<?php

namespace Drupal\Core\Condition;

use Drupal\Component\Plugin\ConfigurablePluginInterface;
use Drupal\Component\Plugin\PluginInspectionInterface;
use Drupal\Core\Cache\CacheableDependencyInterface;
use Drupal\Core\Executable\ExecutableInterface;
use Drupal\Core\Executable\ExecutableManagerInterface;
use Drupal\Core\Plugin\PluginFormInterface;

/**
 * An interface for condition plugins.
 *
 * Condition plugins are context-aware and configurable. They support the
 * following keys in their plugin definitions:
 * - context: An array of context definitions, keyed by context name. Each
 *   context definition is a typed data definition describing the context. Check
 *   the typed data definition docs for details.
 * - configuration: An array of configuration option definitions, keyed by
 *   option name. Each option definition is a typed data definition describing
 *   the configuration option. Check the typed data definition docs for details.
 *
 * @todo Replace the dependency on \Drupal\Core\Form\FormInterface with a new
 *   interface from https://www.drupal.org/node/2006248.
 * @todo WARNING: The condition API is going to receive some additions before release.
 * The following additions are likely to happen:
 *  - The way configuration is handled and configuration forms are built is
 *    likely to change in order for the plugin to be of use for Rules.
 *  - Conditions will receive a data processing API that allows for token
 *    replacements to happen outside of the plugin implementations,
 *    see https://www.drupal.org/node/2347023.
 *  - Conditions will have to implement access control for checking who is
 *    allowed to configure or perform the action at
 *    https://www.drupal.org/node/2172017.
 *
 * @see \Drupal\Core\TypedData\TypedDataManager::create()
 * @see \Drupal\Core\Executable\ExecutableInterface
 * @see \Drupal\Core\Condition\ConditionManager
 * @see \Drupal\Core\Condition\Annotation\Condition
 * @see \Drupal\Core\Condition\ConditionPluginBase
 *
 * @ingroup plugin_api
 */
interface ConditionInterface extends ExecutableInterface, PluginFormInterface, ConfigurablePluginInterface, PluginInspectionInterface, CacheableDependencyInterface {

  /**
   * Determines whether condition result will be negated.
   *
   * @return bool
   *   Whether the condition result will be negated.
   */
  public function isNegated();

  /**
   * Evaluates the condition and returns TRUE or FALSE accordingly.
   *
   * @return bool
   *   TRUE if the condition has been met, FALSE otherwise.
   */
  public function evaluate();

  /**
   * Provides a human readable summary of the condition's configuration.
   */
  public function summary();

  /**
   * Sets the executable manager class.
   *
   * @param \Drupal\Core\Executable\ExecutableManagerInterface $executableManager
   *   The executable manager.
   */
  public function setExecutableManager(ExecutableManagerInterface $executableManager);

}
