<?php
/**
 * datatype.php
 *
 * Copyright 2018 Andy Street <andy@street.me.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 *
 *
 */

namespace libgpx;

/**
 * A GPX data type.
 *
 * @author Andy Street <andy@street.me.uk>
 */
abstract class DataType
{

  /**
   * A name.
   *
   * @var string
   */
  protected $name;

  /**
   * A comment.
   *
   * Sent to GPS as comment.
   *
   * @var string
   */
  protected $comment;

  /**
   * A text description.
   *
   * Holds additional information about the element intended for the user,
   * not the GPS.
   *
   * @var string
   */
  protected $description;

  /**
   * Source of data.
   *
   * Included to give user some idea of reliability and accuracy of data.
   * E.g. "Garmin eTrex", "USGS quad Boston North".
   *
   * @var string
   */
  protected $source;

  /**
   * A list of associated links.
   *
   * @var TypedDoublyLinkedList (Link)
   */
  protected $links;

  /**
   * Type (classification).
   *
   * @var string
   */
  protected $type;

  /**
   * A list of XML snippets describing unsupported data.
   *
   * @var TypedDoublyLinkedList (string)
   */
  protected $extensions;

  /**
   * Fetch the name.
   *
   * @return string|null The name or null if not set.
   */
  public function getName()
  {
    return $this->name;
  }

  /**
   * Set the name.
   *
   * @param string $name The name or null to delete.
   * @return void
   */
  public function setName(string $name = null)
  {
    $this->name = $name;
  }

  /**
   * Fetch a comment.
   *
   * @return string The comment or null if not set.
   */
  public function getComment()
  {
    return $this->comment;
  }

  /**
   * Set a comment.
   *
   * @param string $comment The comment or null to delete.
   * @return void
   */
  public function setComment(string $comment = null)
  {
    $this->comment = $comment;
  }

  /**
   * Fetch the description.
   *
   * @return string The description or null if not set.
   */
  public function getDescription()
  {
    return $this->description;
  }

  /**
   * Set the description.
   *
   * @param string $description The description or null to delete.
   * @return void
   */
  public function setDescription(string $description = null)
  {
    $this->description = $description;
  }

  /**
   * Fetch the source of the data.
   *
   * @return string|null The source or null if not set.
   */
  public function getSource()
  {
    return $this->source;
  }

  /**
   * Set the source of the data.
   *
   * @param string $source The source of the data or null to delete.
   * @return void
   */
  public function setSource(string $source = null)
  {
    $this->source = $source;
  }

  /**
   * Fetch a list of associated links.
   *
   * @param boolean $create Create the list if it does not already exist.
   * @return TypedDoublyLinkedList|null A list of Link objects.
   */
  public function getLinks(bool $create = true)
  {
    if ($create && $this->links === null)
      $this->links = new TypedDoublyLinkedList('libgpx\Link');
    return $this->links;
  }

  /**
   * Fetch the type.
   *
   * @return string|null The type or null if not set.
   */
  public function getType()
  {
    return $this->type;
  }

  /**
   * Set the type.
   *
   * @param string $type The type or null to delete.
   * @return void
   */
  public function setType(string $type = null)
  {
    $this->type = $type;
  }

  /**
   * Fetch a list of XML strings that describe unsupported elements.
   *
   * @param boolean $create Create the list if it does not already exist.
   * @return TypedDoublyLinkedList|null A list of XML strings.
   */
  public function getExtensions(bool $create = true)
  {
    if ($create && $this->extensions === null)
      $this->extensions = new TypedDoublyLinkedList('string');
    return $this->extensions;
  }

}