<?php
// $Id$

/**
 * Get information about fields for a given api request. Getfields information
 * is used for documentation, validation, default setting
 * We first query the scheme using the $dao->fields function & then augment
 * that information by calling the _spec functions that apply to the relevant function
 * Note that we use 'unique' field names as described in the xml/schema files
 * for get requests & just field name for create. This is because some get functions
 * access multiple objects e.g. contact api accesses is_deleted from the activity
 * table & from the contact table
 *
 * @param array $apiRequest api request as an array. Keys are
 *  - entity: string
 *  - action: string
 *  - version: string
 *  - function: callback (mixed)
 *  - params: array, varies
 *  @return array API success object
 */
function civicrm_api3_generic_getfields($apiRequest) {
  static $results = array();
  if ((CRM_Utils_Array::value('cache_clear', $apiRequest['params']))) {
    $results = array();
    // we will also clear pseudoconstants here - should potentially be moved to relevant BAO classes
    if(!empty($apiRequest['params']['fieldname'])){
      CRM_Utils_PseudoConstant::flushConstant($apiRequest['params']['fieldname']);
    }
    if(!empty($apiRequest['params']['option_group_id'])){
      $optionGroupName = civicrm_api('option_group', 'getvalue', array('version' => 3, 'id' => $apiRequest['params']['option_group_id'], 'return' => 'name') );
      if(is_string($optionGroupName)){
        CRM_Utils_PseudoConstant::flushConstant(_civicrm_api_get_camel_name($optionGroupName));
      }
    }
  }
  $entity       = _civicrm_api_get_camel_name($apiRequest['entity']);
  $lcase_entity = _civicrm_api_get_entity_name_from_camel($entity);
  $subentity    = CRM_Utils_Array::value('contact_type', $apiRequest['params']);
  $action       = strtolower(CRM_Utils_Array::value('action', $apiRequest['params']));
  $apiOptions = CRM_Utils_Array::value('options', $apiRequest['params'], array());
  if ($action == 'getvalue' || $action == 'getvalue' || $action == 'getcount') {
    $action = 'get';
  }

  if (empty($action)) {
    $action='get';
  }
  // determines whether to use unique field names - seem comment block above
  $unique = TRUE;
  if (isset($results[$entity . $subentity]) && CRM_Utils_Array::value($action, $results[$entity])
    && empty($apiOptions)) {
    return $results[$entity . $subentity][$action];
  }
  // defaults based on data model and API policy
  switch ($action) {
    case 'getfields':
      $values = _civicrm_api_get_fields($entity, false, $apiRequest['params']);
      $results[$entity][$action] = civicrm_api3_create_success($values,
        $apiRequest['params'], $entity, 'getfields'
      );
      return $results[$entity][$action];

                case 'getfields':
                  return civicrm_api3_create_success(_civicrm_api_get_fields($apiRequest['entity']));
    case 'create':
    case 'update':
    case 'replace':
      $unique = FALSE;
    case 'get':
      $metadata = _civicrm_api_get_fields($apiRequest['entity'], $unique, $apiRequest['params']);
      if (empty($metadata['id']) && !empty($metadata[$apiRequest['entity'] . '_id'])) {
        $metadata['id'] = $metadata[$lcase_entity . '_id'];
        $metadata['id']['api.aliases'] = array($lcase_entity . '_id');
        unset($metadata[$lcase_entity . '_id']);
      }
      break;

    case 'delete':
      $metadata = array(
        'id' => array('title' => 'Unique Identifier',
          'api.required' => 1,
          'api.aliases' => array($lcase_entity . '_id'),
        ));
      break;

    case 'getoptions':
      $metadata = array(
        'field' => array('title' => 'Field to retrieve options for',
        'api.required' => 1,
      ));
        break;
    default:
      // oddballs are on their own
      $metadata = array();
  }

  // find any supplemental information
  $hypApiRequest = array('entity' => $apiRequest['entity'], 'action' => $action, 'version' => $apiRequest['version']);
  $hypApiRequest += _civicrm_api_resolve($hypApiRequest);
  $helper = '_' . $hypApiRequest['function'] . '_spec';
  if (function_exists($helper)) {
    // alter
    $helper($metadata);
  }

  $fieldsToResolve = CRM_Utils_Array::value('get_options', $apiOptions, array());

  foreach ($metadata as $fieldname => $fieldSpec) {
    _civicrm_api3_generic_get_metadata_options($metadata, $fieldname, $fieldSpec, $fieldsToResolve);
  }

  $results[$entity][$action] = civicrm_api3_create_success($metadata, $apiRequest['params'], NULL, 'getfields');
  return $results[$entity][$action];
}

/**
 * API return function to reformat results as count
 *
 * @param array $apiRequest api request as an array. Keys are
 *
 * @return integer count of results
 */
function civicrm_api3_generic_getcount($apiRequest) {
  $result = civicrm_api($apiRequest['entity'], 'get', $apiRequest['params']);
  return $result['count'];
}

/**
 * API return function to reformat results as single result
 *
 * @param array $apiRequest api request as an array. Keys are
 *
 * @return integer count of results
 */
function civicrm_api3_generic_getsingle($apiRequest) {
  // so the first entity is always result['values'][0]
  $apiRequest['params']['sequential'] = 1;
  $result = civicrm_api($apiRequest['entity'], 'get', $apiRequest['params']);
  if ($result['is_error'] !== 0) {
    return $result;
  }
  if ($result['count'] === 1) {
    return $result['values'][0];
  }
  if ($result['count'] !== 1) {
    return civicrm_api3_create_error("Expected one " . $apiRequest['entity'] . " but found " . $result['count'], array('count' => $result['count']));
  }
  return civicrm_api3_create_error("Undefined behavior");
}

