<?php

/**
 * @file
 * Alters webform's schema to add things needed to make export reliable.
 */

/**
 * Implements hook_schema_alter().
 */
function webform_features_schema_alter(&$schema) {
  $schema['webform']['fields']['machine_name'] = array(
    'type' => 'varchar',
    'length' => 32,
    'not null' => TRUE,
    'default' => '',
    'description' => 'The machine name of the webform. Used during exports & for template suggestions.',
  );
  $schema['webform_component']['fields']['machine_name'] = array(
    'type' => 'varchar',
    'length' => 66,
    'not null' => TRUE,
    'default' => '',
    'description' => "The machine name of the webform's component. Used during exports.",
  );
}

/**
 * Implements hook_install().
 */
function webform_features_install() {
  // Add machine_name fields to the weform & webform_component tables.
  $table_names = array('webform', 'webform_component');
  $schema = array();
  foreach ($table_names as $table_name) {
    $schema[$table_name] = array('fields' => array());
  }
  webform_features_schema_alter($schema);
  foreach ($table_names as $table_name) {
    foreach ($schema[$table_name]['fields'] as $name => $spec) {
      db_add_field($table_name, $name, $spec);
    }
  }

  // Populate existing webforms' machine names
  $query = db_select('node', 'n')
    ->fields('n', array('nid', 'title', 'type'))
    ->condition('type', webform_variable_get('webform_node_types'), 'IN')
    ->orderBy('type', 'ASC')
    ->orderBy('title', 'ASC');
  $query->join('webform', 'w', 'n.nid = w.nid');
  $query->fields('w', array('machine_name'))
    ->condition(
      db_or()
        ->isNull('machine_name')
        ->condition('machine_name', '')
    );
  $results = $query->execute()->fetchAll();

  foreach ($results as $result) {
    // Load existing webform
    $node = node_load($result->nid);

    // Build machine name from its title
    $machine_name = $node->title;
    $machine_name = drupal_strtolower($machine_name);
    $machine_name = preg_replace('#[^a-z]+#', '_', $machine_name);

    // Ensure machine name is unique
    $name = substr($machine_name, 0, 32);
    $i = 1;
    $exists = webform_features_machine_name_load($name);
    while (!empty($exists) && $exists->nid != $node->nid) {
      $name = substr($machine_name, 0, 31 - strlen($i)) . '_' . ++$i;
      $exists = webform_features_machine_name_load($name);
    }

    // Save unique machine name
    $node->webform['machine_name'] = $name;
    node_save($node);
  }

  // Populate existing webform_components' machine names
  $query = db_select('webform_component', 'wc')
    ->fields('wc', array('nid', 'cid', 'form_key', 'machine_name'))
    ->orderBy('nid', 'ASC');
  $query->join('webform', 'w', 'wc.nid = w.nid');
  $query->addField('w', 'machine_name', 'webform_machine_name');
  $results = $query->execute()->fetchAll();

  $existing = array();
  foreach ($results as $result) {
    if (!empty($result->machine_name)) {
      $existing[$result->machine_name] = TRUE;
    }
  }

  foreach ($results as $result) {
    if (!empty($result->machine_name)) {
      continue;
    }

    // Build machine name from the webform's one and the form_key
    $wf_machine_name = $result->webform_machine_name;
    $cmp_machine_name = $result->form_key;

    // Ensure machine name is unique
    $name = $wf_machine_name . '__' . substr($cmp_machine_name, 0, 32);
    $i = 1;
    $exists = !empty($existing[$name]);
    while (!empty($exists) && $exists->nid != $node->nid) {
      $name = $wf_machine_name . '__' . substr($cmp_machine_name, 0, 31 - strlen($i)) . '_' . ++$i;
      $exists = !empty($existing[$name]);
    }

    // Save unique machine name
    db_update('webform_component')
      ->fields(array('machine_name' => $name))
      ->condition('cid', $result->cid)
      ->execute();
    $existing[$name] = TRUE;
  }
}

/**
 * Implements hook_uninstall().
 */
function webform_features_uninstall() {
  // Remove machine_name fields to the weform & webform_component tables.
  $table_names = array('webform', 'webform_component');
  $schema = array();
  foreach ($table_names as $table_name) {
    $schema[$table_name] = array('fields' => array());
  }
  webform_features_schema_alter($schema);
  foreach ($table_names as $table_name) {
    foreach ($schema[$table_name]['fields'] as $name => $spec) {
      db_drop_field($table_name, $name);
    }
  }
}