<?php

/**
 * @file
 * Administrative page callbacks for the Forum module.
 */

use Drupal\taxonomy\Plugin\Core\Entity\Term;

/**
 * Page callback: Returns a form for creating a new forum or container.
 *
 * @param $type
 *   What is being added. Possible values are 'forum' and 'container'.
 * @param \Drupal\taxonomy\Plugin\Core\Entity\Term $term
 *   (optional) A forum or container term to be edited. Defaults to NULL.
 *
 * @return
 *   A form for creating a new forum or container.
 *
 * @see forum_menu()
 */
function forum_form_main($type, Term $term = NULL) {
  if (!$term) {
    $term = entity_create('taxonomy_term', array('vid' => config('forum.settings')->get('vocabulary')));
  }

  switch ($type) {
    case 'forum':
      return drupal_get_form('forum_form_forum', $term);
      break;
    case 'container':
      return drupal_get_form('forum_form_container', $term);
      break;
  }
}

/**
 * Form constructor for adding and editing a forum.
 *
 * @param \Drupal\taxonomy\Plugin\Core\Entity\Term $term
 *   A forum term to be edited.
 *
 * @see forum_form_submit()
 * @ingroup forms
 */
function forum_form_forum($form, &$form_state, Term $term) {
  $form['name'] = array('#type' => 'textfield',
    '#title' => t('Forum name'),
    '#default_value' => $term->name->value,
    '#maxlength' => 255,
    '#description' => t('Short but meaningful name for this collection of threaded discussions.'),
    '#required' => TRUE,
  );
  $form['description'] = array('#type' => 'textarea',
    '#title' => t('Description'),
    '#default_value' => $term->description->value,
    '#description' => t('Description and guidelines for discussions within this forum.'),
  );
  $form['parent']['#tree'] = TRUE;
  $form['parent'][0] = _forum_parent_select($term->id(), t('Parent'), 'forum');
  $form['weight'] = array('#type' => 'weight',
    '#title' => t('Weight'),
    '#default_value' => $term->weight->value,
    '#description' => t('Forums are displayed in ascending order by weight (forums with equal weights are displayed alphabetically).'),
  );

  $form['vid'] = array('#type' => 'hidden', '#value' => config('forum.settings')->get('vocabulary'));
  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
    '#button_type' => 'primary',
    '#submit' => array('forum_form_submit')
  );
  if (!$term->isNew()) {
    $form['actions']['delete'] = array(
      '#type' => 'submit',
      '#value' => t('Delete'),
      '#submit' => array('forum_forum_delete'),
    );
    $form['tid'] = array('#type' => 'value', '#value' => $term->id());
  }
  $form['#theme'] = 'forum_form';

  return $form;
}

/**
 * Form submission handler for forum_form_forum() and forum_form_container().
 */
function forum_form_submit($form, &$form_state) {
  $config = config('forum.settings');
  if ($form['form_id']['#value'] == 'forum_form_container') {
    $container = TRUE;
    $type = t('forum container');
  }
  else {
    $container = FALSE;
    $type = t('forum');
  }

  // @todo Set explicit entity properties instead of arbitrary form values.
  form_state_values_clean($form_state);
  $term = entity_create('taxonomy_term', $form_state['values']);
  $status = $term->save();
  switch ($status) {
    case SAVED_NEW:
      if ($container) {
        $containers = $config->get('containers');
        $containers[] = $term->id();
        $config->set('containers', $containers)->save();
      }
      $form_state['values']['tid'] = $term->id();
      drupal_set_message(t('Created new @type %term.', array('%term' => $form_state['values']['name'], '@type' => $type)));
      break;
    case SAVED_UPDATED:
      drupal_set_message(t('The @type %term has been updated.', array('%term' => $form_state['values']['name'], '@type' => $type)));
      // Clear the page and block caches to avoid stale data.
      cache_invalidate_tags(array('content' => TRUE));
      break;
  }
  $form_state['redirect'] = 'admin/structure/forum';
}

/**
 * Returns HTML for a forum form.
 *
 * By default this does not alter the appearance of a form at all, but is
 * provided as a convenience for themers.
 *
 * @param $variables
 *   An associative array containing:
 *   - form: A render element representing the form.
 *
 * @ingroup themeable
 */
function theme_forum_form($variables) {
  return drupal_render_children($variables['form']);
}

/**
 * Form constructor for adding and editing forum containers.
 *
 * @param \Drupal\taxonomy\Plugin\Core\Entity\Term $term
 *   A container term to be edited.
 *
 * @see forum_form_submit()
 * @ingroup forms
 */
function forum_form_container($form, &$form_state, Term $term) {
  $config = config('forum.settings');
  // Handle a delete operation.
  $form['name'] = array(
    '#title' => t('Container name'),
    '#type' => 'textfield',
    '#default_value' => $term->name->value,
    '#maxlength' => 255,
    '#description' => t('Short but meaningful name for this collection of related forums.'),
    '#required' => TRUE
  );

