<?php
// $Id$

/**
 * @file
 * Defines a field type for referencing a user from a node.
 */

/**
 * Implementation of hook_menu().
 */
function userreference_menu() {
  $items = array();
  $items['userreference/autocomplete'] = array(
    'title' => t('Userreference autocomplete'),
    'page callback' => 'userreference_autocomplete',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK
  );
  return $items;
}

/**
 * Implementation of hook_theme().
 */
function userreference_theme() {
  return array(
    'userreference_select' => array(
      'arguments' => array('element' => NULL),
    ),
    'userreference_autocomplete' => array(
      'arguments' => array('element' => NULL),
    ),
    'userreference_formatter_default' => array(
      'arguments' => array('element'),
    ),
    'userreference_formatter_plain' => array(
      'arguments' => array('element'),
    ),
  );
}

/**
 * Implementation of hook_field_info().
 *
 * Here we indicate that the content module will use its default
 * handling for the view of this field.
 */
function userreference_field_info() {
  return array(
    'userreference' => array(
      'label' => t('User Reference'),
      'description' => t('Store the id of a related user as an integer value.'),
      'callbacks' => array(
        'tables' => CONTENT_CALLBACK_DEFAULT,
        'arguments' => CONTENT_CALLBACK_DEFAULT,
        ),
      ),
  );
}

/**
 * Implementation of hook_field_settings().
 */
function userreference_field_settings($op, $field) {
  switch ($op) {
    case 'form':
      $form = array();
      $form['referenceable_roles'] = array(
        '#type' => 'checkboxes',
        '#title' => t('User roles that can be referenced'),
        '#default_value' => is_array($field['referenceable_roles']) ? array_filter($field['referenceable_roles']) : array(),
        '#options' => user_roles(1),
      );
      $form['referenceable_status'] = array(
        '#type' => 'checkboxes',
        '#title' => t('User status that can be referenced'),
        '#default_value' => is_array($field['referenceable_status']) ? array_filter($field['referenceable_status']) : array(1),
        '#options' => array(1 => t('Active'), 0 => t('Blocked')),
      );
      return $form;

    case 'save':
      return array('referenceable_roles', 'referenceable_status');

    case 'database columns':
      $columns = array(
        'uid' => array('type' => 'int', 'unsigned' => TRUE,  'not null' => FALSE),
      );
      return $columns;

    case 'views data':
      $data = content_views_field_views_data($field);
      $db_info = content_database_info($field);
      $table_alias = content_views_tablename($field);

      // Swap the filter handler to the 'in' operator.
      $data[$table_alias][$field['field_name'] .'_uid']['filter']['handler'] = 'views_handler_filter_many_to_one_content';

      // Add a relationship for related user.
      $data[$table_alias][$field['field_name'] .'_uid']['relationship'] = array(
        'base' => 'users',
        'field' => $db_info['columns']['uid']['column'],
        'handler' => 'views_handler_relationship',
      );
      return $data;

  }
}

/**
 * Implementation of hook_field().
 */
function userreference_field($op, &$node, $field, &$items, $teaser, $page) {
  switch ($op) {
    case 'validate':
      foreach ($items as $delta => $item) {
        if (is_array($item) && !empty($item['error_field'])) {
          $error_field = $item['error_field'];
          unset($item['error_field']);
          if (!empty($item['uid']) && !in_array($item['uid'], array_keys(_userreference_potential_references($field)))) {
            form_set_error($error_field, t('%name : Invalid user.', array('%name' => t($field['widget']['label']))));
          }
        }
      }
      return;
  }
}

/**
 * Implementation of hook_content_is_empty().
 */
function userreference_content_is_empty($item, $field) {
  if (empty($item['uid'])) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Implementation of hook_field_formatter_info().
 */
function userreference_field_formatter_info() {
  return array(
    'default' => array(
      'label' => t('Default'),
      'field types' => array('userreference'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
    'plain' => array(
      'label' => t('Plain text'),
      'field types' => array('userreference'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
  );
}

/**
 * Theme function for 'default' userreference field formatter.
 */
function theme_userreference_formatter_default($element) {
  $output = '';

  if (isset($element['#item']['uid']) && $account = user_load(array('uid' => $element['#item']['uid']))) {
    $output = theme('username', $account);
  }
  return $output;
}

