package ru.perveev.container.node;

import java.util.Objects;

/**
 * Class, implementing the double linked list node with generic stored data type
 * <p>
 *
 * @author Sanlovty
 * @version 1.1
 * @since 1.0
 */
public class Node<T> {
    /**
     * Stored data
     */
    public T data;

    /**
     * Pointer to the previous Node
     */
    public Node<T> previous;

    /**
     * Pointer to the next Node
     */
    public Node<T> next;

    /**
     * Creates an instance of Node with the specified data.
     *
     * @param data The data stored inside of Node.
     */
    public Node(T data) {
        this.data = data;
        previous = next = null;
    }

    /**
     * Creates an instance of Node with the specified data, next and previous nodes (pointers to)
     *
     * @param data     The data stored inside of Node.
     * @param next     The pointer to the next Node.
     * @param previous The pointer to the previous Node.
     */
    public Node(T data, Node<T> next, Node<T> previous) {
        this.data = data;
        this.previous = previous;
        this.next = next;
    }

    /**
     * Overriding of equals method from Object class to let correctly check equality
     *
     * @param obj Object, we are trying to compare with
     */
    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }

        if (obj == null) {
            return false;
        }

        if (obj.getClass() != this.getClass()) {
            return false;
        }

        final Node<?> other = (Node<?>) obj;
        return Objects.equals(this.data, other.data);
    }

    /**
     * Overriding of hashCode method from Object class because we override equals and we need to follow the rules Object.hashCode()
     *
     * @return hash of instance
     */
    @Override
    public int hashCode() {
        return 53 * 3 + (this.data != null ? this.data.hashCode() : 0);
    }
}