<?php
// $Id$

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

/**
 * Implementation of hook_menu().
 */
function userreference_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'userreference/autocomplete', 'title' => t('user reference autocomplete'),
      'callback' => 'userreference_autocomplete', 'access' => user_access('access content'), 'type' => MENU_CALLBACK);
  }

  return $items;
}

/**
 * Implementation of hook_field_info().
 */
function userreference_field_info() {
  return array(
    'userreference' => array('label' => t('User Reference')),
  );
}

/**
 * Implementation of hook_field_settings().
 */
function userreference_field_settings($op, $field) {
  switch ($op) {
    case 'form':
      $form = array();
      $form['referenceable_roles'] = array(
        '#type' => 'checkboxes',
        '#title' => t('User roles that can be referenced'),
        '#default_value' => isset($field['referenceable_roles']) ? $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', 'not null' => FALSE, 'default' => NULL),
      );
      return $columns;

    case 'filters':
      return array(
        'default' => array(
          'list' => '_userreference_filter_handler',
          'list-type' => 'list',
          'operator' => 'views_handler_operator_or',
          'value-type' => 'array',
          'extra' => array('field' => $field),
        ),
      );
  }
}

/**
 * Implementation of hook_field().
 */
function userreference_field($op, &$node, $field, &$items, $teaser, $page) {
  switch ($op) {
    case 'validate':
      foreach ($items as $delta => $item) {
        $error_field = isset($item['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_field_formatter_info().
 */
function userreference_field_formatter_info() {
  return array(
    'default' => array(
      'label' => t('Default'),
      'field types' => array('userreference'),
    ),
    'plain' => array(
      'label' => t('Plain text'),
      'field types' => array('userreference'),
    ),
  );
}

/**
 * Implementation of hook_field_formatter().
 */
function userreference_field_formatter($field, $item, $formatter, $node) {
  $text = '';
  if (isset($item['uid'])) {
    $referenced_user = user_load(array('uid' => $item['uid']));
    if ($referenced_user) {
      $text = theme('username', $referenced_user);
    }
  }

  switch ($formatter) {
    case 'plain':
      return strip_tags($text);

    default:
      return $text;
  }
}

/**
 * Implementation of hook_widget_info().
 */
function userreference_widget_info() {
  return array(
    'userreference_select' => array(
      'label' => t('Select List'),
      'field types' => array('userreference'),
    ),
    'userreference_autocomplete' => array(
      'label' => t('Autocomplete Text Field'),
      'field types' => array('userreference'),
    ),
  );
}

/**
 * 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().
 */
function userreference_widget($op, &$node, $field, &$items) {
  if ($field['widget']['type'] == 'userreference_select') {
    switch ($op) {
      case 'prepare form values':
        $items_transposed = content_transpose_array_rows_cols($items);
        // get rid of null values
        $items['default uids'] = array_filter((array) $items_transposed['uid']);
        break;

      case 'form':
        $form = array();

        $options = _userreference_potential_references($field);
        if (!$field['required']) {
          $options = array('none' => t('<none>')) + $options;
        }
        if (empty($items['default uids'])) {
          $items['default uids'][] = 'none';
        }
        $form[$field['field_name']] = array('#tree' => TRUE);
        $form[$field['field_name']]['uids'] = array(
          '#type' => 'select',
          '#title' => t($field['widget']['label']),
          '#default_value' => $items['default uids'],
          '#multiple' => $field['multiple'],
          '#size' => $field['multiple'] ? min(count($options), 6) : 0,
          '#options' => $options,
          '#required' => $field['required'],
          '#description' => t($field['widget']['description']),
        );

        return $form;