/**
 * Theme function for 'plain' userreference field formatter.
 */
function theme_userreference_formatter_plain($element) {
  $output = '';
  if (isset($element['#item']['uid']) && $account = user_load(array('uid' => $element['#item']['uid']))) {
    $output = $account->name;
  }
  return $output;
}

/**
 * Implementation of hook_widget_info().
 *
 * We need custom handling of multiple values for userreference_select
 * because we need to combine them into a options list rather than
 * display multiple elements.
 *
 * We will use the content module's default handling for default value.
 *
 * Callbacks can be omitted if default handing is used.
 * They're included here just so this module can be used
 * as an example for custom modules that might do things
 * differently.
 */
function userreference_widget_info() {
  return array(
    'userreference_select' => array(
      'label' => t('Select List'),
      'field types' => array('userreference'),
      'multiple values' => CONTENT_HANDLE_MODULE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
        ),
    ),
    'userreference_autocomplete' => array(
      'label' => t('Autocomplete Text Field'),
      'field types' => array('userreference'),
      'multiple values' => CONTENT_HANDLE_CORE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
        ),
    ),
  );
}

/**
 * Implementation of FAPI hook_elements().
 *
 * Any FAPI callbacks needed for individual widgets can be declared here,
 * and the element will be passed to those callbacks for processing.
 *
 * Drupal will automatically theme the element using a theme with
 * the same name as the hook_elements key.
 *
 * Autocomplete_path is not used by text_widget but other widgets can use it
 * (see nodereference and userreference).
 */
function userreference_elements() {
  return array(
    'userreference_select' => array(
      '#input' => TRUE,
      '#columns' => array('uid'), '#delta' => 0,
      '#process' => array('userreference_select_process'),
      ),
    'userreference_autocomplete' => array(
      '#input' => TRUE,
      '#columns' => array('name'), '#delta' => 0,
      '#process' => array('userreference_autocomplete_process'),
      '#autocomplete_path' => FALSE,
      ),
    );
}

/**
 * Implementation of hook_widget_settings().
 */
function userreference_widget_settings($op, $field) {
  switch ($op) {
    case 'form':
      $form = array();
      $form['reverse_link'] = array(
        '#type' => 'radios',
        '#title' => t('Reverse Link'),
        '#default_value' => isset($field['reverse_link']) ? $field['reverse_link'] : 0,
        '#options' => array(0 => t('No'), 1 => t('Yes')),
        '#required' => TRUE,
        '#description' => t('If selected, a reverse link back to the referencing node will displayed on the referenced user record.'),
      );
      return $form;
      break;

    case 'save':
      return array('reverse_link');
      break;
  }
}

/**
 * Implementation of hook_widget().
 *
 * Attach a single form element to the form. It will be built out and
 * validated in the callback(s) listed in hook_elements. We build it
 * out in the callbacks rather than here in hook_widget so it can be
 * plugged into any module that can provide it with valid
 * $field information.
 *
 * Content module will set the weight, field name and delta values
 * for each form element. This is a change from earlier CCK versions
 * where the widget managed its own multiple values.
 *
 * If there are multiple values for this field, the content module will
 * call this function as many times as needed.
 *
 * @param $form
 *   the entire form array, $form['#node'] holds node information
 * @param $form_state
 *   the form_state, $form_state['values'][$field['field_name']]
 *   holds the field's form values.
 * @param $field
 *   the field array
 * @param $items
 *   array of default values for this field
 * @param $delta
 *   the order of this item in the array of subelements (0, 1, 2, etc)
 *
 * @return
 *   the form item for a single element for this field
 */
function userreference_widget(&$form, &$form_state, $field, $items, $delta = 0) {
  switch ($field['widget']['type']) {
    case 'userreference_select':
      $element = array(
        '#type' => 'userreference_select',
        '#default_value' => $items,
      );
      break;

    case 'userreference_autocomplete':
      $element = array(
        '#type' => 'userreference_autocomplete',
        '#default_value' => isset($items[$delta]) ? $items[$delta] : NULL,
        '#value_callback' => 'userreference_autocomplete_value',
      );
      break;
  }
  return $element;
}

/**
 * Value for a userreference autocomplete element.
 *
 * Substitute in the user name for the uid.
 */
function userreference_autocomplete_value($element, $edit = FALSE) {
  $field_key  = $element['#columns'][0];
  if (!empty($element['#default_value'][$field_key])) {
    $value = db_result(db_query("SELECT name FROM {users} WHERE uid = '%d'", $element['#default_value'][$field_key]));
    return array($field_key => $value);
  }
  return array($field_key => NULL);
}

