<?php
/**
 * $Id$
 * 
 * @author oncletom
 * @package configuration.lib.amazon-widgets-shortcodes
 * @subpackage AWShortcodesConfigurationOption
 * @since 2.0
 * @version $Revision$
 */
class AWShortcodesConfigurationOption
{
  const TYPE_ARRAY =    'array',
        TYPE_BOOLEAN =  'boolean',
        TYPE_INTEGER =  'integer',
        TYPE_STRING =   'string';

  public static $defaults = array(
    'autoload' =>       false,
    'default' =>        '',
    'onLoadCallback' => null,
    'onSaveCallback' => null,
    'possibleValues' => array(),
    'type' =>           'string', //equivalent to self::TYPE_STRING
    'value' =>          '',
  );

  public static $defaults_for_types = array(
    'array' =>    array(
      'default' =>        'a:0:{}',
      'onLoadCallback' => 'unserialize',
      'onSaveCallback' => 'serialize',
    ),
    'boolean' =>  array(
      'default' =>        0,
      'onSaveCallback' => 'intval',
      'possibleValues' => array(0, 1),
    ),
    'integer' =>  array(
      'default' =>        0,
      'onSaveCallback' => 'intval',
    ),
  );

  public static $create_option_callback = 'add_option';
  public static $delete_option_callback = 'delete_option';
  public static $get_option_callback = 'get_option';
  public static $set_option_callback = 'update_option';

  protected $id,
            $options,
            $prefix;

  private $is_loaded = false,
          $is_new =    false;

  /**
   * Constructs the object
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @param $id string
   * @param $options array [optional]
   */
  public function __construct($id, array $options = array())
  {
    $this->id = $id;
    $this->options = self::$defaults;
    $this->fromArray($options);
  }

  /**
   * Computes the option value
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @return mixed
   */
  public function __toString()
  {
    return $this->getValue();
  }

  /**
   * Removes an option from database
   * 
   * @author oncletom
   * 
   * @return 
   */
  public function delete()
  {
    call_user_func(self::$delete_option_callback, $this->getId());
    $this->fromArray(self::$defaults);
  }

  /**
   * Builds the option from an array
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   */
  public function fromArray(array $options)
  {
    $valid_options = array_intersect_key($options, self::$defaults);
    $this->is_loaded = false;

    /*
     * If we have a type defaults, we override non-defined fields
     */
    if (isset($options['type']) && isset(self::$defaults_for_types[$options['type']]))
    {
      $this->options = array_merge($this->options, self::$defaults_for_types[$options['type']]);
    }

    /*
     * Finally setup given options
     */
    $this->options = array_merge($this->options, $valid_options);
  }

  /**
   * Returns the default value for the option
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @return mixed
   */
  public function getDefaultValue()
  {
    return $this->options['default'];
  }

  /**
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @return mixed
   */
  public function getId()
  {
    return sprintf('%s%s', $this->prefix, $this->id);
  }

  /**
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @return mixed
   */
  public function getPossibleValues()
  {
    return $this->options['possibleValues'];
  }

  /**
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @return mixed
   */
  public function getValue()
  {
    if (!$this->is_loaded)
    {
      $value = call_user_func(self::$get_option_callback, $this->getId(), $this->getDefaultValue());

      if ($value === false)
      {
        $this->is_new = true;
      }

      if ($this->options['onLoadCallback'] && is_callable($this->options['onLoadCallback']))
      {
        $value = call_user_func($this->options['onLoadCallback'], $value);
      }

      $this->options['value'] = $value;
      $this->is_loaded = true;
    }

    return $this->options['value'];
  }

  /**
   * Returns if the option is an autoload or not
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @return boolean
   */
  public function isAutoload()
  {
    return !!$this->options['autoload'];
  }

  /**
   * Saves a value to the persistent storage
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   */
  public function save()
  {
    $value = $this->options['value'];

    if ($this->options['onSaveCallback'] && is_callable($this->options['onSaveCallback']))
    {
      $value = call_user_func($this->options['onSaveCallback'], $value);
    }

    if ($this->is_new)
    {
      call_user_func(self::$create_option_callback, $this->getId(), $value, '', $this->isAutoload() ? 'yes' : 'no');
    }
    else
    {
      call_user_func(self::$set_option_callback, $this->getId(), $value);
    }

    $this->is_new = false;
  }

  /**
   * Sets the database prefix of the object
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @param string $prefix
   */
  public function setPrefix($prefix)
  {
    $this->prefix = $prefix;
  }

  /**
   * Saves a value and stores it through the remote API
   * 
   * @author oncletom
   * @since 2.0
   * @version 1.0
   * @param mixed $value
   */
  public function setValue($value)
  {
    $this->options['value'] = $value;
    $this->save();
  }
}