      case 'process form values':
        if ($field['multiple']) {
          // drop the 'none' option
          unset($items['uids']['none']);
          if (!empty($items['uids'])) {
            $items = array_values(content_transpose_array_rows_cols(array('uid' => $items['uids'])));
          }
          else {
            $items[0]['uid'] = '';
          }
        }
        else {
          $items[0]['uid'] = ($items['uids'] != 'none') ? $items['uids'] : '';
        }
        // Remove the widget's data representation so it isn't saved.
        unset($items['uids']);
        foreach ($items as $delta => $item) {
          $items[$delta]['error_field'] =  $field['field_name'] .'][uids';
        }
    }
  }
  else {
    switch ($op) {
      case 'prepare form values':
        foreach ($items as $delta => $item) {
          if (!empty($items[$delta]['uid'])) {
            $items[$delta]['default user_name'] = db_result(db_query("SELECT name FROM {users} WHERE uid = '%d'", $items[$delta]['uid']));
          }
        }
        break;

      case 'form':
        $form = array();
        $form[$field['field_name']] = array('#tree' => TRUE);

        if ($field['multiple']) {
          $form[$field['field_name']]['#type'] = 'fieldset';
          $form[$field['field_name']]['#description'] = t($field['widget']['description']);
          $delta = 0;
          foreach ($items as $item) {
            if ($item['uid']) {
              $form[$field['field_name']][$delta]['user_name'] = array(
                '#type' => 'textfield',
                '#title' => ($delta == 0) ? t($field['widget']['label']) : '',
                '#autocomplete_path' => 'userreference/autocomplete/'. $field['field_name'],
                '#default_value' => $item['default user_name'],
                '#required' => ($delta == 0) ? $field['required'] : FALSE,
              );
              $delta++;
            }
          }
          foreach (range($delta, $delta + 2) as $delta) {
            $form[$field['field_name']][$delta]['user_name'] = array(
              '#type' => 'textfield',
              '#title' => ($delta == 0) ? t($field['widget']['label']) : '',
              '#autocomplete_path' => 'userreference/autocomplete/'. $field['field_name'],
              '#default_value' => '',
              '#required' => ($delta == 0) ? $field['required'] : FALSE,
            );
          }
        }
        else {
          $form[$field['field_name']][0]['user_name'] = array(
            '#type' => 'textfield',
            '#title' => t($field['widget']['label']),
            '#autocomplete_path' => 'userreference/autocomplete/'. $field['field_name'],
            '#default_value' => $items[0]['default user_name'],
            '#required' => $field['required'],
            '#description' => t($field['widget']['description']),
          );
        }
        return $form;

      case 'process form values':
        foreach ($items as $delta => $item) {
          $uid = '';
          if (!empty($items[$delta]['user_name'])) {
            $uid = db_result(db_query("SELECT uid FROM {users} WHERE name = '%s'", $items[$delta]['user_name']));
          }
          // Remove the widget's data representation so it isn't saved.
          unset($items[$delta]['user_name']);
          $items[$delta]['uid'] = $uid;
          $items[$delta]['error_field'] = $field['field_name'] .']['. $delta .'][user_name';
          // Don't save empty fields except the first value
          if (empty($uid) && $delta > 0) {
            unset($items[$delta]);
          }
        }
    }
  }
}

/**
 * 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($name);
    }
  }
  print drupal_to_js($matches);
  exit();
}

/**
 * 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($op, &$edit, &$account, $category = NULL) {

  switch ($op) {
    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("SELECT DISTINCT(nid) FROM {". $table ."} WHERE ". $column ."=". $account->uid);
        while ($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->content = $additions;
      return;

    case 'view':
      if (!empty($account->content)) {
        $node_types = (array) content_types();
        $values = array();
        $links = array();
        foreach ($account->content as $node_type => $nodes) {
          $links[$node_type] = array('title' => $node_types[$node_type]['label']);
          foreach ($nodes as $node) {
            if ($node->reverse_link) {
              $values[] = l($node->title, 'node/'. $node->nid);
            }
          }
          $links[$node->type]['value'] = '<ul><li>'. implode('</li><li>', $values) .'</li></ul>';
        }
        return array(t('Related Content') => $links);
      }
      break;
  }
}