate();
       } else {
         page = list.subList(start, end + 1);
       }
     }
   }
 
   /* List accessors (uses page) */
 
   public int size() {
     return page.size();
   }
 
   public boolean isEmpty() {
     return page.isEmpty();
   }
 
   public boolean contains(Object o) {
     return page.contains(o);
   }
 
   public Iterator iterator() {
     return page.iterator();
   }
 
   public Object[] toArray() {
     return page.toArray();
   }
 
   public Object[] toArray(Object a[]) {
     return page.toArray(a);
   }
 
   public boolean containsAll(Collection c) {
     return page.containsAll(c);
   }
 
   public Object get(int index) {
     return page.get(index);
   }
 
   public int indexOf(Object o) {
     return page.indexOf(o);
   }
 
   public int lastIndexOf(Object o) {
     return page.lastIndexOf(o);
   }
 
   public ListIterator listIterator() {
     return page.listIterator();
   }
 
   public ListIterator listIterator(int index) {
     return page.listIterator(index);
   }
 
   public List subList(int fromIndex, int toIndex) {
     return page.subList(fromIndex, toIndex);
   }
 
   /* List mutators (uses master list) */
 
   public boolean add(Object o) {
     boolean b = list.add(o);
     repaginate();
     return b;
   }
 
   public boolean remove(Object o) {
     boolean b = list.remove(o);
     repaginate();
     return b;
   }
 
   public boolean addAll(Collection c) {
     boolean b = list.addAll(c);
     repaginate();
     return b;
   }
 
   public boolean addAll(int index, Collection c) {
     boolean b = list.addAll(index, c);
     repaginate();
     return b;
   }
 
   public boolean removeAll(Collection c) {
     boolean b = list.removeAll(c);
     repaginate();
     return b;
   }
 
   public boolean retainAll(Collection c) {
     boolean b = list.retainAll(c);
     repaginate();
     return b;
   }
 
   public void clear() {
     list.clear();
     repaginate();
   }
 
   public Object set(int index, Object element) {
     Object o = list.set(index, element);
     repaginate();
     return o;
   }
 
   public void add(int index, Object element) {
     list.add(index, element);
     repaginate();
   }
 
   public Object remove(int index) {
     Object o = list.remove(index);
     repaginate();
     return o;
   }
 
   /* Paginated List methods */
 
   public int getPageSize() {
     return pageSize;
   }
 
   public boolean isFirstPage() {
     return index == 0;
   }
 
   public boolean isMiddlePage() {
     return !(isFirstPage() || isLastPage());
   }
 
   public boolean isLastPage() {
     return list.size() - ((index + 1) * pageSize) < 1;
   }
 
   public boolean isNextPageAvailable() {
     return !isLastPage();
   }
 
   public boolean isPreviousPageAvailable() {
     return !isFirstPage();
   }
 
   public boolean nextPage() {
     if (isNextPageAvailable()) {
       index++;
       repaginate();
       return true;
     } else {
       return false;
     }
   }
 
   public boolean previousPage() {
     if (isPreviousPageAvailable()) {
       index--;
       repaginate();
       return true;
     } else {
       return false;
     }
   }
 
   public void gotoPage(int pageNumber) {
     index = pageNumber;
     repaginate();
   }
 
   public int getPageIndex() {
     return index;
   }
 
 }