/**
 * Process an individual element.
 *
 * Build the form element. When creating a form using FAPI #process,
 * note that $element['#value'] is already set.
 *
 * The $fields array is in $form['#field_info'][$element['#field_name']].
 */
function userreference_select_process($element, $edit, $form_state, $form) {
  // The userreference_select widget doesn't need to create its own
  // element, it can wrap around the optionwidgets_select element.
  // Add a validation step where the value can be unwrapped.
  $field_key  = $element['#columns'][0];
  $element[$field_key] = array(
    '#type' => 'optionwidgets_select',
    '#default_value' => isset($element['#value']) ? $element['#value'] : '',
    '#element_validate' => array('optionwidgets_validate', 'userreference_select_validate'),

    // The following values were set by the content module and need
    // to be passed down to the nested element.
    '#field_name' => $element['#field_name'],
    '#delta' => $element['#delta'],
    '#columns' => $element['#columns'],
    '#title' => $element['#title'],
    '#required' => $element['#required'],
    '#description' => $element['#description'],
  );
  return $element;
}

/**
 * Process an individual element.
 *
 * Build the form element. When creating a form using FAPI #process,
 * note that $element['#value'] is already set.
 *
 * The $fields array is in $form['#field_info'][$element['#field_name']].
 */
function userreference_autocomplete_process($element, $edit, $form_state, $form) {
  // The userreference autocomplete widget doesn't need to create its own
  // element, it can wrap around the text_textfield element and add an autocomplete
  // path and some extra processing to it.
  // Add a validation step where the value can be unwrapped.
  $field_key  = $element['#columns'][0];

  $element[$field_key] = array(
    '#type' => 'text_textfield',
    '#default_value' => isset($element['#value']) ? $element['#value'] : '',
    '#autocomplete_path' => 'userreference/autocomplete/'. $element['#field_name'],
    '#element_validate' => array('userreference_autocomplete_validate'),

    // The following values were set by the content module and need
    // to be passed down to the nested element.
    '#field_name' => $element['#field_name'],
    '#delta' => $element['#delta'],
    '#columns' => $element['#columns'],
    '#title' => $element['#title'],
    '#required' => $element['#required'],
    '#description' => $element['#description'],
  );
  return $element;
}

/**
 * Afterbuild adjustment of the element.
 *
 * Remove the wrapper layer and set the right element's value.
 */
function userreference_select_validate($element, &$form_state) {
  $field_key  = $element['#columns'][0];
  array_pop($element['#parents']);
  form_set_value($element, $form_state['values'][$element['#field_name']][$field_key], $form_state);
}

/**
 * Validate an autocomplete element.
 *
 * Remove the wrapper layer and set the right element's value.
 */
function userreference_autocomplete_validate($element, &$form_state) {
  $field_key  = $element['#columns'][0];
  $user = $element['#value'][$field_key];
  $uid = NULL;
  if (!empty($user)) {
    $uid = db_result(db_query("SELECT uid FROM {users} WHERE name = '%s'", $user));
  }
  form_set_value($element, $uid, $form_state);
}

/**
 * Implementation of hook_allowed_values().
 */
function userreference_allowed_values($field) {
  $options = _userreference_potential_references($field);
  if (!$field['required']) {
    $options = array('none' => '<'. t('none') .'>') + $options;
  }
  return $options;
}

/**
 * Menu callback; Retrieve a pipe delimited string of autocomplete suggestions for existing users
 */
function userreference_autocomplete($field_name, $string = '') {
  $fields = content_fields();
  $field = $fields[$field_name];

  $matches = array();
  if ($string) {
    foreach (_userreference_potential_references($field, $string) as $uid => $name) {
      $matches[$name] = check_plain($name);
    }
  }
  drupal_json($matches);
}

/**
 * Fetch an array of all candidate referenced users, for use in presenting the selection form to the user.
 */
function _userreference_potential_references($field, $string = '') {
  $where = array();
  $args = array();
  $join = array();

  if (!empty($string)) {
    $where[] = "LOWER(name) LIKE LOWER('%s%%')";
    $args[] = $string;
  }
  else {
    $where[] = "u.uid > 0";
  }

