<?php

/**
 * @file
 * Nodeorder install file.
 */

/**
 * Implements hook_install().
 *
 * Adds field 'weight' to core table 'taxonomy_index'.
 */
function nodeorder_install() {
  $module_name = 'nodeorder';

  // Set field properties
  $spec =  array(
    'type' => 'int',
    'signed' => TRUE,
    'not null' => TRUE,
    'default' => 0,
    'initial' => 0,
    'description' => t('A user-defined weight for each node in its respective category.'),
  );

  // Create an index for 'weight'
  $keys['indexes'] = array('weight' => array('weight'));

  // Add the column to the table
  $ret = array();
  db_add_field('taxonomy_index', 'weight', $spec, $keys);
  $installation_failed = FALSE;

  // Check for query errors
  for ($i = 0; $i < count($ret); $i++) {
    if ($ret[$i]['success'] !== TRUE) {
      $installation_failed = TRUE;
      break;
    }
  }

  if ($installation_failed) {
    drupal_set_message(st('Table installation for the %name module was unsuccessful. The tables may need to be installed by hand.  See %name.install file for a list of the installation queries.', array('%name' => $module_name)), 'error');
  }
  else {
    // Set the weight of the nodeorder module in the system table
    // so that we come after most other modules in module_invoke_all()
    // calls.  This ensures that we can alter forms after, for instance,
    // the taxonomy module...
    // TODO Please review the conversion of this statement to the D7 database API syntax.
    /* db_query("UPDATE {system} SET weight = 5 WHERE name = 'nodeorder' AND type = 'module'") */
    db_update('system')
  ->fields(array(
      'weight' => 5,
    ))
  ->condition('name', 'nodeorder')
  ->condition('type', 'module')
  ->execute();

    drupal_set_message(st('The %name module was installed successfully.', array('%name' => $module_name)));
  }
}

/**
 * Implements hook_uninstall().
 *
 * Drops field 'weight' from core table 'taxonomy_index'.
 */
function nodeorder_uninstall() {
  $module_name = 'nodeorder';

  $ret = array();
  db_drop_index('taxonomy_index', 'weight');
  db_drop_field('taxonomy_index', 'weight');
  
  $installation_failed = FALSE;

  // Check for query errors
  for ($i = 0; $i < count($ret); $i++) {
    if ($ret[$i]['success'] !== TRUE) {
      $installation_failed = TRUE;
      break;
    }
  }

  if ($installation_failed) {
    drupal_set_message(st('Table uninstallation for the %name module was unsuccessful. The tables may need to be installed by hand.  See %name.install file for a list of the installation queries.', array('%name' => $module_name)), 'error');
  }
  else {
    drupal_set_message(st('The %name module was uninstalled successfully.', array('%name' => $module_name)));
  }
}

/**
 * Implements hook_schema_alter().
 *
 * Informs drupal_get_schema() of the field addition to 'taxonomy_index'.
 */
function nodeorder_schema_alter(&$schema) {
  $schema['taxonomy_index']['fields']['weight'] = array(
    'type' => 'int',
    'signed' => TRUE,
    'not null' => TRUE,
    'default' => 0,
    'initial' => 0,
    'description' => t('A user-defined weight for each node in its respective category.'),
  );
}