package org.basex.util.list;

import java.util.*;

import org.basex.util.*;

/**
 * Resizable-array implementation for native booleans.
 *
 * @author BaseX Team 2005-18, BSD License
 * @author Christian Gruen
 */
public final class BoolList extends ElementList {
  /** Element container. */
  private boolean[] list;

  /**
   * Default constructor.
   */
  public BoolList() {
    this(Array.CAPACITY);
  }

  /**
   * Constructor, specifying an initial internal array size.
   * @param capacity initial array capacity
   */
  public BoolList(final int capacity) {
    list = new boolean[capacity];
  }

  /**
   * Adds an element.
   * @param element element to be added
   * @return self reference
   */
  public BoolList add(final boolean element) {
    boolean[] lst = list;
    final int s = size;
    if(s == lst.length) lst = Arrays.copyOf(lst, newSize());
    lst[s] = element;
    list = lst;
    size = s + 1;
    return this;
  }

  /**
   * Returns the element at the specified index.
   * @param index index of the element to return
   * @return element
   */
  public boolean get(final int index) {
    return list[index];
  }

  /**
   * Stores an element at the specified index.
   * @param index index of the element to replace
   * @param element element to be stored
   */
  public void set(final int index, final boolean element) {
    if(index >= list.length) list = Arrays.copyOf(list, newSize(index + 1));
    list[index] = element;
    size = Math.max(size, index + 1);
  }

  /**
   * Pops the uppermost element from the stack.
   * @return the popped element
   */
  public boolean pop() {
    return list[--size];
  }

  /**
   * Pushes an element onto the stack.
   * @param element element
   */
  public void push(final boolean element) {
    add(element);
  }

  /**
   * Returns the uppermost element on the stack, without removing it.
   * @return uppermost element
   */
  public boolean peek() {
    return list[size - 1];
  }

  /**
   * Finishes the int array.
   * @return int array
   */
  public boolean[] toArray() {
    return Arrays.copyOf(list, size);
  }

  /**
   * Returns an array with all elements and resets the array size.
   * @return array
   */
  public boolean[] next() {
    final boolean[] lst = Arrays.copyOf(list, size);
    reset();
    return lst;
  }

  /**
   * Returns an array with all elements and invalidates the internal array.
   * Warning: the function must only be called if the list is discarded afterwards.
   * @return array (internal representation!)
   */
  public boolean[] finish() {
    final boolean[] lst = list;
    list = null;
    final int s = size;
    return s == lst.length ? lst : Arrays.copyOf(lst, s);
  }

  @Override
  public boolean equals(final Object obj) {
    if(obj == this) return true;
    if(!(obj instanceof BoolList)) return false;
    final BoolList bl = (BoolList) obj;
    if(size != bl.size) return false;
    for(int l = 0; l < size; ++l) {
      if(list[l] != bl.list[l]) return false;
    }
    return true;
  }

  @Override
  public String toString() {
    return list == null ? "" : Arrays.toString(toArray());
  }
}