  $roles = array();
  if (isset($field['referenceable_roles']) && is_array($field['referenceable_roles'])) {
    // keep only selected checkboxes
    $roles = array_filter($field['referenceable_roles']);
    // filter invalid values that seems to get through sometimes ??
    $roles = array_intersect(array_keys(user_roles(1)), $roles);
  }
  if (!empty($roles) && !in_array(DRUPAL_AUTHENTICATED_RID, $roles)) {
    $where[] = "r.rid IN (". implode($roles, ',') .")";
    $join[] = 'LEFT JOIN {users_roles} r ON u.uid = r.uid';
  }

  $status = array();
  if (isset($field['referenceable_status']) && is_array($field['referenceable_status'])) {
    // keep only selected checkboxes
    $status = array_filter($field['referenceable_status']);
  }
  if (!empty($status)) {
    // Limit query if only one status should be referenced.
    if (count($status) == 1) {
      $where[] = "u.status = ". array_pop($status);
    }
  }

  $users = array();
  $result = db_query('SELECT u.name, u.uid FROM {users} u '. implode(' ', $join) .' WHERE '. implode(' AND ', $where) .' ORDER BY u.name ASC', $args);
  while ($user = db_fetch_object($result)) {
    $users[$user->uid] = $user->name;
  }
  return $users;
}

/**
 * Provide a list of users to filter on.
 */
function _userreference_filter_handler($op, $filterinfo) {
  $options = views_handler_filter_usercurrent();
  $options = $options + _userreference_potential_references($filterinfo['extra']['field']);
  return $options;
}

/**
 * Implementation of hook_user().
 */
function userreference_user($type, &$edit, &$account) {
  switch ($type) {
    case 'load':
      // find CCK userreference field tables
      // search through them for matching user ids and load those nodes
      $additions = array();
      $types = content_types();

      // Find the table and columns to search through, if the same
      // table comes up in more than one content type, we only need
      // to search it once.
      $search_tables = array();
      $search_links = array();
      foreach ($types as $type_name => $type) {
        foreach ($type['fields'] as $field) {
          if ($field['type'] == 'userreference') {
            $db_info = content_database_info($field);
            $search_tables[$db_info['table']] = $db_info['columns']['uid']['column'];
            $search_links[$db_info['table']] = $field['widget']['reverse_link'];
          }
        }
      }
      foreach ($search_tables as $table => $column) {
        $ids = db_query(db_rewrite_sql("SELECT DISTINCT(n.nid) FROM {node} n LEFT JOIN {". $table ."} f ON n.vid = f.vid WHERE f.". $column ."=". $account->uid. " AND n.status = 1"));
        while ($data = db_fetch_object($ids)) {
          // TODO, do we really want a complete node_load() here? We only need the title to create a link.
          $node = node_load($data->nid);
          $node->reverse_link = $search_links[$table];
          $additions[$node->type][] = $node;
        }
      }
      $account->userreference = $additions;
      return;
      break;

    case 'view':
      if (!empty($account->userreference)) {
        $node_types = content_types();
        $additions = array();
        $values = array();
        foreach ($account->userreference as $node_type => $nodes) {
          foreach ($nodes as $node) {
            if ($node->reverse_link) {
              $values[$node_type][] = l($node->title, 'node/'. $node->nid);
            }
          }
          if (isset($values[$node_type])) {
            $additions[] = array(
              '#type' => 'user_profile_item',
              '#title' => $node_types[$node_type]['name'],
              '#value' => theme('item_list', $values[$node_type]),
            );
          }
        }
        if ($additions) {
          $account->content['userreference'] = $additions + array(
            '#type' => 'user_profile_category',
            '#attributes' => array('class' => 'user-member'),
            '#title' => t('Related Content'),
            '#weight' => 10,
          );
        }
      }
      break;
  }
}

/**
 * FAPI theme for an individual elements.
 *
 * The textfield or select is already rendered by the
 * textfield or select themes and the HTML output
 * lives in $element['#children']. Override this theme to
 * make custom changes to the output.
 *
 * $element['#field_name'] contains the field name
 * $element['#delta]  is the position of this element in the group
 */
function theme_userreference_select($element) {
  return $element['#children'];
}

function theme_userreference_autocomplete($element) {
  return $element['#children'];
}