<?php
/**
 * Abstract Class for CiviRules Generic Field Changed condition
 *
 * @author Jaap Jansma (CiviCooP) <jaap.jansma@civicoop.org>
 * @license AGPL-3.0
 */

abstract class CRM_CivirulesConditions_Generic_FieldChanged extends CRM_Civirules_Condition {

  /**
   * Returns name of entity
   *
   * @return string
   * @access protected
   * @abstract
   */
  abstract protected function getEntity();

  /**
   * Returns name of the field
   *
   * @return string
   * @access protected
   * @abstract
   */
  abstract protected function getField();

  /**
   * Method to check if the condition is valid
   *
   * @param object CRM_Civirules_TriggerData_TriggerData $triggerData
   * @return bool
   * @access public
   */
  public function isConditionValid(CRM_Civirules_TriggerData_TriggerData $triggerData) {
    //not the right trigger. The trigger data should contain also
    if (!$triggerData instanceof CRM_Civirules_TriggerData_Interface_OriginalData) {
      return false;
    }
    $entity = $this->getEntity();
    if ( strtolower($entity) != strtolower($triggerData->getOriginalEntity()) ) {
      return false;
    }
    // we need to check to see if the data being submitted actually contains the field we are comparing. if not, return false, no change
    $compareField = $this->getField();
    $compareEntityData = $triggerData->getEntityData($entity);
    $compareEntityCustomData = $triggerData->getEntityCustomData();
    if ( array_key_exists($compareField, $compareEntityData) || array_key_exists($compareField, $compareEntityCustomData) ) {
      $fieldData = $this->getFieldData($triggerData);
    } else {
      return false;
    }
    $originalData = $this->getOriginalFieldData($triggerData);

    if (empty($fieldData) && empty($originalData)) {
      return false; //both original and new data are null so assume not changed
    } elseif ($fieldData == $originalData) {
      return false; //both data are equal so assume not changed
    }

    return true;
  }

  /**
   * This method could be overridden in subclasses to
   * transform field data to a certain type
   *
   * E.g. a date field could be transformed to a DataTime object so that
   * the comparison is easier
   *
   * @param mixed $fieldData
   * @return mixed
   * @access protected
   */
  protected function transformFieldData($fieldData) {
    return $fieldData;
  }

  /**
   * Returns a redirect url to extra data input from the user after adding a condition
   *
   * Return false if you do not need extra data input
   *
   * @param int $ruleConditionId
   * @return bool|string
   * @access public
   */
  public function getExtraDataInputUrl($ruleConditionId) {
    return false;
  }

  /**
   * Method to get the field data
   *
   * @param object CRM_Civirules_TriggerData_TriggerData $triggerData
   * @return mixed|null
   * @access protected
   */
  protected function getFieldData(CRM_Civirules_TriggerData_TriggerData $triggerData) {
    $entity = $this->getEntity();
    $data = $triggerData->getEntityData($entity);

    $field = $this->getField();
    if (isset($data[$field])) {
      return $this->transformFieldData($data[$field]);
    }
    $customFieldId = str_replace("custom_", '', $field, $customField);
    if ( $customField ) {
      $value = $triggerData->getCustomFieldValue($customFieldId);
      return $this->transformFieldData($value);
    }

    return null;
  }

  /**
   * Method to get the original field data
   *
   * @param object CRM_Civirules_TriggerData_Interface_OriginalData $triggerData
   * @return mixed|null
   * @access protected
   */
  protected function getOriginalFieldData(CRM_Civirules_TriggerData_Interface_OriginalData $triggerData) {
    $entity = $this->getEntity();
    if ( strtolower($triggerData->getOriginalEntity()) != strtolower($entity) ) {
      return null;
    }

    $data = $triggerData->getOriginalData();
    $field = $this->getField();
    if (isset($data[$field])) {
      return $this->transformFieldData($data[$field]);
    }
    return null;
  }


  /**
   * This function validates whether this condition works with the selected trigger.
   *
   * This function could be overriden in child classes to provide additional validation
   * whether a condition is possible in the current setup. E.g. we could have a condition
   * which works on contribution or on contributionRecur then this function could do
   * this kind of validation and return false/true
   *
   * @param CRM_Civirules_Trigger $trigger
   * @param CRM_Civirules_BAO_Rule $rule
   * @return bool
   */
  public function doesWorkWithTrigger(CRM_Civirules_Trigger $trigger, CRM_Civirules_BAO_Rule $rule) {
    $triggerDataClassName = $trigger->getTriggerDataClassName();
    if (in_array('CRM_Civirules_TriggerData_Interface_OriginalData', class_implements($triggerDataClassName))) {
      return $trigger->doesProvideEntity($this->getEntity());
    }
    return false;
  }
}