  $form['description'] = array(
    '#type' => 'textarea',
    '#title' => t('Description'),
    '#default_value' => $term->description->value,
    '#description' => t('Description and guidelines for forums within this container.')
  );
  $form['parent']['#tree'] = TRUE;
  $form['parent'][0] = _forum_parent_select($term->id(), t('Parent'), 'container');
  $form['weight'] = array(
    '#type' => 'weight',
    '#title' => t('Weight'),
    '#default_value' => $term->weight->value,
    '#description' => t('Containers are displayed in ascending order by weight (containers with equal weights are displayed alphabetically).')
  );

  $form['vid'] = array(
    '#type' => 'hidden',
    '#value' => $config->get('vocabulary'),
  );
  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
    '#button_type' => 'primary',
    '#submit' => array('forum_form_submit'),
  );
  if (!$term->isNew()) {
    $form['actions']['delete'] = array(
      '#type' => 'submit',
      '#value' => t('Delete'),
      '#submit' => array('forum_forum_delete'),
    );
    $form['tid'] = array('#type' => 'value', '#value' => $term->id());
  }
  $form['#theme'] = 'forum_form';

  return $form;
}

/**
 * Form submission handler for forum_form_forum() and forum_form_container().
 *
 * Handler for when 'delete' is clicked.
 *
 * @see \Drupal\forum\Form\DeleteForm
 */
function forum_forum_delete($form, &$form_state) {
  $form_state['redirect'] = 'admin/structure/forum/delete/forum/' . $form_state['values']['tid'];
}

/**
 * Form constructor for the forum overview form.
 *
 * Returns a form for controlling the hierarchy of existing forums and
 * containers.
 *
 * @see forum_menu()
 * @ingroup forms
 */
function forum_overview($form, &$form_state) {
  module_load_include('inc', 'taxonomy', 'taxonomy.admin');
  $config = config('forum.settings');

  $vid = $config->get('vocabulary');
  $vocabulary = taxonomy_vocabulary_load($vid);
  $form = taxonomy_overview_terms($form, $form_state, $vocabulary);

  foreach (element_children($form['terms']) as $key) {
    if (isset($form['terms'][$key]['#term'])) {
      $term = $form['terms'][$key]['#term'];
      $form['terms'][$key]['term']['#href'] = 'forum/' . $term->id();
      unset($form['terms'][$key]['operations']['#links']['delete']);
      if (in_array($form['terms'][$key]['#term']->id(), $config->get('containers'))) {
        $form['terms'][$key]['operations']['#links']['edit']['title'] = t('edit container');
        $form['terms'][$key]['operations']['#links']['edit']['href'] = 'admin/structure/forum/edit/container/' . $term->id();
        // We don't want the redirect from the link so we can redirect the
        // delete action.
        unset($form['terms'][$key]['operations']['#links']['edit']['query']['destination']);
      }
      else {
        $form['terms'][$key]['operations']['#links']['edit']['title'] = t('edit forum');
        $form['terms'][$key]['operations']['#links']['edit']['href'] = 'admin/structure/forum/edit/forum/' . $term->id();
        // We don't want the redirect from the link so we can redirect the
        // delete action.
        unset($form['terms'][$key]['operations']['#links']['edit']['query']['destination']);
      }
    }
  }

  // Remove the alphabetical reset.
  unset($form['actions']['reset_alphabetical']);

  // The form needs to have submit and validate handlers set explicitly.
  $form['#submit'] = array('taxonomy_overview_terms_submit'); // Use the existing taxonomy overview submit handler.
  $form['terms']['#empty'] = t('No containers or forums available. <a href="@container">Add container</a> or <a href="@forum">Add forum</a>.', array('@container' => url('admin/structure/forum/add/container'), '@forum' => url('admin/structure/forum/add/forum')));
  return $form;
}

/**
 * Returns a select box for available parent terms.
 *
 * @param $tid
 *   ID of the term that is being added or edited.
 * @param $title
 *   Title for the select box.
 * @param $child_type
 *   Whether the child is a forum or a container.
 *
 * @return
 *   A select form element.
 */
function _forum_parent_select($tid, $title, $child_type) {

  $parents = taxonomy_term_load_parents($tid);
  if ($parents) {
    $parent = array_shift($parents);
    $parent = $parent->id();
  }
  else {
    $parent = 0;
  }

  $vid = config('forum.settings')->get('vocabulary');
  $children = taxonomy_get_tree($vid, $tid, NULL, TRUE);

  // A term can't be the child of itself, nor of its children.
  foreach ($children as $child) {
    $exclude[] = $child->id();
  }
  $exclude[] = $tid;

  $tree = taxonomy_get_tree($vid, 0, NULL, TRUE);
  $options[0] = '<' . t('root') . '>';
  if ($tree) {
    foreach ($tree as $term) {
      if (!in_array($term->id(), $exclude)) {
        $options[$term->id()] = str_repeat(' -- ', $term->depth) . $term->label();
      }
    }
  }
  if ($child_type == 'container') {
    $description = t('Containers are usually placed at the top (root) level, but may also be placed inside another container or forum.');
  }
  elseif ($child_type == 'forum') {
    $description = t('Forums may be placed at the top (root) level, or inside another container or forum.');
  }

  return array('#type' => 'select', '#title' => $title, '#default_value' => $parent, '#options' => $options, '#description' => $description, '#required' => TRUE);
}