<?php
define('NODEFORMCOLS_DEFAULT_REGION', 'main');

/**
 * Implementation of hook_theme().
 */
function nodeformcols_theme($aExisting) {
  return array(
    // This needs to run after node.module's hook_theme(), which we ensure
    // by setting this module's weight to 1 during install.
    'node_form' => array(
      'render element' => 'form',
      'template' => 'node-form',
    ),
    'nodeformcols_configuration' => array(
      'render element' => 'element',
      'template' => 'nodeformcols-configuration',
    ),
  );
}

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

  if (!defined('MAINTENANCE_MODE')) {
    $items['admin/structure/types/manage/%node_type/form'] = array(
      'title' => 'Manage form',
      'page callback' => 'drupal_get_form',
      'page arguments' => array('nodeformcols_configuration_form', 4, 6),
      'access arguments' => array('administer content types'),
      'file' => 'nodeformcols.admin.inc',
      'type' => MENU_LOCAL_TASK,
      'weight' => 3,
    );
  }

  return $items;
}

/**
 * Implementation of hook_ctools_plugin_directory().
 */
function nodeformcols_ctools_plugin_directory($module, $plugin) {
  if ($module == 'ctools') {
    return 'plugins/' . $plugin;
  }
}

function nodeformcols_form_regions() {
  return array(
    'main' => t('Main column'),
    'right' => t('Right'),
    'footer' => t('Footer'),
  );
}

/**
 * Gets default placements for standard fields
 *
 * @return array
 */
function _nodeformscols_default_field_placements() {
  return array(
    'title' => array('region' => 'main'),
    'additional_settings' => array('region' => 'main'),
    'actions' => array('region' => NODEFORMCOLS_DEFAULT_REGION, 'weight' => 100),
  );
}

function nodeformscols_field_placements($content_type, $variant) {
  $default = _nodeformscols_default_field_placements();
  if ($variant != 'default') {
    $default = variable_get('nodeformscols_field_placements_' .
      $content_type . '_default', $default);
  }

  $placements = variable_get('nodeformscols_field_placements_' . $content_type .
    '_' . $variant, $default);

  return $placements;
}

/**
 * Implementation of hook_form_alter().
 */
function nodeformcols_form_alter(&$form, $form_state, $form_id) {
  if (isset($form['#node_edit_form']) && $form['#node_edit_form']) {
    drupal_alter('nodeformcols_pre_form', $form);
    $variant = isset($form['#nodeformcols_variant']) ? $form['#nodeformcols_variant'] : 'default';
    $placements = nodeformscols_field_placements($form['#node']->type, $variant);
    foreach ($placements as $key => $p) {
      if (isset($p['hidden']) && $p['hidden']) {
        $form[$key]['#access'] = FALSE;
      }
    }
    drupal_alter('nodeformcols_post_form', $form);
  }
}

/**
 * Preprocess function to run ahead of other modules.
 */
function template_preprocess_node_form(&$aVars) {
  drupal_add_css(drupal_get_path('module', 'nodeformcols') . '/css/nodeformcols.css');

  $default_region = variable_get('nodeformcols_default_region', NODEFORMCOLS_DEFAULT_REGION);
  $form = &$aVars['form'];
  $class = array('node-form', 'clearfix');

  $regions = array();
  $has_elements = array();
  $weight = 0;
  foreach (nodeformcols_form_regions() as $name => $title) {
    $regions[$name] = array(
      '#prefix' => '<div class="form-region-' . $name . '">',
      '#suffix' => '</div>',
      '#weight' => $weight,
    );
    $weight++;
  }

  drupal_alter('nodeformcols_pre_placement', $form);
  $variant = isset($form['#nodeformcols_variant']) ? $form['#nodeformcols_variant'] : 'default';
  $placements = nodeformscols_field_placements($form['#node']->type, $variant);

  // Track if new fields should be adjusted above the buttons.
  // TODO: This should be generalized to a way to tell nodeformcols where to place new fields (above below field X).
  $adjust_to_buttons = isset($placements['buttons']['region']) && ($placements['buttons']['region'] == $default_region);

  foreach (element_children($form) as $key) {
    $field = $form[$key];
    if (isset($field['#type']) && in_array($field['#type'], array('value', 'hidden', 'token')) ||
        (isset($field['#access']) && $field['#access'] == FALSE)) {
      continue;
    }

    if (isset($placements[$key])) {
      $p = $placements[$key];

      if (isset($p['weight'])) {
        $field['#weight'] = $p['weight'];
      }
      if (isset($p['collapsed']) && isset($field['#collapsible']) && $field['#collapsible']) {
        $field['#collapsed'] = $p['collapsed'];
      }
      $regions[$p['region']][$key] = $field;
      $has_elements[$p['region']] = TRUE;
      unset($form[$key]);
    }
    else { // Set the default placement for unknown fields
      $regions[$default_region][$key] = $field;
      if ($adjust_to_buttons && $regions[$default_region][$key]['#weight'] >= $placements['buttons']['weight']) {
        $regions[$default_region][$key]['#weight'] = $placements['buttons']['weight'] - .1;
      }
      $has_elements[$default_region] = TRUE;
      unset($form[$key]);
    }
  }

  foreach ($has_elements as $name => $has) {
    if ($has) {
      $class[] = 'node-form-has-region-' . $name;
      $form['nodeformcols_region_' . $name] = $regions[$name];
    }
  }

  $aVars['class'] = join($class, ' ');
}

/**
 * Implementation of hook_node_type_delete().
 */
function nodeformcols_node_type_delete($info) {
  $result = db_select('variable')
    ->condition('name', 'nodeformscols_field_placements_' . $info->type . '%', 'LIKE')
    ->fields('variable', array('name'))
    ->execute();
  foreach ($result as $row) {
    variable_del($row->name);
  }
}

/**
 * Implementation of hook_node_type_update().
 */
function nodeformcols_node_type_update($info) {
  if (!empty($info->old_type) && $info->old_type != $info->type) {
    $base = 'nodeformscols_field_placements_' . $info->old_type;
    $new_base = 'nodeformscols_field_placements_' . $info->type;
    $result = db_select('variable')
      ->condition('name', $base . '%', 'LIKE')
      ->fields('variable', array('name'))
      ->execute();
    foreach ($result as $row) {
      $value = variable_get($row->name, NULL);
      $new_name = str_replace($base, $new_base, $row->name);
      variable_set($new_name, $value);
      variable_del($row->name);
    }
  }
}