/**
 * API return function to reformat results as single value
 *
 * @param array $apiRequest api request as an array. Keys are
 *
 * @return integer count of results
 */
function civicrm_api3_generic_getvalue($apiRequest) {
  $apiRequest['params']['sequential'] = 1;
  $result = civicrm_api($apiRequest['entity'], 'get', $apiRequest['params']);
  if ($result['is_error'] !== 0) {
    return $result;
  }
  if ($result['count'] !== 1) {
    $result = civicrm_api3_create_error("Expected one " . $apiRequest['entity'] . " but found " . $result['count'], array('count' => $result['count']));
    return $result;
  }

  // we only take "return=" as valid options
  if (CRM_Utils_Array::value('return', $apiRequest['params'])) {
    if (!isset($result['values'][0][$apiRequest['params']['return']])) {
      return civicrm_api3_create_error("field " . $apiRequest['params']['return'] . " unset or not existing", array('invalid_field' => $apiRequest['params']['return']));
    }

    return $result['values'][0][$apiRequest['params']['return']];
  }

  return civicrm_api3_create_error("missing param return=field you want to read the value of", array('error_type' => 'mandatory_missing', 'missing_param' => 'return'));
}

/**
 * API wrapper for replace function
 *
 * @param array $apiRequest api request as an array. Keys are
 *
 * @return integer count of results
 */
function civicrm_api3_generic_replace($apiRequest) {
  return _civicrm_api3_generic_replace($apiRequest['entity'], $apiRequest['params']);
}

/**
 * API wrapper for getoptions function
 *
 * @param array $apiRequest api request as an array. Keys are
 *
 * @return array of results
 */
function civicrm_api3_generic_getoptions($apiRequest) {
  $field = $apiRequest['params']['field'];
  $getFieldsArray = array(
    'version' => 3,
    'action' => 'create',
    'options' => array('get_options' => $field),
  );
  // First try to retrieve the options from getfields
  $result = civicrm_api($apiRequest['entity'], 'getfields', $getFieldsArray);
  if (!isset($result['values'][$field]) && isset($result['values'][$field . '_id'])) {
    $field = $field . '_id';
  }
  if (!empty($result['values'][$field]['options'])) {
    return civicrm_api3_create_success($result['values'][$field]['options']);
  }
  // If that didn't work, try the constant api
  if (substr($field, -3) == '_id') {
    // Convert foo_id to just plain foo
    $field = substr($field, 0, -3);
  }
  $params = array('name' => _civicrm_api_get_camel_name($field));
  $entity = strtolower($apiRequest['entity']);
  if ($entity == 'contribution') {
    $params['class'] = 'CRM_Contribute_PseudoConstant';
  }
  elseif ($entity == 'event' || $entity == 'participant') {
    $params['class'] = 'CRM_Event_PseudoConstant';
  }
  elseif (strpos($entity, 'membership') === 0) {
    $params['class'] = 'CRM_Member_PseudoConstant';
  }
  require_once 'api/v3/Constant.php';
  return civicrm_api3_constant_get($params);
}

/**
 * Function fills the 'options' array on the metadata returned by getfields if
 * 1) the param option 'get_options' is defined - e.g. $params['options']['get_options'] => array('custom_1)
 * (this is passed in as the $fieldsToResolve array)
 * 2) the field is a pseudoconstant and is NOT an FK
 * - the reason for this is that checking / transformation is done on pseudoconstants but
 * - if the field is an FK then mysql will enforce the data quality (& we have handling on failure)
 * @todo - if may be we should define a 'resolve' key on the psuedoconstant for when these rules are not fine enough
 * 3) if there is an 'enum' then it is split up into the relevant options
 *
 * This function is only split out for the purpose of code clarity / comment block documentation
 * @param array $metadata the array of metadata that will form the result of the getfields function
 * @param string $fieldname field currently being processed
 * @param array $fieldSpec metadata for that field
 * @param array $fieldsToResolve anny field resolutions specifically requested
 */
function _civicrm_api3_generic_get_metadata_options(&$metadata, $fieldname, $fieldSpec, $fieldsToResolve){
  if (array_key_exists('enumValues', $fieldSpec)) {
    // use of a space after the comma is inconsistent in xml
    $enumStr = str_replace(', ', ',', $fieldSpec['enumValues']);
    $metadata[$fieldname]['options'] = explode(',', $enumStr);
    return;
  }

  if(empty($fieldSpec['pseudoconstant'])){
    return ;
  }
  elseif(!empty($fieldSpec['FKClassName']) && !in_array($fieldname, $fieldsToResolve)){
    return;
  }
  if(substr($fieldname, -3) == '_id'){
    $metadata[$fieldname]['api.aliases'][] = substr($fieldname, 0, -3);
  }

  $pseudoParams = $fieldSpec['pseudoconstant'];
  $pseudoParams['version'] = 3;
  $options = civicrm_api('constant', 'get', $pseudoParams);
  if (is_array(CRM_Utils_Array::value('values', $options))) {
    $metadata[$fieldname]['options'] = $options['values'];
  }
}