<?php
// $Id$

/**
 * Implementation of hook_install().
 */
function userreference_install() {
}

/**
 * Add node ID column so we can delete old revisions at node delete time.
 */
function userreference_update_1() {
  $ret = array();

  switch ($GLOBALS['db_type']) {
    case 'pgsql':
      db_add_column($ret, 'node_field_userreference_data', 'nid', 'integer', array('not null' => TRUE, 'default' => 0));
      break;

    case 'mysql':
    case 'mysqli':
      $ret[] = update_sql("ALTER TABLE {node_field_userreference_data} ADD COLUMN nid int(10) NOT NULL DEFAULT 0");
      break;
  }

  return $ret;
}

/**
 * Populate nid column in existing user reference fields.
 */
function userreference_update_2() {
  // Multi-part update
  if (!isset($_SESSION['userreference_update_2'])) {
    $_SESSION['userreference_update_2'] = 0;
    $_SESSION['userreference_update_2_max'] = db_result(db_query("SELECT COUNT(*) FROM {node_field_userreference_data}"));;
  }

  $limit = 20;
  $result = db_query_range("SELECT nr.nid, nfud.vid, nfud.field_name, nfud.delta FROM {node_field_userreference_data} nfud LEFT JOIN {node_revisions} nr ON nr.vid = nfud.vid", $_SESSION['userreference_update_2'], $limit);
  if (db_num_rows($result) == 0) {
    unset($_SESSION['userreference_update_2']);
    unset($_SESSION['userreference_update_2_max']);
    return array();
  }
  while ($data = db_fetch_object($result)) {
    $_SESSION['userreference_update_2']++;
    db_query("UPDATE {node_field_userreference_data} SET nid = %d WHERE vid = %d AND field_name = '%s' AND delta = %d", $data->nid, $data->vid, $data->field_name, $data->delta);
  }

  return array('#finished' => $_SESSION['userreference_update_2'] / $_SESSION['userreference_update_2_max']);
}

/**
 * Data is now stored in per-field tables.
 */
function userreference_update_3() {
  $ret = array();

  include_once('./'. drupal_get_path('module', 'content') .'/content.module');
  include_once('./'. drupal_get_path('module', 'content') .'/content_admin.inc');

  content_clear_type_cache();
  $fields = content_fields();

  foreach ($fields as $field) {
    switch ($field['type']) {
      case 'userreference':
        $columns = array(
          'uid' => array('type' => 'int', 'not null' => TRUE, 'default' => '0'),
        );
        // the following line will trigger (negligible) warnings if content_update_5 was run before
        // (column already exists)
        @content_alter_db_field(array(), array(), $field, $columns);
        $db_info = content_database_info($field);
        $table = $db_info['table'];
        if ($field['multiple']) {
          $ret[] = update_sql('INSERT INTO {'. $table .'} (vid, delta, nid, '. $field['field_name'] ."_uid) SELECT vid, delta, nid, field_uid FROM {node_field_userreference_data} WHERE field_name = '". $field['field_name'] ."'");
        }
        else {
          $ret[] = update_sql('INSERT INTO {'. $table .'} (vid, nid, '. $field['field_name'] ."_uid) SELECT vid, nid, field_uid FROM {node_field_userreference_data} WHERE field_name = '". $field['field_name'] ."'");
        }
        break;
    }
  }

  $ret[] = update_sql('DROP TABLE {node_field_userreference_data}');

  db_query('DELETE FROM {cache}');
  return $ret;
}

/**
 * Set the value columns to accept NULL values
 * and replace 0 with NULL in the field data tables
 */
function userreference_update_4() {
  $ret = array();

  include_once('./'. drupal_get_path('module', 'content') .'/content.module');
  include_once('./'. drupal_get_path('module', 'content') .'/content_admin.inc');

  $fields = content_fields();


  foreach ($fields as $field) {
    switch ($field['type']) {
      case 'userreference':
        $db_info = content_database_info($field);
        $columns_old = $db_info['columns'];
        $columns = $columns_old;
        $columns['uid']['not null'] = FALSE;
        $columns['uid']['default'] = NULL;
        // force the old values : if the db info was rebuilt before the update is run,
        // it will already contain the new values, and nothing gets changed in content_alter_db_field
        $columns_old['uid']['not null'] = TRUE;
        $columns_old['uid']['default'] = 0;

        content_alter_db_field($field, $columns_old, $field, $columns);
        $ret[] = array(
          'query' => strtr('The field %field_name has been updated to accept NULL values.', array('%field_name' => $field['field_name'])),
          'success' => TRUE
        );

        $ret[] = update_sql("UPDATE {". $db_info['table'] ."} SET ". $db_info['columns']['uid']['column'] ." = NULL WHERE ". $db_info['columns']['uid']['column'] ." = 0");
        break;
    }
  }

  db_query('DELETE FROM {cache}');
  return $ret;
}